The relation between inflammation, hemostasis and arterial stiffness is of pathophysiological relevance for the development of cardiovascular disease (CVD). Data investigating this interplay using stiffness index (SI) by digital photoplethysmography are not available yet. Therefore, sex-specific relation between SI and inflammatory and hemostatic biomarkers was investigated within 13,724 subjects from the population-based Gutenberg Health Study. C-reactive protein (CRP), white blood cell count (WBCC), neopterin, interleukin-18, interleukin-1 receptor antagonist (IL-1RA), fibrinogen and hematocrit were measured. Multivariable linear regression analysis with adjustment for cardiovascular risk factors, medication, and hormonal status  revealed an independent association between SI and WBCC, IL-1RA and hematocrit in both sexes, and with fibrinogen in women. There was a joint effect of increasing tertiles of SI and biomarker concentrations for future CVD risk prediction. Subjects with both SI and biomarker concentration above the median had the worst overall survival and with both below the median the best survival during a follow-up period of 6.2 ± 1.7 years, except for hematocrit. The results support the relation between inflammation, hemostasis and arterial stiffness measured by digital photoplethysmography. Markers of inflammation and hemostasis modulate the ability of SI to identify subjects at risk for future CVD or higher mortality. Recently published studies implicated a role of inflammation in the development of hypertension3. It has been further suggested that inflammation might be related to the stiffening of arteries, a condition associated with a normal ageing process or with premature vascular ageing, which occurs in hypertension and numerous metabolic disorders. Possible mechanisms between inflammation and arterial stiffness (AS) might be related to changes within the vessel wall such as e.g. inflammatory cell infiltration or vascular dysfunction4. Furthermore, various pro-inflammatory mediators and markers of oxidative stress promote an increased production of matrix metalloproteinases with subsequent degeneration of compliant elastin fibers that, in turn lead to decreased arterial compliance6. Inflammation might also induce changes in the vascular smooth muscle phenotype with enhanced expression of osteoblasts, resulting in media calcification and subsequently stiffer arteries7.High blood pressure represents one of the potent cardiovascular risk (CV) factor and a leading cause of total and CV mortality17. Most of published data were based on the measurement of carotid-femoral pulse wave velocity (cf-PWV), a widely used method for determination of AS to date18. Another interesting approach for assessment of arterial function and AS in particular might represent stiffness index (SI) by digital photoplethysmography19, which might reflect systemic AS21, rather than providing similar to central PWV information. It represents easily performable and operator independent technique, which might be used in setting, where reliable simplicity of measurement is of relevance. So far, no study exists investigating a possible relationship between SI with markers of inflammation or hemostasis, neither in the general population nor among selected patient groups. Taking into account that SI was found to be markedly lower in females compared to males in our previous investigation22, we investigated such association sex-specifically in a large population-based Gutenberg Health Study (GHS).To date several studies investigated the relation of AS with markers of inflammation and hemostasis in apparently healthy individuals with controversial resultset al.23.) and consequently no calculable SI values. In those subjects, AS was rated as “very stiff”. Within the remaining 12,650 subjects, SI was determined. The clinical characteristics of eligible subjects are summarized in Table From the overall population sample n = 15,010), 1,286 individuals had missing values for SI due to logistical or technical constraints; the characteristics of these persons did not differ significantly from the sample investigated (data not shown). Therefore, assessment of AS was available in 13,724 subjects  in the present population-based sample was markedly higher among male than in female participants. Stiffness index was 1.7 m/s higher in men compared to women.Subjects with very stiff vessels were markedly older than subjects with measureable SI, and presented a higher cardiovascular risk profile, being more obese and having more hypertension and diabetes. Moreover, they were at an approx. 3-fold higher risk for future fatal CVD events  SCORE) and had higher biomarker concentrations in both sexes except for hematocrit (Table When biomarkers were stratified according to sex-specific tertiles (T) of SI, all circulating markers increased with higher tertiles of SI in both sexes except white blood cell count (WBCC) in women Table .Table 2BOverall, linear correlations between biomarkers and SI, however, were very modest; only weak correlations (r between 0.13 and 0.15) were found with fibrinogen in both sexes and interleukin-1 receptor antagonist (IL-1RA) in men and hematocrit in women  increase) and AS are shown in Table Smoking, followed by hypertension were the main factors determining the “biomarker – risk factors” associations, as demonstrated sex-specifically in Supplemental Tables In the next step, the combination of both, biomarkers and SI was evaluated for cardiovascular risk assessment. Increasing values of SI and biomarker (both categorized in tertiles) demonstrated an additive effect on the 10-year risk for fatal MI or stroke according to the German version of the ESC-SCORE . During the follow-up period of 6.2 ± 1.7 years, a total of 511 deaths (332 men/179 women) occurred. Stiffness index was higher at baseline in subjects with an event compared to event-free individuals . Figure For assessing the variation of the association between SI and inflammation according to the cardiovascular risk profile, the individuals from the GHS sample n = 13,724) were stratified in subjects free of CVRFs and manifest CVD , those with prevalent CVRFs and/or CVD  . Functionally, CRP was proposed to have effects that may influence initiation and progression of vascular disease, including mediation of vascular dysfunction, induction of a pro-thrombotic state and cytokine release, activation of the complement system and facilitation of extracellular matrix remodeling24. Though, epidemiological data on a cross-sectional relationship between CRP and measures of AS from the literature are controversial10. Remarkably, CRP was a strong predictor of PWV in a prospective setting within longer follow-up periods of 1611 or 2012 years, whereas the investigation with a shorter follow-up time14 revealed no meaningful relationship of CRP to stiffness measures. This rather suggests a long-term effect of inflammation on AS.C-reactive protein represents the best studied biomarker of cardiometabolic disorders so far26, demonstrated the strongest association with SI in all subsamples with measurable stiffness. It was the only marker associated with SI in the physiological state of presumably healthy males. Its important role as determinant of SI is not surprising, since AS is highly related to mechanical property of blood flow27. The fact that the well-known correlates of hematocrit such as male sex, smoking and blood pressure28 were also major determinants of SI in our previous analysis22, supports a possible synergistical effect of this “risk marker - risk factor” clustering.Hematocrit, a well-known predictor of future cardiovascular events28, the sex difference in this association is remarkable. It was found in females only and remained also after adjusting for hormonal influence, which possibly implies an important role of other conventional CVRFs in vascular stiffening among women. Current published data on the association between fibrinogen and AS are contradictory: no association between fibrinogen and PWV was reported from participants from the Framingham Offspring Study10, 429 apparently healthy middle-aged women15 or patients with end-stage renal disease16. In contrast, a positive association between increased fibrinogen concentrations and cf-PVW was found in 229 hypertensive and 159 age-matched normotensive individuals17.While the association between fibrinogen and SI found in the present analysis is expected, due to close relation between hematocrit and fibrinogen29. Increased IL-1RA concentrations at baseline were found to be associated with an increased risk for incident CVD and type 2 diabetes mellitus30. Only one study has evaluated the role of IL-1RA in decreased arterial compliance so far and identified IL-1RA as a strong predictor of aortic PWV over 16 years11. The non-inverse association between IL-1RA and SI supports the idea of understanding this marker as counter-regulated response to interleukin 1β (IL-1β)-mediated pro-inflammatory stimuli30. Currently, IL-1β represents one of the substantive upstream inflammatory cytokine and major target for immunomodulation, since its inhibition has already been linked to the reduction in IL-6, CRP and fibrinogen concentration in the high vascular risk patients31. Interestingly, although IL-1β and IL-18 belong to the same IL-1 family of cytokines and shear similar regulation by NLRP3 inflammasome32 they seem have differential impact on vasculature within the present analysis. IL-18 is considered as a potent inducer of interferon-γ (INF-γ) production, thereby resulting in the enhanced expression of matrix metalloproteinases, and subsequent degeneration of compliant elastin fibers34. Several differences in IL-1β and IL-18 signaling have been already reported35, with a potent activation of nuclear factor-kappa B by IL-1β and only weak or even null effects on it in case of IL-1836. In distinction, IL-18/IFN-γ effects are mediated mainly through activation of JAK-STAT pathway37. Moreover, to ensure adequate cell activation, IL-18 requires a co-stimulant (most commonly IL-12) as well as the much higher concentration than IL-1β, which, in contrast, is already active in the low picomol range35. Other potential mechanism for the observed discrepancies might include induction of cyclooxygenase-2 expression by IL-1β with subsequent production of prostaglandin E235, as a key mediator of vascular remodeling and negative regulator of IFN-γ-mediated response. On the contrary, neither cyclooxygenase-2 nor other acute phase proteins such as e.g. IL-6 could be sufficiently induced by IL-1835. Thus, one might speculate that other than IFN-γ-mediated effects might be detrimental for the relationship between inflammation and AS. Further indirect confirmation of this represents a fact, that neopterin, as a protein releasing upon stimulation with IFN-γ, was also not associated with SI in the current study. In addition to being a marker of IFN-γ inducible inflammation, neopterin possesses potent pro-oxidative properties that might be responsible for destabilization and vulnerability of the arterial wall37. Despite their hypothetical crucial role in AS, neither IL-18 nor neopterin presented as independent determinant of SI.IL-1RA was strongly positively related with SI in both sexes even after adjustment for traditional CVRFs and various medications within the present analysis. This naturally occurring anti-inflammatory antagonist of the interleukin-1 family of pro-inflammatory cytokines is currently also applied in the treatment of various inflammatory conditionsInterestingly, the patterns of association between circulating biomarkers and AS were varying from low to higher cardiovascular risk profiles  are not as widely available compared to the methods, assessing e.g. stiffness of the large arteries, such as carotid-femoral pulse wave velocity (cf-PWV). Finally, results may not be extrapolated to other populations, ethnicities or age groups.The strengths of this study are the investigated well-characterized, population-representative, large-scale cohort sample with sufficient enough power to assess associations sex-specifically. Various traditional CVRFs were carefully assessed by measurements and not based on self-reported data only, which minimizes a possible misclassification. In contrast to other studies, several inflammatory and hemostatic markers were analyzed simultaneously.The present analysis demonstrated a direct relationship of inflammation and hemostasis with SI measured by digital photoplethysmography, which was modulated by the extent of arterial stiffening. Simultaneous evaluation of biomarkers and SI improved the assessment of the risk for future CV events or mortality. The mediation of the relation between chronic low-grade inflammation and SI by smoking and arterial hypertension supports the idea of nonpharmacological (e.g. smoking cessation) or pharmacological  interventions for improvement of arterial compliance.38. Briefly, individuals between 35 and 74 years of age were randomly selected from the local registration offices. The sample was stratified 1:1 for sex and present residence  with equal strata for decades of age. Exclusion criteria were insufficient knowledge of the German language and physical or mental inability to participate in the examinations. Participation was voluntary and written informed consent was obtained from each subject upon entry into the study. The study conduct is performed according to the principles of good clinical practice and the principles outlined in the Declaration of Helsinki. The study protocol, study documents and sampling design were approved by the local ethics committee ) and the data safety commissioner of the University Medical Center of the Johannes Gutenberg University Mainz, as well as by the steering committee of the Gutenberg Health Study.The GHS is a population-based, prospective, observational, single-center cohort study, including residents of the City of Mainz and the County Mainz-Bingen from Western Germany. Details of the study design have been reported elsewhereThe present analysis is based on baseline data of 15,010 GHS-participants enrolled from April 2007 to April 2012. The outcome investigated in the present analysis was all-cause mortality. Death was ascertained by the respective entry in the registry office and the death certificate. For all 511 subjects (332 men/179 women), who died during follow-up complete information on all variables of interest was available.et al.23), AS was categorized as “very stiff” . This method is based on digital photoplethysmography, which transmits an infrared light at 940 nm through the finger with the amount of absorbed light being proportional to the volume of blood in the finger pulp. The plethysmography transducer, a non-invasive finger clip, was placed on the subject’s ring (or fourth) finger and 10 pulses were recorded to produce a representative pulse waveform. This waveform consists of an early systolic and a second diastolic peak. The time difference between these two peaks  was used to calculate the SI, defined as the subjects height in meter divided by PPT in seconds , where appropriate. The circulating biomarkers were further stratified into tertiles and Mann-Whitney U-test was used to analyze group differences. Correlations between biomarkers and SI were assessed by Pearson correlation coefficients.40. Kaplan–Meier survival analysis was performed to evaluate the combined effect of AS (SI or presence of very stiff vessels) and biomarkers on all-cause mortality. Differences in Kaplan–Meier mortality curves were assessed using the log-rank test.Linear regression analysis was performed to assess the relationship between SI and biomarkers (per one SD increase) with a logarithmic transformation of skewed variables in the model . The basic model was adjusted for age; further analyses were adjusted for traditional CVRFs such as systolic/diastolic BP, obesity, dyslipidemia, smoking, diabetes and family history of myocardial infarction (MI) or stroke and blood-pressure lowering medication  codes: C02, C03, C07, C08, C09), and additionally (in Model 3) for statin intake, antiplatelet therapy, and in females for menopausal status, and intake of oral contraceptives (OC) or hormone replacement therapy (HRT). Results are reported as β-estimates with 95% confidence intervals (CIs). Absolute and relative differences in β-estimates between crude and CVRFs-adjusted model were determined to evaluate the impact of CVRFs on “SI-biomarker” association. The potential additive effect of SI and biomarkers on the 10-year CVD risk was evaluated for the German version of the ESC SCORE and the updated Framingham risk scoreFinally, to evaluate the association between SI and biomarkers in dependence on cardiovascular risk, the study sample was stratified into three subgroups: Individuals without CVRF and established CVD , congestive heart failure (CHF) or stroke)  served as group with low risk; individuals with CVRFs and/or CVD  as group with intermediate risk and subjects with very stiff vessels as an equivalent of a cardiovascular high risk group . In subjects with very stiff vessels, multivariable logistic regression was applied (dependent variable was treated dichotomously as very stiff versus measurable SI). Results are reported as β-estimates or odds ratio (OR) with 95% CIs, where appropriate.http://www.r-project.org).Because of the explorative character of the analysis, a significance threshold was not defined for p-values. P values should be interpreted as a continuous measure of statistical evidence. All statistical analyses were performed using R version 3.14.2 software (Supplementary file


The infiltration of Tbet+ Foxp3+ Tregs was strongly correlated with a concomitant tumor-specific and conventional type 1-oriented intratumoral T cell infiltrate. Both conventional CD4+CD25+CD127–Foxp3hi Tregs and their Tbethi counterparts exhibited an activated phenotype, co-expressed high levels of CTLA4 and Helios and exhibited a maximally demethylated Foxp3 gene locus TSDR, indicating their full capacity to impede a type 1 effector T cell response. Interestingly, while the prognostic value of conventional Tregs was neutral, a high intratumoral frequency of Tbet+ Tregs was associated with prolonged disease-specific survival, most likely because their presence reflected high numbers of effector T cells. The presence of these Tbet+ Tregs may in part explain why a dense type 1-oriented immune infiltrate in OPSCC is not enough to fully control tumor growth.Regulatory T cells (Tregs) may comprise different subsets allowing them to efficiently suppress different types of effector T cells. In this study, we show that high numbers of both conventional and Tbet co-expressing Foxp3The online version of this article (10.1186/s40425-019-0497-0) contains supplementary material, which is available to authorized users. Foxp3+ regulatory T cells (Tregs) are pivotal in suppressing pathological and physiological immune responses . In cancRecent studies have shown that Tregs can adopt different transcriptional profiles allowing them to regulate specific types of effector T cells . In miceSince many head and neck cancers can be infiltrated with type 1-oriented T cells , we hypoThe authors acknowledge the reporting of Minimal Information About T-cell Assays (MIATA).ink4a IHC staining was performed on formalin-fixed paraffin-embedded (FFPE) tumor sections as described -thymidine-based proliferation assay and antigen-specific cytokine production assay as described previously . To thisAntigen-specific cytokine production was determined by cytometric bead array  according to the manufacturer’s instructions. The cutoff value for cytokine production was 20 pg/ml, except for IFNγ for which it was 100 pg/ml. Positive cytokine production was defined as at least twice above that of the unstimulated cells. An example of such an HPV16-specific T cell reactivity test is depicted in Additional file Cryopreserved PBMC and/or single cell tumor samples were thawed and Treg subsets were assessed by flow cytometry as described before . Antibodsnapgene.com). Methylated CpGs were identified by the presence of a C nucleotide at the CpG position whereas demethylated CpGs were identified by a T nucleotide. The percentage of clones showing methylation at each individual CpG as well as the total average of all CpGs per population per patient was determined.Sorted Foxp3– Tconv, Foxp3+Tbet+ Treg and Foxp3+Tbet– Treg cells  were digested with Proteinase K for 4 h at 50 °C to obtain genomic DNA, followed by Bisulfite Conversion using the EZ DNA Methylation-Direct Kit (Zymo Research) according to the manufacturer. The Foxp3 Treg specific demethylation region (TSDR) was amplified  using pt tests were performed when appropriate. Correlation analysis were done the using Pearson’s correlation test. For survival analysis, patients were grouped into two groups according to the median , after which survival was tested using Kaplan–Meier method, and statistical significance of the survival distribution was analyzed by log-rank testing. All statistical tests were performed at the 0.05 significance level, and differences were considered significant when p < 0.05, as indicated with an asterisk . Statistical analyses were performed using GraphPad Prism 7.1 .Non-parametric Wilcoxon signed-rank or Mann–Whitney tests and parametric paired or unpaired p < 0.0001 for all subsets). Furthermore, the numbers of stromal and intraepithelial CD8–Foxp3–Tbet+ (CD4), CD8+Foxp3–Tbet+ and in particular CD8–Foxp3+Tbet+ Treg cells were significantly correlated. This was not the case for the conventional Tregs, which were more often found in the tumor stroma  profile, and expressed high levels of the Treg-associated markers CTLA-4 and Helios. Notably, the TbethiFoxp3hi Tregs expressed higher levels of helios, CTLA-4 and Ki67 than the Tbet– Foxp3+ Tregs  but also in the Foxp3hiTbethi cells  [hiTbethi Tregs specifically accumulated in CxCa tissue and these Tregs also displayed a hypomethylated TDSR locus. Although only three out of seven CxCa tumors were HPV16-driven, a similar association between the higher levels of Foxp3hiTbethi Tregs and the detection of an HPV16-specific immune response was found  , seven fund Fig. .Fig. 4FohiTbethi cells accumulate specifically in tumors with an ongoing type 1 immune response and based on the hypomethylation of all 15 CpG islands in the TDSR region of the Foxp3 intron 1 in these T cells sorted from 3 different patients, are true regulatory T cells.Thus, Foxp3hi regulatory T cell clone 148.31, isolated from an HPV16+ cervical cancer patient with an ongoing local type 1 immune response, and for which we have shown its suppressive capacity in several different in vitro assays [Last but not least, we analyzed the expression of Tbet in CD4+Foxp3o assays . This clhi and Tbet- Tregs infiltrated OPSCC, the prognostic value of both types of Tregs in our OPSCC patient cohort was analyzed. This revealed that the total population of CD8–Foxp3+ Tregs was significantly associated with improved survival Additional File 2:Figure S1. HPV16 E6/E7 specific T cell reactivity testing. Figure S2. Conventional (Tbet–) and Tbet+Foxp3+ Tregs can be found in tumor and stroma of OPSCC samples. Figure S3. The correlation between the number of CD8–Foxp3 + Tbet+ Tregs and CD8–Foxp3–Tbet+ (CD4) T cells and CD8 + Foxp3–Tbet+ T cells is retained in IR- and IR+ OPSCC tumors. Figure S4. Gating strategy for Treg subpopulations. Figure S5. TbethiFoxp3+ Tregs express higher levels of helios, CTLA4 and Ki67. Figure S6. The levels of tumor-infiltrating Foxp3hiTbethi Tregs correlated with the levels of infiltrating CD4 + Tbet+ and CD8 + Tbet+ cells, as well as with levels of highly activated infiltrating CD4+ and CD8+ T cells. Figure S7. Sorting of Tregs. (PPTX3379 kb)


Silver nanowires (AgNWs) have inspired many research interests due to their better properties in optical, electric, and flexible applications. One such exploitable use is as the electrical conductive fillers for print electronics. In this paper, AgNWs with mean a diameter of 80 nm and mean length of 13.49 μm were synthesized using the polyol solvothermal method. A sonication-induced scission process was used to obtain AgNWs with a length range of 7.64–11.21 μm. Further AgNWs inks were prepared with the as-synthesized AgNWs as conductive fillers in anhydrous ethanol. The conductive inks were coated on resin coated photographic paper substrate using the knife coating process and dried at room temperature. The effects of the number of layers of AgNWs coating, the concentration of AgNWs, and the length of AgNWs on the microstructure and electrical properties of samples were investigated by scanning electron microscopy and using the four-point probe method. The results show that the conductivity of the AgNWs coating increases with the increase in the number of layers in the AgNWs coating, concentration and length of the AgNWs.  Paper-based electronic devices have been judged by researchers to hold great promise as an environmentally friendly substrate for flexible electronics due to their inexpensive and common availability worldwide for information storage and packaging ,2,3. In With the development of flexible electronics, AgNWs have stimulated wide attention due to their unique physical and chemical properties, such as excellent electrical and thermal conductivity, malleability, and chemical stability ,10,11,12The properties of silver nanostructures are closely related to morphology and size of AgNWs ,18,19,20To realize the marketization and scale of flexible electronics, it is necessary to improve the manufacturing technology of flexible circuits. Conductive inks are the key to achieve flexible circuits. The conductive inks are coated on flexible substrates, such as fabric, paper, Polyethylene terephthalate (PET) and polyimide (PI) by silkscreen printing, inkjet printing, spraying, screen, knife-over-edge, spray coating, gravure, and slot die, to make flexible conductive pathways or transparent conductive films, which are then applied to flexible electronic products ,3,4,5,29Herein, we prepared AgNWs and obtained AgNWs with the different lengths by the sonication-induced scission method, and further the AgNWs inks were prepared with as-synthesized AgNWs as conductive fillers in anhydrous ethanol. The inks were printed on photographic paper substrate and the effects of the number of AgNWs coating and concentration and size of AgNWs on the microstructure and electrical properties of samples sintered at room temperature were discussed.Silver nitrate (≥ 99.8%) was purchased from Guangdong Guanghua Chemical Reagent Co., Ltd. Guangdong, China; poly(vinylprrolidone)  was purchased from Guoyao Group Chemical Reagent Co., Ltd., Shanghai, China; ferric chloride hexahydrat (≥ 99.5%) was purchased from Chengdu Kelong Chemical Co., Ltd., Chengdu, China; ethylene glycol EG, ≥ 99.7%) and ethanol absolute (≥ 99.7%) were purchased from Tianjin Yongda Chemical Co., Ltd. Tianjin, China; resin coated (RC) photographic papers were purchased from Oracle Technology Co., Ltd. Shenzhen, China. All the chemicals were used as received.3 (0.3 mmol·L−1) was dissolved in 40 mL EG (0.17 mol·L−1) PVP and AgNO3 (0.1 mol·L−1) were dissolved into 40 mL of EG in turn. Then FeCl3-EG solution was dropped into the mixed solution of PVP and AgNO3 with a syringe. Please note that the mixed solution was not stirred during the dropping process, and was immediately transferred the into the reaction kettle after the completion of dropping. The reaction kettle was placed in an oven at 160 °C for 3 h. After the completion of reaction, the sample was removed and cooled down to room temperature. Then, acetone and ethanol were used to wash the product. Each washing process was repeated 3 times to remove the extra solvent and chemical agents (PVP and other reactants). The AgNWs were re-dispersed in ethanol absolute.AgNWs were grown via polyol solvothermal method. FeCl−1 AgNWs solution was put into the beaker filled anhydrous ethanol and sequentially underwent ultrasonication for 1–5 h at a power of 120 W. The ultrasonication was carried out with a bath type sonicator . AgNWs inks were prepared with as-synthesized AgNWs as conductive fillers in anhydrous ethanol. The stability of the dispersion of AgNWs inks was not good enough. AgNWs settled after being kept at room temperature for 7–15 days or so. However, AgNWs inks have good redispersibility which is usually achieved by ultrasonic stirring.For ultrasonication treatment, 10.80 mg·mLThe inks were coated on photographic paper substrate using the knife coating process. The effects of the number of layers of AgNW coating, the concentration of AgNW ink, and the length of AgNWs on the microstructures and electrical properties of samples dried at room temperature were investigated. A scanning electron microscope  was used to characterize the microstructure of AgNWs. The lengths of individual silver nanowires in the images were measured manually according to an image processing software . X-ray diffraction  was used to measure the phase structures. The sheet resistance of the AgNW film was measured using a 4-point probe instrument ST2253 .g of the (111) plane. The equation is as follows:α = 4.0837 Å, which is close to the reported date of α= 4.0862 Å, JCPDS file 04-0783 . It indiSonication is widely applied to disperse materials in liquid media due to the ultrahigh shear rate attained during cavitation events ,31,32. HWith RC photographic paper as a substrate, the AgNWs coating was prepared by the knife coating process and heat treated at the room temperature. Schematic diagram for the steps applied to fabricate AgNW coating on the photographic paper by knife coating process was shown in −1) were dropped and knife coated the surface of RC photographic paper and dried at the room temperature for 15 min. −1. When the length of AgNWs is 7.64 μm, the sheet resistance is 196.4 Ω·sq−1. The sheet resistance increases by 12.5 times. At the conditions of the same concentration and diameter, the shorter the AgNWs are, the more AgNWs there are. Not surprisingly, the contact resistance among the AgNWs at the same coverage area increases with the increase in the number of AgNWs, leading to a sheet resistance increase.As we all know, the properties of AgNW coating are strongly dependent on the morphology, size and distribution of AgNWs on the substrate ,13,14,15−1. −1, respectively. When the layers of coating increased to six the sheet resistance of AgNW coating reduced to 0.45 Ω·sq−1. After that, the sheet resistance of AgNWs coating slightly decreased when coating layers were increased to seven. The formation of electrical conduction paths in AgNW coating is considered to contact among the AgNWs. The contact resistance at the interfaces between AgNWs is considered to be strongly influenced by the contact area. The more AgNWs, the more conductive paths are easily formed, which promotes conductivity. However, when the conductive paths in the coating are well formed, the increase of the number of AgNWs coating layers only slightly reduces contact resistance [Once the effect of the length of AgNWs on the conductivity of the coating is understood, it is necessary to study the effect of the deposition density of the AgNWs on the conductivity of coating. In order to ascertain the deposition density of the AgNWs dependence, we fabricated the AgNWs (13.49 μm) coatings with different layers. To prepare for multi-layer coating, each sample coated layer is put at room temperature for 15 min, and then coated with the next layer. The concentration of AgNW ink (0.1 mL) is 10.80 mg·mLsistance ,17. As tIn order to further analysis of the effect of the number of coating layer on the sheet resistance of AgNWs coating, we observed the microstructures of the samples, as shown in −1) and four coating layers, dried at room temperature for 15 min, as shown in −1, the sheet resistance of AgNW coating is 0.77 Ω·sq−1, which is close to that of the sample prepared with 10.80 mg·mL−1 AgNWs ink and six coating layers (−1, the sheet resistance of AgNW coating increases to 334.90 Ω·sq−1. The more AgNWs that are are added to a coating achieved percolation, the more effective conductive paths are formed, therefore the conductivity of the AgNWs coating will be improved [In order to analyze of the effect of the number of AgNWs on the conductivity of the coating, we prepared the coatings with different AgNW ink concentrations (13.20, 10.80, 8.70, 6.51. 4.32, and 2.65 mg·mLg layers . It is iimproved ,17,18. −1, respectively. It is clear that with the increase of concentration of AgNW ink, the thickness of coatings also increases.The microstructures of AgNW coating with different concentrations, as shown in As discussed above, the AgNW inks are viable in the application of the flexible devices. Here, the potential application of the AgNWs ink by fabricating an LED device on the AgNW electrodes was measured . One 0.5−1. When the length of AgNWs reduces to 7.64 μm, the sheet resistance increases to 196.4 Ω·sq−1. The sheet resistance increases by 12.5 times. When the concentration of AgNW ink is 13.20 mg·mL−1, the sheet resistance of AgNW coating with four layers is 0.77 Ω·sq−1, which is close to that of the sample that was prepared with 10.80 mg·mL−1 AgNW ink and six coating layers.AgNWs with a mean diameter of 80 nm and mean length of 13.49 μm were synthesized using the polyol solvothermal method. Then sonication-induced scission process was used to obtain AgNWs with a length range of 7.64–11.21 μm, and further the AgNWs inks were prepared with as-synthesized silver nanowires as conductive fillers in anhydrous ethanol. The conductive inks were coated on photographic paper substrate using the knife coating process and dried at room temperature for 15 min. We demonstrate that the conductivity and densification of AgNW coating increases with the increase in the number of AgNW coating layers, concentration and length of the AgNWs. When the length of AgNWs is 13.49 μm, the sheet resistance is 15.68 Ω·sq


Growth in nanocoatings technology is moving towards implementing nanocoatings in many sectors of the industry due to their excellent abilities. Nanocoatings offer numerous advantages, including surface hardness, adhesive strength, long-term and/or high-temperature corrosion resistance, the enhancement of tribological properties, etc. In addition, nanocoatings can be applied in thinner and smoother thickness, which allows flexibility in equipment design, improved efficiency, lower fuel economy, lower carbon footprints, and lower maintenance and operating costs. Nanocoatings are utilised efficiently to reduce the effect of a corrosive environment. A nanocoating is a coating that either has constituents in the nanoscale, or is composed of layers that are less than 100 nm. The fine sizes of nanomaterials and the high density of their ground boundaries enable good adhesion and an excellent physical coverage of the coated surface. Yet, such fine properties might form active sites for corrosion attack. This paper reviews the corrosion behaviour of metallic, ceramic, and nanocomposite coatings on the surface of metallic substrates. It summarises the factors affecting the corrosion of these substrates, as well as the conditions where such coatings provided required protection. Corrosion is one of the major research areas that has been attracting the attention of researchers for over 150 years, since it is recognised as a problem causing degradation, failure, and serious accidents and hazards in many industrial processes and domestic systems . CorrosiCorrosion is a natural process that causes the dissolution of a material in the presence of aggressive environments. The most important factors that affect the occurrence of corrosion depend on the material and the environmental conditions. The material corrodes if it is active or adjacent to a nobler material in the galvanic series, which causes the dissolution of the first one. Specific environmental conditions make the material susceptible to corrosion, such as dissolved gases (mainly oxygen and carbon dioxide), temperature, pH, tensile stresses, and cyclic 2 stresses. Corrosion can happen in different forms, depending on the mechanism of corrosion. These can include: uniform, galvanic, crevice, pitting, environmentally-induced cracking, intergranular, dealloying, and erosion corrosion. Uniform corrosion is the form with the most incidences, and the highest tonnage of metal waste. While the others are localised corrosion, and might not consume a lot of material, they are difficult to predict and control, and might undertake an early unnoticeable failure . Unless Material selection, where the material is either relatively unreactive in the galvanic series or can form a protective oxide layer (passivate) in a particular environment; (b) Adjusting the environment conditions, such as the addition of inhibitors [Surface modifications, which is achieved by applying physical barriers such as films and coatings to reduce crevices and cracks [Cathodic protection, where the corrosion current is suppressed and is forced to flow to the metal to be protected. It is achieved by using a power source or attaching a more active (anodic) material to the structure to be protected [Corrosion prevention is performed through different techniques, and choosing the right one should be done while optimising between process cost, process performance, and corrosion effects. Corrosion can be prevented by: (a) hibitors ,9, adjushibitors , oxygen,hibitors , lowerind cracks ,13; (d) rotected . Each prCoating is the most widely used method for preventing, minimising, or controlling corrosion due to an available and possible variety of coating materials and coating processes for different conditions and applications. Coating, either of inner or outer surfaces, can be applied within different temperature ranges; it even provides an additional gain of smoother surfaces that enhances the efficiency of the interface and flow on surfaces . ApplyinRecently, nanomaterials have been introduced as an effective technique to reduce corrosion. Nanomaterials are materials that have at least one of their morphological features such as grain size, particle size, structure size, etc., in the nanoscale (less than 100 nm) . They caA nanocoating is an ultrafine microstructure where all of the constituents  are on the scale of less than 100 nm. These coatings can also be built up by layers that are thinner than 100 nm ,24. TheyNanocoating has one component that is in the nanoscale. Due to the very fine sizes of the particles used in this nanocoating, filling the spaces and blocking the corrosive elements from diffusing into the surface of the substrate will be more efficient. In addition, the high density of the nanocoatings’ grain boundaries provides better adhesion properties, which will increase the lifetime of the coating . NanocoaDue to the extraordinary properties that the nanocoating possess, they are used in everyday practise such as clothing, computers, cell phones, eyeglasses, etc. In the building field, they are used in tiles, windows, flooring, walls, paints, air filters, etc. The utilisation of the nanolayer in these appliances makes them flame-retardant, wear and scratch resistant, anti-graffiti, corrosion resistant, self-cleaning, and electrically conductive. They also have good adherence, optical clarity, anti-fogging and anti-fouling properties, and are suitable as a photovoltaic material ,34,35. INanocoatings can be obtained by three general deposition methods, as shown in Each of the above-mentioned techniques of thin film deposition on the surface of the substrate affect the uniformity and surface properties such as strength, fracture toughness, and ductility . Each teNanocoatings might not function as protective surfaces in some circumstances. A nanocoating is an effective physical barrier at high-temperature applications, as the high density of their grain boundaries provide fast diffusion paths of passivated ions and better adhesion of the protective oxide layer to the substrate’s surface . Yet, thUp until now, the wear/scratch resistance and corrosion behaviour of nanocoated surfaces is still under investigation; more research needs to be performed in this area. According to statistics from a ScienceDirect Journal search, research on the corrosion of nanocoatings started to gain more interest in 1998. Since then, the published papers related to nanocoating and corrosion have been increasing, but in a limited trend, as the maximum number of papers that have been published that are related to this field is around 2500 papers, as In the current paper, the corrosion behaviour of different nanocoatings is introduced by presenting some corrosion testing conducted on these nanocoatings under specific conditions. Each test can measure some corrosion parameters and help with understanding the corrosion mechanism for the tested sample. Immersion tests measure the weight loss of an immersed coupon after being exposed to aqueous solution for a certain time. It is intended to be used for long-term examinations and whenever uniform corrosion mechanism is expected to occur . On the The corrosion rate can be represented by the penetration rate, which is the thickness loss of the material per unit of time. The corrosion rate can be expressed by different units such as mpy , mm/yr, µm/yr, etc. For typical ferrous and nickel alloys, the relative corrosion resistance of a metal can be categorised according to the corrosion rate value as follows ; outstanding corrosion resistance (<0.02), excellent (0.02–0.1), good (0.1–0.5), fair (0.5–1), poor (1–5), and unacceptable (5+). Rates greater than 5 mpy to 200 mpy are usually excessive for more expensive alloys, while rates above 200 mpy are sometimes acceptable for cheaper materials  of a thicker cross-section . The corrosion behaviour of nanocoatings is affected by different factors such as the environment, the substrate, the nanocoating composition, etc. The following sections discuss these factors in detail for different kinds of nanocoatings that were categorised according to the nanocoating material: metallic, ceramic, and nanocomposite coatings. At the end, some conclusions and recommendation for future work to be done in this area are presented. Metallic nanocoating includes one or more of the pure metals such as Cadmium (Cd), Nickel (Ni), Tungsten (W), Zinc (Zn), Phosphorous (P), Cobalt (Co), Iron (Fe), Cupper (Cu), etc. Nanocoating can be of a pure metal ,42,43, oThe corrosion behaviour of metallic nanocoatings involves different factors, which contribute in an individual or combined effect. The most influential factors are introduced in the below section. Introducing metals in the nanocoating improves their physical , chemicaAlloyed metal provides superior properties compared to pure metal, even at the nanoscale. An nanocrystalline Ni–W alloy has better hardness and scratch resistance compared to pure nanocrystalline W . Alloyinf) is higher for a higher P content . However, measured double-layer capacitance (Qdl) and coating capacitance (Qcoat) obtained from Bode plots   and 17.6de plots b,c,e, fosolution . The corrosion rate of the pulse–current electrodeposition of nanocrystalline zinc was 60% lower than the microcrystalline electrogalvanised steel samples (EG) when tested in NaOH solution. Examinations showed a complete coverage of the nanocrystalline zinc protective film, which was attributed to the nanocrystalline structure, and enhanced both the kinetics of passivation and the stability of the passive film . Other rThis was not in agreement with the work of Aledresse and Alfantazi, which showed a better corrosion resistance of nanocrystalline cobalt (67 nm) over polycrystalline cobalt (100 µm) in alkaline media, but a higher corrosion current density. This indicates that finer grain sizes of the coating might provide defect sites at the grain boundaries and triple junctions, which makes the corrosion easier to initiate at these active sites. Nanocrystalline structures have a higher volume fraction of the intercrystalline constituents—more than the polycrystalline structure—and thus more active sites are available in the nanocrystalline structure . The effect of grain size was further studied for different sizes among the nanoscale. A lower or higher nanograin size of the nanomaterial is not necessarily to achieve the same effect in terms of corrosion protection, as a finer nanograin size did not had the best corrosion resistance in all of the research work. The same results of better enhancement with the increase of nanograin size was obtained by Meng et al. A bigger value of impedance and of the phase value for Q235 steel coating was observed with grain size of 50 nm compared to that of 10 nm b,c. This2 produced the lowest size of agglomerated particles, which was tested to produce good corrosion behaviour  towards more positive values compared to the steel that was only coated with CrN [On the other hand, depositing a protective nanocoating through the atomic layer deposition (ALD) method provides the advantage of having a full shield over the surface of the substrate without any pinholes or cracks compared to other depositing methods such as spray pyrolysis, chemical vapour deposition, physical vapour deposition, etc. This was due to the formation of an amorphous phase of deposited nanoparticles that produced dense and conformal films with the precise control of thickness and composition when coated by the ALD method . The samwith CrN . Althougwith CrN . 2 nanoparticles achieved an enhancement in the corrosion resistance of nano TiO2-coated carbon steel in H2SO4 solution [The corrosion protection of titania nanocoating was examined to improve coating performance by monitoring the media, size of the particles and thickness of the nanofilm. Decreasing the pH or increasing the NaCl concentration of the test environment, shifted the corrosion potential towards the more cathodic values of the coated steel . A reducsolution . Modifyisolution . Alumina thin films have unique mechanical properties and corrosion resistance; as a result, they have been implemented in many industrial fields such as surface passivation , gas difThe preparation method of alumina nanocoating was investigated for its effect on the corrosion properties of nanocoating. Ruhi et al. reported a better corrosion resistance of 9Cr-1Mo ferric steel coated with nanostructured sol-gel alumina nanocoating compared to the uncoated steel in an NaCl solution . A plasm2O3 is stable under neutral conditions, according to the Pourbaix diagram. ALD-coated substrate corroded under higher temperatures due to the type of substrate, since carbon steel caused a reduction of oxygen and introduced OH– ions, which increased the pH and initiated the dissolution of the oxide layer [The ALD method has the advantage of obtaining a controlled, smooth, and equally-coated surface. The deposition temperature with this method can be achieved at temperatures from room temperature to 500 °C. High-resolution TEM (HRTEM) images and polarisation tests showed that the best quality films in terms of density and purity are obtained when prepared under higher temperatures of 300 °C, as shown in de layer . 2-Ar plasma, which has 50 nm of Al2O3 deposited by either the thermal or plasma-enhanced ALD method, will increase the corrosion resistance as well. Such treatment increases the adhesion and reduces the porosity of the coated surface [The pre-treatment process affects the structure and the topography of the substrate, and can be performed to enhance the properties of the substrate, but it might have an adverse effect as well. The pre-treatment of carbon steel with H surface . Pre-ann surface . 2O5) is a refractory metal that exhibits attractive physical, structural, optical, and electrical properties such as high dielectric strength [Pentoxide  is another ceramic that exhibited a decrease in the corrosion resistance with the increase in acidity and temperature [Research works related to pentoxide nanocoating showed enhancement in corrosion properties. Coated Ti-6Al-4V alloy with β-Ta4V alloy . Carbon 4V alloy . Diaz et4V alloy . Moreoveperature . 2) has many applications in different fields due to its promising physical and chemical properties such as low friction coefficient, high melting point, high chemical stability, high refractive index, and dielectric constant [Zirconia  over copper films (25-µm thickness), the corrosion rates of copper in an aerated Nae nickel .Nanosized hydroxyapatite (n-HA) has been deposited on orthopaedic implant material  and characterised for its corrosion resistance in Hank solution. During corrosion testing, for n-HA coated titanium alloys, the initial open circuit potential (OCP) continued to increase until the protective air–oxide film reached its protective capacity. This shows that n-HA coated titanium alloys are robust towards corrosion resistance .Nanocomposite coating is a material composed of at least two immiscible phases, which are separated by an interface region. The main component in nanocomposite coating is the matrix, in which the filler is dispersed . The matCommon nanocomposites that are used for coating are matrix-reinforced. Polymer and metallic matrices nanocomposite coatings will be discussed in the following sections. Their corrosion behaviour will be the major concern, as well as how the enhancement in different properties will affect it. In the polymer nanocomposite field, a conductive polymer nanocomposite where the host matrix used is a conductive polymer will be discussed for its importance and huge potentials in different applications. In addition, a recent type of polymer nanocomposite coating, which is waterborne, will be studied for its corrosion behaviour. In the metallic/ceramic nanocomposite section, an electroless Ni nanocomposite will be briefly discussed due to its improved characteristics over the conventional electrodeposited techniques. At the end, Polymer nanocomposite coatings have evoked a great deal of interest in the corrosion protection applications due to the extraordinary properties that they can offer. With polymers used as host matrices in various composite films, nanomaterials are incorporated in the polymer matrix as a filler or pigment. When fillers are embedded into a polymer, the resulted hybrid organic–inorganic material is known as a polymer nanocomposite ,117. Usually, nanofillers are incorporated in the polymer matrix in order to increase the stiffness, strength, conductivity, and thermal resistance; they also reduce the thermal expansion, permeability, solvent attack, flammability, and fouling, and retain elongation, transparency, density, processability, cost, and chemical resistance ,120,121.Processing polymer nanocomposites is critical. Depending on the synthesis process, we may end up with either a perfect dispersion of nanofiller in the polymer matrix or with an agglomerated nanocomposite. The perfect dispersion and distribution of nanofillers in the matrix reflect the best possible enhancement in the properties. Several chemical processes are used to mix a polymer matrix with solid nanoparticles such as in situ polymerisation, emulsion polymerisation, solution intercalation, and melt intercalation ,125,126.2O3 [2 [2O3 nanoparticles were blended into the polymer, the mechanical properties were strengthened while sustaining the corrosion resistance of the polymer itself. The potentiodynamic test results in In the literature for polymer nanocomposites that coat the surface of stainless steel, different fillers are used to incorporate with polymers. MWCNT , Al2O3 [2O3 , graphen2O3 , ZrO [122O3 , and SiO2O3 [2  were add2O3 [2 . When AlAnother property that can be enhanced by the addition of nanofillers is hydrophobicity, which can return an enhancement in corrosion resistance. The introduction of GA and oleic acid (OA) to the chitosan to produce the nanocomposite coating of CS/GO-OA (oleic acid-grafted chitosan/graphene oxide), improved the corrosion protection over carbon steel in an NaCl solution. The large alkyl group of the OA resulted in the higher hydrophobicity of the coating’s surface, as it is revealed by the higher surface contact angle with the water that is shown in 2/EP) was prepared and then coated over a steel sheet, as shown in 2 in the EP using FE-SEM images showed the absence of clusters’ aggregation. In addition, the results showed an improvement in the adhesion strength of the interface between the coating and the metal substrate when GO and ZrO2 were incorporated with the EP. When tested for corrosion resistance in NaCl solution using EIS, the hybrid coating (GO–ZrO2/EP) showed the highest resistance compared to EP, GO/EP, and ZrO2/EP coatings. The combination of the GO–ZrO2 provided a physical barrier to obstruct electrolyte permeation, since they have a 2D sheet structure, high aspect ratio, and uniform dispersion and exfoliation within the EP matrix [A hybrid nanocomposite coating of graphene oxide–zirconia dioxide/epoxy  nanocomposite loading in alkyd resin, together with the increase in the impact strength of the nanocomposite polymer (PANI) [2/Graphene oxide (TiO2/GO) showed better stability in seawater than the polymeric nanocomposite coating of polyvinyl alcohol/polyaniline/few-layers graphene (PVA/PANI/FLG) when both were used to coat cast-iron pipelines. Such a better corrosion performance was due to the lower population of observed pores in the ceramic nanocoating. In addition, polymeric nanocoating had higher capacitance and was able to store higher charge, which allowed faster degradation [Polymer coatings modified with nanocomposite have been tested for their anti-corrosion properties as coatings for steel protection. The PANI nanocomposite tends to enhance the resistivity of the coating with its redox behaviour and self-healing effect when it is threatened to be destroyed due to scratch or scribble ,137,138.sistance . A PANI–ano TiO2 . The samano TiO2 ,137. Ther (PANI) . The cerradation .Another nanocomposite examined for corrosion properties was highly crystalline graphene integrated polyaniline (PaniGn) nanostructured composites over mild steel; it was measured for different concentrations of graphene. The results showed a decline in corrosion current of up to four orders of magnitude in HCl solution, where 1.92 wt.% graphene loading showed the best corrosion protection. It was suggested that the coating provided a physical barrier to the corrosive environment and imparted non-wetting characteristics . FurtherCurrent paint formulations contain volatile organic compounds (VOCs) as plasticisers to facilitate polymer diffusion, reduce ductility, and increase the flexibility of the paint. However, such technology showed a negative environmental impact . One of 3O4, Fe2O3, and ZnO were studied for their corrosion behaviour [2O3 were incorporated into an alkyd-based waterborne coating system in different concentrations [3O4) dispersed in waterborne epoxy acrylate-butylated melamine formaldehyde (EpAc-BMF) coatings showed a nobler reaction towards corrosion compared to a neat steel substrate [3O4 nanoparticles within the coating material provided a locking effect, and acted as a strong barrier at the coating–metal interface by filling the interstitial spaces and other coating artefacts , which will not allow the penetration of corrosive ions to the coating metal interface [Polymer-based waterborne coating integrated with nanoparticles such as Feehaviour ,145,146.ubstrate . A physinterface . 2SO4 solution. Without applying any friction force, the coating maintained a stable passivation layer. However, a depassivation–repassivation process was observed on the surface of the steel at the start and at the end of applying the friction force, respectively [Different types of nanoparticles were incorporated with nanocrystalline metal matrices coating such as silicon carbide, titanium dioxide, and alumina, to produce nanocomposite coatings ,154,155.ectively .2 nanoparticles were electrodeposited in composite coating with nickel over a sintered NdFeB magnet, it helped prevent the corrosive pits from growing up and accelerating the passivation process of the metal matrix as well [2O3 nanoparticles were incorporated into nickel coatings over steel, and tested for corrosion resistance in K2SO4 and NaCl solution, the results showed a nobler act for coated steel compared to bare steel. Al2O3 act as insulators on the composite surface, where a slightly better resistivity was found in NaCl solution [2O3 nanoparticles in a nickel matrix refine the nickel grain and change the preferential orientation of the composite coating [2O3 nanoparticles were found to play a key role in the corrosion behaviour study. Two types of electrodeposition techniques were used: sediment co-deposition (SCD) and adopting conventional electroplating (CEP), with different concentrations of nanoparticles. Using a CEP coating technique resulted in better corrosion resistance, which increased with the increase of Al2O3 particle concentration in the nickel matrix [In addition, when TiO as well . When Alsolution . Moreove coating . The typl matrix . 2O3 and Cr2O3 oxides layer to prevent oxygen diffusion into the bulk film at higher temperatures. However, corrosion rate values for Crx1−AlxN coatings increased with an increase in the aluminium fraction, as the incorporation of Al in the CrN lattice increases the roughness and porosity [100 deposited by a multi-arc ion plating method on the surface of Ti–6AL–4V resisted the aggressive conditions of a hot corrosion test. The mechanism of layered oxidation relieved thermal stresses and avoided the peeling that was caused by growth stress during oxidation [xN nanocoating improved the charge transfer resistance of the surface of AISI420 stainless steel substrate when the substrate was examined with EIS testing in a 3.5 wt.% NaCl solution. According to XRD pattern and TEM images, the addition of Si retarded the columnar structure growth that is permeable to corrosive ions, and a dense coating with equiaxial grains was revealed [Metal nitride films are widely used as a protective layer due to their superior mechanical properties and their enhanced wear and corrosion resistances. These films are used in a binary  or ternaporosity . A 0.9 rporosity . Anotherporosity . The addporosity  and erosporosity . It was porosity . Anotherxidation . Moreoverevealed . It shouA summary for the reviewed work of this section can be found in In the metal nanocomposite coating research field, nickel had received a great amount of attention due to its ability to act as the host matrix for electroless nickel plating. Electroless nickel plating is a chemical reduction process where coating is achieved by the catalytic reduction of nickel ions using a reducing agent such as sodium hypophosphite without applying electric current. Since it is a chemical reduction process, a uniform coating thickness can be obtained, along with uniform mechanical and physical properties. This was found to be an attractive and alternate method of producing a thin and uniform deposit on the substrate when compared to conventional electroplating ,167. The2, Al2O3, SiC, and SiO2 nanoparticles into the Ni–P alloy electroless coating caused an improvement in the corrosion resistance [The corrosion resistance of electroless-coated nickel phosphorous alloy is influenced by more than one factor. An increase in the corrosion resistance of the electroless nickel coating was noticed with the increase of phosphorus in the alloy. In addition, studies revealed that the incorporation of TiOsistance ,174,175.2-Ni–P nanocoating over low carbon steel was reported to be significantly dependent on the type of the surfactant and its concentration [2. The using of DTAB at an optimum concentration to incorporate TiO2 in an Ni–P matrix showed the lowest corrosion rate compared with bare low carbon steel, Ni–P coating, and TiO2–Ni–P + SDS coating. The increase in corrosion resistance of the TiOntration . Sodium 2O3 nanoparticles had an adverse effect on its corrosion resistance when heat-treated [2 nanoparticles and Ni–P with SiC nanoparticles, it was found to enhance corrosion resistance [In addition, heat treatment of the nanocomposite coating was found to have two opposite effects on the corrosion resistance, depending on the incorporated nanoparticles. It was reported that the nanocomposite coating of the Ni–P alloy with Al-treated , while fsistance ,175. A summary for the reviewed work of this section can be found in Nanocoatings have significant potentials to offer superior enhancements in the corrosion performance of surfaces compared to micromaterial coatings. Nanocrystalline structures are superior over microstructures for corrosion enhancement due to the fine grain sizes, which provide better space filling and a higher integrity of the coated surface. Applying nanocoating onto the surface of the substrate makes it harder, tougher, and improves its adhesive properties. However, the coating thickness and composition should be designed so as not to decrease its protective characteristics towards corrosive and eroding influences.Nanocoatings act through different mechanisms to provide enhanced corrosion resistance, and in some cases, they might bring up adverse effects. The fine sizes of nanocoatings form a uniform physical barrier on the surface of the material. Furthermore, nanoparticles possess improved adhesion properties due to the high density of their grain boundaries, thus increasing the corrosion resistance of the substrate. On the other hand, the higher grain boundary fraction and uneven surface generated from the agglomeration of the fine particles can foster the chance of forming anodic sites, which will make the surface more susceptible for corrosion attack. Hence, it is important to consider all of the surrounding factors related to nanocoating and substrates, in order to achieve the expected corrosion protection. The corrosion of metallic nanocoating has been studied with respect to the effect of several factors. It should be noted that there is no factor that affects the corrosion resistance alone in one dimension, neither one can alone contribute to the corrosion behaviour of the nanocoating. Nevertheless, they all play a role in determining the corrosion performance of the nanocoating. nanocrystalline Ni and its alloy have great potential as a promising metallic nanocoating, especially in the form of the nanocrystalline Ni–P alloy. A range of 14–17 wt.% of nickel in Zn–Ni alloys was shown to have the best corrosion resistance. The addition of phosphorus improves the corrosion behaviour in neutral and acidic media, with a composition of around 9–11 wt.% in the alloy. In regard to the grain size, there was no trend in corrosion behaviour for different sizes of the nanoparticles encountered in the nanocoating; nanocoating composition and the acidity of the media can dominate the effect of the grain size. Pulse electrodeposition was found to provide better corrosion properties than direct current, as the former technique produces a finer surface. The concentration of additives encountered in the nanocoating should be optimised for the best corrosion properties. 2O3, doping TiO2 with nitrogen anions, or pre-etching the surface before coating it with Ta2O5 reported better corrosion resistance. Both TiO2 and Ta2O5 show high resistance towards corrosion in NaCl solutions. Comparing values of corrosion current densities for the studied ceramics nanocoatings in the present paper showed that the corrosion resistance of titanium oxide and tantalum oxide is higher than that for zirconia and alumina. Zirconia has the potential to replace toxic chromium in nanocoating applications, as zirconia nanocoated surfaces reveal to have fairly low corrosion current densities in various kinds of solutions. The corrosion behaviour of ceramic nanocoating has been studied for different kinds of oxides, and every kind was found to have specific corrosion characteristics depending on the substrate, surroundings, and nanomaterial type and characteristics. Alumina nanocoating is shown to have enhanced corrosion characteristics when it is deposited with a plasma-enhanced ALD technique compared to thermal ALD deposition. Pre-treatment processes improves the surface properties and corrosion characteristics of the coated surface. Pre-annealing the copper substrate before coating it with Al2, SiC, and SiO2 have positive corrosion behaviour when added to the Ni–P matrix in a NaCl solution for electroless Ni coating, while for electrodeposition coating, Al2O3 showed a good corrosion resistance when blended in an Ni matrix. For polymer nanocomposite coating, conductivity has become a point of interest. For nanocomposite coatings, a filler of ceramic or metallic nanoparticles is dispersed in the host matrix, which enhances the physical properties of that matrix, and enables it to be used as an effective nanocoating. Corrosion protection with nanocomposite coating is achieved by building a compact barrier and preventing charge transfer such as oxygen permeability and ion transportation. In addition, nanocomposite coating improves some of the other properties that help in enhancing the corrosion behaviour of the nanocomposite, such as: cohesive and adhesive properties, hydrophobicity, agglomeration, and dispersion and distribution properties. The corrosion of nanocomposite coating is affected by the same factors as those mentioned above. In addition to those, the corrosion behaviour of nanocomposite coatings is influenced by the nanocomposite synthesis method, type, and concentration of the filler, as well as whether the coated substrate is heat-treated or not. TiOThe corrosion resistance of a material defines its stability and durability, and it is important to identify it as a part of material’s performance assessment. Corrosion research provides information regarding the fundamental kinetics and mechanisms of the corrosion process. Nanocoating contains ultrafine constituents that might influence the resulting surface regarding aspects of lattice structure, grain size, porosity, intermetallic particles’ distribution, surface state, etc. These constituents have very small and dense grain boundaries that make it challenging to develop new corrosion theories for their interaction with the surface. For example, smoothening the surface increases the integrity, uniformity, and fatigue performance of the ultrathin coatings, which would decrease the possibility of pit initiation at such surfaces. At the same time, having nanoparticles covering the surface provides excessive smoothness that might weaken the adherence of the coating and cause detachments of parts of the coating. In addition, lowering the surface roughness might increase the possibility for preferential intergranular corrosion, that allows the growth of a more defective and permeable coating at the triple-junction grain boundaries. These two mechanisms allows the nanomaterials to interact with the surface in two opposite directions, and it is difficult to identify which theory is applicable. In addition, due to presence of such nanomaterials on the surface of the substrate, oxide formation is affected; hence, the transition mechanism of the surface state differs, and will be difficult to detect. Surface state transition from passivation to pit initiation and then to the breakdown of the film is influenced. Depending on the initial conditions of the uncoated surface and the cleanness of the final coated surface, the new state is defined, which will affect the overall surface corrosion. Due to the nonuniform distribution of the nanoparticles on the surface of the coated substrate, ions might accumulate and create weak points of higher potential that cause pit initiation. On the other hand, an accumulated coating might physically isolate the substrate surface from electrolyte ions. Predicting the transition mechanism is challenging, and it requires deeper corrosion research.


This work investigating the dependence of the optoelectronic properties of AgNW-FTCFs on AgNW length provides design guidelines for development of AgNW-FTCFs.Flexible transparent conductive films (FTCFs) composed of silver nanowires (AgNWs) have become an important research direction because of their potential in flexible electronic devices. The optoelectronic properties of FTCFs composed of AgNWs of different lengths were evaluated in this study. AgNWs, with an average diameter of about 25 nm and length of 15.49–3.92 μm were obtained by a sonication-induced scission process. AgNW-FTCFs were prepared on polyethylene terephthalate substrates using a Meyer bar and then dried in the ambient environment. The sheet resistance, non-uniformity factor of the sheet resistance, the root mean square roughness, and haze of the FTCFs increased as the length of AgNWs decreased. The transmittance of the films increased slightly as the length of AgNWs increased. AgNWs with a length of 15.49 μm provided an AgNW-FTCF with excellent properties including haze of 0.95%, transmittance of 93.42%, and sheet resistance of 80.15 Ω∙sq As the demand for flexible and wearable electronic devices has increased over the last 20 years, the development of the flexible transparent conducting films (FTCFs) with excellent electrical conductivity, flexibility, and optical transparency has become important. At present, indium tin oxide (ITO) is a widely used material for the transparent conducting films; however, because of its intrinsic brittleness, relative rarity, and expensive deposition and post-treatment processes, ITO is not suitable for flexible device fabrication. To circumvent the shortcomings of ITO, many materials, including carbon nanotubes ,2, graphSilver nanowire (AgNW) films have excellent optical and electrical properties comparable to that of ITO and are regarded as a leading candidate for FTCFs ,6,7,8. T−1. Bergin et al. recently reported that the transmittance of AgNW-FTCFs with AgNWs of a given diameter is linearly to area coverage, and does not depend on the length of the AgNWs. In addition, they found that decreasing AgNWs diameter improved optoelectronic performance only for AgNWs with a diameter of less than 20 nm [Generally, it is challenging to fabricate a high-performance AgNWs film with both high transmittance and high electrical conductivity, because AgNWs are not transparent. Meanwhile, the haze of AgNW-FTCFs strongly depends on the diameter of AgNWs and is decreased by using AgNWs with a smaller diameter ,20,21. Han 20 nm . Sorel ean 20 nm . They foan 20 nm ,26,27,28Herein, we produce AgNWs with different lengths by a sonication-induced scission process and explained relationship of the length of AgNWs with ultrasonic time and then fabricate FTCFs composed of the AgNWs of different lengths. Furthermore, the influence of AgNWs length on the sheet resistance, non-uniformity factor of the sheet resistance, transmittance, haze, and root mean square roughness of AgNW-FTCFs were discussed in a systemic way. In addition, the relationship of the optoelectronic properties of film with microstructures was discussed. The uniformity of the AgNWs networks decreases with decreasing of AgNWs length. The resulting FTCF composed of 15.5 μm AgNWs has high transparency, low sheet resistance and haze and root mean square roughness, and high uniformity. We would like to point out that the AgNW-FTCFs conductive film prepared have no any additional post-treatment.−1) after sonication-induced scission at an ultrasonic power of 300 W for 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 h, are presented in t is the ultrasonic time and L(t) represents the average length of AgNWs at a certain t. The ultrasonic energy at constant ultrasonic power is proportional to the ultrasonic treatment time. NUF) to evaluate the standard deviation of the sheet resistance of the films from the average value as follows [n is the number of measurements of the film of different sites, and iR and NUF, the more uniform the film. According to this method, we divided film into 64 regions of the same size, measured the sheet resistance of each region and recorded the data. Conductive films consisting of AgNWs of different lengths were fabricated on polyethylene terephthalate (PET) substrates using a Meyer bar. A schematic diagram of the fabrication of an AgNW-FTCF is shown in  follows :(2)NUF=∑NUF of the sheet resistance of films consisting of AgNWs of different lengths. Results for the films containing AgNWs with average lengths of 5.17 and 3.92 μm are not shown in −1, respectively. As the length of the AgNWs decreased from 15.5 to 7.86 μm, the sheet resistance of the film increases by about 6400%. As the length of the AgNWs in the AgNW-FTCFs decreased from 15.5 to 7.86 μm, NUF rose from 0.29 to 0.52, indicating that the distribution uniformity of AgNWs on the PET surface decreased. As the distribution uniformity of AgNWs decreases, it is difficult to AgNWs to form continuous and effective conductive paths in all direction of our films were considerably smaller than those reported in the literature [terature ,33, indiTransmittance spectra and the transmittance values at a wavelength of 550 nm of the AgNW-FTCFs containing AgNWs of different lengths are depicted in SEM analysis provided an explanation for the influences of AgNW length of on the optical and electric performances of the AgNWs films. L) that are widthness in two dimensions, the critical number density (CN) of sticks required for percolation is given by Equation (3) [CN of AgNWs required to form a percolation network is inversely proportional to the square of L. Therefore, a low number density of long AgNWs can form a sparse and effective percolation network. Such a network can not only increase the light transmission, but also improve conductivity forming long percolation routes with few nanowire junctions. iR is the internal resistance of AgNW and cR is the contact resistance between AgNWs. The total resistance of the conductive film can be regarded as the sum of iR and cR, where cR can be considered equivalent to the concentrated resistance, which is the resistance produced when the current flows through a very small conductive contact point and is compressed by convergence. For network structures composed of AgNWs, the number of contact points between AgNWs obviously depends on AgNW lengths. A junction resistance always exists between AgNWs. The higher the number of contact points, the higher the junction resistance in an AgNW network. In general, a typical AgNW-FTCF shows low conductivity because the AgNWs network contains numerous contact points, which leads to high junction resistance. For films composed of long AgNWs, the junction resistance is low because of the limited number of contact points. Conversely, for film composed of short AgNWs, the junction resistance is high because of the numerous contact points. This indicates that minimizing the junction resistance was important to obtain AgNW-FTCFs with high conductivity without post-treatment. Tighter contact between crossed AgNWs resulted in higher conductivity; the long AgNWs in the network provided multiple electrical pathways from one edge of the network to the other, which meant that breaking a relatively small number of junctions would still leave alternative electrical paths from one edge of the network to the other. However, when the length of AgNWs and the distribution uniformity decrease, the discontinuous AgNWs networks are formed and the contact resistance increased considerably, resulting in a substantial decrease of electrical conductivity. In addition, for the theoretical sticks with a given length (tion (3) ,35:NC × For a given concentration of AgNWs, decreasing the length of AgNWs increases the number, which results in increased contact resistance of their film. In addition, with the decreasing AgNW lengths, the distribution uniformity of AgNWs on the substrate surface decreased, resulting in difficulty forming an effective conductive network between AgNWs, which increased the film resistance. Meanwhile, increasing the number of AgNWs increased their deposition density on the substrate, which decreased the transmittance. The effect of AgNW length on optoelectronic properties is especially important at high transmittance (low area coverage), where there are relatively few connections between nanowires, i.e., the film is porous.FoM) is defined the ratio DCσ/Opσ, where Opσ (λ) is the optical conductivity and DCσ is the direct current (DC) conductivity of the film, which is one of the important parameters for evaluating the optoelectronic properties of optoelectronic films. Here, we calculated FoM of the film, as shown in FoM decreased gradually. When the AgNW length decreased from 15.5 m to 7.86 m, the film FoM decreased from 67.9 to 0.86, which was reduced by about 790%. This result indicated that the AgNW length has great influence on optoelectronic properties of film. As we know that transparent conductive film as electrode to be used in optoelectronic devices, the DCσ/Opσ value is at least 35, which corresponds to the resistance sheet less than 100 Ω with a transmittance at 550 nm over 90%, meanwhile, DCσ/Opσ values of film need over 50 and 10 when they are used in liquid crystal display and touch screen panels, respectively [In general, figure of merit (ectively . We woulRMS) values of the film with AgNW lengths of 15.5, 9.24, and 7.86 μm were 12.9, 18.4, and 22.3 nm, respectively. These RMS values are low approximately the diameter of a nanowire. The RMS values of the films increases with decreasing AgNW length, which may be related to the non-uniform distribution and high local deposition density of AgNWs.To further study the effect of AgNW length on morphology, the films with AgNW lengths of 15.5, 9.24, and 7.86 μm were analyzed by AFM as shown in −1 without post-treatment. This performance is acceptable for use of the film in display devices. Haze is defined as the ratio of diffuse transmittance to total transmittance according to ISO 14782 ,38. FiguAfter linear fitting of the data points plotted on a logarithmic scale, the following relationship between the haze and transmittance was found:To demonstrate the applicability of the AgNWfilms, we connected green and blue LEDs to the conductive film, as shown in −1. Polyethylene terephthalate (PET) substrates were purchased from Hefei Microcrystalline Materials Co., Ltd., China. Ethanol absolute (99.7%) was purchased from Jinan Liyang Chemical Co., Jinan, Ltd., China. All the chemicals were used as received. An AgNW suspension was purchased from Suzhou Gushi New Materials Co., Ltd., Suzhou, China. The suspension contained AgNWs with an average diameter and length of 25 nm and 15.49 μm, respectively, dispersed in isopropyl alcohol at a concentration of 10 mg∙mL−1 with isopropyl alcohol and then subjected to ultrasonication for 0.5–3 h at a power of 300 W. The ultrasonication was carried out in a bath-type sonicator . For ultrasonication treatments, the AgNWs suspension was diluted to 2 mg∙mL−1) films were then dried in the ambient environment for 15 min. AgNWs films were fabricated on PET substrates using a Mayer bar  and AgNWs suspension . The lengths of individual AgNWs visible in the images were measured manually using image processing software . For one sample, we obtained six SEM images. The lengths of individual AgNW in the SEM image were measured manually according to an image processing software. The number of AgNW measured for each sample should not be less than 80. The sheet resistances of films were characterized using a four-probe system  and optical transmittances were measured using a thin film transmittance meter . Diffuse reflectance was measured with an ultraviolet-visible spectrophotometer . Optical transmittance and sheet resistance of AgNW-FTCFs were measured at 20 different sites, from which average values were calculated. The transmission and diffuse reflectance were measuredusing a PET film as a reference. The surface morphology was analyzed via atomic force microscopy .NUF of the AgNW-FTCFs increased s by about 6400% and 178%, respectively, as the AgNWs length decreased from 15.5 to 7.86 μm. These results indicated that the distribution uniformity of AgNWs on the PET surface o decreased as the ANW length shortened. The transmittance of the film at 500 nm decreased slightly from 93.42% to 91.99% and haze increased from 0.95% to 1.03% as the AgNWs length decreased from 15.49 to 7.86 μm. RMS values of the films were low (close to the diameter of a nanowire). The film consisting of AgNWs with a length of 15.5 μm exhibited haze of 0.95%, transmittance of 93.42%, and sheet resistance of 80.15 Ω∙sq−1 without any additional post-treatment. These highly uniform and mechanically stable AgNW-FTCFs meet the requirement for numerous applications and could soon play a major role in the display market AgNWs with an average diameter of about 25 nm and a length of 3.92–15.49 μm were obtained by sonication-induced scission. AgNW-FTCFs were then prepared on PET substrates and dried in the ambient environment. The film contains AgNWs with lengths of 5.17 and 3.92 μm were non-conductive because of the poor contact between the AgNWs. The sheet resistance and


The bromine ions were used as pivotal passivating agent. When the molar ratio of Br−/Cl− was 1:4, the average diameter of AgNWs was as low as ~40 nm, the average length was as high as ~120 μm, and the aspect ratio reached 2500. Networks of AgNWs were fabricated using as-prepared high-quality AgNWs as conducting material and hydroxyethyl cellulose (HEC) as the adhesive polymer. As a result, a low sheet resistance down to ~3.5 Ω sq−1 was achieved with a concomitant transmittance of 88.20% and a haze of 4.12%. The ultra-low sheet resistance of conductive film was attributed to the long and thin AgNWs being able to form a more effective network. The adhesion of the AgNWs to the substrate was 0/5B (ISO/ASTM). The insights given in this paper provide the key guidelines for bromine ion-assisted synthesis of long and thin AgNWs, and further designing low-resistance AgNW-based conductive film for optoelectronic devices.High aspect ratio silver nanowires (AgNWs) with ultra-long length and thin diameter were synthesized through bromine ion (Br With the emergence of flexible photoelectric devices and the scarcity of indium resources, great efforts have been made to develop new flexible transparent conductive films  to replace traditional indium tin oxide (ITO). Until now, conductive polymers ,2,3, silTo our knowledge, the properties of AgNW-based TCFs mainly depend on characteristics including the nanowire structure and the overall network morphology. In general, the length, diameter, and aspect ratio of nanowires are critical factors for enabling the high transparency with a low haze, low sheet resistance, and superior mechanical compliance and strength . However−) as co-nucleant can effectively reduce the diameter of AgNWs, but a small AgNW length is always obtained owing to the harsh conditions. Lee et al. reported that employing NaCl and KBr as nucleants could control the diameter of AgNWs in the range of 15–30 nm, however the length was below 20 μm [3 and KBr as co-nucleants and achieved thin AgNWs with an average diameter of 26 nm, but only about 21 μm in length [- decreased diameter of AgNWs while increasing length, and through controlling the growth of AgNWs obtained AgNWs with a large aspect ratio [Through performing an extensive literature search and seriously comparing and summarizing the factors that affect the morphology of AgNWs in the synthetic process, it was found that, except for the reaction temperature and time, it appears that the varieties and quantities of nucleant are crucial. Search results showed that bromide ions  to form conductive ink and coated onto polyethylene glycol terephthalate (PET) to fabricate AgNW-based TCFs with a transmittance of 88.20% and a haze of 4.12% while achieving a low sheet resistance of ~3.5 Ω sq3, ≥99.8%), sodium chloride  and potassium bromide  were purchased from Sinopharm Chemical Reagent Co., Ltd.  poly-vinylpyrrolidone  was acquired from Sigma Aldrich . Hydroxyethyl cellulose (HEC) was purchased from Dow . Ethylene glycol  and ethanol  were obtained from Xilong Scientific Co., Ltd. . Polyethylene glycol terephthalate (PET) was gained from Yingshang Electronic Materials Co., Ltd. . Deionized (DI) water was purified by laboratory water purification system with a resistivity of 18.2 MΩ·cm and a working temperature of 25 °C.All chemicals were of analytical grade and used as received without further purification. Silver nitrate . Then, 1.792 g of AgNO3 and 11.12 g of PVP were dissolved into 240 mL EG, to get transparent solution, as “b” solution. Later, the “b” solution was poured into “a” solution to form a light orange mixed solution. After magnetically stirring for 10 min, 400 mL of the mixture was transferred into a Teflon-lined stainless steel autoclave with a capacity of 500 mL and reacted under solvothermal conditions at 170 °C for 2.5 h. The autoclave was cooled down to room temperature in a standard atmosphere. The grayish-green product was centrifuged, and alternately washed with ethanol and DI water, dispersed in a certain amount of DI water. The solid content of AgNWs was measured to be 0.95%.As the most common reagent, KBr was chosen as the chemical auxiliary of synthesize ultra-long AgNWs. As is known, the existence of KBr will lead to uncontrollable nanoparticles. To avoid the formation of many nanoparticles, and prepare ultra-long AgNWs, while further performing the function of KBr thin AgNWs, NaCl was used to assist KBr, and collectively realize the synthesis of ultra-long AgNWs. In a typical synthetic experiment, 1:4 molar ratio of BrAgNW ink was prepared by a simple physical method. Specifically, AgNWs were dispersed into the solvent system that matched matrix resin. First, 1.0 g HEC was dissolved into 100 mL DI water to form a 1.0 wt % solution. Then, 12 mL of above solution were transferred into a beaker, and stirred at room temperature. After that, 26 mL of aqueous AgNWs dispersion liquid were immersed into the solution, and 12 mL of DI water was further added, making the solid contents of AgNWs and HEC 0.5% and 0.25%, respectively. After being stirred for about 3 h, the final ink was obtained for fabricating TCFs.The AgNW-based TCFs were fabricated on a BEVS1811/2 bar coater with a vacuum plant . The fabrication process comprised the following steps: first, the bare PET substrate was adsorbed onto the platform by vacuum. Then, a bar of 20 μm was put down to hold the substrate, and dumped the AgNW ink on substrate. The length and speed of coating were set as 10 cm and 300 mm/s, respectively, and then the start button was pressed. The bar pushed the ink to glide over the substrate. After that, the coated-film was taken down and put in an air dry oven of 130 °C and curing 5 min, and obtained a flexible transparent conductive film.θ, and scanned in steps of 0.02° (2θ) from 20° to 90°. The microstructures of the sample were observed on a FEI-Versa3D field emission scanning electron microscopy  operating at 30 KV. Before FE-SEM test, the sample was dispersed in ethanol and further dripped on silicon wafer. The transmission electron micrography  was performed on a Zeiss EM 912 Ω instrument at an acceleration voltage of 120 KV, while high-resolution transmission electron microscopy (HRTEM) and fast Fourier transform (FFT) were examined on a Philips CM200-FEG microscope . Due to the very brittle structure of AgNWs, the sample used for TEM was dispersed in ethanol with no need for ultrasound treatment, and the dispersion was then dropped on carbon–copper grid. The UV-vis spectra of the sample were performed on a UV-vis spectrophotometer  with a scan range from 190 nm to 900 nm. SGW-820 transmittance and haze analyzer  were employed to study the transmittance and haze of AgNW-based TCFs, and a bare PET film was used as blank test. The four-point probe (SB100A/2) was used to examine the sheet resistance of AgNW-based TCFs with a probe current of 2 mA. Tests for adhesion were conducted by a Cross-Cut Tester scratching  the PET substrate with AgNW-based TCF. Then kapton tape was stuck to the film, and then peeled off. The pattern obtained was examined visually and classified by means of a reference table. According to the standard applied, an identification number was assigned to classify the adhesion properties of the tested coating. The grade of 0/5B indicates the best adhesion.X-ray diffraction  with a copper Kα radiation (λ = 1.54056 Å) was used for the crystal structure and the phase identification, where the diffracted X-ray intensities were recorded as a function of 22O could be detected, indicating the high crystallinity and purity. Besides, the intensity of (111) Bragg reflection was largest, suggesting that the AgNWs grew along the (111) Bragg reflection. Its crystallite size was estimated to be about 20 nm, which was a prerequisite for the formation of thin AgNWs.The XRD pattern of the as-synthesized sample is depicted in The detailed structures of the obtained AgNWs were further observed via TEM, HRTEM and FFT. - can influence the size of the initial nucleus, and the AgBr cubes are much smaller than the AgCl [+, the Br− adsorbs on the surface of original AgNWs, and the Br- can passivate the {100} facets, limit lateral growth, and further promote the formation of thinner AgNWs [− leads to a slower release of Ag atoms contributing also to thin and high aspect ratio AgNWs [6. Due to the increase in chain length, the solution would possess a high viscosity, slowing down the growth kinetics and leading to the formation of MTPs. Furthermore, the PVP with a higher molecular would strongly adsorb on Ag nanocrystal surface, leading to a confinement to the lateral growth [The evolution of morphologies from original nucleation to high aspect ratio AgNWs was demonstrated by schematic diagram, as compared in the AgCl . Then, wer AgNWs . Next, iio AgNWs . The secl growth . The thil growth . In addition to FE-SEM and TEM, the UV-Vis absorption is another characterization method for analyzing AgNWs morphology. As is known, the UV-Vis spectra can be used to describe the morphology, as Ag nanostructures with different sizes and shapes display surface plasmon resonance (SPR) bands at different frequency ranges. For AgNWs, there are two plasmon adsorption resonances, corresponding to the transverse oscillation of electrons and the oscillation of electrons along the long axis . Figure −1, which was much less than previous reports [To explore potential applications, as-synthesized AgNWs was used as a conductive material to prepare conductive ink using HEC as adhesive. The inset of  reports ,39,40,41Afterwards, the optical property of as-fabricated AgNW-based TCFs was elucidated, as shown in The mechanism for the ultra-low sheet resistance was caused by ultra-long and high aspect ratio AgNWs, as schematically represented in 3 was translated into AgBr and NaCl, and was reduced into Ag via solvothermal at 170 °C. It was found that the as-synthesized AgNWs exhibited a diameter of ~40 nm, a length of ~120 μm, and aspect ratio up to 2500. The flexible transparent conductive film based on as-synthesized AgNWs exhibited ultra-low sheet resistance of ~3.5 Ω sq−1, as well as high transmittance and low haze, strong adhesion, which were mainly attributed to long AgNWs with small diameter being able to form a more effective network. These findings not only offer a novel route to synthesize high-quality AgNWs, but also provide a promising method to prepare environmentally friendly aqueous AgNW-based conductive ink, and further obtain high-performance flexible AgNW-based TCFs.In summary, ultra-long and thin AgNWs were one-step synthesized by adding KBr as co-nucleant with a molar ratio of 1:4 of KBr/NaCl. Subsequently, AgNO


Cardiovascular disease (CVD) remains the leading cause of global mortality. Individuals with disabilities are at increased risk of CVD in part due to their musculoskeletal and/or cognitive impairments that can challenge their participation in physical activities. Gait ability has been associated to several key health outcomes including morbidity. Unfortunately, there is little research done to understand how individuals with obstructed mobility  grow older. Our research team , evaluated the prevalence of CVD risk factors and age-related health outcomes associated to aging on a cohort of adults with cerebral palsy with obstructed mobility. Metabolic syndrome was identified in 17.1% of the cohort, higher than the 10% in the NHANES sample. CVD risk factors were much higher in this cohort as compared to normative population data. There was a positive correlation between mobility level, waist circumference , and waist-to-hip ratio .