pinecone/core-2020-05-10-deduplication huggingface dataset:
Surface characterization of polyester resins formulated with different cross-linking agents

Coil Coating is an industrial process widely used to apply a paint layer to metal coil stock, in order to improve the resistance to corrosion as well as the aestetics of the surface. Three thermally cured coatings, formulated on a low Tg ispophtalic based polyester, were investigated by XPS and ToF-SIMS. A model formulation was employed for all three coatings investigated, however, the crosslinking agents used were varied for each formulation. Hexamethoxymethyl melamine (HMMM), tris isocyanurate (TIC) and a combination of HMMM and TIC were included as the cross linking agents in the three coating formulations. The use of TIC alone required a Sn based catalyst to promote the curing reaction. The aim of this work was to investigate the difference in the surface composition of the three coatings and the different behaviour of the different crosslinking agents used. This was in preparation for further studies which will involve interfacial analysis in order to elucidate the mechanism behind intercoat adhesion. The XPS analysis of the air/coating surfaces revealed a nitrogen concentration consistent with the concentration expected from the formulation for the coating containing HMMM. In the other two formulations a lower concentration then that calculated from the formulation was observed. The surface concentration of the two crosslinking agents is not influenced by the presence of the others, indeed the formulation containing both crosslinking agents is, in term of nitrogen concentration, merely a simple combination of the other two coatings. Peaks diagnostic of the cross linking agents were observed in ToF-SIMS spectra acquired from the air/coating surfaces. The coating with HMMM revealed peaks not present on the coating with TIC and vice versa, however the coating with a combination of HMMM and TIC showed all the peaks, with different relative intensities. In the positive spectrum of the sample with TIC the characteristic pattern of the tin catalyst can be observed. By XPS and ToF-SIMS analysis, we have been able to determinate that the HMMM and the TIC have a different distribution on the coating/air surface. Their distribution is not affected by the presence of the other crosslinking agent
Interfacial studies of Al2O3 deposited on 4H-SiC(0001)

Al2O3 films deposited on 4H-SiC(0001) by atomic layer deposition (ALD) were characterized by x-ray photoelectron spectroscopy (XPS), and high resolution transmission electron microscopy (HRTEM). The effect of medium and high temperature (873, 1273 K) annealing on samples with oxide thicknesses of 5-8nm and 100-120nm was studied. XPS indicated presence of a thin (~1nm) SiOx layer on the as-grown samples which increased to ~3 nm after annealing above crystallization temperature (1273 K) in Ar atmosphere. Upon annealing the stoichiometry of the interfacial oxide approaches that of SiO2. HRTEM showed that the thickness of the interfacial oxide formed after annealing at 1273 K was not uniform. No significant increase in the thickness of the interfacial oxide, was observed after annealing at 873 K in a N2 (90%) / H2 (10%) atmosphere
Surface characterization of a cross-linked cytochrome c film on cysteamine-modified gold electrodes

The aim of the present paper is to characterize a cross-linked horse heart cytochrome c (HHC) film on cysteamine-modified gold electrodes. The HHC film was deposited using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) as a coupling agent. Attenuated total reflection infrared (ATR-IR) spectroscopic analyses were performed to characterize the newly formed surface on a qualitative and conformational level. The film thickness was measured using a noncontact optical surface profiler, while quantitative data and information on the heterogeneity of the film were obtained by means of synchrotron radiation X-ray micro fluorescence (SR micro-XRF). Results indicate that, in addition to electrochemical studies, spectroscopic analysis methods are essential to gain insight in the effect of immobilization strategies on protein conformations. The latter is of relevance in the development and optimization of biosensors
Peak-fitting of high resolution ToF-SIMS spectra: a preliminary study

Peak-fitting has been performed on a series of peaks obtained by ToF-SIMS analysis in order to assess whether information may be obtained from this procedure on the samples’ characteristics. A variety of samples were examined including a range of treatments for aluminium leading to different surface roughnesses, polymer films with a range of polydispersities, molecular weight and thicknesses as well as aluminium samples with adsorbed adhesion promoters on the surface. Variation of peak-fitting was assessed by varying the peak intensity, full width at half maximum and peak asymmetry. Although further studies are needed it is possible to say that the peak width increases with roughness whereas peak asymmetry seems to be related to oxide thickness. Polymer characteristics do not seem to influence the width whereas the peak asymmetry increases either versus molecular weight or polydispersity. A possible assumption is that the peak asymmetry relates to the ion formation processes. Additional work with varying polymer films thickness indicates that both FWHM and peak asymmetry may be related to sample charging and this could be used for assessment of film thicknesses. Finally, peak-fitting was used to obtain a more reliable peak area when peaks are too close in mass to use current methods
Examination of the interface of a model adhesive joint by surface analysis: a study by XPS and ToF-SIMS

Model samples of the interface of an adhesive joint containing small levels of aminopropyl triethoxysilane (APS) have been prepared in order to examine the interface formed with an aluminium substrate. X-ray photoelectron (XPS) and time of flight secondary ion mass spectrometry (ToF-SIMS) has been used to analyse and image the interface region in between the aluminium and an epoxy adhesive in order to ascertain the reactions by the organosilane, present as a minor component within the system. It was found that APS was present at the interface between the adhesive and the substrate and that it had reacted with the substrate forming a covalent bond and was also crosslinked within the adhesive. Evidence of near to full hydrolysis of APS is also present within the spectra
Corrosion behaviour of mechanically polished AA7075-T6 aluminium alloy

In the present study, the effects of mechanical polishing on the microstructure and corrosion behaviour of AA7075 aluminium alloy are investigated. It was found that a nano-grained, near-surface deformed layer, up to 400 nm thickness, is developed due to significant surface shear stress during mechanically polishing. Within the near-surface deformed layer, the alloying elements have been redistributed and the microstructure of the alloy is modified; in particular, the normal MgZn2 particles for T6 are absent. However, segregation bands, approximately 10-nm thick, containing mainly zinc, are found at the grain boundaries within the near-surface deformed layer. The presence of such segregation bands promoted localised corrosion along the grain boundaries within the near-surface deformed layer due to microgalvanic action. During anodic polarisation of mechanically polished alloy in sodium chloride solution, two breakdown potentials were observed at −750 mV and −700 mV, respectively. The first breakdown potential is associated with an increased electrochemical activity of the near-surface deformed layer, and the second breakdown potential is associated with typical pitting of the bulk alloy
The potential for the application of X-ray photoelectron spectroscopy in forensic science

The potential for the use of X-ray photoelectron spectroscopy (XPS) in forensic science is reviewed, taking as a starting point a series of examples and case histories this review speculates on other areas where XPS may be able to make a contribution. The topics that are considered include chemical speciation of fingerprints, thin layers deposited on substrates as a result of explosions and/or fire, particulate materials and cosmetics and finally sequestration of marker elements and molecules on surfaces. It is concluded that XPS has much to offer the forensic science community but investigations may be hampered by the need to compare crimes scene specimens with known standards. Until this issue is addressed it is likely that XPS will continue to be used on an ad hoc basis for particularly challenging specimens in high profile cases
Inhibition effect of cerium in hybrid sol–gel films on aluminium alloy AA2024

Aluminium alloys such as AA2024 are susceptible to severe corrosion attack in aggressive solutions (e.g. chlorides). Conversion\ud
coatings, like chromate, or rare earth conversion coatings are usually applied in order to improve corrosion behaviour of\ud
aluminium alloys. Methacrylate-based hybrid films deposited with sol–gel technique might be an alternative to conversion\ud
coatings.Barrier properties,paint adhesion andpossibly self-healing ability are important aspects for replacement of chromatebased\ud
pre-treatments. This work evaluates the behaviour of cerium as corrosion inhibitor in methacrylate silane-based hybrid\ud
films containing SiO2 nano-particles on AA2024. Hybrid films were deposited on aluminium alloy AA2024 by means of dipcoating\ud
technique. Two different types of coating were applied: a non-inhibited film consisting of two layers (non-inhibited\ud
system) and a similar film dopedwith cerium nitrate in an intermediate layer (inhibited system). The film thickness was 5 μmfor\ud
the non-inhibited system and 8 μm for the inhibited system. Film morphology and composition were investigated by means\ud
of GDOES (glow discharge optical emission spectroscopy). Moreover, GDOES qualitative composition profiles were recorded in\ud
order to investigate Ce content in the hybrid films as a function of immersion time in 0.05 M NaCl solution. The electrochemical\ud
behaviour of the hybrid films was studied in the same electrolyte by means of EIS technique (electrochemical impedance\ud
spectroscopy). Electrochemicalmeasurements provide evidence that the inhibited system containing cerium displays recovery\ud
of electrochemical properties. This behaviour is not observed for the non-inhibited coating. GDOES measurements provide\ud
evidence that the behaviour of inhibited system can be related to migration of Ce species to the substrate/coating interfacePeer reviewe
Chemical composition and structural changes of porous templates obtained by anodising aluminium in phosphoric acid electrolyte

Ordered anodic aluminium oxide (AAO) filmswere first prepared by anodising in a phosphoric acid electrolyte and then studied extensively and characterised by field emission gun-scanning electron microscopy (FEG-SEM), X-ray diffraction, Raman and infrared spectroscopy at a macroscopic scale. These analyses showed that the as-prepared AAO film is in fact amorphous, partially hydrated and that its initial global chemical  composition can be described, in agreement with previous works, as: Al2O3, 0.186AlPO4 · 0.005H2O. Additional analyses (thermogravimetric analysis, differential thermal analysis and FEG-SEM) showed geometrical changes of the film structure at different scales, explained by various steps of dehydration and allotropic transformations of the resulting crystallised alumina. However, because their structure remains unchanged up to 900 ◦C, the phosphoric templates appear to be particularly suitable for applications or processes atmedium or high temperatures, such as the preparation of carbon nanotubes or oxide rods
Effect of substrate surface topography on forensic development of latent fingerprints with iron oxide powder suspension

This is a pre-print version of the article. The official published version can be accessed from the link below - Copyright @ 2010 Wiley-BlackwellLatent fingerprint deposition and effectiveness of detection are strongly affected by the surface on which prints are deposited. Material properties, surface roughness, morphology, chemistry and hydrophobicity can affect the usefulness or efficacy of forensic print development techniques. Established protocols outline appropriate techniques and sequences of processes for broad categories of operational surfaces. This study uses atomic force microscopy and scanning electron microscopy to investigate a series of surfaces classified as smooth, non-porous plastic. Latent prints developed with iron oxide powder suspension are analysed on a range of scales from macro to nano to help elucidate the interaction mechanisms between the latent fingerprint, development agent and underlying surface. Differences between surfaces have a strong effect, even within this single category. We show that both average roughness and topographical feature shape, characterised by skew, kurtosis and lay, are important factors to consider for the processing of latent fingerprints. Copyright (C) 2010 John Wiley & Sons, Ltd.This work is part-funded by the UK Home Office project 7088762
The characterization of the interfacial interaction between polymeric methylene diphenyl diisocyanate and aluminum: A ToF-SIMS and XPS study

Time of flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS) have been employed to study the interfacial interaction between polymeric methylene diphenyl diisocyanate (PMDI) and aluminium produced by the deposition of a thin PMDI layer on the aluminium, in order to improve adhesion and/or abhesion performance. When the PMDI concentration increases, the intensity ratio fragments indicative of the reaction product with water (m/z = 106 u: C7H8N+) to that of isocyanate group (m/z = 132 u: C8H6NO+) decreases. A very thin MDI layer on oxidised aluminium samples exhibits lower 106/132 ratio than degreased samples as a result of less hydroxide/hydroxyl spices on the surface. This suggests that water reactions occur both at the surface of PMDI and at the PMDI/aluminium interface. The variation of the PMDI chemistry has also been studied by exposing PMDI treated samples to the air for various periods of time (a few hours to 14 days), in order to assess the reaction of the PMDI surface and PMDI/aluminium interface. At the interface, the yield of reaction with water is limited because of the finite amount of hydroxyl groups on the aluminium surface, and the water reaction is completed in a short period of time. However, the PMDI surface continues to react with water from the atmospheric. This methodology was also used to establish the presence of specific interactions at the PMDI/aluminium interface, and a fragment indicative of covalent bond formation between PMDI and aluminium (AlCHNO3-) is observed at the interface
Zero-energy SIMS depth profiling: The role of surface roughness development with XeF2-based etching

To obtain monolayer depth resolution in the zero-energy SIMS concept, an almost atomically flat surface during the electron beam-induced etching (EBIE) is crucial. However, the surface roughness observed with Si EBIE and XeF2 shows the same characteristics as observed during spontaneous etching of Si with XeF2. The subsurface fluorine concentration in a Si EBIE process (even in amass transport limited regime) can influence the unactivated formation of the SiFx reaction layer as well, and therefore, contribute to observed roughness development. SiO2 EBIE leads to extreme pit formation due to preferential etching of Si at the SiO2/Si interface. In general, preferential etching can deteriorate or enhance the depth resolution as shown on a SiGe epilayer structure. Finally, the capabilities of zero-energy SIMS are shown on an ultra-shallow SiGe structure demonstrating a narrow surface transient and a very good depth resolution in the surface region. Copyright (C) 2010 John Wiley & Sons, Ltd.status: publishe
Surface characterisation of PET modified using a p-DC or HIPIMS reactive sputter pre-treatment

Surface-sensitive techniques have been employed to characterise a model polymer substrate surface, poly(ethylene terephthalate) (PET), after a reactive sputter pre-treatment using magnetically enhanced Cu or Ti sputter targets in a mixed Ar-O glow discharge plasma. The plasmas are produced using either medium-frequency pulsed direct current (p-DC) or low-frequency high power impulse (HIPIMS) sources. X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and sessile drop water contact angles were employed to investigate changes in PET surface chemistry and properties following surface modification using different p-DC and HIPIMS process parameters. The XPS results indicate that the chemical composition of plasma-treated PET surfaces (p-DC or HIPIMS) depends strongly on the processing parameters employed such as sputter target material, magnetic array type and power supply technology. XPS results demonstrate that the sputter target material employed is of primary importance as it dictates the quantity of metal deposited/implanted into the PET surface. XPS results show that the use of a Cu target resulted in ∼ 31-35 at.% of Cu incorporated into the PET surface (as CuO), while the use of a Ti target resulted in only 1-4 at. % incorporation (as TiO ). The SIMS spectra and XPS depth profiles of Cu-treated PET indicate that the CuO has formed a discrete film at the surface, offering predominant or total coverage of the underlying PET. However, for Ti-treated PET, both PET and Ti SIMS peaks are observed, and the XPS C1s peak shape is characteristic of PET, indicating that Ti has not formed a discrete film, but instead TiO species have been incorporated, probably as an island-like distribution into the surface of the PET. The formation of CuO and TiO on the PET surface leads to a reduction in the contact angle compared to native PET. Hence, both p-DC and HIPIMS reactive plasma pre-treatments result in a more hydrophilic surface, promoting adhesion and offering a flexible means to introduce a wide range of surface chemistries and properties to polymeric surfaces. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd
The classical molecular dynamics simulation of graphene on Ru(0001)
  using a fitted Tersoff interface potential

The accurate molecular dynamics simulation of weakly bound adhesive
complexes, such as supported graphene, is challenging due to the lack of an
adequate interface potential. Instead of the widely used Lennard-Jones
potential for weak and long-range interactions we use a newly parameterized
Tersoff-potential for graphene/Ru(0001) system. The new interfacial force field
provides adequate moir$\acute{e}$ superstructures in accordance with scanning
tunnelling microscopy images and with DFT results. In particular, the
corrugation of $\xi \approx 1.0 \pm 0.2$ $\hbox{\AA}$ is found which is
somewhat smaller than found by DFT approaches ($\xi \approx 1.2$ $\hbox{\AA}$)
and is close to STM measurements ($\xi \approx 0.8 \pm 0.3$ $\hbox{\AA}$).The
new potential could open the way towards large scale simulations of supported
graphene with adequate moir$\acute{e}$ supercells in many fields of graphene
research. Moreover, the new interface potential might provide a new strategy in
general for getting accurate interaction potentials for weakly bound adhesion
in large scale systems in which atomic dynamics is inaccessible yet by accurate
DFT calculations.Comment: 7 pages, 3 figures, 2 tables, + supplementary materia
XPS and AES studies of UHTC ZrB2-SiC-Si3N4 treated with solar energy

The microstructure of ultra-high-temperature ceramics based on the ZrB2–SiC composition and a sintering additive (Si3N4) was investigated using XPS and AES techniques. These ZrB2–SiC–Si3N4 materials were treated in air plasma at high temperature (T > 1750 K) in the MESOX facility developed at the PROMES-CNRS laboratory (Moyen d'Essai Solaire d'OXydation for the measurement of atomic oxygen recombination coefficients). The surfaces were characterized before and after the air plasma treatment. Surface modifications were observed and induced by the oxidation process. The elementary composition was determined using AES and XPS. Core level spectroscopy (XPS) was used to determine the atomic composition and the nature of the chemical bonds from the Zr 3d3/2,5/2, Si 2p1/2,3/2, O 1s and C 1s photoelectron peaks. The microstructural analyses revealed the presence of oxide layers: Silica and zirconia compounds were detected at temperatures near 1800 K, and a zirconia compound was mainly detected above 2200 K
A study of interface adhesion between polyamide 6 (PA6) and nitrile rubber (NBR)

This is the peer reviewed version of the following article: Wang Y., Ghita O., Kavanagh D., and Chandler D. (2014), A study of interface adhesion between polyamide 6 (PA6) and nitrile rubber (NBR), Surf. Interface Anal., 10-11, pages 1000–1004, which has been published in final form at 10.1002/sia.5488. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving: http://olabout.wiley.com/WileyCDA/Section/id-820227.html#termsThe mechanism of interface bonding of a selected nitrile rubber compound vulcanized on polyamide 6 was studied using transmission electron microscopy. The two types of interfaces identified were formed through mechanical clamping and enhanced by hydrogen bonding between polyamide 6 and silane coupling agent in nitrile rubber compoun
Electronic properties of zero-layer graphene on 6H-SiC(0001) substrate decoupled by silicon intercalation

International audienceGraphene exhibits electronic properties that are very sensitive not only to defects but also to the interaction with extra molecules or atoms and underlying substrate. To overcome this limitation for application and mass device production, various methods have been investigated to decouple graphene from substrate and to form quasi-free standing layer. Silicon has shown to be able to softly decouple the zero-layer graphene from the substrate. However, the electronic properties of decoupled zero-layer graphene (ZLG) by silicon intercalation on 6H-SiC(0001) stay unknown. The decoupling process of the ZLG terminated surface happens at lower temperature compared with ZLG covered by 1 monolayer graphene. The presence of extra graphene layer appears to be of an impediment to silicon intercalation. The decoupled ZLG exhibits electronic properties of a quasi-free-standing monolayer graphene. Ab initio calculation corroborates the experimental data and confirms the evolution of the ZLG band structure with silicon intercalation