bluuebunny/crossref_metadata_2025_split huggingface dataset:
AA-CVD and ALD of Vanadium Pentoxide Thin Films for Electrochromic Applications
Authors: Kazadojev I I , O'Brien S , Louloudakis D , Katsarakis N , Koudoumas E , Vernardou D , Pemble M E , Povey I. M 
Published: February 2020

Despite the high potential impact of vanadium based electrochromic devices, there are still many issues to be resolved before widespread market implementation can be realised. The current limitations arise from cost, the slow electrochemical kinetics and the poor cycling stability of vanadium pentoxide.
In this work we initially employed aerosol assisted chemical vapor deposition (AACVD) at 400°C in combination with a 600°C anneal in air to grow films on fluorine doped tin dioxide (FTO) coated glass. The aerosol was generated from a methanolic solution of vanadyl (IV) acetlyacetonate using an ultrasonic humidifier and a nitrogen carrier gas. All annealed films were found to be monoclinic vanadium pentoxide but only the thicker films demonstrated a viable electrochemical response. The lack of response from the thinner films was proposed to be due to either the formation of an unstable interfacial oxide or non-uniform growth due to the aerosol method. To determine the reasons for this limitation two experiments were performed, firstly the addition of a sub-nm alumina barrier layer by atomic layer deposition between the FTO and the V2O5 to inhibit the formation of any interfacial mixed oxide; Secondly, the low temperature growth of V2O5via atomic layer deposition using vanadyl triisopropoxide and oxygen as reagents.
Initial indications are that the inclusion of an alumina barrier layer does not improve the uniformity of the thinner AACVD films. The ALD grown V2O5 films however demonstrated significant improvements in uniformity even at very high optical transparencies. These observations are discussed with reference to electron microscopy, UV-visible spectroscopy, XRD and the samples’ electrochemical responses.
Charge Transport and Structural Dynamics in Polymerized Ionic Liquids
Authors: Sangoro Joshua R , Paddison Stephen J. 
Published: February 2020

Polymerized ionic liquids (PolyILs) are a novel class of functional polymers that combine the unique physicochemical properties of molecular ionic liquids with the outstanding mechanical characteristics of polymers [1-2]. This special mix of features might help to circumvent the key limitations of low molecular weight ionic liquids, namely, leakage and poor mechanical properties while utilizing their outstanding characteristics such as low vapor pressures, wide liquidus ranges, high thermal stability, high ionic conductivity, and wide electrochemical windows. PolyILs have shown remarkable advantages when employed in electrochemical devices such as dye-sensitized solar cells, lithium batteries, actuators, field-effect transistors, light emitting electrochemical cells, and electrochromic devices, among others. Despite their promising prospects as ideal polymer electrolytes, the role of molecular structure, morphology, and polymer dynamics on charge transport in PolyILs remains poorly understood.
According to classical theories, the self-diffusion and ion transport in electrolytes are controlled by structural relaxation. These approaches predict similar temperature dependence for the dc conductivity and structural dynamics. Although this prediction has been shown to hold reasonably well for low molecular weight aprotic ionic liquids [3], it fails for PolyILs [2]. In addition, the impact of morphology charge transport is not considered within the framework of these theories.
In this talk, new insights obtained from both experimental studies employing broadband dielectric spectroscopy, temperature-modulated differential scanning calorimetry, and scattering techniques along with multiscale modeling investigations to elucidate charge transport and structural dynamics in a systematic series of polymerized ammonium- and imidazolium- based ionic liquids will be presented. Detailed analyses reveal strong decoupling of these processes in the PolyILs, implying failure of the classical theories in describing charge transport and molecular dynamics in these materials. In addition, the strong correlation observed between ionic conductivity from dielectric experiments and morphologies from scattering studies will be discussed.

References

1) Mecerreyes, D. Progress in Polymer Science 2011, 36, 1629.
2) Sangoro, J. R. et al., Soft Matter 2014, 10, 3536.
3) Sangoro, J. R.; Kremer, F. Accounts of Chemical Research 2012, 45, 525; J. R. Sangoro, C. Iacob, A. Serghei, C. Friedrich, F. Kremer, Phys. Chem. Chem. Phys. 11, 913, (2009)
(Keynote) Dielectrophoresis: Exploring the â€˜2nd Frontierâ€™ of Its Application in the Biomedical Sciences
Authors: Pethig Ronald 
Published: February 2020

Dielectrophoresis (DEP) has been widely studied for its potential as a biomarker-free method of sorting cells based on their intrinsic dielectric properties [1-4]. Under appropriate experimental conditions the DEP frequency spectrum typically exhibited by a viable mammalian cell in suspension is characterized by two frequencies, f
xo1 and f
xo2. At these two characteristic frequencies the effective conductance and capacitance values of the cell exactly match those of the fluid it has displaced, and are commonly known as the DEP cross-over frequencies.
At low frequencies (<10 kHz) viable cells typically exhibit negative DEP and move away from electrodes, with the transition to positive DEP occurring at f
xo1 - where the cells move towards high field regions at the electrodes. The investigation, understanding (in terms of cell biology) and biomedical exploitation of this phenomenon can be considered to represent exploration of the ‘1st frontier of dielectrophoresis’. The results of this work, extending over more than 25 years, are now exploited in the form of various commercial devices for clinical and biomedical applications. The status of this activity will be reviewed.
A transition back to negative DEP occurs at f
xo2 (~150 MHz). The factors that control the high frequency DEP cross-over at f
xo2 have only recently been explored, and the status and implications of this ‘2nd frontier of dielectrophoresis’ will also be reviewed in this presentation.
1. Pethig, R. Review Article - Dielectrophoresis: Status of the theory, technology, and applications. Biomicrofluidics 4, 022811 (2010).
2. Gagnon, Z.R. Cellular dielectrophoresis: Applications to the characterization, manipulation, separation and patterning of cells. Electrophoresis
32: 2466-2487 (2011).
3. Pethig, R. Dielectrophoresis: An assessment of its potential to aid the research and practice of drug discovery and delivery. Adv. Drug Deliv. Rev.
65: 1589-1599 (2013).
4. Gascoyne, P.R.C. and Shim, S. Isolation of circulating tumor cells by dielectrophoresis, Cancers
6: 545-579 (2014).
5. Chung, C., et al. Dielectrophoretic characterisation of mammalian cells above 100 MHz, J. Elec. Bioimpedance 2: 64-71 (2011)
The Effect of Carbon Nanotubes Solid Contact Dispersing Agent on the Parameters of Resulting Potentiometric Sensors
Authors: Michalska Agata , Jaworska Ewa , Maksymiuk Krzysztof 
Published: February 2020

Carbon nanotubes are important nanostructured material for different applications, including electrochemical sensors [1,2]. Among other advantages related to electrochemical properties of carbon nanotubes, they can be applied in simple procedure, resulting in electronically conducting layers. For sensor purposes (e.g. ion-selective electrodes, field effect-transistors) carbon nanotubes (CNTs) suspension (called ink) can be simply drop cast or spray coated on different substrates. However, to prepare a useful and stable CNTs suspension in water application of stabilizing agent is necessary. This agent is usually an ion or polymer that spontaneously absorb on CNTs – e.g. sodium dodecylsulfate, sodium dodecylbenzene sulfate or carboxymethyl celulose [1-4]. As a consequence this substance is present also in obtained CNTs layer and potentially can affect their performance.
In this study potassium selective electrodes with CNTs solid contact were prepared. The CNTs transducer layers were obtained by drop casting, using suspensions stabilized with different agents – surafctants as well as complexing ligands. The effect of CNTs suspension stabilizing agent on performance of potentiometric sensors - analytical parameters (sensitivity, selectivity, detection limit) as well as stability of potentiometric responses in time were studied. Potentiometric (open circuit), chronopotentiometric and impedance studies have confirmed that the nature of dispersing agent used as well as its amount used affects performance of the sensor. Dispersing agent used can partition into sensor layers – e.g. ion-selective membrane - significantly altering their properties. Herein obtained results are potentially important for all applications in which CNTs layer are fabricated using stable dispersion of nanomaterial.
REFERENCES
1. G. A. Crespo, S. Macho, F. X Rius, Anal. Chem. 2008, 80. 1316.
2. F. X. Rius - Ruiz, G. A. Crespo, D. Bejarano - Nosas, P. Blondeau, J. Riu, F. X. Rius, Anal. Chem. 2011, 83, 8810.
3. K. Melzer, A. M. Münzer, E. Jaworska, K. Maksymiuk, A. Michalska, G. Scarpa, Analyst 2014, 139, 4947
4. E. Jaworska, M. Schmidt, G. Scarpa, K. Maksymiuk, A. Michalska Analyst 2014, 139, 6010.
Spray-Coated All-Solid-State Potentiometric Sensors
Authors: Jaworska Ewa , Schmidt Morten , Scarpa Giuseppe , Maksymiuk Krzysztof , Michalska Agata 
Published: February 2020

Recent reports on application of nanostructurized materials for potentiometric sensing purposes point out advantages of novel structures [1]. Here a methods of ions-selective electrodes preparation using solely spray coating method was reported [2]. As an electrical lead support and transducer spray coated CNT layers were used. The ion-selective membrane was coated also by spraying membrane cocktail over a part of a CNTs layer. This method offers significant advantages compared to screen-printed electrodes used also for potentiometric applications [3]. The benefits of the herein-proposed approach include fully automatic sensor preparation and minimized use of chemicals allowing for the production of low-cost sensors that can be applied as disposables. The obtained sensors (as the model system potassium-selective sensors were prepared) are characterized with analytical parameters well comparable with that of conventional, all-solid-state, ion-selective electrodes. In addition, the applicability of the herein-proposed approach to prepare other ion-selective electrodes was tested on examples of H+ and Cl- sensors.
REFERENCES
1. A. Düzgün, G.A. Zelada-Guillén, G.A. Crespo, S. Macho, J. Riu, F.X. Rius, Anal. Bioanal. Chem., 2010, 399, 171-181.
2. E. Jaworska, M. Schmidt, G. Scarpa, K. Maksymiuk, A. Michalska, Analyst 2014, 139, 6010-6015.
3. R. Koncki, Ł. Tymecki, E. Zwierkowska and S. Głab, Fresenius. J. Anal. Chem., 2000, 367, 393.
Metal Halides in Li-Ion Batteries
Authors: Bridges Craig A , Powell Jonathan M , Veith Gabriel M , Banerjee Arnab , Nagler Stephen E. , Dai Sheng 
Published: February 2020

There is a critical need for improved electrical energy storage in terms of capacity, voltage, recharge time, safety and cost for a renewable energy grid, practical electric vehicle technology, and future portable energy technology. One approach under consideration to overcome current limitations in lithium ion batteries is to utilize a multielectron conversion electrode. [i] Much focus has been placed on the use of metal fluorides for secondary batteries, due to promising cell voltages and chemistry. Here we present recent work looking at the use of metal chlorides, and understanding the mechanism of lithiation and delithiation.
[i] Gao, X.-P.; Yang, H.-X.; “Multielectron reaction materials for high energy density batteries”, Energy Environ. Sci.
3 (2010) 174-189.
Optimization of Dispersion Property of a Thin Ceramic-Coating Layer on Thermal and Electrochemical Properties of Separator for Lithium-Ion Batteries
Authors: Kim Hyunsik 
Published: February 2020

In this poster, a optimized dispersity propery of ceramic-coating separator for lithium-ion batteries is successfully prepared by forming a ceramic layer consisted of Al2O3 powder and mix binder onto one side of pristine PE separator.
During the preparation of the separator, water is used as solvent and a very small amount of a mixture binder is applied as binder to obtain better thermal stability. The effect of dispersity property of the ceramic-coating layer on its thermal stability, physical properties and electrochemical performance is also investigated. The results clearly showed that the ceramic-coating separator with SBR–CMC binder has wonderful thermal stability, good wettability and high uptake of liquid electrolyte.
Synthesis at Low Cost and Large Scale of Silicon Powder Suitable for Li-Ion Anodes
Authors: Reale Hernandez Cuauhtemoc , Karkar Zouina , Guyomard Dominique , Lestriez Bernard , Roué Lionel 
Published: February 2020

Silicon is considered as one of the most promising materials to replace graphite in Li-ion batteries. The main inconvenient of that material is its huge volume expansion during lithiation which induces the disintegration of the electrode architecture with cycling. Nanosized Si materials (nanoparticles, nanowires, nanocomposites…) better accommodate large volume variation without cracking. However, the use of such materials by industries is unlikely because of their high synthesis cost, handling difficulties and low tapping density.
We have recently demonstrated that Si powder produced by high-energy ball milling (using a laboratory vibratory-type miller) present the same benefits of nanometric Si in terms of performance but not the drawbacks1. Milled Si powder is constituted of micrometric agglomerates (median size of ca. 10 µm), made of submicrometric cold-welded particles with a crystallite size of ca. 10 nm. The micrometric particle size provides handling and non-toxicity advantages compared to nanometric powders, as well as four times higher tap density. The nanocrystalline structure of the ball-milled Si powder is assumed to induce a smoother phase transition upon cycling.1,2

In the present study, ball-milled Si powder is produced at larger scale (500 g/batch compared to 5g/batch in previous work) using a pilot-scale attritor (Fig. 1). Using optimal milling parameters and appropriate composite electrode formulation, this material displays very good electrochemical performance (see Fig. 2). Various analyses will be presented in order to understand the influence of the milling time on the physicochemical characteristics and electrochemical behavior of the Si powder. During these investigations, we noticed that the storage conditions of the electrodes prior to assembling the cell have also a major influence on the electrochemical performance. This aspect will be also discussed.
References
1. M. Gauthier, D. Mazouzi, D. Reyter, B. Lestriez, P. Moreau, B. Lestriez, D. Guyomard, L. Roué. A low-cost and high-performance Si-based electrode for Li-ion batteries. Energy Environ. Sci. 6 (2013) 2145–2155.
2. M. Gauthier, D. Reyter, D. Mazouzi, P. Moreau, D. Guyomard, B. Lestriez, L. Roué. From Si wafers to cheap and efficient Si electrodes for Li-ion batteries. J. Power Sources 256 (2014) 32-36.

Figure 1
Ccto-P(VDF-CTFE) 0-3 Composites for Energy Storage Application
Authors: Tong Yang , Zhang Lin , Cheng Z.-Y. 
Published: February 2020

ABSTRACT
Recently, there is a great need to develop a new ceramic-polymer composite which exhibits relatively high dielectric constant, high dielectric strength, low dielectric loss and high flexibility for applications ranging from electronic packaging, embedded capacitors, to energy storage [1, 2]. The electric energy density (Ue) can be calculated by the equation Ue=1/2ε0εrEb
2, where ε0 is the vacuum permittivity (8.85×10-12 F/m), εr is dielectric constant of composite, and Eb is dielectric breakdown field. A higher dielectric constant or dielectric strength would allow a higher energy density, are highly desirable for the dielectrics used in energy storage devices [2]. Ceramic-polymer composites have been detail studied by researchers, and most of the recent studies were focused on the PVDF-based composites.
In this experiment, the nano-sized CaCu3Ti4O12 powder and P(VDF-CTFE) 88/12 mol.% are used for prepare composites by solution cast with high dielectric constant in previous work [3, 4]. To enhance the uniform distribution of ceramic filler in polymer matrix, the CCTO powder was firstly coated with the coupling agent 1 H, 1H, 2H, 2H Perfluorooctyltrichlorosilane, which can be used to improve the dielectric breakdown field. The coated powder was mixed with P(VDF-CTFE) in dimethyl formamide (DMF) solution then casting as thin film at 70oC and annealed with different temperatures. The dielectric constant and dielectric strength of the composites were studied using Impedance Analyzer and H.V. Supply Amplifier/Controller respectively. The annealing effect, amount of coupling agent and temperature dependence of dielectric properties were studied for these composite films. The energy density in these nanocomposites can reach around 4.5 J/cm3 with volume fraction of CCTO around 15 vol.%, which makes them attractive for high energy density capacitors and electric energy storage devices.
REFERENCES
[1] B. Chu, X. Zhou, K. Ren, B. Neese, M. Liu, Q. Wang, F. Bauer and Q. M. Zhang, “A dielectric polymer with high electric energy density and fast discharge speed,” Science vol.313, 334-336, 2006.
[2] Z. M. Dang, J. K.Yuan, S. H. Yao, and R. J. Liao “ Flexible nanodielectric materials with high permittivity for power energy storage,” Adv. Mater., vol. 25, pp. 6334-6365, 2013.
[3] L. Zhang, X. B. Shan, P. X. Wu and Z.-Y. Cheng, “Dielectric characterization of CaCu3Ti4O12/P(VDF-TrFE) nanocomposites,” Appl. Phys. A, vol. 107, pp. 597-602, 2012.
[4] X. B. Shan, L. Zhang, X. Q. Yang, and Z.-Y. Cheng, “Dielectric composite with a high and temperature-independent dielectric constant,” J. Adv. Ceram. Vol.1, pp. 310-316, 2012.

Figure 1
Dissolution and Repassivation Behaviour of Ti, Ti-6Al-4V, Type316L and Co-27Cr-5.5Mo in Bio-Mechano-Chemical Environment
Authors: Doi Kotaro , Miyabe Sayaka , Fujimoto Shinji 
Published: February 2020

Dissolution and Repassivation during and after passivity breakdown of four kinds of metallic biomaterials in simulated body fluid were examined using rapid straining electrode test. The materials were pure titanium, Ti-6Al-4V alloy, type 316L stainless steel and Co-Cr alloy. Rapid straining was applied for electrodes of these materials that were immersed in a simulated body fluid containing proteins for 1 day, 1 week or 1 week with cell culturing prior to the test, then changes in strain, stress and anodic current were observed simultaneously.
The maximum anodic current density during rapid straining was observed for pure titanium. However, maximum charge density generated after rapid straining until 100 s from the termination of rapid elongation was observed for type 316L stainless steel. These results suggest that the amount of dissolution of metallic biomaterials with passivity breakdown depends on the equilibrium potential of metal substrates and repassivation rate.
The charge densities generated on the samples immersed for 1 week in the simulated body fluid prior to the rapid elongation and covered with cells was larger than that generated on the sample immersed for 1 day in pure Ti, Ti-6Al-4V alloy and type 316L stainless steel. The highest increase rate of the charge density was confirmed in the sample covered with cells of type 316L stainless steel.
Heterogeneous Thermal Oxide Film Formed on Polycrystalline Pure Iron
Authors: Takabatake Yu , Kitagawa Yuichi , Nakanishi Takayuki , Hasegawa Yasuchika , Fushimi Koji 
Published: February 2020

The thermally-grown oxides formed on pure iron have characteristic composition, structure, and thickness, depending on the oxidation condition such as temperature and oxygen partial pressure. The crystallographic orientation of iron surface also affected the rate of thermal oxidation1. However, the heterogeneity on the thermal oxide film formed on polycrystalline iron has not been discussed sufficiently. In order to well understand the non-uniform oxidation that progresses on polycrystalline iron, it is important to elucidate the precise characteristics of the thermal oxide film from the viewpoint of crystallographic orientation. In this study, we investigated the heterogeneity of thermal oxide film formed on polycrystalline pure iron by using a 2D-ellipsometer and a micro-capillary-cell (MCC) method2.
The sample specimen was an annealed iron plate with a purity of 99.99%. After mirror-like polishing, the surface orientations of the sample were identified by using an electron backscatter diffraction patterning. Subsequently, the sample was kept at 573 K in air for 3.6 ks to form thermal oxide film. The thickness of the oxide film on the surface was mapped with the 2D-ellipsometer. The characteristics of the oxide film formed on each single grain were evaluated by electrochemical impedance spectroscopy (EIS) by means of an MCC with an inner diameter of 180 µm.
The sample surface as polished was smooth like a mirror showing metallic luster. After thermal oxidation, however, it showed various colors, depending on the surface metallographic structure due to interference of light. The colors of the sample surface indicated that the thermal oxides grew at different rate depending on the surface orientation of single grains on the substrate. The non-uniform oxide formation on the polycrystalline iron was also confirmed by two-dimensional thickness mapping with the ellipsometer. EIS measurements showed that the electric resistance and capacitive behavior of the oxide films were depended on the orientation of substrate surface. Furthermore, the results of Mott-Schottky analysis implied that the surface orientation affected the defect structure of the thermal oxides. It was considered that the grain-dependency on the thermal oxide film was originated in anisotropic growth of the oxide determined by the crystallographic orientation of the substrate iron surface. The detailed consideration of the grain-dependency on the oxide film is discussed on site.
References
[1] W. E. Boggs, R. H. Kachik, and G. E. Pellissier, J. Electrochem. Soc., 114, 32 (1967).
[2] Y. Takabatake, K. Fushimi, T. Nakanishi, and Y. Hasegawa, J. Electrochem. Soc., 164, C594 (2014).