Electrophoretic Co-deposition Research Articles

One-step fabrication of NiOx-decorated carbon nanotubes-NiCo2O4 as an advanced electroactive composite for supercapacitors

Tailoring of battery-type NiCo2O4 with carbon-based materials for supercapacitors usually involves several steps, which require prolonged syntheses at high temperatures. Here, a facile one-step strategy is presented for the fabrication of a binder-free composite, made of NiOx decorated multi-walled carbon nanotubes (CNTs) and NiCo2O4 nanoparticles on nickel foam to form a stable supercapacitor with high specific capacity. The process is based on the electrophoretic co-deposition of carboxylated-CNTs and NiCo2O4 NPs, which were positively charged using Ni2+. The latter played a double role by stabilizing the nanomaterials and improving the electrochemical performance by decorating the nanomaterials with NiOx species. The well-dispersed NiCo2O4 NPs in the highly conductive porous matrix of CNTs provide efficient electron transfer, high surface area and superior electrochemical performance, such as high charge storage, high rate delivery and good cycling stability. The nanocomposite film exhibited high specific capacitance of 1363 F gr−1 at 2 A gr−1, while retaining 82% of the capacitance at higher current density (20 A gr−1). The straightforward fabrication process and the excellent electrochemical activity are of generic nature and can be applied for assembling other well-structured carbon-based composites.

Electrophoretic co-deposition of Fe2O3 and Mn1,5Co1,5O4: Processing and oxidation performance of Fe-doped Mn-Co coatings for solid oxide cell interconnects

Fe-doped Mn1,5Co1,5O4 coatings on Crofer22APU were processed by an electrophoretic co-deposition method and the corrosion resistance was tested at 750 °C up to 2000 h.The “in-situ” Fe-doping of the manganese cobalt spinel was achieved by electrophoretic co-deposition of Mn1,5Co1,5O4 and Fe2O3 powders followed by a two-step reactive sintering treatment. The effects on the coating properties of two different Fe-doping levels (5 and 10 wt.% respectively) and two different temperatures of the reducing treatment (900 and 1000 °C) are discussed. Samples with Fe-doped coatings demonstrated a lower parabolic oxidation rate and thinner oxide scale in comparison with both the undoped Mn1,5Co1,5O4 spinel coating and bare Crofer 22 APU. The best corrosion protection was achieved with the combined effect of Fe-doping and a higher temperature of the reducing step at 1000 °C.

Fabrication of microwave absorbing Fe3O4/MWCNTs@CFs nanocomposite by means of an electrophoretic co-deposition process

The current study reports the fabrication of a nanocomposite with improved microwave absorption and interference shielding properties by introducing multi-wall carbon nanotubes and Fe3O4 nanoparticles onto carbon fibers through an electrophoretic co-deposition process. The results revealed that the Fe3O4/multi-wall carbon nanotubes@carbon fiber nanocomposite structure with a high specific surface area of 87.12 m2. g−1 was successfully fabricated. The epoxy-based composite filled with the nanocomposites had both of the magnetic and dielectric losses at 8.2–18 GHz frequency range. The maximum reflection loss of −17.1 dB with an effective absorption bandwidth of 8 GHz was obtained for the sample filled with 20 wt.% of the nanocomposite with a thickness of 2 mm. The best electromagnetic interference shielding effectiveness of 35 dB was observed for the sample with a thickness of 5 mm. The achieved excellent microwave absorbing properties are attributed to the different wave attenuation mechanisms of the nanocomposite and their synergetic effects.

Electrophoretic Co-Deposition of Alumina-Resin Composites on Metal Substrate Using Polydimethylsiloxane-Based Organic-Inorganic Hybrid Materials as Binders

Electrophoretic Co-Deposition of Alumina-Resin Composites on Metal Substrate Using Polydimethylsiloxane-Based Organic-Inorganic Hybrid Materials as Binders

In Situ Conductive Coating Strategies for Nanocrystal-Based Li-Ion Battery Electrodes Beyond Carbonization

One of the critical issues in Li-ion battery systems is overcoming the inherent poor electronic conductivity of the electrodes and the associated slow electrode/electrolyte interfacial electrochemical kinetics because of the formation of solid electrolyte interphase (SEI). This issue is particularly challenging when high-safety electrode materials like lithium iron phosphate (LiFePO4-LFP) and lithium titanate (Li4Ti5O12-LTO) are employed. Also inevitable material degradation occurs at such interfaces that, for example, was recently discussed in connection to 2D LTO nanocrystals (1) and the spontaneous reaction between Li2FeSiO4 (LFS) and LiPF6-based electrolyte (2). Michel Armand’s pioneering work (3) on carbon coating provides an elegant and economic strategy to overcome aforementioned issues, leading to their successful commercialization by Hydro-Québec. With the advent of different nanocrystals as active electrode materials for high energy or power applications new opportunities arise for innovative engineering the electrode/electrolyte interfaces at the nanoscale. Herein two modification processes are tailored to fabrication of 2D nano-Li4Ti5O12 as anodes and to mechanochemically-nanosized orthorhombic Li2FeSiO4 (Pmn21 LFS) as cathodes. With the goal on one hand replacing the expensive NMP-PVDF coating process and on the other hand tackling the low nominal capacity issue of LTO electrodes, we are working on an alternative sustainable fabrication method involving in situ coating of reduced graphene oxide (redGO) onto 2D nano-LTO. This process involves electrophoretic co-deposition of hydrated lithium titanate (Li2−xHx)Ti2O5·yH2O) and GO that is followed by controlled thermal conversion into redGO-LTO composite anodes. Meanwhile, the exploration of Pmn21 Li2FeSiO4 as high-capacity cathode has been impeded because of lacking suitable surface modification techniques. Traditional carbon coating at elevated temperature is not suitable here as it would induce a phase transformation of LFS from orthorhombic Pmn21 into monoclinic P21/n. Therefore, in another development we have successfully coated Pmn21 LFS with a conductive polymer via in situ polymerization at room temperature. In developing this method we discovered significant differences between LFP and LFS as substrates reflecting differences in surface redox reactivity between the orthophosphate and orthosilicate polyanionic frameworks. Thanks to this low-T non-C coating method the nanometric Pmn21 LFS cathode reveals itself as very promising high-energy density and stable cathode material. H. C. Chiu, X. Lu, J. Zhou, L. Gu, J. Reid, R. Gauvin, K. Zaghib and G. P. Demopoulos, Adv. Energy Mater., 7, 1601825 (2017).Z. Arthur, H. C. Chiu, X. Lu, N. Chen, V. Emond, K. Zaghib, D. T. Jiang and G. P. Demopoulos, ChemCommun, 52, 190 (2016).M. Armand et al., Method for synthesis of carbon-coated redox materials with controlled size, US Patent No. 2004/0033360A1, Feb. 19, 2004.

Electrophoretic deposition and microstructure development of Si3N4/polyetheretherketone coatings on titanium alloy

Nanocomposite Si3N4/PEEK coatings were deposited on the model Ti-13Nb-13Zr titanium alloy by cathodic electrophoretic deposition. The use of different dispersion media and surfactants, the cationic polyelectrolytes polyethylenimine and chitosan, added to the suspensions has been studied. Understanding of the deposition mechanism process was obtained by monitoring the suspension properties, concentration of coating components, pH and zeta potential as well as investigation of interaction between solid particles in the suspension by electron microscopy. Based on the electrokinetic properties of suspensions and observations of the as-deposited coating morphology, the electrophoretic co-deposition of amorphous Si3N4 nanoparticles and PEEK micro-particles parameters, constant voltage and deposition time, were elaborated. It was found that the coating, 120 μm thick, deposited from the suspension containing a low amount of Si3N4 stabilized by chitosan under a constant voltage of 15 V during 90 s and with a constant distance between electrodes of 10 mm, was homogeneous. The coating structure and morphology changed as a result of post-deposition heat treatment from amorphous with a granular morphology into a semi-crystalline continuous and solid matrix. The separate Si3N4 nanoparticles and their agglomerates were relatively homogeneously distributed within the PEEK matrix. The coatings deposited from the suspension containing chitosan exhibited higher scratch resistance than the coatings deposited from the suspension stabilizing by polyethylenimine. The results demonstrate that electrophoretic deposition is a useful method to deposit homogeneous composite Si3N4/PEEK coatings well-adhered to the titanium alloy substrate, which could potentially improve both the bioactive and bio-tribological properties of titanium alloys used in biomedical applications.

Electrophoretic co-deposition of PEEK-hydroxyapatite composite coatings for biomedical applications.

This study focuses on the optimization of electrophoretic deposition (EPD) and suspension parameters for producing PEEK-hydroxyapatite (HA) coatings with feasible microstructure, adhesion strength, and in-vitro bioactivity. Nanostructured hydroxyapatite (HA) micro-granules were incorporated with PEEK to form PEEK-hydroxyapatite composite coatings via EPD. After EPD, a heat-treatment at 375 °C was applied for densification of the coatings and for enhancing the adhesion between the coatings and the substrates. It was found that both adhesion strength and in-vitro bioactivity of the coatings were dependent on the PEEK and HA relative contents. Thus, increasing the amount of HA improved the bioactivity while decreased the adhesion strength of the coatings. Apatite-like layer formation was observed on coatings with high HA content after incubation for three days in simulated body fluid (SBF). Finally, a deposition mechanism was proposed for the EPD of the PEEK-hydroxyapatite composite system.

Electrophoretic Co-Deposition of Graphene/Metal Oxide Platelets for Composite Electrode Fabrication

Graphene-metal oxide composites have been recently introduced as promising materials for energy storage and heterogeneous catalysis. The synergy between graphene and metal oxide enhances the performance of these composite materials in comparison to their individual components.1 Improved electrochemical properties such as high capacity and cycling stability makes graphene-NiCo2O4 composite a promising supercapacitor electrode.2 In this work, we assemble the composite electrode by electrophoresis on graphite electrode. We firstly disperse graphene sheets in the electrolyte solution by electrochemical exfoliation3 of the graphite electrode. NiCo2O4 platelets, separately prepared from Ni and Co salts by chemical synthesis route4, were then added into the electrolyte solution to form graphene sheet-NiCo2O4 platelet mixture suspension. Finally, graphene sheets and NiCo2O4 platelets are assembled on the exfoliated surface of the original graphite electrode in one electrophoretic deposition step. Deposition parameter-composite microstructure relationship was studied in detail. Controlled parameters include nominal input mass ratio of the two components, magnitude of the electrical field, and electrolyte solution composition. The final composite electrode were characterized using cyclic voltammetry and electrochemical impedance spectroscopy to estimate its functionality for supercapacitor application. Wu, Zhong-Shuai et al., Nano Energy 1, 107 (2012).Wang, Huanlei et al., Nano Research 5, 605 (2012).Parvez, Khaled et al., J. Am. Chem. Soc. 136, 6083 (2014).Joshi, Nirav et al., RSC Advances 6, 92655 (2016).

A facile strategy for ZnFe2O4 coating preparing by electrophoretic deposition and its supercapacitor performances

The development of low-cost and efficient coating technology for ZnFe2O4 in the application of supercapacitor, electronic devices, chemical sensors, is desirable but remains a challenge. In this study, a facile fabrication of ZnFe2O4 coatings via electrophoretic deposition (EPD) methods has been realized by employing hydrothermal synthesized ZnFe2O4 nanoparticles as starting materials. Benefiting from systematic investigation for the deposition kinetic of ZnFe2O4 nanoparticles in the dispersion system of ethanol-acetylacetone with the addition of nitric acid, smooth ZnFe2O4 coating with good film characteristics was successfully and rapidly fabricated. With a preliminary study of ZnFe2O4 coatings as supercapacitor electrode, the specific capacitance decayed from 198 to 17.1 F g−1 when the deposition time increased from 0.5 to 10 min because of the poor electric conductivity. Therefore, an electrophoretic codeposition of ZnFe2O4 and conductive carbon material is necessary in the given application with desire of good electron transfer ability.

Orthopaedic bioactive glass/chitosan composites coated 316L stainless steel by green electrophoretic co-deposition

Single-step electrophoretic co-deposition (EPD) technique was used to enhance the bioactivity of the 316L stainless steel (316L SS) surface by bioactive glass/chitosan composite coatings. Two modified glass compositions of Bioglass® by the addition of boron were utilized to prepare such composite layers, and the Bioglass® was synthesized for comparison. Different EPD coating factors were studied. Namely, voltage, time, glass powder, and chitosan concentrations, to obtain crack-free and good adhesive coatings. The achieved surfaces were characterized by SEM/EDX, TGA, XRD and FTIR and their wettability and roughness were investigated. The in vitro bioactivity of the coated metals was compared in simulated body fluid (SBF) and Dulbecco's modified eagle medium (DMEM) for up to 15days. The electrochemical corrosion behavior of the coated metals was evaluated using potentiodynamic polarisation and impedance techniques in the two biological solutions SBF and DMEM at 37°C. The results showed that the achieved coatings were uniform, homogenous and crack-free with desirable thickness. Moreover, the coating layers were exhibited by very high wettability, and their roughness values ranged from 170±18 to 234±17μm. The in vitro bioactivities proved that the coating layers represented a better ability to form hydroxyapatite crystals on their surfaces in SBF than in DMEM. The corrosion resistance of 316L SS was improved by the bioactive composite coatings.

Bilayered BMP2 Eluting Coatings on Graphene Foam by Electrophoretic Deposition: Electroresponsive BMP2 Release and Enhancement of Osteogenic Differentiation.

Recent development of three-dimensional graphene foam (GF) with conductive and interconnected macroporous structure is attracting particular attention as platforms for tissue engineering. However, widespread application of GF as bone scaffolds is restricted due to its poor mechanical property and inert surface character. To overcome these drawbacks, in this study, a bilayered biopolymer coating was designed and successfully deposited covering the entire surface area of GF skeleton. A poly(lactic-co-glycolic acid) layer was first dip-coated to strengthen the GF substrate, followed by the electrophoretic codeposition of a hybrid layer, consisting of chitosan and BMP2, to functionalize GF with the ability to recruit and induce osteogenic differentiation of hMSC. Our data indicated that the mechanical property of GF was significantly increased without compromising the macroporous structure. Importantly, the immobilized BMP2 exhibited sustained and electroresponsive release profiles with rapid response to the electric field exerted on GF, which is beneficial to balancing BMP2 dose in a physiological environment. Moreover, the osteogenic differentiation of hMSC was significantly improved on the functionalized GF. Taking advantage of the unique macrostructure from GF as well as the superior mechanical properties and BMP2 release profile supported by the deposited coatings, it is therefore expected that the developed GF could be a promising alternative as innovative bone-forming favorable scaffolds.

Fabrication of a resin-bonded ultra-fine diamond abrasive polishing tool by electrophoretic co-deposition for SiC processing

A resin-bonded ultra-fine diamond abrasive polishing tool is fabricated by electrophoretic co-deposition (EPcD), and the processing performance of the tool is evaluated in this study. The dispersion stability of suspensions is characterized by a laser particle size analyzer and settlement ratio. The cathodic EPcD of composite powder is realized by adding Al3+ into the suspension. The sintering temperature of composite coatings is determined by differential thermal analysis/thermogravimetry. The surface morphology of the composite coating is observed under a confocal microscope. Results show that uniform, dense, and smooth coatings with diamond and resin particles distributed homogeneously are obtained from the steel substrate. A large (Φ150mm) polishing tool with a 20μm-thick coating is successfully prepared using the above process. A smooth mirror surface of SiC wafer with a nanoscale roughness (4.3nm) is achieved after processing with the ultra-fine diamond abrasive polishing tool.

Electrochemical Deposition of Materials for Biomedical Applications

Electrochemical methods have been developed for the deposition of biopolymer films containing hydroxyapatite, and other bioceramics, such as titania, silica and bioglass. Different electrochemical methods have been utilized for the deposition of natural biopolymers, such as chitosan, polyacrylic acid and hyaluronate. Chitosan was protonated and dissolved in acidic solutions and then deposited cathodically. In this approach the charge neutralization of cationic chitosan in the high pH region at the electrode surface resulted in the precipitation of insoluble chitosan. Electrodeposition of alginic acid was performed from sodium alginate solutions. In this method the pH decrease at the anode surface resulted in the charge neutralization of alginate macromolecules and the fabrication of alginic acid films on anodic substrates. A similar approach has been utilized for the deposition of hyaluronic acid from the sodium hyaluronate solutions. It was demonstrated that cathodic and anodic deposition methods can be used for the deposition of other biopolymers. Nanoparticles of hydroxyapatite were prepared by a chemical precipitation method. Precipitation was performed at 70 °C by the slow addition of a 0.6 M ammonium phosphate solution into a 1.0 M calcium nitrate solution. The pH of the solutions was adjusted to 11 by NH4OH. Stirring was performed during 8 h at 70 °C and then 24 h at room temperature. The precipitate was washed with water and finally with ethanol. The average length of the needle-shape HA crystals, prepared by this method, was about 150 nm and the average aspect ratio was 8. The composite films containing HA nanoparticles in chitosan, alginic acid and hyaluronic acid matrix were prepared on stainless steel, Ti and NiTi alloy substrates. The results of thermogravimetric analysis showed that hydroxyapatite content in the polymer matrix was varied in the range of 35-80 wt% by variation of hydroxyapatite or polymer concentration in the solutions. The deposition yield was studied at different deposition conditions. It was shown that film thickness can be varied in the range of 0.1-200 microns by variation of the deposition time in the range of 1-10 min and deposition voltage in the range of 10-60 V. The composite films were prepared as monolayers or multilayers containing hydroxyapatite-polymer layers, separated by the layers of pure polymer. The co-deposition of inorganic materials with biopolymers resulted in the fabrication of novel composite materials containing bioactive glass and other bioactive materials, such as silica and titania in a polymer matrix. Electrochemical techniques have been also applied for the fabrication of materials of graded composition (FGM) containing biopolymers, hydroxyapaite and other bioceramics and bioglass. Electrochemical impedance spectroscopy and potentiodynamic polarization studies showed that the composite coatings provided corrosion protection of the metallic substrates in simulated body fluid solutions. The use of biopolymers enabled the room temperature processing of the coatings, eliminating the problems related to the sintering of hydroxyapatite and other bioceramics. Moreover, the method enabled the incorporation of drugs and proteins in the composite material. Electrochemical strategies have been developed for the deposition of composite films containing heparin and albumin in a biopolymer matrix. The room temperature processing offers a possibility of co-deposition of other functional materials and fabrication of advanced nanocomposite coatings for biomedical applications. New deposition methods were developed for cathodic deposition of chiral biopolymers, such as poly-l-lysine and polyl-ornithine. As an extension of these investigations, the composite films, containing HA nanoparticles and other functional biomaterials in the matrix of chiral biopolymers were obtained and investigated. Further development of new deposition methods resulted in the development of electrophoretic strategies and deposition mechanisms for the deposition of linear polyethylenimine, polypyrrole, polyetheretherketone, polyacrylic acid. Fundamental mechanisms were developed for the co-deposition of enzymes and proteins with various biopolymers. We discovered a possibility of electrophoretic co-deposition of halloysite nanotubes with cationic and anionic biopolymers, such as chitosan, poly-l-lysine and polyl-ornithine, alginic acid, hyaluronic acid, polyacrylic acid. The halloysite nanotubes can be loaded with drugs and antimicrobial agents for the controlled release. The new composite materials are prtomising for applications in biomedical implants and biosensors. We investigated functional properties of new materials, fundamental deposition mechanisms and kinetics of deposition.

Effect of co-deposited SiC nanowires and carbon nanotubes on oxidation resistance for SiC-coated C/C composites

To protect carbon/carbon composites (C/Cs) against oxidation, SiC coating toughened by SiC nanowires (SiCNWs) and carbon nanotubes (CNTs) hybrid nano-reinforcements was prepared on C/Cs by a two-step technique involving electrophoretic co-deposition and reactive melt infiltration. Co-deposited SiCNWs and CNTs with different shapes including straight-line, fusiform, curved and bamboo dispersed uniformly on the surface of C/Cs forming three-dimensional networks, which efficiently refined the SiC grains and meanwhile suppressed the cracking deflection of the coating during the fabrication process. The presence of SiCNWs and CNTs contributed to the formation of continuous glass layer during oxidation, while toughed the coating by introducing toughing methods such as bridging effect, crack deflection and nanowire pull out. Results showed that after oxidation for 45h at 1773K, the weight loss percentage of SiC coated specimen was 1.35%, while the weight gain percentage of the SiCNWs/CNTs reinforced SiC coating was 0.03052% due to the formation of continuous glass layer. After being exposed for 100h, the weight loss percentage of the SiCNWs/CNTs reinforced SiC coating was 1.08%, which is relatively low.

Macroporous carbon nanotube-carbon composite electrodes

Macroporous carbon nanotube-carbon composite electrodes (CNT-C) have been fabricated and characterized. CNT/polystyrene beads assembly was first prepared by electrophoretic co-deposition. Polypyrrole (PPy) was then polymerized electrochemically in the pore volume generated by the CNT assembly. After removal of the polystyrene template and pyrolysis of the conductive polymer between 650 and 950 °C, a macroporous composite material made of CNT and an amorphous carbon binder (quoted as C) was obtained. Increasing the amount of PPy allowed to improve the mechanical properties of the composite, as measured by the Young's modulus extending from 7 (CNT alone) to 663 GPa (CNT-C composite). CNT-C composite was characterized by Raman and X-ray photoelectron spectroscopies. Its surface area was dramatically enhanced, as evidenced by the increase in capacitance from 6 mF cm−2 to 199 mF cm−2 in the presence of the largest content of amorphous carbon. The influence of the amount of deposited carbon was discussed regarding the VO2+/VO2+ electrochemistry (i.e., the most critical redox couple in vanadium redox flow batteries). A 50 μm thick macroporous CNT-C composite gave rise to 5 times enhancement of the electrochemical response compared to a nonmacroporous CNT-layer).

Electrophoretic co-deposition of cellulose nanocrystals-45S5 bioactive glass nanocomposite coatings on stainless steel

An organic-inorganic nanocomposite coating consisting of fibrous cellulose nanocrystals and 45S5 bioactive glass, intended as a bioactive surface for bone implants, was developed by a one-step electrophoretic deposition. The composition, surface roughness and wettability of the deposited coatings, influenced by the concentration of each component in the suspension, were controllable as a result of the simplicity of the coating technique. Bioactive glass particles were individually wrapped with porous cellulose layers, forming a porous coating with uniform thickness. Bioactivity test in simulated body fluid revealed a rapid hydroxyapatite formation on the deposited nanocomposite coating. Furthermore, electrochemical test was carried out to understand the corrosion behavior of the deposited coatings during incubation in simulated body fluid. According to the results of this study, the obtained cellulose-bioactive glass coatings with tunable properties represent a promising approach for biofunctionalization of metallic orthopedic implants.

Cellulose Nanocrystals--Bioactive Glass Hybrid Coating as Bone Substitutes by Electrophoretic Co-deposition: In Situ Control of Mineralization of Bioactive Glass and Enhancement of Osteoblastic Performance.

Surface functionalization of orthopedic implants is being intensively investigated to strengthen bone-to-implant contact and accelerate bone healing process. A hybrid coating, consisting of 45S5 bioactive glass (BG) individually wrapped and interconnected with fibrous cellulose nanocrystals (CNCs), is deposited on 316L stainless steel from aqueous suspension by a one-step electrophoretic deposition (EPD) process. Apart from the codeposition mechanism elucidated by means of zeta-potential and scanning electron microscopy measurements, in vitro characterization of the deposited CNCs-BG coating in simulated body fluid reveals an extremely rapid mineralization of BG particles on the coating (e.g., the formation of hydroxyapatite crystals layer after 0.5 day). A series of comparative trials and characterization methods were carried out to comprehensively understand the mineralization process of BG interacting with CNCs. Furthermore, key factors for satisfying the applicability of an implant coating such as coating composition, surface topography, and adhesion strength were quantitatively investigated as a function of mineralization time. Cell culture studies (using MC3T3-E1) indicate that the presence of CNCs-BG coating substantially accelerated cell attachment, spreading, proliferation, differentiation, and mineralization of extracellular matrix. This study has confirmed the capability of CNCs to enhance and regulate the bioactivity of BG particles, leading to mineralized CNCs-BG hybrids for improved bone implant coatings.

Micro-fibres containing composites prepared by EPD

Presented article summarises preparation of fibre reinforced alumina and alumina laminates containing zirconia micro-fibres. Electrophoretic deposition was performed from concentrated isopropanolic suspensions stabilised by monochloracetic acid containing mixture of alumina powder and certain amount of zirconia micro-fibres. A method for in-situ monitoring the deposition of alumina and zirconia micro-fibres mass was applied to control deposition kinetics. Two different approaches for composite deposition were applied: (i) electrophoretic deposition of powders mixture and (ii) electrophoretic co-deposition from sonicated suspension containing stabilization aid. Applying the optimised procedure the alumina laminates reinforced with zirconia fibres were prepared. The co-deposition of ceramic micro-fibres and powder led to the preparation of microstructures having unique orthogonal fracture properties. Developed laminate with layers created by zirconia micro-fibres in the alumina matrix seems to be the most promising. This type of material exhibited potential of the crack trapping and deflection even when very small amount of micro-fibres was used.

Electrophoretic Co-Deposition of Chitosan and Graphene Oxide Results in Antibacterial Coatings for Medical Applications

Chitosan – graphene oxide (GO) composite coatings intended for antibacterial applications were obtained by cathodic electrophoretic deposition (EPD) on stainless steel. The coatings were characterized using SEM, FTIR, contact angle and roughness measurements and by antibacterial studies againstE.coli. The coating was observed to consist of a polymer matrix with embedded, agglomerated graphene oxide sheets. A decrease in bacteria cell viability of at least 50 % was measured on the chitosan – GO surface in comparison to uncoated stainless steel.

Electrochemical Performance of Electrophoretically Deposited Nanostructured LiMnPO4-Sucrose Derived Carbon Composite Electrodes for Lithium Ion Batteries.

The present study reports an approach by which thin films of sucrose added olivine type LiMnPO4-Ccomposite and pristine LiMnPO4 is made by a technique of electrophoretic co-deposition in which pristine and composite samples were synthesized by a sol-gel route. These thin films with enhanced surface area is used to fabricate cathodes for rechargeable Li ion batteries. XRD confirms phase pure single crystalline orthorhombic structure. Transmission Electron Microscopy (TEM) images shows the carbon coating over LiMnPO4 and the particle size restricted in the nano regime. The presence of sp2 hybridized carbon on LiMnPO4 particles is confirmed by X-ray Photon spectroscopy (XPS). To explore the electrochemical behavior, cyclic voltammetry (CV) and cycling studies were performed. The specific capacity for LiMnPO4-C is found to be increased by 43% in comparison to the pristine LiMnPO4. It also exhibited 86% retention in capacity compared to the pristine LiMnPO4 (52%). The result indicates that a proper carbon coating can significantly improve the electronic conductivity and hence the specific capacity.