Papers by Keyword: EPD

Abstract: Sustainability and environmental impact assessment are essential to orient new generation of materials for building and construction. In this study, life cycle assessment was applied to a set of 21 mural paints produced by a paint factory in Italy. Data collection covered upstream processes (i.e., raw materials extraction and supply), the core process (i.e., paint manufacture and packaging) and downstream processes (i.e., transport to retailers). Material and energy inputs and outputs for the main components employed in paint manufacturing (e.g., antifoaming agents, dispersants, coalescing agents, additives, biocides and similar) were gathered from primary and secondary data sources. Life cycle impact assessment results were estimated for global warming potential (on average, 1.03 ± 0.60 kg CO₂/kg paint), photochemical oxidation (0.60 ± 0.46 g C₂H₄/kg paint), abiotic depletion (1.94 ± 1.58 g Sb/kg paint), acidification (6.80 ± 6.64 g SO₂/kg paint), and eutrophication (1.96 ± 1.47 g PO₄/kg paint). Overall, upstream processes are responsible for the greatest environmental impact (on average, more than 70% for global warming potential), with titanium rutile from sulfates being the most impacting raw material. The results informed decision makers and provided a basis for achieving improvement and greener production strategies in paint manufacturing.

Abstract: Total hip replacement (THR) that is widely used today is the cemented type, which its application will lead to aseptic loosening. To avoid the occurrence of aseptic loosening, THR coated with hydroxyapatite (HA) is required because HA is osteoconductive which can stimulate the growth of osteoblasts. This study aims to determine the optimum sinter temperature which produce HA coating suitable as implant material. To achieve these objectives, the electrophoretic deposition (EPD) conducted coating method at concentrations of HA 1,0M, voltage of 100V for 30 minutes and then sintered at temperatures are 550°C, 700°C and 900°C respectively detention for 10 minutes. The results showed that the treatment of sintering after the coating process through the EPD method affect the characteristics of the layer thus formed. Sintering process affects the crystallinity of the HA layer. The higher the sintering temperature the higher its crystallinity. The higher the crystallinity the stronger the HA layer attached to the substrate cobalt alloy. Based on this research, the selected sintering temperature was 900 °C for 10 minutes which produced a layer of HA with the best characteristics that meet the standard of implant prosthesis, the crystallinity of 89.4%, thick layer of 70.80 ± 4.18 μm, adhesion strength of 21.87 ± 0.23 MPa, the corrosion rate of 0.025 mpy and 70.3% cell viability.

Abstract: A simple and low temperature approach has been used for the deposition of manganese oxide (MnO₂) film and nanoparticles on silicon nanowires (SiNWs). Firstly, SiNWs were grown using hot wire chemical vapour process (HWCVP) technique via Vapor-Liquid-Solid (VLS) mechanism using Sn as a catalyst and then electrophoretic deposition method (EPD) was used to deposit MnO₂ on them. Since SiNWs have good electron transportation and high aspect ratio, the role of SiNWs is thus for improving the electrical conduction and the surface area for MnO₂ for its application in a desired form. First the deposition parameters were optimized on a transparent conductive oxide (TCO) coated glass substrate to control the thickness of the MnO₂ film and then it was synthesized on SiNWs. The deposition of MnO₂ has been confirmed by FEG-SEM and EDX. This structure of MnO₂-SiNWs could be useful for various applications.

Abstract: The aim of the study was to obtain zirconium and calcium doped zirconium coatings using sol-gel methodology and their further modification with electrophoretically deposited hydroxyapatite. Both systems phase composition was investigated using Raman spectroscopy. Their morphology and composition was studied using scanning electron microscope (SEM) with X-ray microanalysis (EDS), while their topography was observed using atomic force microscope (AFM). The osseointegrative properties of both coatings were investigated using in vitro Simulated Body Fluid (SBF) test. The resulting systems were studied using the same methods that were applied to the two coatings.

Abstract: 45S5 bioactive glass (BG) based multilayer coatings on stainless steel were produced by a combination of electrophoretic deposition (EPD) and layer-by-layer (LbL) deposition. The properties of the multilayer coating were tested with different characterization methods including SEM, FTIR, XRD, laser profilometer and water contact angle measurements. Degradation and in-vitro bioactivity behaviors were tested in simulated body fluid (SBF) over different time periods. The decomposition of the coating was inhibited and the hydroxyapatite (HA) formation after short immersion period (0.5d) was confirmed. At the same time, levofloxacin, used as a model antibiotic, was incorporated into the multilayer structure for antibacterial purpose.

Abstract: In this work, we present a facile technique based on electrophoretic deposition (EPD) to produce transition metal hydroxide decorated carbon nanotubes (CNT) for electrochemical applications. We specifically explore the performance of nickel-cobalt hydroxides given their high activity, conductivity and stability as compared to the individual hydroxides. We exploit the high local pH at the negative electrodes during water-based EPD to form nanoparticles of nickel-cobalt hydroxides in situ on the CNT surface. We focus our work here on obtaining functional and conductive deposits on CNTs. The hydrophilic binderless deposits of Ni-Co double hydroxide decorated CNTs obtained here are used for non-enzymatic glucose detection. XPS data and electrochemical testing reveal difference in the deposited double hydroxide based on chronology of charging salt addition even at the same ratio. When cobalt and nickel salts are sequentially added at a ratio of 1:1, the deposited double hydroxides show excellent glucose sensitivity of ~3300μA/mM.cm² at applied potential of 0.55V vs. Ag/AgCl reference electrode.

Abstract: Bilayer thick films of sacrificial titanium dioxide and Nb-doped lead zirconate titanate (PZTN) have been deposited on bare silicon wafers using electrophoretic deposition (EPD) technique. Deposition of such ceramic particles, dispersed ethanol-based suspensions, on semiconductor substrate has been made possible after preparation of alloyed junctions Al/Si characterized by ohmic behaviour. Sintering of green TiO₂/PZTN films was performed at 900 °C for 1 h. The composition of the films, the thickness and relative density of the deposited materials have been analysed by EDS-SEM analysis. The lead diffusion through the silicon wafer has been reduced.

Abstract: The interaction between bioactive glass particles and polymers with different functional groups has been established in this work to better understand and control the colloidal processing of the bioactive glass phase. Cationic polyvinylpyrrolidone (PVP), anionic polyacrylic acid (PAA) and neutral polyvinyl alcohol (PVA) were selected and the surface reactions in alcoholic media and between bioactive glass particles and polymers were considered. All three polymers were successfully employed to obtain soft composite coatings incorporating bioactive glass particles.

Abstract: Recently it was possible to prepare tailored laminates with perfect and strong interface of layers with precise thickness management. Tailoring of ceramic laminates to obtain optimal mechanical properties with enhanced fracture resistance is possible when predictions based on numerical calculations are employed. Extraordinary mechanical properties were achieved via high internal stresses development during material processing. The aim of this investigation can be seen in two directions. The enhanced crack free green bodies through incorporating small volume fraction of micro-fibres to the powders were prepared. Additionally, control of the crack propagation by incorporated directionally oriented micro-fibres both in the volume and in individual layers. In this contribution both alumina and zirconia micro-fibres were used to help eliminate drying defects in the green body stage before sintering. The co-deposition of ceramic micro-fibres and powder led to the preparation of microstructures having unique orthogonal fracture properties. Developed laminate with thin 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.

Abstract: The preparation of a ZSM-5 zeolite membrane on porous stainless steel disk by hydrothermal synthesis with electrophoretic deposition (EPD) as a seeding method was investigated. Micron size ZSM-5 crystal powder was seeded by EPD on the support disk by using ZSM-5 powder dispersed in ethanol. The seeded amounts were easily controlled by the deposition time during EPD. The membrane after secondary growth had a low amount of zeolite in comparison with the in situ seeding method and the permeance of single gas such as He, N₂ and CO₂ was also low in comparison with that of the in situ seeding method.