Abstract: Titanate nanosheet thick films were prepared on indium-tin oxide (ITO)-coated glass substrates by electrophoretic deposition. Three types of sols with different preparation procedures and pH values were prepared. In the case of titanate nanosheet films prepared from a sol with pH=7.0, surface of the films was flat and nanosheets which deposited on substrates were uniformly dense. Titanate nanosheet thick film deposited from the sol using dimethyl ethanol amine for the exfoliation showed a high photocatalytic activity due to the high crystallinity
Abstract: In this work we investigated the possibility to use electrophoretic deposition from organic solvents in order to deposit catalytically active surface-stabilized nanoparticles on a substrate. This permits to functionalize a surface by depositing a catalytic layer or simply offers a way to collect the synthesized nanoparticles e.g. for subsequent characterization. As an example, Co nanoparticles were prepared using a sonochemical method, and subsequently deposited on a substrate by electrophoretic deposition. We used ionic liquids (IL) in order to increase the ζ-potential of the nano particles.
Abstract: Nobel metal particles with nanometer size have attracted keen interest because of, for example, their high catalytic activity to be applied for industrial applications. In this study, nano-sized gold particles were deposited onto a graphite carbon plate by two approaches: 1) electrophoresis of colloidal gold nanoparticles, 2) electrolysis of chlorauric acid. For former case, commercially-available gold nanoparticle and anionic mercapto ligand-stabilized gold nanoparticles, synthesized by citric acid reduction of chlorauric acid, were used. Size and morphology of the gold particles deposited were characterized by scanning electron microscopy. Electrolytic deposition resulted in larger gold particles around tens to hundreds nm in size. Electrophoretic deposition accomplished particle sizes smaller than 15 nm, which basically reflected the size of colloidal gold particles used.
Abstract: Titania Nanopowders were successfully deposited on stainless steel sheet by means of electrophoretic deposition method from titania suspension in which isopropanol was employed as a solvent and Triethanolamine as a dispersant. The effect of TEA addition on the stability of nanopowders in suspensions was examined by sedimentation test; in addition, Malvern zeta sizer was employed for determination their particle size. Electrophoretic Deposition was done at different deposition conditions of voltage (5-20 volts) and time (5-60 sec) and the scanning electron microscopy (SEM) was used to investigate the effect of suspension composition and deposition parameters on the microstructure of coatings. Furthermore, the effect of deposition parameters on the consistencies of different coatings was analyzed by Scanning Probe Microscope (SPM).
Abstract: In this paper, electrophoretic deposition of multiwall carbon nanotubes (MWNTs) using low frequency (0.01-1000 Hz) AC electric fields, is reported. The effect of depositing parameters such as frequency and waveform on deposit yield is investigated. Results show that the deposit yield decreases with frequency. The rectangular waveform yields more deposit yield than sinusoidal and triangular waveforms. The deposition pattern is also different in AC and DC electric fields. This technique may be used for deposition of MWNTs thick films.
Abstract: Multi-walled carbon nanotubes (CNTs) were deposited by electrophoretic deposition on stainless steel substrates forming homogeneous porous CNT deposits. These CNT structures were then coated with a thin layer of Ni by electrodeposition. SEM and TEM observations confirmed that the Ni layer covered uniformly the CNT surfaces. This Ni coating treatment could facilitate the dispersion of CNTs in metal matrix composites leading to improved mechanical and thermal properties.
Abstract: Electrophoretic deposition (EPD) has been demonstrated to be a convenient processing technique to fabricate composite ceramic coatings containing ordered arrays of carbon nanotubes. In this investigation, EPD was used to coat Ti6Al4V medical implants with hydroxyapatite (HA) layers reinforced with surface functionalized multi-walled carbon nanotubes (MWCNTs). The functionalization of MWCNTs by treating them with an acid mixture was successfully achieved in order to create functional groups on the MWCNT surfaces enabling them to be homogeneously dispersed in water. The surface treatment was also used to induce the adsorption of HA nanoparticles on MWCNT surfaces. Some critical issues, such as microcracking and peeling of HA layers after EPD, were effectively solved by the use of MWCNTs.
Abstract: We have studied the processing of lead-zirconate-titanate PbZr0.53Ti0.47O3 (denoted PZT) based thick films using an electrophoretic deposition (EPD) process in order to obtain the active film with desired thickness and porosity at low the sintering temperature. The colloidal suspensions were prepared by mixing the ceramic powder in ethanol with the controlled addition of a polyelectrolyte salt and an organic base. In order to optimise the deposition process, the stability of the PZT and Pb5Ge3O11 (denoted PGO) particles in ethanol-based suspensions was studied. The electrophoretic deposition of PZT-PGO was performed from a mixture of optimal PZT and PGO suspensions in an appropriate molar ratio. PZT and PGO acting as a sintering aid were deposited on an Al2O3/Au substrate at a constant applied current and sintered at 850 oC. The thickness of the deposit was controlled by the deposition time and the applied current. PZT-PGO thick films deposited at 1.2 mA for 60 seconds and sintered at 850oC for 8 hours exhibited a room-temperature dielectric permittivity of 1050, dielectric losses of 0.038, a remanent polarisation Pr of 29 C/cm2, a coercive field Ec of 21 kV/cm and a d33 of 97pC/N.
Abstract: Electrophoretic deposition method was applied to prepare some solid-electrolyte thick-films of Na1+xZr2SixP3-xO12 (x = 2, 3; NASICON) and Na5DySi4O12 (NDSO) on Au-coated alumina substrates. With the ethanol-based medium, the deposition process was investigated under constant voltage mode. The concentration of the suspension and applied voltage were optimized with respect to the rate of deposition and quality of the deposit. The NASICON (Na3Zr2Si2PO12) -based solid-state ionic conductor thick-film as a host ceramic with a guest Cu+ ion has been produced as a noble phosphor thick-film by using an electrochemical ion doping method. The photoluminescence (PL) device of the NASICON:Cu+ film showed good photo-luminescent peaks near 450-500nm depending on the host materials.
Abstract: The electrophoretic deposition of polystyrene/divinylbenzene (PS/DVB) star polymer-europium sulphide (EuS) nanocomposite films from a colloidal suspension is reported. Liquid suspension, containing both the PS/DVB star polymer and EuS nanocrystals were prepared by separately injecting dichloromethane (DCM) based solutions of EuS nanocrystals and of the star polymers, respectively, into a stratified liquid combination of hexane and DCM. Scanning electron microscopy illustrates images of the dependence of surface morphology on nanocrystal concentration of the PS/DVB-EuS star polymer film. These polymer-encased nanocrystal films may be a more practical option for the fabrication of magneto-optical thin film devices, such as optical switches, optical isolators, and optical memories.