Electrophoretic deposition as a tool for separation of protein inclusion bodies from host bacteria in suspension

This paper shows, for the first time, that the electrophoretic deposition technique is able to selectively collect protein inclusion bodies (PBs) from the host bacteria suspensions. In the first step, zeta potential as a function of pH is carefully determined for both species involved. Based on the obtained dependencies, the pH of the mixture of PBs and bacteria is precisely adjusted and the electrophoretic experiment is carried out. We show that the efficiency of separation and the yield depends not only on the electrokinetic properties of given species but also on the electrode composition and surface morphology. The deposited species are easily removed by forced washing or reverse electric field. As a whole, the selectivity and the yields are higher than in most alternative state-of-the art techniques.     

Electrophoretic deposition of calcium phosphates from non-aqueous media

Electrophoretic deposition of ultrafine calcium phosphates from non-aqueous suspensions onto metallic substrates was attempted in order to obtain coatings with varying porosities. Aging effects were studied by measuring changes in the electrophoretic deposition behavior of the calcium phosphate particles in the non-aqueous suspensions. It was observed that the surfaces of the calcium phosphates develop significant electrostatic charge during aging in order to enable the formation of a dense and uniform deposit. The addition of surface charge conditioners such as HCl was found to have a similar effect. Dispersion conditions were varied to obtain coatings of the desired green densities, which were sintered to different microporosities.     

High performance anode-supported intermediate temperature solid oxide fuel cells (IT-SOFCs) with La0.8Sr0.2Ga0.8Mg0.2O3−δ electrolyte films prepared by electrophoretic deposition

Remarkable power density was obtained for anode-supported solid oxide fuel cells (SOFCs) based on La_0.8Sr_0.2Ga_0.8Mg_0.2O_3−δ (LSGM) electrolyte films, fabricated following an original procedure that allowed avoiding undesired reactions between LSGM and electrode materials, especially Ni. Electrophoretic deposition (EPD) was used for the fabrication of 30 μm-thick electrolyte films. Anode supports were made of La_0.4Ce_0.6O_2−x (LDC). The LSGM powder was deposited by EPD on an LDC green tape-cast membrane added with carbon powder, both as pore former and substrate conductivity booster. A subsequent co-firing step at 1490 °C produced dense electrolyte films on porous LDC skeletons. Then, a La_0.8Sr_0.2Fe_0.8Co_0.2O_3−δ (LSFC) cathode was applied by slurry-coating and calcined at 1100 °C. Finally, the porous LDC layer was impregnated with molten Ni nitrate to obtain, after calcination at 900 °C, a composite NiO–LDC anode. Maximum power densities of 780, 450, 275, 175, and 100 mW/cm² at 700, 650, 600, 550, and 500 °C, respectively, were obtained using H₂ as fuel and air as oxidant, demonstrating the success of the processing strategy. As a comparison, electrolyte-supported SOFCs made of the same materials were tested, showing a maximum power density of 150 mW/cm² at 700 °C, more than 5 times smaller than the anode-supported counterpart.     

Electrophoretic deposition of nickel, iron and aluminum nanoparticles on carbon fibers

The electrophoretic deposition (EPD) of nickel (Ni), iron (Fe) and aluminum (Al) nanoparticles fabricated by an active hydrogen plasma evaporation method on the surface of carbon fibers was investigated, which will allow the obtained composites to be applied as practical catalysts or electrodes. SEM observations show that the Ni nanoparticles can build up a thick EPD coating with some cracks on the surface of carbon fibers, and the analyses of X-ray diffraction (XRD) and BET specific surface area indicate that fine particles from the as-received Ni powders were finally deposited after the EPD process without crystal growth. The surface oxidation of Fe and Al nanoparticles takes serious effect on the EPD process and the morphology of the as-prepared coatings.     

Electrophoretic mobility of the polymer-like micelles of tetradecyldimethylamine oxide hemihydrochloride

Effects of the surfactant concentration C_d and the NaCl concentration C_s on the electrophoretic mobilities U of the well-characterized polymer-like micelles have been investigated by the electrophoretic light scattering, using tetradecyldimethylamine oxide hemihydrochloride (C14DMAO·1/2HCl). At the high ionic strength of 0.1 mol kg⁻¹ NaCl, the electrophoretic mobilities were independent of C_d (5 mM < C_d < 100 mM), despite the concentration-dependent micelle growth of the polymer-like micelles. This suggests that the electrophoretic mobility of the polymer-like micelle at high ionic strengths is independent of the contour length (i.e., the molecular weight), as found on linear polyelectrolytes. Somewhat surprisingly, the entanglements of the polymer-like micelles gave small effect on the electrophoretic mobilities in the examined range of the surfactant concentration above an overlap concentration. The mobilities of the polymer-like micelle decreased with √C_s in a single exponential manner in the range of C_s from 0.02 to 0.3 mol kg⁻¹. It is suggested that the cylinder model can be applied to the electrophoretic mobilities of the polymer-like micelles at high ionic strengths (i.e. a free-draining behavior), since the persistence length of the polymer-like micelle (20 nm) is much larger than the Debye length at high ionic strength.     

钛基表面纳米羟基磷灰石涂层的电泳沉积

应用沉淀法合成纳米羟基磷灰石,并以电泳沉积法在粗糙化的钛表面制备纳米结构的羟基磷灰石涂层.纳米涂层有利于保持羟基磷灰石的化学组成和结构,制备的涂层均匀并且无裂缝,烧结后涂层仍保持纳米结构,其烧结温度也明显降低。钛表面经化学处理后,可形成很多微孔和TiO2薄层,增强了涂层和基体之间的结合.涂层的结合力为 18±2. 5MPa,硬度和杨式模量分别为 32. 0和 2. 4GPa.     

电子墨水微胶囊及电泳显示原型器件的制备

TiO2 particles coated with polystyrene which were prepared via in situ polymerization and oil green dye were dispersed in tetrachloroethylene and xylene, the mixture came to be electrophoretic ink and was encapsulated in to microcapsules by complex coacervation from gelatin and a hydrolyzed copolymer of styrene and maleic anhydride(SMA). It was demonstrated that the membranes of the microcapsules were formed from nano sized coacervate droplets resulting from gelation and hydrolyzed SMA, which leads to a compact membrane structure. Microcapsules were characterized in terms of microstructure, morphologies by scanning electron microscopy(SEM). Electrophoretic display prototype was prepared by coating electrophoretic ink microcapsules slurry on ITO glass with nearly single layer and sealed by UV curable adhesires. The characters “Zheda” in Chinese was firstly displayed at a low volt 9 V D. C..     

Aptamer-based Electrochemical Biosensors for Highly Selective and Quantitative Detection of Adenosine

A new adenosine biosensor based on aptamer probe is introduced in this article. An amino-labeled aptamer probe was immobilized on the gold electrode modified with an o-phenylenediamine electropolymerized film. When adenosine is bound specifically to the aptamer probe, the interface of the biosensor is changed, resulting in the decrement of the peak current. The response current is proportional to the amount of adenosine in sample. The used electrode can be easily regenerated in hot water. The proposed biosensor represents a linear response to adenosine over a concentration range of 1.0x 10^-7-l.0x10^-4 mol/L with a detection limit of 1.0xl0^-8 mol/L. The presented biosensor exhibits a nice specificity towards adenosine. It offers a promising approach for adenosine assay due to its excellent electrochemical properties that are believed to be very attractive for electrochemical studies and electroanalytical applications.     

Electrophoretic deposition of hydroxyapatite–CaSiO3–chitosan composite coatings

Electrophoretic deposition (EPD) method has been developed for the fabrication of hydroxyapatite (HA)–CaSiO₃ (CS)–chitosan composite coatings for biomedical applications. The use of chitosan enabled the co-deposition of HA and CS particles and offered the advantage of room temperature processing of composite materials. The coating composition was varied by the variation of HA and CS concentrations in the chitosan solutions. Cathodic deposits were obtained as HA–CS–chitosan monolayers, HA–chitosan/chitosan multilayers or functionally graded materials (FGM) containing HA–chitosan and CS–chitosan layers of different composition. The thickness of the individual layers was varied in the range of 0.1–20 μm. The deposition yield was studied at different experimental conditions and compared with the results of modeling. It was shown that the moving boundary model for the two component system can explain the non-linear increase in the deposition yield with increasing HA concentration in chitosan solutions. The obtained coatings were studied by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and scanning electron microscopy (SEM). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies showed that these coatings provided corrosion protection of stainless steel substrates in Ringer's physiological solution. The deposition mechanism and kinetics of deposition have been discussed.     

Dye-sensitized solar cells based on ordered titanate nanotube films fabricated by electrophoretic deposition method

Dye-sensitized solar cells (DSSCs) are fabricated based on ordered titanate nanotube (TNT) films obtained by electrophoretic deposition (EPD) method. Calcination temperatures show a great influence on the performance of TNT solar cells. At 300 °C, the cells exhibit very low photo-electric conversion efficiency. At 400 °C, the efficiency obviously increases. At 600 °C, the cells show the highest efficiency, which is higher than the efficiency of the cells made from commercial-grade Degussa P25 TiO₂ nanoparticles (P25).     

电泳沉积制备ZnO-C60和ZnO-MWCNT合涂层电极及其光电性质

在氧化铟锡( ITO)导电玻璃表面电泳沉积制备ZnO-C60和ZnO-MWCNT复合涂层电极,经后续热处理增强其结合强度,通过SEM观察2种电极复合涂层的表面形貌,并使用CHI 705电化学分析仪和PMI-E电致化学发光系统测定其光电性质.结果表明,ZnO-C60复合涂层电极具有较高的稳定性,在可见光辐照下,该电极显示...     

基于电泳沉积法碳纤维表面改性的研究进展及应用

近些年来,碳纤维(CF)由于具有优异的力学性能,被用作复合材料的增强体.但CF表面缺少极性基团,呈现化学惰性,使CF与树脂(EP)之间的界面粘结性能较差.为了改善该问题,需要对CF表面进行改性.氧化石墨烯(GO)和碳纳米管(CNT)具有大的比表面积,且表面含有大量的极性基团,将二者引入CF表面,可以有效改善CF与EP之...     

Assembly of two-dimensional ordered monolayers of nanoparticles by electrophoretic deposition

In this article the effect of field strength, temperature and square-wave pulse on the deposition structure of gold nanoparticles is investigated and 2D structures of silver and two kinds of rare-earth carbonate particles are synthesized by electrophoretic deposition (EPD). The results indicate that EPD is a general phenomenon that occurs on the electrode/sol interface and that the EPD method may be developed for the assembling of 2D structures of nanoparticles. On the other hand, the results also show that the composition and surface condition as well as the size distribution of the particles can affect the order of the particles in the monolayer. Received: 7 October 1999/Accepted: 25 January 2000     

交流电在Al2O3模板中沉积金属机理探讨

以铝阳极氧化形成有序的多孔氧化铝为模板,利用交流电在模板孔洞中沉积金属Ag得到纳米Ag粒子/Al2O3组装体系,透射电镜观察证实在氧化铝模板中有金属纳米Ag粒子存在.分析了交流电能在孔洞中沉积金属的原因是由于Al/Al2O3界面的整流特性,测量了Al/Al2O3界面的I－U关系曲线.     

电泳显示微胶囊的制备和性能

以有机颜料联苯胺黄为显色粒子, 四氯乙烯和甲苯混合溶液为分散介质, 油溶性蓝N为吸光染料, 用超分散剂CH-2C分散颜料粒子, 脲醛树脂为壁材, 通过一步原位聚合法制备了电泳显示微胶囊. 通过显微镜检查微胶囊的表面形貌及粒径, 并对微胶囊内颜料粒子的电场响应特性和显示性能进行考察. 结果表明, 所得微胶囊表面光滑, 囊壁透明, 囊内颜料粒子对电场变化能够快速可逆地响应, 并具有双稳显示特性.     

Cathodic electrophoretic deposition of manganese dioxide films

Cathodic electrophoretic deposition (EPD) method has been developed for the deposition of manganese dioxide films. It was shown that phosphate ester (PE) is an effective charging additive, which provides stabilization of manganese dioxide nanoparticles in suspensions. The influence of PE concentration and deposition voltage on the deposition efficiency has been studied. EPD has been utilized for the fabrication of porous nanostructured films with thickness in the range of 0.5–20 μm for application in electrochemical supercapacitors (ES). Cyclic voltammetry and chronopotentiometry data for the films tested in the 0.1 M Na₂SO₄ solutions showed capacitive behavior in the voltage window of 1 V. The highest specific capacitance (SC) of 377 F g⁻¹ was obtained at a scan rate of 2 mV s⁻¹. The SC decreased with increasing film thickness and increasing scan rate in the range of 2–100 mV s⁻¹. The deposition mechanism, kinetics of deposition and charge storage properties of the films are discussed.     

电泳沉积法制备介孔TiO2/单壁碳纳米管薄膜

采用电泳沉积法, 在FTO/介孔TiO2薄膜上制备了介孔TiO2/单壁碳纳米管(SWCNTs)薄膜电极, 用Raman和SEM等手段对薄膜电极进行了表征. 结果表明, SWCNTs已沉积到介孔TiO2薄膜上. 分别用四羧基苯基卟啉(TCPP)和联吡啶钌化合物N719对其进行敏化, 并组装成太阳能电池. 研究结果表明, 与单纯的TiO2粒子膜相比, 介孔TiO2和SWCNTs的紧密结合可使得光生电子更容易传输, 光电转换效率显著提高.     

电泳法制备TiO_2纳米管/纳米颗粒复合薄膜的电化学阻抗谱分析(英文)

由于一维(1D)氧化钛纳米结构具有提高染料敏化太阳能电池(DSCs)中的电子传输性能从而进一步提高电池性能的特性,该领域吸引了越来越多研究者的关注.但是一维氧化钛纳米结构如何影响电子传输性能却少有报道.本研究利用电化学阻抗谱(EIS)分析来探索氧化钛纳米颗粒和纳米管复合薄膜的电子传输特性.使用两种不同尺寸(25和100nm)的纳米颗粒和纳米管作为原料,采用电泳沉积方法制备了氧化钛复合薄膜并研究了原料的组成对染料敏化电池的影响以获得最佳的组成.研究结果表明,在大颗粒的质量分数低于20%时,大颗粒的掺入有利于改善氧化钛薄膜的电子传递与电池性能.与完全由颗粒组成的薄膜相比,纳米管的加入有利于电子在氧化钛薄膜里的传输.纳米管、100nm颗粒及25nm颗粒的最佳质量比例为20:16:64.     

交流电在Al_2O_3模板中沉积金属机理探讨

以铝阳极氧化形成有序的多孔氧化铝为模板,利用交流电在模板孔洞中沉积金属Ag得到纳米Ag粒子/Al2O3组装体系,透射电镜观察证实在氧化铝模板中有金属纳米Ag粒子存在.分析了交流电能在孔洞中沉积金属的原因是由于Al/Al2O3界面的整流特性,测量了Al/Al2O3界面的I－U关系曲线.     

Electrophoretic rotation of doublets composed of two spheres almost in contact

Colloidal doublets formed from spheres with different zeta potentials rotate as dipoles into alignment with an applied electric field. The rate of rotation is proportional to the difference in the electrophoretic mobilities of the isolated spheres times a dimensionless rotation coefficient (N). The coefficient N, which describes the interaction effects between the particles, has been previously calculated numerically under the assumptions of infinitesimal double layers and uniform zeta potentials on each sphere. These numerical values have been used to interpret experiments which probe the tangential forces between two particles almost in contact. But since these assumptions might not hold for the small gaps in actual experiments, it is important to know how N is affected when the double layers of two spheres overlap or when the charge is nonuniformly distributed on the sphere surfaces (especially in the gap region). Using an extension of the Lorentz reciprocal theorem for Stokes flow, we have developed a semi-analytical solution for N which is valid in the asymptotic limit of small (but finite) gaps of fluid between the spheres. For infinitesimal double layers and uniform zeta potentials, this result shows that N is weakly singular in the gap between the spheres. Our method also enables us to examine the effects of overlapping double layers and nonuniform zeta potentials in the gap region, and an important result of this paper is that even when these effects are considered, the result for infinitesimal double layers and uniform zeta potentials remains a very good approximation.