Preparation of coatings from a series of silicone/fluorine‐functionalized polyacrylates via electrophoretic deposition

Silicone/fluorine‐functionalized polyacrylates were synthesized and subsequently used to prepare corrosion‐resistant transparent coatings via electrophoretic deposition. The coated tin plate with the functionalized polyacrylate had a gloss value higher than 95.0 GU and resisted rust after immersion in a 5 wt% NaCl solution for 10 days. In addition, these coatings remained adhered strongly to the tin plates even after they were bent. It is hoped that this work will provide useful experimental data and assist researchers with the design of applicable coatings with desirable properties. Copyright © 2015 John Wiley & Sons, Ltd.     

管状电沉积铀靶的制备和检测

研究了管状电沉积铀靶的制备工艺,确定了铀的最佳电沉积条件,并对电沉积铀靶的电沉积量、均匀性、牢固性、堆照核发热及热传导等检测分析技术进行了研究,建立了电沉积铀靶的检测分析流程,对于铀靶的质量检测和靶件在反应堆内的辐照安全评价具有重要意义。     

Preparation and characterization of electrophoretically deposited high-temperature superconductor coatings

The high-temperature superconductor, YBa₂Cu₃O_7–x (x = 0.1–0.2) [YBCO], was prepared using an optimized calcination and sintering process. Thin layers of a few microns of this material were deposited on a silver substrate by applying a simplified electrophoretic deposition technique in a suspension of the fine, < 10 m, superconductor powder in a non-aqueous liquid. To get a uniform and strongly adherent coating, the deposition process is repeated several times, followed by an appropriate sintering procedure. The initially prepared YBCO powder and the coatings produced were characterized for their superconducting properties by X-ray diffraction analysis (XRD), magnetization measurements with a Superconducting Quantum Interference Device (SQUID) and electrical resistivity measurements. By scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) the grain size of the YBCO film, its thickness and impurity content, respectively, were estimated.     

Preparation and microstructure study of borosilicate coatings produced by sol-gel

Borosilicate coatings in the systems (100–x)SiO₂–xB₂O₃ (x=20, 30) and 75SiO₂-20B₂O₃-5Na₂O have been obtained using the dip-coating procedure. Stable solutions were prepared from TEOS and trimethylborate, H₂O/TEOS ratios being changed from 2 to 6. Sodium acetate in aqueous solution was used as Na₂O precursor. Coatings were prepared in an airtight glove-chamber with humidity and temperature control. Good and transparent films were obtained only for RH<20%. Microstructure evolution and phase separation phenomena were investigated by TEM studying their dependence on the water content of the solution, temperature and time of the heat treatment and thickness of the coatings. A comparison with similar melted glasses and bulk glasses prepared by sol-gel has been also established.     

化学气相沉积法制备ZnO纳米结构薄膜及其SERS活性研究

提供了半导体作为光、电和生物等功能材料的表面和界面信息, 同时也为SERS的研究开拓了新的领域.     

Preparation of composited Nano‐TiO2 and its application on antimicrobial and self‐cleaning coatings

Composite nano‐TiO₂ with doping Fe³⁺ and Ag was prepared, and further modified by 3‐methacryloxypropyltrimethoxysilane. They were characterized by Zetasizer Nano ZS Particle and Zeta Potential Analyzer, X‐ray diffraction, UV–Vis spectrophotometer, FT–IR spectra, and transmission electron microscopy. The modified composite nano‐TiO₂ was applied to prepare multifunctional fluorocarbon coatings (FCC). Antibacterial activity of multifunctional FCC containing modified composite nano‐TiO₂ was investigated. Its photocatalytic antibacterial activity reached 92%. The influence of doping ingredients, amount of composite nano‐TiO₂, different light houses, or surface modification was discussed. The surface of FCC cannot be easily smirched by oiliness, dust or water because of hydrophobic fluorosilicone emulsion. It would be an available modern interior building coating for its remarkable photocatalytic antibacterial property as well as self‐cleaning function. Copyright © 2009 John Wiley & Sons, Ltd.     

LC4铝合金表面电泳沉积硅锆有机-无机杂化涂层的制备及性能

采用阴极电泳沉积的方法在LC4铝合金表面制备硅锆有机-无机杂化涂层, 并探讨了电泳沉积条件对涂层形貌、结构以及耐蚀性的影响. 采用纳米粒度仪检测了不同硅锆杂化溶胶的zeta电位; 采用扫描电子显微镜(SEM)和原子力显微镜(AFM)观察了涂层的表面微观形貌和粗糙程度; 采用傅里叶红外光谱(FTIR)研究了涂层的化学结构; 采用电化学方法研究了沉积电压对涂层耐蚀性能的影响, 进而探讨了电泳沉积增强杂化涂层耐蚀性的机理. 结果显示沉积体系的pH为1.6、沉积电压为5 V时为最佳的沉积条件, 所获得的硅锆有机-无机杂化涂层表面均匀致密性最好, 粗糙程度和耐蚀性都得到了明显的改善, 在3.5% NaCl溶液中体现出较好的耐蚀作用.     

Electrodeposition and characterization of chromium–tungsten carbide composite coatings from a trivalent chromium bath

The electrodeposition of chromium from a trivalent chromium bath has been described in this work. The electrocomposite coatings of chromium with hard abrasive particles were investigated. The chromium–tungsten carbide (Cr? WC) composite coatings were obtained by suspending different concentrations of WC particles in a trivalent chromium plating solution to improve the various properties of the chromium deposit layers. The effect of operating conditions on the deposit layers has been studied. On the other hand, the effect of non‐ionic polymeric surfactant [nonyl phenol ethoxylate with 12 units of ethylene oxide (NPE)] as an additive in enhancing the incorporation of the WC ceramic particles in the chromium metal matrix was investigated. It was found that the co‐deposition of the WC ceramic particles depends on the concentration of the additive and its efficiency in reducing the surface tension of the electroplating solution. The mechanism of incorporation of WC particles into a growing deposit was suggested and discussed in view of the zeta potential and degree of wetability of WC particles in the plating solution. Furthermore, the adsorption behaviour of the additive on WC particles was analysed according to the Frumkin isotherm. The surface morphology and the distribution of WC in the chromium metal matrix were investigated. The properties of the deposit layers, hardness, corrosion resistance and wear resistance were determined and compared with free chromium deposits. The test results reveal that the Cr? WC deposit layer shows better performance compared with the chromium‐free deposit. Copyright © 2005 John Wiley & Sons, Ltd.     

Potential use of Plasma-Deposition Techniques in the Preparation of Recognition Coatings for Mass Sensors 1

Abstract

The potential use of plasma-deposition techniques for the preparation of recognition coatings for mass sensors was investigated. Ethylenediamine and 4-vinylpyridine plasma-produced coatings and solution-deposited coatings from commercially available polyethyleneimine and poly(4-vinylpyridine) on quartz crystal microbalances (QCMs) were examined for the detection of acetic acid and other vapors. Freshly prepared QCM plasma-deposited recognition coatings from both ethylenediamine and 4-vinylpyridine were found to be very sensitive to acetic acid vapors. However the sensitivity decreased rapidly with time. Aging effects with solution deposited polymers films were noted as well. It was concluded that plasma-deposition of recognition coatings has great potential in the preparation of recognition coatings. In addition to well known advantages of the use of plasmas for surface film preparation or modification, the technique offers a one-step process of synthesizing and depositing high molecular weight films from volatile compounds not polymerizable by conventional means. A major disadvantage is that the chemical nature of the resulting coating is not easily predictable. However, careful choice of carrier gas and recognition film precursor can do much to simplify the design of effective recognition coatings.

     

丙烯酸酯改性水性聚氨酯乳液的制备及性能研究

采用共聚的方法制备出丙烯酸酯改性的水性聚氨酯共聚乳液(PUA乳液),并对PUA乳液的制备方法和工艺、耐溶剂性、机械稳定性进行了初步的研究。结果表明,具有IPN结构的PUA乳液耐溶剂性、机械稳定性比水性PU有明显的提高。     

TiN和TiC涂层对碳氢燃料裂解结焦的影响

采用化学气相沉积(CVD)法,在304型不锈钢管道内壁分别沉积了TiN和TiC涂层,并采用SEM、EDS、金相显微镜和热冲击等方法对其进行了性能表征和测试。结果表明,两种涂层均匀致密,TiN涂层厚度为7.24μm,TiC涂层为11.52μm,且均具有良好的结合强度。为评价涂层抑制结焦效果,选用某碳氢燃料A,采取程序升温法进行超临界裂解实验,当反应管前后压差超过1 MPa时停止实验,结果表明,304空白管由于严重结焦,在650℃只运行了180 s;而TiC和TiN涂层管分别在780℃运行了275和1560 s。通过压差、产气组成和积炭微观形貌的综合分析表明,TiN、TiC涂层均呈现出优良的抑焦效果,且TiN涂层抑焦效果更优。     

Recent Advances in Sample Preparation for Cosmetics and Personal Care Products Analysis

The use of cosmetics and personal care products is increasing worldwide. Their high matrix complexity, together with the wide range of products currently marketed under different forms imply a challenge for their analysis, most of them requiring a sample pre-treatment step before analysis. Classical sample preparation methodologies involve large amounts of organic solvents as well as multiple steps resulting in large time consumption. Therefore, in recent years, the trends have been moved towards the development of simple, sustainable, and environmentally friendly methodologies in two ways: (i) the miniaturization of conventional procedures allowing a reduction in the consumption of solvents and reagents; and (ii) the development and application of sorbent- and liquid-based microextraction technologies to obtain a high analyte enrichment, avoiding or significantly reducing the use of organic solvents. This review provides an overview of analytical methodology during the last ten years, placing special emphasis on sample preparation to analyse cosmetics and personal care products. The use of liquid–liquid and solid–liquid extraction (LLE, SLE), ultrasound-assisted extraction (UAE), solid-phase extraction (SPE), pressurized liquid extraction (PLE), matrix solid-phase extraction (MSPD), and liquid- and sorbent-based microextraction techniques will be reviewed. The most recent advances and future trends including the development of new materials and green solvents will be also addressed.     

Influence of velocity and surface temperature of alumina particles on the properties of plasma sprayed coatings

In this paper are described the main characteristics of the plasma spraying process of alumina deposits, i.e., the temperature and flow field of the plasma jets obtained with the classical spraying torches, the injection of the particles into the plasma jet, the particle surface temperature and velocities in the plasma (measured for calibrated alumina particles), and the coating generation. The measurements on the alumina particles are compared with the predictions of a mathematical model. The experimental and computed particle velocities are in rather good agreement. However, this is not the case for the particle surface temperature. Possible reasons for the discrepancy are proposed (influence of the carrier gas, thermophoretic forces, and poor penetration of the particles into the plasma core even for an injection velocity twice that of the optimal calculated one, as shown by recent measurements). Finally the correlations between the particle velocities and surface temperature, and the properties of the alumina coating (porosity, crystal structure, mechanical properties) are studied.     

Comparison of Two Sample Preparation Methods for a HPLC-DAD Assay of Tolbutamide from Human Plasma

ABSTRACT

Two sample preparation methods were applied for the determination of Tolbutamide in the human plasma, at concentration levels ranging from 5 to 50 ppm. One method is based on the drug extraction into ethyl acetate. This solvent has never been used for Tolbutamide extraction from plasma matrix. The other method is a non-extraction one, based on the protein precipitation in presence of methanol. Both methods were successfully applied to in-vivo monitoring of plasma levels of Tolbutamide for a 24-hours period, as required for a pharmacokinetic study. The main parameters in both methods were optimized in order to achieve the acceptance criteria imposed by the bioavailability studies.     

Preparation, characterization, and electrocatalytic properties of hybrid coatings of hexacyanometalate-doped-cationic films

Electrochemically active hybrid coatings based on cationic films, didodecyldimethylammonium bromide (DDAB), and poly(diallyldimethylammonium chloride) (PDDAC) are prepared on electrode surface by cycling the film-covered electrode repetitively in a pH 6.5 solution containing Fe(CN)₆ ³⁻ and Ru(CN)₆ ⁴⁻ anions. Modified electrodes exhibited stable and reversible voltammetric responses corresponding to characteristics of Fe(CN)₆ ^3−/4− and Ru(CN)₆ ^4−/3− redox couples. The cyclic voltammetric features of hybrid coatings resemble that of electron transfer process of surface-confined redox couple. Electrochemical quartz crystal microbalance results show that more amounts of electroactive anionic complexes partitioned into DDAB coating than those doped into PDDAC coating from the same doping solution. Peak potentials of hybrid film-bound redox couples showed a negative shift compared to those at bare electrode and this shift was more pronounced in the case of DDAB. Finally, the advantages of hybrid coatings in electrocatalysis are demonstrated with sulfur oxoanions.     

纳米碳管电极的制备与电化学检测性能研究

纳米碳管由于其独特的物理和化学性能及广阔的应用前景而备受关注,其相关研究涉及到众多领域[1￣3]。在电化学分析领域,与其它碳电极材料相比,纳米碳管电极具有较大的电极表面积和较高的电子传递速率,其使用能增大响应电流、降低检出限,是目前电化学分析电极中一个十分引人注目     

Preparation of fluorine containing hybrid coatings: investigation of coating performance onto ABS and PMMA substrates

UV‐curable fluorinated organic–inorganic hybrid coatings were prepared by the sol–gel technique. Perfluorinated urethane modified alkoxysilane was synthesized by the reaction between perfluoro alcohol and 3‐isocyanatopropyltrimethoxysilane. The prepared formulations were applied onto poly(methyl methacrylate) (PMMA) and acrylonitrile butadiene styrene (ABS) panels and polymerized by UV‐curing. The properties of the hybrid coatings such as hardness, chemical resistance, thermal stability, surface morphology, double bond conversion, and also contact angle measurements were investigated. Contact angle measurements have shown that the addition of fluorinated silane precursor to the hybrid system improved the water repellency and increased the contact angle from 65° to 106°. Copyright © 2009 John Wiley & Sons, Ltd.     

Preparation and characterization of polyurethane electrical insulating coatings derived from novel soybean oil‐based polyol

As a viable alternative to the petrochemical polyols in polyurethanes (PUs), a new soybean oil‐based polyol (PSBO) with high functionality of hydroxyl groups and built‐in (preformed) urethane bonds was introduced. At first, a facile and improved method was developed for the transformation of epoxidized soybean oil (ESBO) to carbonated soybean oil (CSBO). Then ring‐opening reaction of carbonated oil with ethanolamine (ETA) led to the polyol. After characterization by conventional spectroscopic and analytical methods, PSBO was used for the formulation of novel one‐pack PU electroinsulating wire enamels. Tunable mechanical, thermal, and electrical properties for the final PUs were achieved by replacing 10 wt% of PSBO with poly(propylene glycol) (PPG) at different number average molecular weights of 725, 1000, 2000, 4000. Investigation of the results showed that these soy‐based PUs offer excellent thermal and electrical insulating properties. Copyright © 2009 John Wiley & Sons, Ltd.     

低温等离子体制备与改性纳米催化材料的研究进展

低温等离子体属于非热平衡等离子体,它具有较高的电子温度和较低的气体温度,是一种纳米催化剂制备与改性的新方法。 低温等离子体因其高效、环境友好、材料易实现功能化等特点在制备和改性纳米催化材料方面引起了广泛关注,在纳米催化材料的非常规制备、掺杂、缺陷和空位制造中展现了突出的优势,因而被广泛用于各类催化剂的制备与改性中。 本文主要综述了低温等离子体在氧还原(ORR)、氧析出(OER)、析氢(HER)和燃料氧化反应(FOR)催化剂制备与改性方面的研究进展,从不同角度阐述了上述各类催化剂性能改善的原因,并对低温等离子体在纳米催化剂制备与改性方面存在的成本相对较高、反应器放大、材料可控制备等挑战进行了总结,最后对等离子体制备与改性纳米催化剂的发展趋势进行了预测。     

电镜用双层支持膜的制备及应用

本文综合了Formvar膜强度大和火棉胶膜分散性好的优点,制备出了Formvar-火棉胶双层支持膜。Formvar膜在下层增大了膜的强度,火棉胶膜在上层改善了膜的分散性。根据电镜对支持膜的特殊要求,摸索出了制备双层支持膜的原料溶液的浓度范围及浓度配比范围,并且通过红外光谱(IR)证实了双层支持膜结构的存在。通过实际应用,发现双层支持膜具有高分辨率、强电子束照射下膜保持稳定不破损等优点,双层支持膜比以前传统使用的单层支持膜在许多方面都取得了较大的改善,尤其适用于纳米材料的电镜观察,因此,值得进一步推广应用。