Preparation of titanium dioxides in the W/C microemulsions and their photocatalytic activity

TiO₂ nanoparticles were produced by controlled hydrolysis of TTIP in the W/C microemulsions stabilized by polymeric surfactants. The prepared particles were characterized using TGA-DTA, FT-IR, XRD, SEM and TEM. It was found that the residual hydroxyl group and the organic compounds were completely removed by calcination at 350°C and the amorphous phase transformed to an anatase structure above 420°C, though the particles dried at 105°C without calcination were amorphous. The crystallite size could be controlled by the water-to-surfactant mole ratio, W₀, and the particle size increases from 8 to 18 nm with an increase of the W₀ ratio. In addition, the photocatalytic activity decreases with an increase of the W₀ ratio, though still higher than that of normal bulk TiO₂.     

反相微乳液聚合机理及模型化处理

在阐述反相微乳液聚合液滴成核及粒子增长机理的基础上，提出了丙烯酰胺反相微乳液聚合过程的物理模式，并对反相微乳液聚合模型化处理时的关键问题作了扼要讨论。     

Gd2O3：Yb，Er纳米材料的制备及上转换发光研究

利用Triton X-100／正己醇／环己烷／正己烷／水制成W／O微乳反胶团体系制备Gd2O3：Yb，Er上转换材料。利用扫描电镜观察氧化物粉体的颗粒形貌均为球形；通过改变掺杂元素Yb和Er的比例，在980nm的红外光激发下，观察研究氧化物颗粒的发光性质。该粉体在波长为980nm的半导体激光器激发下发射出绿色和红色的上转换荧光，分别对应于Er^3＋离子的。^S3／2／^2H11／2→^4I15／2跃迁和。^F9／2→^I15／2跃迁。     

Effects of the cosurfactant 1‐butanol and feed composition on nanoparticle properties produced by microemulsion copolymerization of styrene and methyl methacrylate

The concentration of the cosurfactant 1‐butanol (BuOH) determined the polymer weight and size for a series of poly(styrene‐co‐methyl methacrylate)s (P(St‐co‐MMA)) synthesized by the free‐radical (o/w) microemulsion technique. A factorial design established the levels of the experimental conditions for the polymerization i.e., concentration of the surfactant, sodium dodecyl sulfate (SDS); concentration of the cosurfactant, BuOH; temperature and ratio of the styrene (St) to methyl methacrylate (MMA). An increase in the weight‐average molecular weight (M_w) and number‐average molecular weight (M_n) was observed in the P(St‐co‐MMA) series with an increase in BuOH concentration from 1 to 5 wt %. These effects could arise from the micellar aggregation induced by interfacial BuOH. The unique micellar conditions could be exploited to synthesize copolymers of varying molecular weight and size. Additionally, the composition of the copolymers was virtually templates of the feed composition. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Electrochemical behavior of K3Fe（CN）6 in water-in-oil microemulsion

A water-in-oil (W/O) microemulsion composed of Triton X-100, n-hexanol, n-hexane and water solution with hydrochloric acid was prepared. K₃Fe(CN)₆ was added in as a water-soluble electroactive probe, and its electrochemical behavior was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It is found that the H⁺ concentration of the water phase has a great effect on the conductivity of the W/O microemulsion, and hence influences the electrochemical behavior of K₃Fe(CN)₆. When the pH value of water phase is about 7, the electrical conductivity of the W/O microemulsion is only 1.2×10⁻⁶ S/cm, and K₃Fe(CN)₆ almost cannot react at the glassy carbon electrode. But when the H⁺ concentration is more than 3 mol/L, the W/O microemulsion has a good electrical conductivity and K₃Fe(CN)₆ shows good electrochemical performance in it. The results of CV and EIS studies indicate that the electrochemical behavior of Fe(CN)₆ ³⁻/Fe(CN)₆ ⁴⁻ in the W/O microemulsion is different from that in the aqueous solution. This may be due to the unique liquid structure of the W/O microemulsion and the unique mass transfer in the W/O microemulsion. Foundation item: Projects(20673036, J0830415) supported by the National Natural Science Foundation of China; Projects(05JT1026, 2007JT2013) supported by the Science Technology Project of Hunan Province, China     

阳离子染料在D5反相微乳体系中的染色性能研究

分析阳离子染料在D5反相微乳体系中染色的可行性,确立阳离子染料在D5反相微乳体系中上染腈纶织物的工艺,并探讨入染前织物带液率、反相微乳液含水量对染色性能的影响。实验结果表明:腈纶织物在温度为60℃、pH值为4.5~5的水中进行预处理后,以一定带液率入染反相微乳体系的方法可行;优化的阳离子染料在D5反相微乳体系中的染色工艺为:染色温度85℃、染色时间20 min、浴比1∶10;研究中还发现入染前织物带液率的高低对织物得色深度有较大影响,随着带液率的增加,染色K/S值先增加后减少;反相微乳体系的含水量对织物的得色深度无明显影响。     

仿生黏附性聚多巴胺丁香酚抑菌微胶囊的制备

以丁香酚（EO）为芯材,多巴胺（DA）为壳材,通过乳液模板-界面聚合法成功制备出尺寸可控的聚多巴胺丁香酚（PDA@EO）微胶囊。通过FTIR、TG、UV-Vis、SEM和TEM对微胶囊的化学结构、形貌、粒径及性能进行表征和分析,结果表明,所制备的微胶囊呈规整球形,粒径在55～94 nm之间,丁香酚包封率为25.35%,包封量为0.6288 g/g,24 h时累积释放率达到68.39%。通过对比实验证明,PDA@EO微胶囊在不同材料表面均具有优异的黏附性能;作用于口腔感染部位常见细菌金黄色葡萄球菌和大肠杆菌24 h,PDA@EO微胶囊较游离丁香酚的抑菌活性分别提高了36.84%和35.52%;当微胶囊质量浓度达到2.0 g/L时,PDA@EO微胶囊对两种细菌的抑菌活性均达到99%以上。     

微乳液泡沫驱油技术原理、挑战和研究进展

微乳液驱和泡沫驱是强化采油领域中的两个重要技术。前者利用表面活性剂形成油-水微乳液提高增溶能力,降低油水界面张力和毛细管阻力,从而提高驱替效率和微观采收率;后者利用泡沫剂将气体稳定地分散在水相中,在油藏孔隙中形成泡沫,封堵优势通道和已驱替区域,从而扩大波及体积并提高宏观采收率。通过综述两个技术的国内外发展历史和研究进展,阐明了其优势和局限性。近年来提出的微乳液泡沫驱油技术,又称为低张力泡沫驱,其既可以保留两个独立技术的优势,又可以克服他们的缺点,最终同时提高微观和宏观采收率。但是在实际研究中,微乳液泡沫驱技术却面临理论和应用上的双重挑战。通过调查国内外相关研究进展,详细阐述了微乳液泡沫驱技术目前面临的挑战、研发思路和研究建议。     

一种复合型天然除螨抑菌微乳性能研究及在洗护产品中的应用

通过采用苦参精油和广藿香精油与二氯苄醇和伞花烃-o-5醇复配,制备得到除螨抑菌微乳。经测试分析,除螨抑菌微乳水溶性好,稳定性强,对各个菌种的最低抑制浓度为1 000 ~5 000 mg/L;0.35%除螨微乳对螨虫灭杀作用24 h,其灭杀率高达95%,将0.35%除螨微乳添加到洗衣液和沐浴露中,灭杀作用48 h,对螨虫灭杀率约100%。