反胶团或微乳液法制备超细颗粒的研究进展

本文对超细颗粒的各种化学制备方法进行了综合评述，并重点介绍了一种新的超细颗粒制备法──反胶团或微乳法。从以下几个方面对反胶团或微乳法制备超细颗粒的研究工作进行了归纳和总结：各种用于制备超细颗粒的反胶团或微乳体系，已经制得的超细颗粒种类，反胶团或微乳中颗粒的形成机理，以及反胶团或微乳法制备超细颗粒的影响因素等。     

反胶团法制备CdS半导体纳米粒子

以十六烷基三甲基溴化铵(CTAB)为表面活性剂、正己醇为助表面活性剂制备了水/CTAB/正己醇/正庚烷的四元反相胶束体系,利用该体系制备了尺寸可控、均一、单分散的半导体CdS纳米材料,其中反相胶束体系被认为是一个"微反应器".获得了一个CdS纳米微粒的最佳制备条件.通过研究CTAB四元反相胶团体系的成相区域、稳定性、微液滴大小和尺寸分布和胶团组成,得出了反相胶团组成与胶团中微液滴大小的关系,采用TEM、XRD等分析技术对所制备的CdS纳米颗粒进行了性能表征.     

反胶团微乳液法制备超微细颗粒的研究进展

简要阐述了用反胶团微乳法制备超微细颗粒的基本理论，介绍了在使用该法制备超微细颗粒中的几种具体模式，并讨论了相关的影响因素。     

表面活性剂在纳米材料形貌调控中的作用及机理研究进展

介绍了表面活性剂在纳米材料合成中的软模板作用和稳定分散作用,重点综述了利用表面活性剂在溶液中聚集形成的胶团、反胶团、微乳液、囊泡、液晶等各种有序聚集体辅助制备纳米材料的作用机理.展望了表面活性剂在纳米材料形貌调控中的应用前景.     

反胶团酶膜反应器研究进展

两亲分子溶入有机溶剂时可自组织形成球形聚集体，称作反胶团，酶能溶入反胶团的水池中以催化特定的反应文中对反胶团介质中的酶反应进行了介绍，并对膜反应器在反胶团酶反应中的应用进行了综述     

用反向胶团制备稳定ZrO2超细粉的研究

以注入法研究了金属离子及氨水在ＡＯＴ－ｉｓｏｏｃｔａｎｅ－ｗａｎｔｅｒ反胶团中的溶解性，用光散射技术测定了胶团的大小，用冷冻蚀刻复形技术表征了反胶团的微观结构；研究了以反胶团为基础溶液多种制备方式对粉末的影响，实验制备了Ｙ２Ｏ３及ＣｅＯ２稳定的四方相ＺｒＯ２超细粉，研究表明，将金属离子包溶于反胶团是制备良好颗粒的必要条件。     

高浓度水相Sb2O5胶体直接制备环己酮Sb2O5胶体

以体积质量浓度为60％的高浓度水相Sb2O5胶体为原料制备环己酮Sb2O5肢体。直接向该水相Sb2O5胶体中加入数种表面活性剂和环已酮，经过胶团在水中聚沉、胶团表面改性、胶团重新分散于环己酮等几个步骤生成环己酮Sb2O5胶体，原水相Sb2O5胶体中的水随之一起成胶。经试验，该胶体可以与聚氨酯以任意比例互相融合。     

一种制作沟槽型同位素微电池表面电极的新工艺

开发了一种利用SU8胶剥离工艺制作沟槽型同位素微电池表面电极的新工艺,通过使用BP212正胶作为牺牲层,有效地解决了在制作沟槽型同位素微电池表面电极时,堆胶以及沟槽中SU8胶不易去除的难题.该工艺操作简单、可靠,成本低,因此具有很大的实用价值.     

聚苯乙烯微球自组装胶态晶体的研究及其应用进展

胶态晶体作为一种新型材料被广泛关注,一般采用胶态粒子自组装的方法制备胶态晶体。聚苯乙烯(PS)微球是一种常见的胶态粒子,综述了PS微球自组装形成胶态晶体的常用方法,包括垂直沉积法、重力场沉积法、界面自组装法、旋涂法及物理限制法等,并对PS胶态晶体用作模板或掩膜制备纳米结构材料的进展进行了总结。     

用扩散理论解释激光选择性催化的原理(英文)

激光选择性催化(LISA)技术可用于高分子的选择性电镀,本文主要研究了Pd/Sn催化系统在这个过程中的原理.实验表明在催化后的清洗步骤对电镀的选择性有很大影响,由于激光处理后在高分子表面产生了多孔结构,相对于在未被激光处理的表面上,Pd/Sn催化胶团需要更长的时间才能被清洗掉.本文中,采用扩散理论描述催化和清洗后在样品表面催化胶团的浓度分布,其中催化胶团在多孔介质中的扩散系数是研究的难点.采用NanosightR颗粒检测仪器测量胶粒的尺寸,用AliconaInfiniteFocus显微镜对激光处理后的表面多孔结构进行了测量和表征.最后测得催化胶团的浓度百分比曲线,可用于表征催化和清洗时间对浓度的影响.     

Structure and rheology of charge-free reverse micelles in aromatic liquid phenyloctane

Reverse micelles formulation requires an inclusion of water or other polar molecules in the binary mixture of ionic surfactant and oil and generally exhibit spheroid geometry with a small aggregation number. Here, we report structure and rheology of charge-free (nonionic) reverse micelles in surfactant/oil systems. We have systematically investigated intrinsic parameters for the shape, size, and internal cross section structure control of such micelles using small-angle X-ray scattering (SAXS) and the rheometry. We found that diglycerol monomyristate (C14G2) when added into an aromatic organic liquid phenyloctane, spontaneously self-assembles into spheroid micelles with maximum diameter ca. 6.7 nm. Decrease in surfactant chain length favors globular-to-rod type transition and micellar aggregation number (N(agg)) increases significantly. On the other hand, increase in surfactant weight fraction induces one-dimensional (1-D) micellar growth; N(agg) increases in parallel to the surfactant concentration. Reverse micelles shrink with the rise of temperature, which is close to the rod-to-sphere type transition. However, water causes a significant micellar growth; N(agg) increases drastically, which shows that water not only increase reverse micellar size but also increases the number of surfactant molecules per micelle. All these microstructure transitions could be understood in terms of the modification of the critical packing parameter (cpp). The SAXS results are very well supported by the geometrical model fittings and rheometry.     

Surfactant-assisted synthesis of water-soluble and biocompatible semiconductor quantum dot micelles

We report a simple, rapid approach to synthesize water-soluble and biocompatible fluorescent quantum dot (QD) micelles by encapsulation of monodisperse, hydrophobic QDs within surfactant/lipid micelles. Analyses of UV-vis and photo luminescence spectra, along with transmission electron microscopy, indicate that the water-soluble semiconductor QD micelles are monodisperse and retain the optical properties of the original hydrophobic QDs. The QD micelles were shown to be biocompatible and exhibited little or no aggregation when taken up by cultured rat hippocampal neurons.     

Heterogeneous photocatalytic degradation of phenanthrene in surfactant solution containing TiO2 particles

Photocatalytic degradation of phenanthrene (PHE) over TiO(2) in aqueous solution containing nonionic surfactant micelles was investigated. All photocatalytic experiments were conducted using a 253.7 nm mercury monochromatic ultraviolet lamp in a photocatalytic reactor. The surfactant micelles could provide a nonaqueous "cage" to result in a higher degradation rate of PHE than in an aqueous solution, but the higher Triton X-100 concentration (more than 2 g/L) lowered the degradation ratio of PHE because the additional surfactant micelles hindered the movement of micelles containing PHE so as to reduce their adsorption onto titania. Pseudo-second-order kinetics was observed for the photocatalytic degradation of PHE. Alkaline solution environment was beneficial to the photocatalytic degradation of PHE. PHE degradation could mainly be attributed to the formation of hydroxyl radicals as evident from the comparison of degradation efficiencies when O(2), H(2)O(2) and tert-butyl alcohol (TBA) were applied as oxidants or hydroxyl radical scavenger. Based on the GC/MS analysis of the intermediates, the possible pathways of the photocatalytic degradation of PHE were proposed.     

Formation of monetite nanoparticles and nanofibers in reverse micelles

Reverse micelles solution of water and cyclohexane containing either cetyltrimethylammonium bromide (CTAB) or polyoxyethylene-8-dodecyl ether (C₁₂E₈) surfactants and n-pentanol as co-surfactant have been used as organized reaction microenvironments for monetite (dicalcium phosphate anhydrous, DCPA) precipitation. Well-crystallized monetite nanoparticles with various morphologies such as spheres, nanofibers and bundles of nanowires were obtained in CTAB reverse micelles solution. The molar ratio of water and surfactant (W _o) and the molar ratio of co-surfactant and surfactant (P _o) have great influence on the structure and morphology of the final products. A generalized mechanism for the growth of monetite in reverse micelles is proposed, in which the interaction between the surfactant molecules and PO₄³⁻ ions leads to the formation of a surfactant/CaHPO₄ complex. It is because of this central complex that the further fusion with reactant ions containing reverse micelles will occur only in one direction. Changing the content of water and co-surfactant has great influence on the morphology of reverse micelles and on the interaction between the surfactant/CaHPO₄ complex leading to a fine tuning of the morphology of products. By contrast, lacking of this interaction in the C₁₂E₈ system only tablet amorphous calcium phosphate can be formed.     

以汞为反应介质制备氧化锌纳米空心球

以汞为反应介质, 表面活性剂胶束为模板, 通过锌的氧化反应制备了氧化锌空心球. 采用SEM、EDX、TG、DTA、XRD、IR等测试手段对产物的形貌和结构进行了表征, 并考察了表面活性剂对产物生长的影响. 研究表明, 氧化锌空心球为无定型结构, 壁厚为纳米尺度, 由氧化锌纳米粒子组装而成, 煅烧后转变为六方纤锌矿结构. 加入适量PEG或CTAB, 能制备出氧化锌空心球; 不加入表面活性剂、加入过量PEG或SDBS, 则不能制备出氧化锌空心球.     

Reverse micelle microstructural transformations induced by surfactant molecular structure, concentration, and temperature

We have investigated the microstructural transformations of nonionic surfactant reverse micelles induced by surfactant molecular architecture, surfactant concentration, and temperature in nonaqueous media. The investigations were based on small-angle X-ray scattering (SAXS) and rheometry techniques. Polyglycerol polyoleic acid esters spontaneously self-assembled into reverse micelle in n-decane under ambient conditions, whose shape, size, and internal structure could be controlled by the surfactant molecular architecture, concentration, and temperature. The maximum size of the micelles was found to increase with an increase in the hydrophilic headgroup size of the surfactant. On the other hand, an opposite trend was observed with an increase in the number of oleate chain per surfactant molecules, which was well supported by rheology data; viscosity decreased with the number of oleate chain per surfactant molecule. The SAXS and rheology data have shown a clear evidence of one dimensional micellar growth with increase in the surfactant concentration. The relative viscosity, eta(r), of the reverse micelle exhibited steeper concentration dependence behavior than those predicted for a dispersion of spherical particles based on the Krieger-Dougherty relation which provided a clear evidence of the presence of elongated micelles at higher concentration. An ellipsoidal prolate-to-sphere type transition was observed upon heating.     

胶束强化超滤技术分离水溶液中有色金属离子的研究

胶束强化超滤是一种实现水溶液中小分子量物质分离的新技术.该技术利用表面活性剂胶束对金属离子的吸附作用,结合超滤工艺,进而达到去除Cd2 ,Cu2 ,Ni ,Pb2 ,Co2 ,Zn2 等有色金属离子的目的.介绍了胶束强化超滤技术分离水溶液中有色金属离子的研究现状,分析了该技术目前存在的问题以及今后的应用前景.     

Principles for microscale separations based on redox-active surfactants and electrochemical methods.

We report principles for microscale separations based on selective solubilization and deposition of sparingly water-soluble compounds by an aqueous solution of a redox-active surfactant. The surfactant, (11-ferrocenylundecyl)trimethylammonium bromide, undergoes a reversible change in micellization upon oxidation or reduction. This change in aggregation is exploited in a general scheme in which micelles of reduced surfactant are formed and then put in contact with a mixture of hydrophobic compounds leading to selective solubilization of the compounds. The micelles are then electrochemically disrupted, leading to the selective deposition of their contents. We measured the selectivity of the solubilization and deposition processes using mixtures of two model drug-like compounds, o-tolueneazo-beta-naphthol (I) and 1-phenylazo-2-naphthylamine (II). By repeatedly solubilizing and depositing a mixture that initially contained equal mole fractions of each compound, we demonstrate formation of a product that contains 98.4% of I after six cycles. Because the aggregation states of redox-active surfactants are easily controlled within simple microfabricated structures, including structures that define small stationary volumes (e.g., wells of a microtiter plate) or flowing volumes of liquids (e.g., microfabricated channels), we believe these principles may be useful for the purification or analysis of compounds in microscale chemical process systems. When used for purification, these principles provide separation of surfactant and product.     

Structure of diglycerol monomyristate reverse micelles in styrene: a small-angle X-ray scattering (SAXS) study

Structure of diglycerol monomyristate (designated as C14G2) nonionic surfactant reverse micelles in aromatic solvent styrene has been investigated as a function of surfactant concentration, temperature, and water addition by using small-angle X-ray scattering (SAXS) technique. Structure of micelles in real-space so called pair-distance distribution function, p(r), was obtained by the generalized indirect fourier transformation (GIFT) evaluation of SAXS data. It was found that C14G2 spontaneously self-assembles into spheroid reverse micelles with maximum diameter approximately 3.0 nm when added into styrene under ambient condition. The micellar shape and size remained essentially the same despite a wide variation in surfactant concentration (5 to 30%) but an opposite trend was observed with the rise of temperature; size decreased by approximately 25% with increase in temperature from 25 to 75 degrees C. Addition of traces water favored micellar growth and eventually ellipsoid prolate type micelles were formed, whose scenario is understood in terms of decrease in the critical packing parameter (cpp); water hydrates the surfactant's headgroup and decreases cpp. At a particular concentration of water, increasing temperature decreased the micellar size due to dehydration of headgroup. It is interesting to note that size of 1.57% water incorporated micelle is approximately 2.5 times bigger than the empty micelles.