表面活性剂在FePt纳米颗粒形貌控制中的应用

采用湿化学还原法制备FePt纳米颗粒,选择复配型表面活性剂柠檬酸和聚乙二醇(PEG)、油酸和油胺,以及单一型表面活性剂十二烷基苯磺酸钠对FePt纳米颗粒进行修饰,比较了三者在FePt纳米颗粒形貌及磁性能上的作用区别。XRD、TEM以及振动样品磁强计表征结果显示,表面活性剂的选择对制备FePt纳米颗粒的结构没有影响,均显示化学无序的面心立方结构;复配型表面活性剂有利于诱导生成各向异性纳米结构,聚合物表面活性剂PEG诱导生成了棒状和米粒状纳米结构;室温下颗粒均显示超顺磁性,但饱和磁化强度M s差别很大,球形颗粒M s相对最大,而棒状颗粒M s相对较小。     

分光光度法测定银铈氧化锌纳米复合材料中自由基含量

利用直接沉淀技术,制备系列稀土掺杂纳米粒子,并且加入适当的表面活性剂聚丙烯酸钠(PAAS)以减小粒子之间的团聚,使得掺杂型纳米复合材料一系列优异的性能得到更好的发挥。文章应用分光光度法测定表面活性剂对纳米复合材料产生羟基自由基含量,从而间接的得出对其分散效果的影响。实验结果表明,表面活性剂可增加纳米粒子间的相互排斥作用,避免纳米粒子的团聚,提高纳米复合材料的分散性,增加其产生的羟基自由基含量还能改善或提高纳米粒子与其它物质的相容性。     

非离子表面活性剂在纳米粒中的应用

综述了聚合物纳米粒和固体脂质纳米粒的有关研究进展,重点对非离子表面活性剂在聚合物纳米粒和固体脂质纳米粒制备方法、表面修饰中的应用进行了介绍,指出了非离子表面活性剂在纳米粒研究和应用中具有广阔的前景。     

表面活性剂在纳米材料制备领域的研究概况

表面活性剂是用途非常广泛的一类两亲分子,现如今已运用在纳米粒子模板,有机化学制备等诸多领域。而纳米材料的微乳液合成方法是一项日趋完善的技术,它可以用于控制许多有机和无机材料的粒子尺寸。本文将对表面活性剂,以及表面活性剂在溶液中形成的微乳液制备纳米材料的应用趋势做详细的介绍。     

表面活性剂在纳米材料领域中的应用

主要介绍了表面活性剂在防止纳米粒子团聚方面的应用以及表面活性剂在一些纳米材料如碳纳米管、纳米晶和纳米磁性液体等方面的最新应用；同时介绍了纳米技术在改造表面活性剂工业上的应用，说明了表面活性剂与纳米材料千丝万缕的联系，指出了表面活性剂在与纳米技术的结合中，本身也在不断地发展，并展望了表面活性剂在纳米材料领域广阔的应用前景。     

溶胶-凝胶法制备纳米TiO2及其分散性研究

本文研究了以钛酸丁酯为起始原料通过溶胶—凝胶法制备纳米TiO2粒子,分别从醇钛比、水钛比、pH值等可控条件设计正交实验,优化制备纳米TiO2的工艺条件。并在此基础上,选择不同的表面活性剂以及不同的加入方式对纳米TiO2粒子进行表面改性,利用粒度分析仪分析了表面活性剂对TiO2颗粒团聚行为以及稳定性的影响。并利用稳定机理对水溶液中TiO2分散稳定性作了解释。     

二元乳状液稳定性影响因素的研究

制备了聚合物/表面活性剂二元乳状液,考察了聚合物相对分子质量、聚合物质量浓度、表面活性剂质量分数、油水比(原油与聚合物/表面活性剂二元乳状液体积比)对二元乳状液稳定性的影响。结果表明:提高表面活性剂的质量分数和聚合物的质量浓度,采用相对分子质量较低的聚合物,降低油水比,有利于二元乳状液的稳定。     

烯丙基型可聚合表面活性剂的性能

可聚合表面活性剂是指带有如不饱和双键或叁键等可聚合基团的表面活性剂。它除了含有亲水、亲油基团外,还包括了一个可聚合的官能团。在起传统表面活性剂作用的同时,还能够参与乳液聚合,并以共价键的方式永久地结合到聚合物粒子的表面,成为聚合物的一部分,避免了表面活性剂从乳胶粒子上解吸或在乳胶膜中迁移,从而使乳液的稳定性得以改善。     

表面活性剂含量对微乳液法合成纳米氧化锆粉体结构与性能的影响

采用水/环己烷/TritonX-100/正己醇四元油包水体系,通过微乳液法制备了纳米ZrO2粉体.用X射线衍射、透射电镜等表征所制备的纳米粉体,重点研究表面活性剂含量对ZrO2纳米粒子结构与性能的影响,分析产生团聚的原因,并提出改进措施.结果表明:所制备的纳米单斜相ZrO2粉体的晶粒尺寸可控制在15nm左右;随表面活性剂含量的增加,晶粒的尺寸有所减小,团聚现象亦有所减少.     

表面活性剂在纳米材料科学中的应用

介绍了表面活性剂在纳米材料制备及其表面改性等方面的应用，表面活性剂对纳米材料粒度与形状的影响，并展望了表面活性剂在纳米材料科学以及其他高新技术产业的应用前景。     

Evolution of the water–monomer dynamic interfacial properties during methyl methacrylate radical polymerization in a single monomer droplet: dependence on the chemical structure of the surfactant

This paper deals with the monitoring of the methyl methacrylate (MMA) droplet interface during its polymerization in one single monomer droplet by using a drop tensiometer. The droplet is stabilized by various molecular and polymer surfactants, in particular Pluronic® F68 and pullulan‐block‐Jeffamine®. The polymerization in one single droplet of the tensiometer can be seen as a way to study the interface of polymer nanoparticles during a mini‐emulsion polymerization assuming the concept of a perfect nanoreactor. It was found that the experimental results (surface tension and interfacial rheology) can be connected with MMA radical polymerization. These results demonstrate that the drop tensiometer technique enables interface evolution to be followed during polymer polymerization. © 2013 Society of Chemical Industry     

Study on ultrasonic induced encapsulating emulsion polymerization in the presence of nanoparticles

In this paper, the ultrasonic induced encapsulating emulsion polymerization technique was used to prepare polymer/inorganic nanoparticle composites. The main affecting factors in ultrasonic induced encapsulating emulsion polymerization were studied systematically. The experimental results suggested that the pH value, the type of monomers, the type, content, and surface properties of nanoparticles, the type and concentration of surfactant have great influence on the ultrasonic induced encapsulating emulsion polymerization and the obtained latex stability. If selecting cationic emulsifier (such as cetyl trimethylammonium bromide), low water soluble monomer (such as n‐butyl acrylate and styrene), and hydrophobic nano silica, the inorganic nanoparticles could be encapsulated by polymers through ultrasonic irradiation successfully under alkalescent condition, forming a novel polymer/inorganic nanoparticles composite. The mechanism of ultrasonic induced encapsulating emulsion polymerization and the composite latex stabilization are proposed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1130–1139, 2001     

细乳液聚合最新研究进展

随着高分子合成技术的迅速发展,乳液聚合法的发展创新趋势较为明显,其聚合过程对商品聚合物的生产至关重要,所制备出的聚合物乳液可直接用作水性涂料和胶粘剂等。文中具体介绍了细乳液聚合体系的设计方法、聚合过程及稳定机理,重点综述了近年来细乳液聚合在高固含量细乳液制备、纳米复合材料制备（荧光聚合物纳米粒子、有机 /无机纳米复合材料）及聚合物空心球或微球制备等方面的研究进展。     

Inifer surfactants in emulsion polymerization

Thiol-ended non-ionic surfactants, used in combination with t-butyl hydroperoxide are components of a redox system able to initiate the emulsion polymerization of styrene, as well as control the molecular weight by transfer. Most of the surfactants remain as side products in the water phase, while multimodal molecular weight distributions of polymer are observed depending on the structure of the surfactant, the conversion of the monomer and the process used for feeding the reactor. The maximum incorporation yield of these reactive surfactants in the polymer is around 40%.     

Growth mechanism and pH-regulation characteristics of composite latex particles prepared from Pickering emulsion polymerization of aniline/ZnO using different hydrophilicities of oil phases

A Pickering emulsion polymerization of aniline, using different hydrophilicities of oil phases, was stabilized by ZnO nanoparticles and performed to synthesize composite latex particles of polyaniline/ZnO. Ammonium peroxydisulfate (APS) was used as an oxidizing agent. The morphologies and growth mechanisms of the resulted composite latex particles were studied. The pH-regulation capacity of the composite latex particles was discussed. When toluene was used as the oil phase, the composite latex particles showed hollow structure, irregular morphology, and hundreds of nanometer in size. It was ascribed to the polymerization of aniline on the interfaces of droplets/water. ZnO nanoparticles, with 50-100 nm in size, acted as surfactants to stabilize the emulsion. When THF was used as an oil phase, the composite latex particles showed spherical morphology and enwrapping ZnO nanoparticles. It was attributed to the homogeneous nucleation of polyaniline in the aqueous phase. ZnO nanoparticles acted as templates for the polyaniline particles. The stability of the Pickering emulsion polymerization was affected by the volume ratio of the oil phase to water. The aqueous solution with pH 3-9 could simply be regulated to about pH 7 by the composite latex particles. It was contributed by the dissolution of ZnO nanoparticles and doping-dedoping of polyaniline in the acidic and alkaline aqueous solutions.     

Gemini and Bicephalous Surfactants: A Review on Their Synthesis,Micelle Formation,and Uses

The use of surfactants in polymerization reactions is particularly important, mainly in emulsion polymerizations. Further, micelles from biocompatible surfactants find use in pharmaceutical dosage forms. This paper reviews recent developments in the synthesis of novel gemini and bicephalous surfactants, micelle formation, and their applications in polymer and nanoparticle synthesis, oil recovery, catalysis, corrosion, protein binding, and biomedical area, particularly in drug delivery.     

新型带有磺酸基团的高分子表面活性剂的制备

采用COBF[his（aqua）bis（dinuomboryl）dimethyl yoximato）cobalt（II）]为催化剂,AIBN为引发剂,以甲基丙烯酸丁酯、2-丙烯酰胺基-2-甲基-丙磺酸,甲基丙烯酸-β-2-羟乙酯等合成了带有磺酸基团和羟基的高分子表面活性剂。运用红外光谱IR和-HNMR对合成的产物进行了结构表征,测定了聚合物的表面张力、临界胶束浓度,结果表明,合成的聚合物具有良好的表面活性。把得到的聚合物用于乳液聚合,通过动态光散射和原子力显微镜测定乳液的粒径、观察形貌,乳胶粒粒径分布均匀。     

表面引发原子转移自由基聚合合成聚苯乙烯接枝纳米SiO2复合乳液

采用偶联剂对纳米SiO2粒子表面进行处理,将原子转移自由基聚合(ATRP)引发剂引入到SiO2粒子表面合成大分子引发剂,通过细乳液聚合工艺制备了相对分子质量分布窄的聚合物基纳米SiO2复合乳液,利用红外光谱(FT-IR)、X射线光电子能谱(XPS)和凝胶色谱(GPC)等对复合乳液粒子及表面接枝聚苯乙烯进行了表征分析。结果表明:聚合物的相对分子质量在反应过程中随单体转化率的增大呈线性增长趋势,相对分子质量分布较窄(Mw/Mn=1.34),接枝在纳米SiO2粒子表面聚苯乙烯的分子大小比较均匀;TEM和SEM观察表明:通过合成复合乳液使纳米SiO2粒子在涂膜中达到均匀的单分散状态;所合成的纳米复合粒子在功能涂层材料方面具有良好的应用潜能。     

以SiO2纳米粒子为种子的甲基丙烯酸甲酯乳液聚合

本文采用SiO2纳米粒子作为种子进行了甲基丙烯酸甲酯的乳液聚合。初步探讨了此类种子乳液聚合的过程；也分析了SiO2的用量对所生成的残渣率的影响，SiO2在残渣中的实际含量均比在乳液聚合物中略高，这是由于总有一些单体转移到不含SiO2的自由胶束中进行聚合而造成的。所得的复合乳液聚合物的力学和热学性能测试结果表明材料的这两种性能均随SiO2含量的增加而降低。     

γ-甲基丙烯酰氧丙基三(三甲基硅氧基)硅烷的制备及其乳液聚合研究

通过 γ-甲基丙烯酰氧丙基三甲氧基硅烷 ( KH-5 70 )与三甲基氯硅烷共水解 ,进一步发生缩合反应 ,制备了γ-甲基丙烯酰氧丙基三 (三甲基硅氧基 )硅烷。并通过乳液聚合法制备了该单体的自聚乳液 ,对聚合工艺进行了初步探讨 ,用红外光谱对聚合产物进行了表征。同时 ,研究了乳化剂的种类及用量对反应的影响 ,发现采用有机硅乳化剂和阴离子乳化剂复配的乳化体系 ,可得到稳定性强、粒度适中的自聚乳液。