Slovak Academy of Sciences, Polymer Institute, Dúbravská cesta, Bratislava, Slovakia.
Adv Colloid Interface Sci. 2010 Apr 22;156(1-2):35-61. doi: 10.1016/j.cis.2010.02.006. Epub 2010 Feb 12.
Inverse monomer miniemulsions can be generated by sonification of the polar monomer, water, stabilizer and costabilizer in organic solvents as the unpolar continuous phase. The inverse miniemulsion obtains its stability by using a combination of effective surfactant and osmotic pressure agent, so called lypophobe, which is practically insoluble in the continuous phase and prevents the minidroplets from Ostwald ripening. Inverse miniemulsions are typically sterically stabilized with a nonionic surfactant blend so as to provide a relatively condensed interface. The monomer droplet nucleation proceeds under an uncomplete coverage of the monomer and polymer particles with surfactant. Inverse monomer miniemulsions can be easily polymerized to latexes by using water and oil-soluble initiators. The rate of inverse miniemulsion polymerization of water-soluble monomers increased with increasing both initiator and emulsifier concentrations. The inverse polymerization is very fast and the high conversion is reached during a few minutes. The dependence of the polymerization rate vs. conversion can be described by a curve with the two rate intervals. The abrupt increase in the polymerization rate can be attributed to the increased number of reaction loci and the gel effect. The partitioning of unsaturated monomers between the aqueous and continuous phases favours the contribution of homogeneous nucleation. The desorption of monomeric radicals from the small polymer particles favours the polymerization in the continuous phase. The miniemulsion polymerization and copolymerization is ideal process for the preparation of composite nanoparticles with different structures. This procedure can be used to develop novel thermally responsive polymer microspheres, for example, based on N-isopropylacrylamide monomer. The composite magnetic nanoparticles are prepared by polymerization of both water-soluble and oil-soluble monomers in the presence of water- and oil-soluble iron oxide nanoparticles. The inverse miniemulsion copolymerization of acrylic acid and sodium acrylate in the presence of inorganic nanoparticles and substances produces poly(acrylic acid-co-sodium acrylate)/inorganic phase composite nanoparticles. The presence of hydrophobic monomer in the miniemulsion system favours the formation of hollow nanoparticles. The composite latex particles owned better thermal stability and higher colloidal stability than pure latex particles.
反相单体微乳液可以通过在有机溶剂中超声分散极性单体、水、稳定剂和共稳定剂来制备，其中有机溶剂为非极性连续相。反相微乳液通过使用有效的表面活性剂和渗透压剂（即疏水剂）的组合来获得稳定性，疏水剂在连续相中几乎不溶，防止了微滴的奥斯特瓦尔德熟化。反相微乳液通常使用非离子表面活性剂混合物进行空间稳定，以提供相对致密的界面。单体液滴成核是在单体和聚合物颗粒不完全被表面活性剂覆盖的情况下进行的。反相单体微乳液可以很容易地用水溶性和油溶性引发剂聚合为乳胶。水溶性单体的反相微乳液聚合速率随着引发剂和乳化剂浓度的增加而增加。反相聚合非常快，在几分钟内即可达到高转化率。聚合速率与转化率的关系可以用两条速率区间的曲线来描述。聚合速率的突然增加可归因于反应位置的增加和凝胶效应。不饱和单体在水相和连续相之间的分配有利于均相成核的贡献。单体自由基从小聚合物颗粒上的解吸有利于连续相中的聚合。微乳液聚合和共聚是制备具有不同结构的复合纳米粒子的理想方法。该方法可用于制备新型温敏聚合物微球，例如基于 N-异丙基丙烯酰胺单体。在水溶性和油溶性氧化铁纳米粒子存在下，水溶性和油溶性单体的聚合可制备复合磁性纳米粒子。在无机纳米粒子和物质存在下，丙烯酸和丙烯酸钠的反相微乳液共聚生成聚（丙烯酸-co-丙烯酸钠）/无机相复合纳米粒子。在微乳液体系中存在疏水性单体有利于空心纳米粒子的形成。复合乳胶粒子比纯乳胶粒子具有更好的热稳定性和更高的胶体稳定性。
