Department of Chemistry & Chemical Biology, McMaster University, Hamilton, ON, Canada L8S 4M1.
Langmuir. 2010 Dec 7;26(23):17926-35. doi: 10.1021/la102867v. Epub 2010 Oct 28.
This Article describes a new microencapsulation method based on a Pickering emulsion templated interfacial atom transfer radical polymerization (PETI-ATRP). Cationic LUDOX CL nanoparticles were coated electrostatically with an anionic polymeric ATRP initiator, poly(sodium styrene sulfonate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate) (PSB), prepared by radical copolymerization of sodium styrene sulfonate and 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM). The resulting PSB-modified CL particles were surface active and could be used to stabilize oil-in-water Pickering emulsions. ATRP of water-soluble cross-linking monomers, confined to the oil-water interface by the surface-bound PSB, then led to nanoparticle/polymer composite shells. This method allowed encapsulation of core solvents (xylene, hexadecane, perfluoroheptane) with different solubility parameters. The microcapsule (MC) wall chemistry could accommodate different monomers, demonstrating the versatility of this method. Double-walled MCs were formed by sequentially carrying out PETI-ATRP and in situ polymerization of encapsulated monomers. The double-walled structure was verified by both transmission electron microscopy (TEM) and scanning transmission X-ray microscopy (STXM).
本文描述了一种新的基于 Pickering 乳液模板界面原子转移自由基聚合（PETI-ATRP）的微胶囊化方法。阳离子 LUDOX CL 纳米颗粒通过静电作用包覆阴离子聚合 ATRP 引发剂，聚（苯乙烯磺酸钠-co-2-（2-溴异丁酰氧基）乙基甲基丙烯酸酯）（PSB），由苯乙烯磺酸钠和 2-（2-溴异丁酰氧基）乙基甲基丙烯酸酯（BIEM）的自由基共聚制备。所得的 PSB 改性 CL 颗粒具有表面活性，可用于稳定油包水 Pickering 乳液。在水溶性交联单体的 ATRP 中，通过表面结合的 PSB 限制在油水界面内，然后导致纳米颗粒/聚合物复合壳。该方法允许用不同溶解度参数的核溶剂（二甲苯、十六烷、全氟庚烷）进行封装。微胶囊（MC）壁化学可适应不同的单体，证明了该方法的多功能性。通过顺序进行 PETI-ATRP 和封装单体的原位聚合形成了双层 MC。通过透射电子显微镜（TEM）和扫描透射 X 射线显微镜（STXM）都验证了双层结构。
