Gao Yong, Xiang Zhe, Zhao Xi, Wang Guoxiang, Qi Chenze
Key Laboratory of Alternative Technologies for Fine Chemicals Process of Zhejiang Province, College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang 312000, China.
College of Chemistry and Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education; Key Laboratory of Polymeric Materials & Application Technology of Hunan Province, Key Laboratory of Advanced Functional Polymeric Materials of College of Hunan Province, Xiangtan University, Xiangtan, Hunan Province 411105, China.
Langmuir. 2021 Oct 12;37(40):11695-11706. doi: 10.1021/acs.langmuir.1c01609. Epub 2021 Sep 27.
Responsive Pickering emulsions exhibit promising application in industry owing to the integration of the high storage stability with on-demand demulsification. In this study, stimuli-responsive Pickering emulsions stabilized by poly[oligo(ethylene glycol) methyl ether methacrylate]--poly(diacetone acrylamide) (ED) worms were indicated, in which ED worms were prepared reversible addition-fragmentation chain transfer-based aqueous dispersion polymerization using thermo-sensitive POEGMA as both the stabilizer block and macro-chain transfer agent. The factors influencing the morphologies of copolymers during polymerization-induced self assembly have been investigated. A series of different morphological polymer nanoparticles including spheres, worms, and vesicles could be produced through rational synthesis. ED worms demonstrated excellent emulsifying performances and could be used as emulsifiers to form -dodecane-in-water Pickering emulsions at a low content. The formed -dodecane-in-water Pickering emulsions revealed a slow demulsification at pH 10 or 70 °C or pH 10/70 °C combinations, and several hours were needed for the demulsification of Pickering emulsions. However, -dodecane-in-water Pickering emulsions displayed a rapid demulsification (∼10 min) at an elevated temperature, such as 90 °C. The different demulsification rates were attributed to different sensitivities of ED worms to external stimuli. Pickering emulsions integrating a rapid responsive demulsification with a slow one would be well satisfactory on different occasions.
响应型Pickering乳液由于兼具高储存稳定性和按需破乳的特性，在工业领域展现出了广阔的应用前景。在本研究中，我们展示了由聚[聚（乙二醇）甲基醚甲基丙烯酸酯] - 聚（双丙酮丙烯酰胺）（ED）蠕虫状胶束稳定的刺激响应型Pickering乳液，其中ED蠕虫状胶束是通过基于可逆加成-断裂链转移的水分散聚合反应制备的，使用热敏性的聚乙二醇甲基丙烯酸酯作为稳定剂嵌段和大分子链转移剂。研究了聚合诱导自组装过程中影响共聚物形态的因素。通过合理的合成方法，可以制备出一系列不同形态的聚合物纳米颗粒，包括球形、蠕虫状和囊泡状。ED蠕虫状胶束表现出优异的乳化性能，可在低含量下用作乳化剂来形成水包十二烷Pickering乳液。所形成的水包十二烷Pickering乳液在pH值为10或70°C或pH值为10/70°C组合条件下破乳缓慢，Pickering乳液破乳需要数小时。然而，水包十二烷Pickering乳液在高温（如90°C）下表现出快速破乳（约10分钟）。不同的破乳速率归因于ED蠕虫状胶束对外部刺激的不同敏感性。兼具快速响应破乳和缓慢破乳特性的Pickering乳液在不同场合下将非常令人满意。
