文献类型：期刊文献

中文题名：多重响应性嵌段共聚物稳定的乳液相反转行为

英文题名：Multi-Responsive Phase Inversion of Emulsions Stabilized by Responsive Block Copolymers

作者：黄利民[1];彭文丽[1];韩霞[1];刘洪来[1]

机构：[1]华东理工大学化学与分子工程学院,上海200237

年份：2020

卷号：33

期号：5

起止页码：460

中文期刊名：功能高分子学报

外文期刊名：Journal of Functional Polymers

收录：CSTPCD;;北大核心:【北大核心2017】；CSCD:【CSCD_E2019_2020】；

基金：国家自然科学基金(91534103);中国石油科技创新基金项目(2017D-5007-0204)。

语种：中文

中文关键词：两亲性;嵌段共聚物;乳液;刺激响应性;相反转

外文关键词：amphiphilic;block copolymer;emulsion;stimuli-responsive behavior;phase inversion

摘要：利用聚乙二醇单甲醚(mPEG)和聚苯乙烯(PS)的溶剂响应性、双硫键(S?S)的氧化还原响应性,设计合成了具有溶剂响应性和氧化还原响应性的两嵌段共聚物聚乙二醇单甲醚-b-聚苯乙烯(mPEG-S-S-PS)。通过核磁共振氢谱和凝胶渗透色谱表征了mPEG-S-S-PS的结构与组成;通过溶剂分散和显微镜观察对乳液的相反转行为进行了研究。研究表明,该嵌段共聚物体系具有两亲性,可稳定油水两相体系形成乳液。对于甲苯-水体系,甲苯是mPEG和PS的非选择性良溶剂,嵌段共聚物无论是先分散在甲苯中还是先分散在水中都形成油包水(W/O)型乳液;但对于环己烷-水体系,由于环己烷是PS的选择性良溶剂,当mPEG-S-S-PS先分散在水中时,形成水包油(O/W)型乳液;当mPEG-S-S-PS先分散在环己烷中时,形成W/O型乳液。基于mPEG-S-SPS的氧化还原响应性,通过添加还原剂二硫苏糖醇(DTT)或谷胱甘肽(GSH)可诱导甲苯-水乳液体系发生相反转,由W/O型变为O/W型乳液。通过调节油水体积比可诱导乳液的相反转,当水体积分数(φw)小于0.7时,乳液为W/O型;但当φw≥0.7时,体系发生突变反相,得到O/W型乳液。
An amphiphilic block copolymer(mPEG-S-S-PS)with a hydrophilic poly(ethylene glycol)methyl ether(mPEG)block,a hydrophobic polystyrene(PS)block and a disulfide linker was synthesized via atom transfer radical polymerization(ATRP).The structure and composition of mPEG-S-S-PS were characterized by nuclear magnetic resonance spectroscopy(NMR)and gel permeation chromatography(GPC).Through solvent dispersion and microscopic observation,phase inversion of emulsions stabilized by mPEG-S-S-PS was studied.Thanks to the amphiphilic property of mPEG-S-S-PS and the insolubility of PS block in cyclohexane,the diblock copolymer self-assembled to form micelles composing of PS cores and mPEG coronas in water and to form inverse micelles composing of mPEG cores and PS coronas in cyclohexane.Therefore,for cyclohexane-water biphasic system with equal volumes,W/O type emulsions were preferred for copolymer initially dissolved in cyclohexane,while for copolymer initially dissolved in water,O/W type emulsions were obtained.However,for toluene-water biphasic systems,W/O type emulsions were always obtained no matter where the copolymers were dissolved because toluene was a non-selective and good solvent for both PS and mPEG blocks.Based on redox responsiveness of mPEG-S-S-PS copolymer,the addition of reducing agent DTT or GSH could induce the phase inversion of toluene-water emulsion from W/O type to O/W type.The catastrophic phase inversion was obtained in this system by adjusting the oil-water volume ratio.When the fraction of water volume(φw)was less than 0.7,the emulsion was W/O type.However,whenφw≥0.7,a catastrophic phase inversion occurred where the system shifted in the opposite direction and O/W type emulsion was obtained.These results will have potential applications in the field of controlling drug release.