基于可逆共价键构建响应性乳化剂及其稳定的乳液

发布时间：2018-03-30 23:32

本文选题：动态共价键　切入点：乳液　出处：《湘潭大学》2017年硕士论文

【摘要】：乳液是两种不相容的液体在乳化剂存在下经乳化作用形成的热力学上稳定的分散体系。刺激响应性乳液是指乳液的形成和去乳化可通过外界条件,如温度、酸碱性、离子强度的改变来调控。具有响应性去乳化的乳液在采油、界面反应等领域有重要应用。本论文基于B-O可逆共价键构建刺激响应性乳化剂,借助B-O共价键的可逆性调控乳液的稳定性,从而制备出pH及糖响应乳液。论文研究内容主要包括以下两个部分:(1)核动态共价键交联聚合物纳米粒子稳定的响应性Pickering乳液。首先通过可逆加成断裂链转移(RAFT)聚合方法合成聚(N,N-二甲基丙烯酰胺)-b-聚(丙烯酰氨基苯硼酸)(PDMA-b-PAPBA)嵌段聚合物。在嵌段聚合物的水溶液中,利用PDMA-b-PAPBA中苯硼酸(PBA)侧基基团与聚乙烯醇(PVA)二醇基团之间复合,获得具有核-壳结构、核可逆共价键交联的聚合物纳米粒子(CCPNs)。以CCPNs为粒子乳化剂,正癸醇为油相,水为连续相制备水包油Pickering乳液。由于B-O动态共价键的pH及葡萄糖响应性,CCPNs的结构和形貌随pH和葡萄糖浓度变化而变化。CCPNs的界面活性随粒子结构和形貌的变化而变化,并赋予其稳定的乳液pH及葡萄糖响应性去乳化特性。详细研究了CCPNs结构刺激响应性以及CCPNs稳定的Pickering乳液的刺激响应性去乳化特性。(2)动态接枝共聚物油-水界面原位生成及其稳定的响应性乳液。首先通过RAFT聚合方法合成聚(N,N-二甲基丙烯酰胺)-ran-(聚丙烯酰氨基苯硼酸)(PDMA-ran-PAPBA)无规共聚物和端双羟基的聚苯乙烯(PS(OH)2)。将(PDMA-ran-PAPBA)和PS(OH)2分别以一定浓度溶于碱性水和甲苯,并将两种聚合物溶液以一定体积混合并经高速均质搅拌后得到稳定的水包油乳液。借助(PDMA-ran-PAPBA)中苯硼酸(PBA)侧基基团与PS(OH)2链端二醇基团之间复合,PS聚合物通过B-O键接枝到(PDMA-ran-PAPBA)骨架上,从而在油水界面原位形成两亲性可逆共价接枝共聚物。形成的两亲性可逆共价接枝共聚物吸附在分散相液滴表面并稳定分散相液滴。详细研究了聚合物浓度对乳液形成影响及pH和葡萄糖对乳液稳定性的影响。
[Abstract]:Emulsion is a thermodynamically stable dispersion system formed by emulsification of two incompatible liquids in the presence of emulsifier. The emulsion with reactive deemulsification has important applications in oil recovery, interfacial reaction and other fields. In this paper, a stimulative and responsive emulsifier is constructed based on B-O reversible covalent bond. The stability of emulsion is regulated by the reversibility of B-O covalent bond. Thus, pH and sugar responsive emulsions were prepared. The main contents of this thesis include the following two parts: 1: 1) the stable responsive Pickering emulsion of nuclear dynamic covalent crosslinked polymer nanoparticles. Firstly, the polymer was polymerized by reversible addition of breaking chain transfer (RAFT). Poly (N (N) N-dimethylacrylamide) -b-Poly (acrylaminoboric acid) block polymer was synthesized by the method. In the aqueous solution of the block polymer, the block polymer PDMA-b-PAPBA was synthesized. The polymer nanoparticles with covalent structure and reversible covalent bond crosslinking in PDMA-b-PAPBA were prepared by recombination of the side group of phenoboric acid (PBA) and polyvinyl alcohol (PVA) diol group. CCPNs was used as particle emulsifier and decanol as oil phase. Oil in water Pickering emulsion was prepared with water as a continuous phase. The structure and morphology of B-O dynamic covalent bond and glucose responsive CCPNs changed with the change of pH and glucose concentration. The interfacial activity of CCPNs changed with the change of particle structure and morphology. The stable emulsion pH and glucose-responsive deemulsification properties were given. The stimuli response of CCPNs structure and CCPNs stable Pickering emulsion were studied in detail. Site formation and stable responsive emulsions. Firstly, poly (N- (N-)-dimethylacrylamide)-ran-ran- (polyacrylamide) random copolymers and dihydroxyl-terminated polystyrene (PS)-OH _ (2) were synthesized by RAFT polymerization. The PS(OH)2 and PMA-ran-PAPBA were prepared in a certain amount, respectively. Concentration dissolved in alkaline water and toluene, A stable oil-in-water emulsion was obtained by mixing the two polymer solutions in a certain volume and stirring at high speed and homogeneously. The composite PS polymer was grafted onto the framework of the PDMA-ran-PAPBA with the help of the side group of phenylborate group and the diol group at the end of the chain of PS(OH)2, and the polymer was grafted onto the framework of the PDMA-ran-PAPBA by B-O bond. The amphiphilic reversible covalent graft copolymers were formed at the oil-water interface. The amphiphilic reversible covalent graft copolymers were adsorbed on the surface of dispersed droplets and stabilized the dispersed droplets. The effects of polymer concentration on emulsion were studied in detail. The effects of pH and glucose on the stability of emulsion were investigated.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O648.23

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