pH响应性阳离子型微凝胶的制备及性质研究  

Synthesis and Properties of pH-Responsive Cationic Microgels

作　　者：孙桂香[1] 张明祖[1] 许杨[1] 陆一鸣[1] 倪沛红[1] 

机构地区：[1]江苏省有机合成重点实验室苏州大学材料与化学化工学部,苏州215123

出　　处：《化学学报》2009年第14期1685-1690,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20474041);江苏省自然科学基金(No.BK2008157);江苏省高校"青蓝工程"科技创新团队及苏州大学"先进化学与生物材料"创新团队资助项目

摘　　要：以甲基丙烯酸-(N,N-二甲氨基)乙酯(DMAEMA)和丙烯酸乙酯(EA)为共聚单体,二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,采用半连续乳液聚合法,制备了具有pH响应性的阳离子型微凝胶,并研究不同聚合条件对所合成的微凝胶性质的影响.利用透射电子显微镜(TEM)、激光粒度分析仪和流变仪对微凝胶进行一系列表征.研究了介质pH值对微凝胶的形态、平均粒径、zeta电位、溶液浊度(透光率)的影响,以及NaCl盐溶液对微凝胶分散体系稳定性的影响.结果表明,这类阳离子型微凝胶体系具有良好的pH响应性,在pH=7左右发生相转变.此外,研究表明不同浓度NaCl溶液对微凝胶的稳定性有一定影响,临界絮凝浓度约为1.3mol·L-1.A series of pH-responsive cationic microgels have been synthesized via semi-batch emulsion polymerization with 2-（N,N-dimethylamino）ethyl methacrylate （DMAEMA） and ethyl acrylate （EA） as comonomers, and ethylene glycol dimethaerylate （EGDMA） as cross-linker. The effects of various conditions on the emulsion polymerization and the stability of microgels were studied in detail. The resultant microgels were characterized by transmission electron microscopy （TEM）, dynamic light scattering （DLS） and rheometry. The pH-responsive behavior of the microgels was investigated by the measurements of Z-average diameter, zeta potentials, and the solution transmittance of the microgels at different pH values. Furthermore, the influence of NaCl solution on the stability of the microgels in aqueous solution was also studied. All the results show that the cationic microgels possess well pH-responsive property, and the phase variation happens at pH = 7. Furthermore, the addition of NaCl solution can influence the stability of the microgels and the critical flocculent concentration is about 1.3 mol·L^-1.

关 键 词：乳液聚合 阳离子型微凝胶 PH响应性 甲基丙烯酸-(N N-二甲氨基)乙酯 

分 类 号：O648.17[理学—物理化学]