摘要
采用表面引发原子转移自由基聚合(SI-ATRP)的方法合成具有温度响应的杂化颗粒SiO_2-PNIPAM(PNIPAM:聚(N-异丙基丙烯酰胺),通过傅里叶变换红外(FTIR)光谱、扫描电镜(SEM)、热失重(TGA)、动态光散射(DLS)对接枝前后的杂化颗粒进行表征与分析,结果表明:SiO_2-PNIPAM为单分散的球形颗粒,具有温度响应性,最低临界溶液温度(LCST)为30℃,接枝率为103.7%。讨论了不同种类阴离子各浓度梯度下颗粒润湿性的变化,结果表明,二价的阴离子对其影响更为显著。以SiO_2-PNIPAM为乳化剂制备的Pickering乳液在40和10℃时稳定性有着明显的差异,此外,水油界面吸附的颗粒絮凝程度对乳液的稳定性有着显着的影响,改变不同阴离子种类及浓度,实现不同程度的静电作用和溶剂化效应引起盐析的共同作用来调控颗粒的絮凝程度,从而研究其对乳液稳定性的影响。
Thermoresponsive hybrid particles of SiO_2-PNIPAM（PNIPAM： poly（N-isopropyl acrylamide） were synthesized by surface initiated atom transfer radical polymerization（SI-ATRP）. The structure of hybrid particles was characterized by Fourier transform infrared（FTIR） spectroscopy and scanning electron microscopy（SEM）.The grafting ratio of PNIPAM on the silica surface was about 103.7% as measured by thermogravimetric analysis（TGA）. The thermoresponsive behavior of monodisperse hybrid particles was analyzed by dynamic light scattering（DLS）, and its lower critical solution temperature（LCST） is 30 ℃. The influence of anions on the wettability of hybrid particles was studied by measuring the surface contact angle. A large stability difference of the emulsion based on SiO_2-PNIPAM exists between 40 and 10 ℃. The degree of flocculation of hybrid particles shows a significant influence on the stability of the emulsion. The emulsion stability is dependent on the electrostatic interaction and salting out caused by the solvation effect. This stability is tunable by introducing different anions at different concentrations.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2016年第3期763-770,共8页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(51103117)
陕西省自然科学基金(2013JQ2010,2013/M2012)
西北工业大学基础研究基金(3102014JCQ01089)资助项目
