摘要
报告一个简便、有效的方法在溶液中构筑聚异丙基丙烯酰胺(PNIPAM)包裹聚苯乙烯(PS)的核壳结构和PNIPAM空心球.方法的要点是利用憎水相互作用,将憎水性的偶氮异丁腈引发剂集中在PS球周围,让分散在水相中的单体异丙基丙烯酰胺和交联剂甲叉双丙烯酰胺在PS球表面发生聚合.控制反应温度,利用聚异丙基丙烯酰胺聚合物在水溶液中的独特的热行为,即当温度升高到32℃以上时会突然发生亲水到憎水的转变而产生沉淀粘附在PS球表面上形成核壳结构.用氯仿溶解聚苯乙烯核制备了聚异丙基丙烯酰胺空心球.
This paper has reported a facile and effective way of fabricating Polystyrene/poly （Nisopropylacrylamide） （PS/PNIPAM） core-shell particles and the corresponding PNIPAM hollow spheres. We also explained its formation mechanism and characterized the average hydrodynamic diameter of thermosensitve PS/ PNIPAM core-shell particles as a function of temperature, we found that the average hydrodynamic diameter of thermosensitve PS/PNIPAM core-shell particles changed from 435 nm to 220 nm as the temperature increased from 25 ℃ to 50 ℃. Their morphology and structure were characterized by Transmission Electron Microscope （TEM）, Dynamic light scattering （DLS） and Fourier-transform infrared （FTIR） spectroscopy etc. In this process, the initiator azodiisobutyronitrile is dispersed around the surface of the PS particles and the polymerization of NIPAM and the crosslinker methylene bisacrylamide （MBA） takes place at the periphery of the PS nanoparticles due to the hydrophobic interaction. The key fact used in this process is the unique character of PNIPAM, namely, the hydrophilic PNIPAM will turn to hydrophobic when temperature rises to 32 ℃, which is more favorable for them to adhere to the PS particles as a result of their hydrophobicity. Meanwhile, the hollow PNIPAM spheres were obtained by etching the PS core with chloroform （CHCl3）. In addition, the core-shell particles might have a potential application in catalysis area as a support; the hollow spheres also could be used as a away release capsule.
出处
《南京大学学报（自然科学版）》
CAS
CSCD
北大核心
2007年第5期483-488,共6页
Journal of Nanjing University（Natural Science）
基金
国家自然科学基金(20571040)
江苏省自然科学基金重点项目(KB2006717)
关键词
聚异丙基丙烯酰胺
聚苯乙烯
核壳聚合物
合成
poly（N-isopropylacrylamide）, polystyrene, core-shell polymer, synthesis
