PS/CaCO_3复合纳米粒子及PS纳米空心球的制备研究

PREPARATION OF PS/CaCO_3 COMPOSITE NANOPARTICLES AND PS HOLLOW NANO-SPHERES

以CaCO3为核,采用原位乳液聚合法合成了表面接枝型和交联型PS/CaCO3复合纳米粒子,然后用稀盐酸刻蚀,得到PS纳米空心球.考察了乳化剂类型和用量、引发剂加入方式、加料间隔对乳液稳定性以及复合粒子收率、PS接枝效率的影响,并采用TGA、FT-IR和TEM等手段对刻蚀前后粒子的组成及形貌进行了表征.结果表明,阳离子型乳化剂更有利于乳液体系的稳定性;CTAB用量为3.7%~5.5%时,可获得较高的收率和接枝效率,随CTAB用量增加,粒径减小,分布变宽;AIBN应避免和单体、CaCO3粒子一起超声波处理,否则会导致不可逆凝聚;随着加料间隔延长,收率和接枝效率下降,一步加料法可获得具有高收率和高接枝效率(或交联程度)的复合粒子;经刻蚀,两种类型的复合粒子均可以制得空心粒子,但经过交联的聚合物外壳具有更好的尺寸和形状稳定性,刻蚀后仍然能保持球状的外形.

Surface-grafted or cross-linked polystyrene(PS)/CaCO_3 composite nanoparticles with nanometer CaCO_3 as the core were synthesized by in situ emulsion polymerization.Subsequently,PS hollow nano-spheres were prepared by etching the core with dilute hydrochloric acid.The effects of the type and amount of emulsifier,the addition method of initiator and the feeding interval on emulsion stability,the yield and grafting efficiency were investigated.Composition and morphology of composite nanoparticles before and a...