基于碳酸钙模板的特殊形状层层组装微胶囊的制备

Fabrication of Microcapsules with Special Shapes by Layer-by-layer Assembly on CaCO_3 Microparticles

以Na_2CO_3和CaCl_2为原料,聚烯丙基胺盐酸盐(PAH)为添加剂,通过磁力搅拌和超声混合的方式分别制备了两面凸碟形仿血小板形状和纺锤形的碳酸钙微粒.仿血小板形状的碳酸钙微粒为球霰石晶相,而纺锤形碳酸钙微粒为文石晶相.模板微粒中均掺杂了少量PAH.溶液混合方式和PAH添加剂的协同作用导致了特殊形状碳酸钙微粒的形成.以这2种粒子为模板通过层层组装技术分别制备了仿血小板形状和纺锤形微胶囊.得到的微胶囊能够在水中分散良好并保持模板的特殊形状.

Biconvex platelet-like and spindle-like calcium carbonate particles were prepared by mixing Na_2CO_3 and CaCl_2 solutions in the presence of poly（ allylamine hydrochloride）（ PAH） under magnetic stirring and ultrasound treatment,respectively. The platelet-like CaCO_3 particles were vaterites,while the spindle-like ones were mainly aragonites. These two kinds of particles were both doped with small amount of PAH. The formation of CaCO_3 particles with specific shapes was due to the synergistic effect of mixing method and PAH additives. Then platelet-like and spindle-like polyelectrolyte multilayer microcapsules were fabricated via layer-by-layer（ LbL） assembly method using the CaCO_3 particles with corresponding shape as templates. The fabricated micrcapsules could be well dispersed in aqueous medium and maintain their original shapes.