【摘要】 通过在CaCO3制备过程中加入不同浓度聚苯乙烯磺酸钠(PSS)的方法来控制掺杂进CaCO3粒子中的PSS含量,得到了PSS掺杂量为4%～11%,尺寸均匀的CaCO3球形微粒.在微粒表面仅吸附一层聚烯丙基胺盐酸盐(PAH)后,用乙二胺四乙酸二钠(EDTA)使碳酸钙溶解;释放出的PSS与PAH原位凝聚制备得到了分散良好且完整的聚电解质复合物微胶囊.在所研究的范围内,模板微粒中PSS的含量对微胶囊的形态结构和性能没有明显影响.与传统的层层组装微胶囊相比,聚电解质复合物微胶囊有较好的热稳定性,但在高盐浓度下尺寸收缩程度较大.由于和层层组装微胶囊相比缺乏结合紧密的有序结构,原位凝聚法制备的微胶囊囊壁的截留分子量较大.更多还原

【Abstract】 The fabricating conditions for the in situ coacervated polyelectrolyte microcapsules were optimized,and their influences on the capsule structures and properties were elucidated.Poly（styrene sulfonate）（PSS）doped CaCO₃ was first used as an additive to modify the growth of CaCO₃ microparticles.During this process,the PSS molecules were integrated into the CaCO₃ particles or adsorbed on their surfaces.By changing the feeding concentration of the PSS during the fabrication,the PSS doped CaCO₃ particles with a PSS content of 4%～11% were obtained.After only one layer of poly（allylamine hydrochloride）（PAH）was adsorbed onto the PSS-doped CaCO₃ particles,the templates were dissolved by disodium ethylene diamine tetraacetate dihydrate（EDTA）to liberate the PSS molecules,which in situ coacervated with the coated PAH to form the capsule walls.After complete removal of the templates,intact complex microcapsules were successfully obtained.Results showed that all the CaCO₃ particles with different PSS amount could be used as the templates to fabricate the coacervated microcapsules.The structures of the as-prepared microcapsules were characterized by confocal laser scanning microscopy（CLSM）,transmission electron microscopy（TEM）and scanning force microscopy（SFM）,finding no significant influence of the PSS doped amount in the CaCO₃ particles.Compared with layer-by-layer（LbL）assembled polyelectrolyte microcapsules,the complex microcapsules shrank more seriously in 5 mol/L NaCl solution because their walls have net negative charge which is more sensitively screened by the salt.Due to the repulsion of the negative charge in the capsule walls,the complex microcapsules showed better ability against the thermal induced shrinkage.Because of the less ordered structures compared with the LbL microcapsules,the coacervated walls of the complex microcapsules possessed higher cut-off molecular weight.Therefore,one can conclude that the amount of the doped PSS in the CaCO₃ particles has no significant influence on the structures and properties of the coacervated microcapsules,and thus the method is more attractive in terms of quality control.Moreover,the method can be extended to other polyelectrolyte systems as well,for example,natural biomacromolecules.更多还原