Department of Chemical Engineering, Graduate School of Engineering, Tohoku University, Aoba-ku, Sendai, Japan.
Colloids Surf B Biointerfaces. 2012 Apr 1;92:372-6. doi: 10.1016/j.colsurfb.2011.11.005. Epub 2011 Nov 27.
Hollow silica particle was obtained with a vesicle template synthesis in water under ambient conditions in the presence of ammonia. Biomimetic vesicles, liposomes were used, which consisted of a zwitterionic phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and a tiny amount of charged amphiphiles, hexadecylamine (HDA) or dicetylphosphate (DCP). Aggregation of silica occurred for DPPC or cationic DPPC/HDA liposome, whereas well-dispersed hollow silica particle could be obtained for anionic DPPC/DCP liposome. The hollow particle synthesized with the anionic liposome had single-layered and raspberry-like structures. Electrostatic repulsion between anionic vesicles maintained stable dispersion of the as-synthesized particles during the reaction. Formation of the raspberry-like morphology is explained by silica particle precipitation selectively induced around the liposomes under basic conditions due to affinity of silica precursors for the liposomes. Synthesis of well-dispersed hollow silica particle with a raspberry-like morphology is the first report in vesicle template syntheses.
在氨存在的条件下，于室温的水环境中，通过囊泡模板合成法得到了中空硅粒子。仿生囊泡（脂质体）由两性离子磷脂 1,2-二棕榈酰基-sn-甘油-3-磷酸胆碱（DPPC）和少量带电荷的两亲体十六烷基胺（HDA）或二油酰基磷酸胆碱（DCP）组成。对于 DPPC 或带正电的 DPPC/HDA 脂质体，硅发生聚集，而对于带负电的 DPPC/DCP 脂质体，可得到分散良好的中空硅粒子。用阴离子脂质体制备的中空粒子具有单层和覆盆子状结构。在反应过程中，阴离子囊泡之间的静电排斥作用保持了合成粒子的稳定分散。在碱性条件下，由于硅前体对脂质体的亲和力，选择性地在脂质体周围诱导硅粒子沉淀，从而解释了覆盆子状形态的形成。用囊泡模板合成法制备分散良好的具有覆盆子状形态的中空硅粒子，这在该领域尚属首次报道。
