EFFECTS OF INORGANIC SALTS AND pH ON MICELLAR MORPHOLOGY OF PCL-A-PEO BLOCK COPOLYMERS IN AQUEOUS SOLUTION
It has been reported that for micelles of poly (ferrocenylsilane)-containing block copolymer with a crystalline core the block copolymer micelles can be used as buliding blocks to construct block comicelles. This finding is of great importance, since it provides a way for preparing composite micelle and controlling the structure of complex micelles. In this manscript, inorganic salts were added into the aquesous solution of poly(ecaprolactone)-6-poly(ethylene oxide) (PCL-fc-PEO) block copolymers with pre-formed spherical semicrystalline micelles, and the micellar morphology and size were examined by TEM and DLS, respectively. It is observed that inorganic salts can trigger the growth of the semicrystalline spherical micelles to form cylinderical or lamellar micelles. The effect of various inorganic salts was investigated. The result shows that the ability of inorganic salts to induce morphological transformation of PCL-6-PEO micelles is basically in accordance with their positions in Hofmeister series. It is also found that the pH value of the solution affects the micellar morphology. In alkali solution the size of the micelles becomes larger, indicating that coalescence of different micelles occurs, whereas in acidic solution the micellar size almost remains unchanged. The growth mechanism for formation of cylinderical and lamellar micelles was discussed in terms of the morphology observed. It shows that the lamellar micelles are formed by growth of spherical micelles on a single cylinderical micelle, instead of direct mergence of different cylinderical micelles or spherical micelles.
Wei-Na He Jun-Ting Xu Bin-Yang Du Zhi-Qiang Fan
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science
国际会议
PP’2010，Jinan International Symposium on Polymer Physics(2010济南国际高分子物理学术研讨会)
济南
英文
132
2010-06-06（万方平台首次上网日期，不代表论文的发表时间）