Acta Phys. -Chim. Sin. ›› 2007, Vol. 23 ›› Issue (02): 139-144.doi: 10.1016/S1872-1508(07)60011-4

• ARTICLE •     Next Articles

Mesoscopic Simulation of the Phase Separation on Triblock Copolymer in Aqueous Solution

ZHANG Xiu-Qing;YUAN Shi-Ling;XU Gui-Ying;LIU Cheng-Bu   

  1. Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, P. R. China;Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China
  • Received:2006-07-18 Revised:2006-10-10 Published:2007-02-01
  • Contact: YUAN Shi-Ling E-mail:shilingyuan@sdu.edu.cn

Abstract: The microphase separation dynamics of triblock copolymer surfactant [(ethylene oxide)27(propylene oxide)61-(ethylene oxide)27](P104) in aqueous solution was simulated by a dynamic variant of mean-field density functional theory for Gaussian chains. Different morphologies depending on the simulation concentration and time were shown in low concentration (φ<35%). With the increase of the concentration, the self-assemble aggregates changed from spherical micelles, micellar clusters, to disk-like micelles. (1) In the spherical micellar region (5%-10%, φ), the result of the simulation was similar to that of the experiment in that micelle was a dense core consisting mainly of PPO and a hydrated PEO swollen corona. (2) Due to the coalescence among spherical micelles, larger micellar clusters are formed in a concentration ranging from 11% to 15%(φ). (3) Owing to the attractions between the PEO coronas of micellar clusters, series of disk-like micelles were found above the concentration 16%(φ). The order parameters showed that the phase separation of spherical micelles was easily formed, while the micellar cluster or disk-like micelles required a longer time to acquire steady equilibrium.

Key words: block copolymer, Mesoscopic simulation, Micelle