Simulation on the Phase Separation Behavior of Triblock Copolymers EO20PO70EO20 by Dissipative Particle Dynamics

Mesoporous materials were synthesized by template possess regular channel structure, narrow pore size distribution and high surface area, which are greatly related to the self-assembly of template. In order to investigate the template aggregates in the preparation process of mesoporous materials, dissipative particle dynamics(DPD) was adopted to simulate phase behaviors of EO20PO70EO20 (P123) in water, ethanol/water solutions and silica sol. In the aqueous solution, P123 formed different morphologies at different mass fractions and four aggregation types were observed: spherical micelle(10% P123), ellipsoid micelle(20% P123), cylindrical micelle(30% P123) and 3D-cubic phase(50% P123). In the ethanol/water system, the stability of template micelles decreased with the increasing of ethanol concentration. In the silica sot, the micelle did not form when the mass fraction of P123 was less than 5%; the 3D spherical structure was observed when the mass fraction of P123 increased to 10%; and the 3D ellipsoid structure(20%), 3D-cubic phase(40%) and lamellar phase(60%) formed with the increasing of P123 mass fraction. Simulation results obtained in this work consisted with the experimental data reported in the literatures, which indicated that DPD simulation method can be used to study the influence of template on the structure of mesoporous material and guide the preparation of mesoporous material.