Morphology and conformation analysis of self-assembled triblock copolymer melts

We used the dissipative particle dynamics method to simulate the self-assembly of symmetric triblock copolymers of the type ABA. Depending on the volume fraction of the end blocks f(A), several mesophases including lamellar, perforated lamellar, gyroid hexagonal cylinders and bcc spherical micelles were obtained. The order-disorder transition (ODT) at f(A) = 0.5 was found to be about chi N = 19.8. The ODT for the cylindrical mesophase at symmetrical points on the phase diagram had different values, indicating asymmetry in the phase diagram. We were also able to estimate the bridge fraction in the different mesophases. They range from about 0.44 for the lamellar mesophase to about 0.75 for the spherical micelles. Our simulation results are in good agreement with previously reported theoretical calculations and experimental observations.