Frank-Kasper Phases of Diblock Copolymer Melts Studied with the DPD Model

We have included the dissipative particle dynamics (DPD) model (i.e., compressible melts of discrete Gaussian chains with the DPD potential) into the newly released C++/CUDA version of PSCF¹, and performed real-space self-consistent field (SCF) calculations of the Frank-Kasper (FK) phases formed by diblock copolymer (DBC) melts based on the DPD model. Comparisons with the SCF results based on the “standard” model (i.e., incompressible melts of continuous Gaussian chains with the Dirac d-function potential) clearly reveal the effects of model differences on the stability of FK phases. This also enables us to unambiguously quantify, using DPD simulations, the fluctuation/correlation effects inherently neglected by the SCF theory, which are important to the low-molecular weight DBCs forming such phases in experiments.