Simulations of Linear Block Copolymers in Liquid Chromatography at the Critical Condition

Abstract

Liquid chromatography at the critical condition (LCCC) is often used for analysis of block copolymers where solvent conditions are chosen such that the molecular weight dependence of one of the blocks upon retention is negligible. In this work, Gibbs ensemble Monte Carlo simulations are used to determine partition constants of block copolymer chains moving between mobile and spherical- or cylindrical-shaped stationary phases. With these simulations, we explore the limitations of using LCCC to characterize the molecular weight distribution of block copolymers with various sequences. Thermodynamic properties of transfer are shown to vary with sequence and are dependent on temperature. Informed by the monomer-level adsorption analysis, new calibration equations relating partition constant and sequence are proposed.