Simple model for chain packing and crystallization of soft colloidal polymers.

We study a simple bead-spring polymer model exhibiting competing crystallization and glass transitions. Constant-pressure molecular dynamics simulations are employed to study phase behavior and morphological order. For adequately slow quench rates, chain systems exhibit a first-order phase transition (crystallization) below a critical temperature T=T(cryst). We observe the formation of close-packed crystallites of FCC and/or HCP order, separated by domain walls, twin defects, and amorphous regions. Such crystal structures closely resemble the corresponding ordered morphologies of athermal polymer packings: fully flexible chains retain random-walk-like configurations in the crystalline state and do not form lamellae, while semiflexible chains do form lamellae. The model presented here is well suited to the modeling of granular and colloidal polymers, in particular for elucidating the factors that dictate the formation of specific ordered morphologies.