Crystallization-driven Fibril Growth Of Diblock Copolymers Studied By Monte Carlo Simulations

Quasi-one-dimensional crystal growth of diblock copolymers is a fundamental issue in the investigation of nanotechnology and neurodegenerative diseases. We performed dynamic Monte Carlo simulations of lattice polymers to study the crystallization-driven fibril crystal growth of diblock copolymers under two circumstances of solutions:sporadic crystals with the feeding mode of almost constant polymer concentrations, and massive crystals with the depleting mode of decaying polymer concentrations. We confirmed that anisotropic driving forces are the necessary conditions for a steady growth of fibril crystals. The lamellar crystal width is confined by the non-crystalline block below a critical concentration that decreases with the decrease of the non-crystallizable compositions. In the depleting mode, the long-axis dimension at the early stage of fibril crystal growth can be fitted well by an exponential-decay function of time, and the growth rates decrease almost linearly with polymer concentrations by following the growth rates in the feeding mode, appearing as consistent with our previous simulation results of homopolymer solutions.