Simulation and theory of self-assembly and network formation in reversibly cross-linked equilibrium polymers.
A simulation model of hard spheres capable of reversible assembly into chains, which then may reversibly cross-link into networks, has been studied through grand canonical Monte Carlo simulation. Effects of varying intra- and interchain bond strengths, chain flexibilities, and restrictions on cross-linking angle were investigated. Observations including chain-length distributions and phase separation could be captured in most cases using a simple model theory. The coupling of chain growth to cross-linking was shown to be highly sensitive to the treatment of cross-linking by chain ends. In some systems, ladderlike domains of several cross-links joining two chains were common, resulting from cooperativity in the cross-linking. Extended to account for this phenomenon, the model theory predicts that such cooperativity will suppress phase separation in weakly polymerizing chains and at high cross-link concentration. In the present model, cross-linking stabilizes the isotropic phase with respect to the nematic phase, causing a shift in the isotropic-nematic transition to higher monomer concentration than in simple equilibrium polymers.
Kindt
James T
JT
Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA. jkindt@emory.edu
D003198:Computer Simulation; D008956:Models, Chemical; D009010:Monte Carlo Method; D044367:Phase Transition; D011108:Polymers / Q000737:chemistry*; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry*
D011108:Polymers; D011506:Proteins