Elastic Properties of Semi-Flexible Chains and Networks

摘要

Elastic properties of noncharged polymers of stiffness ranging from flexible to rigid chains are determined from Monte Carlo simulations. The discrete wormlike chain (WLC) model with self-interacting units is applied to chains of intermediate lengths. Elastic free energy and the force-extension profiles of chains of variable stiffness are computed in an isometric ensemble. Occurrence of a plateau on the force-extension curves at intermediate chain stiffness is noted. Qualitative differences are found between force profiles from simulations and from the standard (ideal) WLC model. The single-chain data on influence of bending stiffness were employed in the three-chain model of networks. Stress-strain relations for networks show a highly nonlinear behavior with the marked strain-stiffening effect.