| Abstract Scope |
The mechanical properties of elastomers are governed by the force-extension response of individual polymer chains that make up their network structures. For many polymer chemistries, the force-extension response of a chain can be accurately captured by the freely-jointed chain (FJC) model. However, the FJC model assumes that the polymer is composed of 1 monomer species, but many natural polymers, like proteins, are copolymers composed of many different amino acids. Currently, there is no comprehensive theoretical model for the force-extension response of copolymers with chemically distinct units. Here, we apply molecular dynamics simulations to study force-extension response in copolymers containing hydrophobic and hydrophilic monomers. We simulate copolymers at varying temperatures and externally applied tensions and measure the resulting chain extension R(T,f). Consistent with experiments, we find copolymers display a coil-to-globule transition below a sequence-specific critical temperature. This transition produces abrupt jumps in force-extension response as chains partially unravel. |