Gels are an increasingly important class of soft materials with applications ranging from regenerative medicine to commodity materials. A major drawback of gels is their relative mechanical weakness, which worsens further under strain. We report a new class of responsive gels with latent crosslinking moieties that exhibit strain-stiffening behavior. This property results from the lability of disulfides, initially isolated in a protected state, then activated to crosslink on-demand. The active thiol groups are induced to form inter-chain crosslinks when subjected to mechanical compression, resulting in a gel that strengthens under strain. Molecular shielding design elements regulate the strain-sensitivity and spontaneous crosslinking tendencies of the polymer network. These strain-responsive gels represent a rational design of new advanced materials with on-demand stiffening properties with potential applications in elastomers, adhesives, foams, films, and fibers.
@article{arxiv.1707.09077,
title = {Strain-stiffening gels based on latent crosslinking},
author = {Yen H. Tran and Matthew J. Rasmuson and Todd S. Emrick and John Klier and Shelly R. Peyton},
journal= {arXiv preprint arXiv:1707.09077},
year = {2017}
}