The Swelling of Olympic Gels

TL;DR

This study uses Monte Carlo simulations to analyze how Olympic gels, made of entangled cyclic polymers, swell differently from traditional networks, revealing that larger chains lead to less swelling due to ring desinterspersion.

Contribution

It demonstrates that Olympic gels with larger cyclic polymer chains swell less, contrasting with chemically crosslinked networks, and explains this through ring desinterspersion mechanisms.

Findings

Swelling degree decreases with increasing chain length N.

Swelling degree scales as Q ∝ N^{-0.28} φ_0^{-0.72}.

Desinterspersion of rings explains the reduced swelling.

Abstract

The swelling equilibrium of Olympic gels, which are composed of entangled cyclic polymers, is studied by Monte Carlo Simulations. In contrast to chemically crosslinked polymer networks, we observe that Olympic gels made of chains with a \emph{larger} degree of polymerization, $N$, exhibit a \emph{smaller} equilibrium swelling degree, $Q\propto N^{-0.28}\phi_{0}^{-0.72}$, at the same polymer volume fraction $\phi_{0}$ at network preparation. This observation is explained by a desinterspersion process of overlapping non-concatenated rings upon swelling.