The Swelling of Olympic Gels

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.