Neutron Spin Echo Studies on Poly(Vinyl Alcohol) Gel in a Mixture of Dimethyl Sulfoxide and Water

Abstract

Dynamics of poly(vinyl alcohol) (PVA) gel have been investigated using a neutron spin echo technique. The intermediate scattering function I(Q,t) of the gel shows a very rapid decay and a non-decaying component in time ranges shorter and longer than about 3 ns, respectively, in the Q range of 0.03–0.1 Å⁻¹. This Q range corresponds to the so-called Porod’s region, suggesting that we are seeing the dynamics of cross-linking points of the gel. We therefore analyzed the data assuming that the cross-linking point performs a random motion in a restricted region around its quasi-equilibrium position.