Publications [#368097] of Stephen L Craig

Journal Articles

1. Xu, D; Olsen, BD; Craig, SL, Relaxation dynamics of supramolecular polymer networks with mixed cross-linkers, Journal of Rheology, vol. 66 no. 6 (November, 2022), pp. 1193-1201 [doi]
   (last updated on 2026/01/16)

   Abstract:
   The linear rheological properties of supramolecular polymer networks formed by mixtures of two different bis-Pd(II) cross-linkers with poly(4-vinylpyridine) in dimethyl sulfoxide are examined. The changes in storage and loss moduli of the networks with mixed cross-linkers are compared to those of samples with a single type of cross-linkers. While the plateau moduli, and presumably network topology, of the networks remain equal regardless of the cross-link distribution, the relaxation time contributed by the faster cross-linkers is increased (by a factor of about 1.5 for the specific samples used in this work) by the presence of the slower cross-linkers, while the reverse influences are not significant. This effect can be explained by the fact that a certain fraction of the elastically effective strands cross-linked with fast cross-linkers is pinned on one end by slow cross-linkers, reducing by half the rate of fast chain relaxation. This effect is anticipated to be general for gels with two well-separated relaxation times.