The relationship between the plateau modulus (G0) and the persistence length (Lp) of entangled semiflexible polymers is still uncertain. Some previous theoretical models have predicted that G0 decreases with increasing Lp, while experiments indicated the opposite. In this study, we extend the primitive chain network (PCN) model to incorporate bending rigidity at the scale of the entanglement length, consistently with the coarse graining of the model. Simulations investigate the effects of rigidity (and of molecular weight) on chain conformation and relaxation modulus. Our results reveal a relationship described as G0 ~ Lp2/3, indicating that G0 increases with increasing Lp, consistently with experiments. It should be considered, however, that implicit in our simulations is the condition that the entanglement length is kept fixed with changing Lp.
All the papers published in the 52nd volume of Nihon Reoroji Gakkaishi (Journal of the Society of Rheology, Japan) are summarized to clarify the latest trend of rheology in Japan. This volume consists of five issues published in 2024. As for the publication statistics, the total number of articles is 33, and the ratio of papers written in English is 0.64. The second issue has specially collected four original articles and one review article relating to rheology of surface and interface. It should be also noted that this volume contains seven excellent articles by young winners of Research Paper Encouragement Award.