Multiscale Dynamics of Inhomogeneity-Free Polymer Gels

作者：Hiroi Takashi; Ohl Michael; Sakai Takamasa; Shibayama Mitsuhiro^*

来源：Macromolecules, 2014, 47(2): 763-770.

DOI：10.1021/ma402439v

For precise understanding of the dynamics of gels, it is necessary to distinguish the effect of inherent cross-linking from accompanying inhomogeneity. This separation is realized by the use of inhomogeneity-free gel such as Tetra-PEG gel. We investigated the dynamics of Tetra-PEG gel by quasi-elastic scattering. Mesoscopic (length scale: similar to 100 nm) motion was measured by dynamic light scattering (DLS). In addition to this scale, we used neutron spin echo (NSE) to measure microscopic (length scale: similar to 1 nm) motion. From these measurements, it is revealed that the gels with no connectivity/topological inhomogeneities show the transition from Zimm mode to collective diffusion mode in larger length scale, even beyond the q-range of NSE. In addition to this, the absence of spatial inhomogeneities is reflected as disappearance of nondecay component in the intermediate dynamic structure factor. Through the combination analysis of DLS and NSE, the multiscale dynamics of gels is elucidated.

• 出版日期2014-1-28