The swelling dynamics of polymer gels are characterized by the (collective) diffusion coefficient $D$ of the polymer network. Here, we measure the temperature dependence of $D$ of polymer gels with controlled homogeneous network structures using dynamic light scattering. An evaluation of the diffusion coefficient at the gelation point $D_{\mathrm{gel}}$ and the increase therein as the gelation proceeds $\mathrm{\Delta }D\equiv D-D_{\mathrm{gel}}$ indicates that $\mathrm{\Delta }D$ is a linear function of the absolute temperature with a significantly large negative constant term. This feature is formally identical to the recently discovered “negative energy elasticity” [Y. Yoshikawa et al. Phys. Rev. X 11, 011045 (2021)], demonstrating a nontrivial similarity between the statics and dynamics of polymer networks.

中文翻译：

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聚合物网络扩散的温度依赖性

聚合物凝胶的溶胀动力学由（集体）扩散系数表征 $D$聚合物网络。在这里，我们测量温度依赖性$D$使用动态光散射具有受控均匀网络结构的聚合物凝胶。凝胶点扩散系数的评估$D_{\mathrm{凝胶}}$ 随着凝胶化的进行，其中的增加 $\mathrm{\Delta }D\equiv D-D_{\mathrm{凝胶}}$ 表明 $\mathrm{\Delta }D$是绝对温度的线性函数，具有非常大的负常数项。这个特征与最近发现的“负能量弹性”[Y. 吉川等人。 物理 Rev. X 11 , 011045 (2021)]，证明了聚合物网络的静力学和动力学之间的非平凡相似性。