交联凝胶中孔隙弹性粗化和弹性阻滞的标度关系
Scaling of poroelastic coarsening and elastic arrest in crosslinked gels
AI总结：
研究通过耦合毛细驱动达西渗透与聚合物网络的粘弹性到弹性过渡，揭示了交联凝胶中溶剂富区粗化及弹性阻滞的标度关系，提出了基于刚度的粗化和阻滞定律。
摘要：
最近关于从溶剂丰富到溶剂贫乏条件淬火的交联凝胶的实验显示，溶剂丰富的区域嵌入凝胶丰富的基质中。这些区域粗化后，在微米尺度上在数小时内经历动力学阻滞，随后在更长的时间内宏观排水至平衡。受这些观察启发，我们开发了一个最小模型，将毛细驱动的达西渗透与聚合物网络的粘弹性到弹性过渡耦合。在粘弹性阶段，弯曲的溶剂-凝胶界面的杨-拉普拉斯张力在凝胶的溶剂孔隙中产生压力梯度，驱动溶剂流动和粗化。在弹性阶段，相同的界面张力由弹性应力平衡。这种力平衡消除了凝胶中溶剂填充孔隙中的压力梯度，消除了达西驱动力并阻滞粗化。利用动力学准则 $t(λ_{ m arrest}) \sim τ_{ m el}$，我们预测了与刚度相关的粗化和阻滞定律。对于类似熔融的、聚合物丰富的凝胶，$λ(t)\sim G^{-1/2} t^{1/4}$ 和 $λ_{ m arrest}\sim G^{-1/2}$。对于低聚合物分数，其中网格尺寸控制传输，$λ(t)\sim G^{-1/3} t^{1/3}$ 和 $λ_{ m arrest}\sim G^{-1/3}$。预测的 $G^{-1/2}$ 阻滞标度关系对于熔融状凝胶与实验一致。
英文摘要：
Recent experiments on crosslinked gels quenched from solvent-rich to solvent-poor conditions show solvent-rich domains embedded in a gel-rich matrix. These domains coarsen and then undergo kinetic arrest at micron scales for hours, before macroscopic drainage to equilibrium over even longer times. Motivated by these observations, we develop a minimal model that couples capillarity-driven Darcy permeation to the viscoelastic-to-elastic crossover of the polymer network. In the viscoelastic regime, the Young--Laplace traction at curved solvent--gel interfaces generates a pressure gradient in the solvent pores of the gel that drives solvent flow and coarsening. In the elastic regime, the same interfacial traction is balanced by elastic stress. This force balance eliminates pressure gradients in the solvent-filled pores of the gel, removing the Darcy driving force and arresting coarsening. Using the kinetic criterion $t(λ_{\rm arrest}) \sim τ_{\rm el}$, we predict stiffness-dependent coarsening and arrest laws. For melt-like, polymer-rich gels, $λ(t)\sim G^{-1/2} t^{1/4}$ and $λ_{\rm arrest}\sim G^{-1/2}$. For low polymer fractions where the mesh size controls transport, $λ(t)\sim G^{-1/3} t^{1/3}$ and $λ_{\rm arrest}\sim G^{-1/3}$. The predicted $G^{-1/2}$ arrest scaling for melt-like gels agrees with experiment.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
