Deformation-dependent polydimethylsiloxane permeability measured using osmotic microactuators
Deformation-dependent polydimethylsiloxane permeability measured using osmotic microactuators
复制标题
使用渗透微执行器测量变形相关的聚二甲基硅氧烷渗透率
DOI：
10.1039/d2sm01666d
复制
发表时间：
2024
期刊：
影响因子：
3.4
通讯作者：
Hutchens, Shelby B.
中科院分区：
文献类型：
--
作者：
Spitzer, Alexandra R.;Hutchens, Shelby B.
在软固体中，大变形会显著改变分子结构和器件几何形状，这可能会影响其他性质。在质量传输的情况下，通量和机械变形之间会产生相互作用。在这里，我们展示了一个同时表征机械渗透选择性的平台，使用水通过聚二甲基硅氧烷(PDMS)的(缓慢)传输作为一个具有挑战性的测试案例。该平台使用微米大小的圆柱形、充满氯化钠溶液的PDMS室，由选择性渗透的PDMS薄膜封装。当置于高化学势(高水势)环境中时，腔体与环境之间的渗透压差会导致水通过PDMS膜流入腔体，导致膜膨胀。结合膜通量和非线性弹性的模型很好地捕捉到了随时间变化的响应，但仅当使用与变形相关的渗透率时。值得注意的是，水通过PDMS的渗透率下降了近一个数量级，从2×10−12下降到5×10−13 m2 S−1，主要是由于其厚度随着平均双向拉伸从1增加到2.75时减少了近一个数量级。
In soft solids, large deformations significantly alter molecular structure and device geometry, which can impact other properties. In the case of mass transport, an interplay between flux and mechanical deformation results. Here we demonstrate a platform for the simultaneous characterization of mechano-permselectivity using the (slow) transport of water through polydimethylsiloxane (PDMS) as a challenging test case. The platform uses micron-sized, cylindrical, NaCl solution-filled PDMS chambers encapsulated by selectively-permeable PDMS thin film membranes. When placed in a high chemical potential environment (high water potential) the osmotic pressure difference between the chamber and environment induces water to flow through the PDMS membrane into the chamber, resulting in membrane bulging. A model combining membrane flux and nonlinear elasticity captures the time-dependent response well, but only when a deformation-dependent permeability is used. Notably, the permeability of water through PDMS decreases by nearly an order of magnitude, from 2 × 10−12 to 5 × 10−13 m2 s−1, due primarily to its thickness decreasing by nearly an order of magnitude as the average biaxial stretch increases from 1 to 2.75.