Many systems of biophysical and technological interest consist of multiple interpenetrating chains in a confined volume, i.e., a confined polymer solution. Using nanofluidic approaches developed originally for the study of single chains in confined geometries, we develop an assay to create confined polymer solutions on-chip and then probe the solution response to applied compressive forcing. In our approach, multiple chains are introduced into a nanoslit via hydrodynamic flow and are then concentrated against a barrier that is permeable only to solvent. For sufficiently high concentration, the compressed solution profile can be described by a mean-field polymer model based on Doi’s two-fluid approach, with the chain free energy described by a Ginzburg-type free energy functional. This theory furnishes a partial differential equation based description of the concentration profile in terms of a nonlinear Schrödinger-type equation, providing a general theoretical framework for modeling confined polymer solution dynamics.

中文翻译：

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纳米缝隙受限聚合物溶液的压缩

许多具有生物物理和技术意义的系统由一定体积（即有限的聚合物溶液）中的多个互穿链组成。使用最初为研究受限几何结构中的单链而开发的纳米流体方法，我们开发了一种检测方法，可在芯片上创建受限聚合物溶液，然后探查溶液对施加的压缩强迫的响应。在我们的方法中，通过流体动力流将多条链引入纳米缝中，然后在仅能渗透溶剂的屏障上浓缩。对于足够高的浓度，可以通过基于Doi双流体方法的平均场聚合物模型来描述压缩溶液的轮廓，而链自由能则由Ginzburg型自由能泛函来描述。