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Concentration dependence of the global and anisotropic dimensions of confined macromolecules

机译：受限大分子整体尺寸和各向异性尺寸的浓度依赖性

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The chain dimensions [R-2] of nondilute polymer solutions confined to a slit of the width D were studied using lattice simulations. It was found that the chain compression induced in good solvents by the concentration phi is enhanced in a slit relative to the bulk. The global dimensions of chains also change with phi in confined and unconfined theta solutions. At intermediate slit widths, a region was noted where coils are squeezed along all three axes. This region is manifested as a channel on the three-dimensional surface [R2](D,phi) in both good and theta solvents. The coil anisotropy, given by the ration of the parallel and perpendicular components of the chain dimensions [R-y(2)]/[R-x(2)], reaches high values at strong confinements where coils form quasi-two-dimensional pancakes. The concentration-induced reduction of the global chain dimensions in good solvents is almost fully transmitted to the parallel component [Ry2]. The computed effects of concentration and confinement were compared with the predictions of mean-field and scaling theories, and implications of the results to ultrathin films and layered nanocomposites were discussed. In addition, the distribution functions of the components of the end-to-end distance R perpendicular and parallel to the plates. W(R-x) combined with the concentration profile phi (x) along the pore provided details of the chain structure close to walls. A marked difference in the pace of the filling up of the depletion layer was noticed between chains in theta and good solvents. From the distribution functions W(Rx) and W(R-y), the highly anisotropic force-elongation relations imply the deformations of chains in confined solutions and ultrathin bulk films. [References: 26]
机译：使用晶格模拟研究了限制在宽度D的狭缝中的非稀释聚合物溶液的链尺寸[R-2]。已经发现，在良好的溶剂中，由浓度phi引起的链压缩相对于主体在狭缝中得到增强。在有限制和无限制theta解中，链的全局尺寸也随phi的变化而变化。在中间狭缝宽度处，注意到沿所有三个轴挤压线圈的区域。该区域在良溶剂和theta溶剂中均表现为三维表面[R2]（D，phi）上的通道。由链尺寸[R-y（2）] / [R-x（2）]的平行和垂直分量的比值给出的线圈各向异性在线圈形成准二维薄饼的强约束条件下达到很高的值。在良好的溶剂中，浓度引起的总链尺寸的减小几乎完全传递给平行组分[Ry2]。将浓度和限制的计算效果与平均场和比例理论的预测结果进行了比较，并讨论了结果对超薄膜和层状纳米复合材料的影响。另外，垂直和平行于板的端到端距离R的分量的分布函数。 W（R-x）与沿孔的浓度分布phi（x）相结合，提供了靠近壁的链结构的详细信息。在θ中的链和良好的溶剂之间注意到耗尽层的填充速度的显着差异。从分布函数W（Rx）和W（R-y），高度各向异性的力-伸长关系暗示了约束溶液和超薄块状薄膜中链的变形。 [参考：26]

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