Shifting the Isotropic–Nematic Transition in Very Strongly Confined Semiflexible Polymer Solutions
Shifting the Isotropic–Nematic Transition in Very Strongly Confined Semiflexible Polymer Solutions
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DOI：
10.1021/acs.macromol.6b00986
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发表时间：
2016-08
期刊：
影响因子：
5.5
通讯作者：
D. Luzhbin;Yeng-Long Chen
中科院分区：
文献类型：
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作者：
D. Luzhbin;Yeng-Long Chen
我们研究了如何非常强的限制，小于聚合物的持久长度LP，影响各向同性的半柔性聚合物解决方案，使用GPU加速朗之万动力学的过渡。壁促进聚合物排列，并在强准二维狭缝限制下，I-N过渡被发现是一个连续的过渡发生通过毛细管nematization。我们发现狭缝中的I-N跃迁是一个二级跃迁，并且跃迁体积分数随狭缝高度H的减小而减小。当H < lp时，序参量的临界指数β = 0.3-0.5。当H高于临界高度时，β急剧增加，表明开始了不同的壁诱导相变。发现较高的吸湿性较大的H，这是与增加的单体包装附近的墙壁，并对应于部分润湿过渡预测的自洽场理论。
We investigated how very strong confinement, smaller than the polymer persistence length lp, affects the isotropic–nematic transition for semiflexible polymer solutions using GPU-accelerated Langevin dynamics. Walls facilitate polymer alignment, and under strong quasi-two-dimensional slitlike confinement, the I–N transition is found to be a continuous transition occurring via capillary nematization. We found that the I–N transition in the slit is a second-order transition, and the transition volume fraction ϕcr decreases with decrease of the slit height H. For H < lp, the critical exponent of the order parameter is found to be β ≈ 0.3–0.5. β sharply increases for H higher than a critical height, indicating the onset of a different wall-induced phase transition. Higher ϕcr are found for larger H, which is associated with increased monomer packing near the walls and correspond to the partial wetting transition predicted by self-consistent field theory.