Enhancement of surface nonwettability by grafting loops
Enhancement of surface nonwettability by grafting loops
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通过接枝环增强表面不润湿性
DOI：
10.1039/c6cp07596g
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发表时间：
2017
影响因子：
3.3
通讯作者：
Lu Zhong-Yuan
中科院分区：
文献类型：
--
作者：
Pei Han-Wen;Liu Xiao-Li;Liu Hong;Zhu You-Liang;Lu Zhong-Yuan
我们提出了一个计算机模拟研究的非润湿性的平面与可变形的环状聚合物链栓系。研究了两种环：单分散环（长度相同的环）和多分散环（长度不同的环）。这两种类型的回路包括两种布置：具有规则拴系的站点和具有随机拴系的站点。规则接枝的环在表面上形成典型的凹槽，而随机接枝的环形成更粗糙的表面。对于单分散回路，我们分析了当改变回路的刚度时影响非润湿性的因素。根据我们先前的分析程序（Phys. Chem. Chem. Phys.，2016，18，18767-18775）：刚性环和柔性环。研究发现，微弧可以部分形成凹状结构，这有助于提高表面的非润湿性。具有接枝环的表面具有增加的非润湿性，特别是那些接枝有柔性链的表面。然而，对于刚性链，由于大的顶层密度，环结构上的接触角不能进一步增加（Phys. Chem. Chem. Phys.，2016，18，18767-18775）。对于多分散环，接触角与接触液滴的长环的刚性高度相关。与单分散微环不同，多分散微环的非润湿性机理是由微环的支撑能力（刚性）决定的。
We present a computer simulation study on the nonwettability of a flat surface tethered with deformable looped polymer chains. Two kinds of loops are studied: monodispersed loops (loops with the same length) and polydispersed loops (loops with different lengths). Both kinds of loops include two arrangements: with regularly tethered sites and with randomly tethered sites. Regularly grafted loops form typical grooves on the surface, while randomly grafted loops form a more rugged surface. For monodispersed loops, we analyze the factors that influence the nonwettability when varying the rigidity of the loops. The loops are divided into two categories based on their rigidity according to our previous analysis procedure (Phys. Chem. Chem. Phys., 2016, 18, 18767–18775): rigid loops and flexible loops. It is found that the loop can partially form a re-entrant-like structure, which is helpful to increase the nonwettability of the surface. The surfaces with grafted loops have increased nonwettability, especially those grafted with flexible chains. However, the contact angle on the loop structure cannot further increase for the rigid chains due to a large top layer density (Phys. Chem. Chem. Phys., 2016, 18, 18767–18775). For polydispersed loops, the contact angle is highly related to the rigidity of the long loops that contact the droplet. Different from monodispersed loops, the mechanism of the nonwettability of polydispersed loops is attributed to the supporting ability (rigidity) of long loops.