Modeling swelling behavior of thermoresponsive polymer brush with lattice density functional theory.
Modeling swelling behavior of thermoresponsive polymer brush with lattice density functional theory.
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DOI：
10.1021/la5003429
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发表时间：
2014-04
期刊：
影响因子：
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通讯作者：
Cheng Lian;Le Wang;Xueqian Chen;Xia Han;Shuangliang Zhao;Honglai Liu;Ying Hu
中科院分区：
文献类型：
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作者：
Cheng Lian;Le Wang;Xueqian Chen;Xia Han;Shuangliang Zhao;Honglai Liu;Ying Hu
在固体表面设计热敏聚合物电刷的一个关键问题是找到目标热敏性能与可控条件之间的关系。通常，无论是通过实验还是理论研究，都会选择一条反映聚合物刷的热膨胀行为的温度-厚度曲线作为关系。本文采用晶格密度泛函理论(LDFT)研究了五种不同类型聚合物刷的温度-厚度曲线，并将LDFT计算得到的聚合物刷密度分布与模拟结果进行了直接比较。研究发现，聚合物电刷的热响应行为可以用其相应的聚合物溶液的本体相行为来表征，包括UCST、LCST、UCST和LCST、闭合环状和沙漏状，这意味着聚合物溶液的本体相图可以帮助我们找到适合于目标热响应行为的聚合物刷子。作为一个例子，我们表明，实验中发现的热响应性聚合物刷的溶胀行为可以用我们的LDFT结果来预测，只有真实聚合物溶液的体相图才能预测。
A key problem in designing thermoresponsive polymer brushes on a solid surface is to find a relation between the targeted thermoresponsive properties and controllable conditions. Usually, a temperature-thickness curve showing the heating-induced swelling behavior of polymer brushes is chosen as the relation by either experimental or theoretical investigation. In this work, a lattice density functional theory (LDFT) developed previously is employed to investigate the temperature-thickness curves for five different types of polymer brushes, where the density profiles of polymer brushes calculated by LDFT are compared directly with simulation. It is found that the thermoresponsive behavior of a polymer brush can be characterized by the bulk phase behaviors of its corresponding polymer solution, including UCST, LCST, both UCST and LCST, closed LOOP and hourglass-shaped, which implies that the bulk phase diagram of polymer solutions can help us to find an appropriate polymer brush for a targeted thermoresponsive behavior. As an example, we show that the swelling behavior of a thermoresponsive polymer brush found in the experiment could be predicted by our LDFT results with the bulk phase diagram of real polymer solution only.