Effects of strongly selective additives on volume phase transition in gels.
Effects of strongly selective additives on volume phase transition in gels.
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DOI：
10.1063/1.4732857
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发表时间：
2012-05
期刊：
影响因子：
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通讯作者：
Y. Uematsu;Takeaki Araki
中科院分区：
文献类型：
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作者：
Y. Uematsu;Takeaki Araki
基于三组分Flory-Reynner理论，研究了凝胶在混合溶剂中的体积相变。当少数溶剂组分对聚合物网络的选择性强时，凝胶倾向于随着添加剂浓度的增加而收缩，无论其是好的还是差的。这一现象源于凝胶内外添加剂浓度的差异。我们还发现，通过加入强选择性溶质，可以控制相变点处凝胶体积的差距。例如，通过溶解强不良添加剂，可以消除不连续的体积相变。此外，我们观察到，另一个体积相变发生远离原来的转变点。这些行为可以很好地解释了一个简化的理论忽略了添加剂浓度的非线性。
We investigate volume phase transition in gels immersed in mixture solvents, on the basis of a three-component Flory-Rehner theory. When the selectivity of the minority solvent component to the polymer network is strong, the gel tends to shrink with an increasing concentration of the additive, regardless of whether it is good or poor. This behavior originates from the difference of the additive concentration between inside and outside the gel. We also found the gap of the gel volume at the transition point can be controlled by adding the strongly selective solutes. By dissolving a strongly poor additive, for instance, the discontinuous volume phase transition can be extinguished. Furthermore, we observed that another volume phase transition occurs far from the original transition point. These behaviors can be well explained by a simplified theory neglecting the nonlinearity of the additive concentration.