Mechanics of electrophoresis-induced reversible hydrogel adhesion
Mechanics of electrophoresis-induced reversible hydrogel adhesion
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DOI：
10.1016/j.jmps.2018.12.007
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发表时间：
2019-04
影响因子：
5.3
通讯作者：
A. Xin;Runrun Zhang;Kunhao Yu;Qiming Wang
中科院分区：
文献类型：
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作者：
A. Xin;Runrun Zhang;Kunhao Yu;Qiming Wang
软材料的附着力是一把双刃剑，有利也有弊。软材料与外部刺激的粘附的按需控制自然是期望的。电泳诱导的水凝胶粘附是这样一种技术，其诱导电触发的可逆粘附，并且可用于各种工程应用。尽管有潜力，但详细的机制仍然难以捉摸。在这里，我们建立了一个分析的理论框架来模拟的电子束诱导的可逆粘附。我们认为，在电泳过程中，自由带电链在电场的驱动下穿过界面，相互渗透到各自的材料基质中，并与带相反电荷的链形成弱离子键。我们模型的带电聚合物链的相互渗透作为一个电驱动的扩散反应过程。链扩散遵循电驱动的类似爬行的运动，阳离子-阴离子键的形成遵循钟状化学反应。我们预测，随着电泳时间的增加，海藻酸钠诱导的粘附增加，并达到一个平台，电泳过程是足够长的。我们从理论上研究了电场力、聚合物链长和链摩擦系数对水凝胶粘附的影响。我们还预测，在反向电泳下，水凝胶粘附力随处理时间而降低。我们的理论结果与实验结果吻合得很好，无论是在电子束诱导的粘附和粘附释放。我们希望我们的理论模型可以促进定量的理解和优化的各种方法，主动控制软材料的粘附。
Adhesion of soft materials is a double-edged sword that can induce both advantages and disadvantages. On-demand control of the adhesion of soft materials with external stimuli is naturally desirable. Electrophoresis-induced hydrogel adhesion is such a technology that induces electrically-triggered reversible adhesion and may be useful for various engineering applications. Despite the potential, the detailed mechanism is still elusive. Here, we establish an analytical theory framework to model the electrophoresis-induced reversible adhesion. We consider that during the electrophoresis process, free charged chains are driven by the electric field to move across the interface to interpenetrate into the respective material matrix, and form weak ionic bonds with chains with opposite charges. We model the interpenetration of the charged polymer chains as an electrically-driven diffusion-reaction process. The chain diffusion follows an electrically-driven reptation-like motion, and cationic-anionic bond formation follows a bell-like chemical reaction. We predict that the electrophoresis-induced adhesion increases with the electrophoresis time and reaches a plateau as the electrophoresis process is long enough. We theoretically study the effects of the electric force, the polymer chain length, and the chain friction coefficient on the hydrogel adhesion. We also predict that under reverse electrophoresis the hydrogel adhesion decreases with the process time. Our theoretical results agree well with the experiments for both electrophoresis-induced adhesion and adhesion releasing. We expect our theoretical model may facilitate the quantitative understanding and optimization of various methods for actively controlling the adhesion of soft materials.