Enhanced Dynamic Adhesion in Nematic Liquid Crystal Elastomers
Enhanced Dynamic Adhesion in Nematic Liquid Crystal Elastomers
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DOI：
10.1002/adma.201902642
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发表时间：
2019-07-01
影响因子：
29.4
通讯作者：
Terentjev, Eugene M.
中科院分区：
文献类型：
--
作者：
Ohzono, Takuya;Saed, Mohand O.;Terentjev, Eugene M.
响应外部刺激而发生可逆分离的智能粘合剂在家用产品、医疗设备或制造业中具有广泛的应用。这里提出了一种用于设计智能软粘合剂的新模型系统，可以动态响应其环境。通过利用向列液晶弹性体 (LCE) 中的动态软弹性效应，证明了对固体玻璃表面的粘附力的温度依赖性控制。与各向同性相相比，LCE 在向列相中的粘附强度是各向同性相的两倍多，并且在较高的脱离率下进一步增加。与粘合剂接触的界面能相关的静态粘合功在探索的温度范围内变化很小。因此，观察到向列相中粘附力的增强主要归因于分离过程中内部能量耗散的增加。这种粘附效应与向列 LCE 中固有的体动态机械响应相关。所报道的增强的动态粘合力可以导致新型刺激响应粘合剂的开发。
Smart adhesives that undergo reversible detachment in response to external stimuli enable a wide range of applications in household products, medical devices, or manufacturing. Here, a new model system for the design of smart soft adhesives that dynamically respond to their environment is presented. By exploiting the effect of dynamic soft elasticity in nematic liquid crystal elastomers (LCE), the temperature-dependent control of adhesion to a solid glass surface is demonstrated. The adhesion strength of LCE is more than double in the nematic phase, in comparison to the isotropic phase, further increasing at higher detachment rates. The static work of adhesion, related to the interfacial energy of adhesive contact, is shown to change very little within the explored temperature range. Accordingly, the observed enhanced adhesion in the nematic phase is primarily attributable to the increased internal energy dissipation during the detachment process. This adhesion effect is correlated with the inherent bulk dynamic-mechanical response in the nematic LCE. The reported enhanced dynamic adhesion can lead to the development of a new class of stimuli-responsive adhesives.