Li Wenbing, Liu Junhao, Wei Wanting, Qian Kun
Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University Wuxi 214122 PR China
RSC Adv. 2021 Jun 1;11(32):19616-19622. doi: 10.1039/d1ra01473k. eCollection 2021 May 27.
Reversible adhesion switching on the micron scale greatly extends the functionality of shape memory polymers. Herein, we report the first usage of polystyrene microparticles for the reversible dry adhesive of the on/off switch between bonding and debonding. The reversible dry adhesive property is attributed to the stiffness change under the varying temperature of the polystyrene microparticle, as well as its ability to lock a temporary shape and recover to its original shape. The decrease in the modulus/viscosity of polystyrene microparticles at high temperature improves the surface wetting/contact and enhances the adhesive bond by contact pressure. Then, when heating above its glass transition temperature after bonding, the adhesive recovers to its initial shape, resulting in almost a zero adhesion strength. Besides, adhesion tests reveal that the magnitude of adhesion variations depends on substrates, contact pressures, and particle sizes. Therefore, as a thermotropic-induced shape memory material, the adhesive (polystyrene microparticles) can be used to create joints and can be heated to achieve its own restoration.
微米尺度上的可逆粘附切换极大地扩展了形状记忆聚合物的功能。在此，我们报道了聚苯乙烯微粒首次用于在粘结和脱粘之间进行开/关切换的可逆干粘合剂。这种可逆干粘合性能归因于聚苯乙烯微粒在不同温度下的刚度变化，以及其锁定临时形状并恢复到原始形状的能力。高温下聚苯乙烯微粒的模量/粘度降低，改善了表面润湿性/接触，并通过接触压力增强了粘合剂粘结。然后，在粘结后加热到其玻璃化转变温度以上时，粘合剂恢复到其初始形状，导致粘附强度几乎为零。此外，粘附测试表明，粘附变化的幅度取决于基材、接触压力和颗粒尺寸。因此，作为一种热致形状记忆材料，粘合剂（聚苯乙烯微粒）可用于创建接头，并可加热以实现自身恢复。
