Abstract:
Supramolecular adhesion material systems based on small molecules have shown great potential to unite the great contradiction between strong adhesion and reversibility. However, these material systems suffer from low adhesion strength/narrow adhesion span, limited designability, and single interaction due to fewer covalent bond content and action sites in small molecules. Herein, an ultrahigh-strength and large-span reversible adhesive enabled by a branched oligomer controllable self-aggregation strategy is developed. The dense covalent bonds present in the branched oligomers greatly enhance adhesion strength without compromising reversibility. The resulting adhesive exhibits a large-span reversible adhesion of ≈140 times, switching between ultra-strong and tough adhesion strength (5.58 MPa and 5093.92 N m-1) and ultralow adhesion (0.04 MPa and 87.656 N m-1) with alternating temperature. Moreover, reversible dynamic double cross-linking endows the adhesive with stable reversible adhesion transitions even after 100 cycles. This reversible adhesion property can also be remotely controlled via a voltage of 8 V, with a loading voltage duration of 45 s. This work paves the way for the design of reversible adhesives with long-span outstanding properties using covalent polymers and offers a pathway for the rational design of high-performance adhesives featuring both robust toughness and exceptional reversibility.
摘要:
基于小分子的超分子粘附材料体系在结合强粘附性和可逆性之间的巨大矛盾方面显示出巨大的潜力。然而,这些材料系统具有低粘合强度/窄粘合跨度,有限的可设计性,和单一相互作用,由于小分子中共价键含量和作用位点较少。在这里,开发了一种通过支化低聚物可控自聚集策略实现的超高强度和大跨度可逆粘合剂。存在于支化低聚物中的致密共价键极大地增强粘合强度而不损害可逆性。所得粘合剂表现出约140倍的大跨度可逆粘附力,在交变温度下,在超强和坚韧的粘附强度(5.58MPa和5093.92Nm-1)和超低粘附力(0.04MPa和87.656Nm-1)之间切换。此外,可逆动态双交联赋予粘合剂稳定的可逆粘合过渡,即使在100个循环。这种可逆粘附特性也可以通过8V的电压进行远程控制,加载电压持续时间为45s。这项工作为使用共价聚合物设计具有长跨度出色性能的可逆粘合剂铺平了道路,并为合理设计具有强大韧性和出色可逆性的高性能粘合剂提供了途径。