Department of Materials Science and Engineering, Clemson University, Clemson, SC 29634, USA.
Department of Chemistry, Clemson University, Clemson, SC 29634, USA.
Science. 2018 Oct 12;362(6411):220-225. doi: 10.1126/science.aat2975.
Self-healing materials are notable for their ability to recover from physical or chemical damage. We report that commodity copolymers, such as poly(methyl methacrylate)/n-butyl acrylate [p(MMA/nBA)] and their derivatives, can self-heal upon mechanical damage. This behavior occurs in a narrow compositional range for copolymer topologies that are preferentially alternating with a random component (alternating/random) and is attributed to favorable interchain van der Waals forces forming key-and-lock interchain junctions. The use of van der Waals forces instead of supramolecular or covalent rebonding or encapsulated reactants eliminates chemical and physical alterations and enables multiple recovery upon mechanical damage without external intervention. Unlike other self-healing approaches, perturbation of ubiquitous van der Waals forces upon mechanical damage is energetically unfavorable for interdigitated alternating/random copolymer motifs that facilitate self-healing under ambient conditions.
自修复材料的显著特点是能够从物理或化学损伤中恢复。我们报告说，商品共聚物，如聚（甲基丙烯酸甲酯）/正丁酯 [p（MMA/nBA）] 及其衍生物，在机械损伤后可以自行修复。这种行为发生在具有优先交替结构的共聚物拓扑结构的狭窄组成范围内，并且与随机成分（交替/随机）相关，归因于有利的链间范德华力形成关键和锁式链间连接。使用范德华力而不是超分子或共价重键或封装反应物消除了化学和物理变化，并能够在没有外部干预的情况下在机械损伤后进行多次恢复。与其他自修复方法不同，在机械损伤时，普遍存在的范德华力的干扰对于促进在环境条件下自修复的交错交替/随机共聚物基序在能量上是不利的。
