超薄材料制备中的断裂力学

Fracture mechanics for preparation of ultrathin materials

超薄材料(如石墨烯、二硫化钼、二维纳米金属材料等)具有优异物理和力学性质,是力学、凝聚态物理和材料科学等众多领域的长期研究热点,而对超薄材料的剥离和转移是开展相关实验研究的重要环节.本文对超薄材料的实验制备,以及制备中的断裂力学研究进展进行概述,分别介绍了经典机械剥离法与衬底表面屈曲剥离法的界面断裂力学原理及剥离准则.与经典机械剥离法相比,表面屈曲剥离法引入的薄膜应力较小,可成功实现对强黏附超薄材料的制备.最后,对超薄材料界面断裂力学的未来方向进行了展望.

Owing to their outstanding physical and mechanical properties,ultrathin materials(e.g.,graphene,molybdenum disulfide,and two-dimensional metallic nanomaterials)have long-term research interests in mechanics,condensed matter physics,materials science,and other fields.Exfoliation and transfer of ultrathin materials are important procedures in related experimental studies.This article reviews the progress in the preparation of ultrathin materials in the laboratory and studies fracture mechanics during the preparation process.The principles of interfacial fracture and exfoliation criteria are introduced for the classical mechanical exfoliation and polymer substrate buckling-enabled exfoliation(PSBEE)methods,respectively.Compared with the classical mechanical exfoliation method,PSBEE introduces smaller membrane stress in the materials,resulting in ultrathin materials with large in-plane sizes.Finally,future research directions are discussed concerning the interfacial fracture mechanics for ultrathin materials.