| Autor: |
Wei X; Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.; Theoretical and Applied Mechanics Program, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA., Mao L; Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA., Soler-Crespo RA; Theoretical and Applied Mechanics Program, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA., Paci JT; Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.; Department of Chemistry, University of Victoria, British Columbia, V8W 3V6, Canada., Huang J; Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois, 60208, USA., Nguyen ST; Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA., Espinosa HD; Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.; Theoretical and Applied Mechanics Program, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA. |
| Abstrakt: |
The ability to bias chemical reaction pathways is a fundamental goal for chemists and material scientists to produce innovative materials. Recently, two-dimensional materials have emerged as potential platforms for exploring novel mechanically activated chemical reactions. Here we report a mechanochemical phenomenon in graphene oxide membranes, covalent epoxide-to-ether functional group transformations that deviate from epoxide ring-opening reactions, discovered through nanomechanical experiments and density functional-based tight binding calculations. These mechanochemical transformations in a two-dimensional system are directionally dependent, and confer pronounced plasticity and damage tolerance to graphene oxide monolayers. Additional experiments on chemically modified graphene oxide membranes, with ring-opened epoxide groups, verify this unique deformation mechanism. These studies establish graphene oxide as a two-dimensional building block with highly tuneable mechanical properties for the design of high-performance nanocomposites, and stimulate the discovery of new bond-selective chemical transformations in two-dimensional materials. |
