Chemically modified graphene films with tunable negative Poisson's ratios.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31164652.
- Also identified by DOI 10.1038/s41467-019-10361-3 and PMC identifier 6547682.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Graphene-derived macroscopic assemblies feature hierarchical nano- and microstructures that provide numerous routes for surface and interfacial functionalization achieving unconventional material properties. We report that the microstructural hierarchy of pristine chemically modified graphene films, featuring wrinkles, delamination of close-packed laminates, their ordered and disordered stacks, renders remarkable negative Poisson's ratios ranging from -0.25 to -0.55. The mechanism proposed is validated by the experimental characterization and theoretical analysis. Based on the understanding of microstructural origins, pre-strech is applied to endow chemically modified graphene films with controlled negative Poisson's ratios. Modulating the wavy textures of the inter-connected network of close-packed laminates in the chemically modified graphene films also yields finely-tuned negative Poisson's ratios. These findings offer the key insights into rational design of films constructed from two-dimensional materials with negative Poisson's ratios and mechanomutable performance.