Delamination of graphite oxide in a liquid upon cooling
| Autor: | Alexey Klechikov, Alexandr V. Talyzin, Nikolai Severin, Nataliya V. Avramenko, M. Fardin Gholami, Mikhail V. Korobov, Jürgen P. Rabe, Anastasiya T. Rebrikova |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Nanoscale. 7:12625-12630 |
| ISSN: | 2040-3372 2040-3364 |
| DOI: | 10.1039/c5nr02564h |
| Popis: | Graphite oxide (GO) in liquid acetonitrile undergoes a transition from an ordered phase around ambient temperature to a gel-like disordered phase at temperatures below 260 K, as demonstrated by in situ X-ray diffraction. The stacking order of GO layers is restored below the freezing point of acetonitrile (199 K). The reversible swelling transition between a stacked crystalline phase and an amorphous delaminated state observed upon cooling provides an unusual example of increased structural disorder at lower temperatures. The formation of the gel-like phase is attributed to the thermo-responsive conformational change of individual GO flakes induced by stronger solvation. Scanning force microscopy demonstrates that GO flakes deposited onto a solid substrate from acetonitrile dispersions at a temperature below 260 K exhibit corrugations and wrinkling which are not observed for the flakes deposited at ambient temperature. The thermo-responsive transition between the delaminated and stacked phases reported here can be used for sonication-free dispersion of graphene oxide, micro-container applications, or the preparation of new composite materials. |
| Databáze: | OpenAIRE |
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