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发布时间：2019-03-12

论文类型：期刊论文

发表时间：2018-08-01

发表刊物：CARBON

收录刊物：SCIE

卷号：135

页面范围：180-186

ISSN号：0008-6223

关键字：FEW-LAYER GRAPHENE; LIQUID-PHASE EXFOLIATION; SUPERCRITICAL CO2; RAMAN-SPECTROSCOPY; NANOSHEETS; SYSTEMS; OXIDE

摘要：A simple and effectivemethod of producing pristine graphene sheets was investigated in this study. Natural graphite flakes were exfoliated in CO2 expanded N-methylpyrrolidone with a low speed agitation of 1000 rpm followed by 30min sonication. Few-layer graphene were obtained with the concentration of 0.0576 mg/mL after centrifugation at 4000 rpm for 30min. More than 90% of the product were two or three-layer graphene and 12-38% were even monolayer. In addition, ethylene glycol and ethanol were also proved to be effective solvents with the assistance of CO2 intercalation, but they were not good solvents for the exfoliation in the subsequent sonication process. Finally, Agitation time, the system pressure and temperature were systemically investigated to find out more appropriate parameters for the production. (C) 2018 Elsevier Ltd. All rights reserved.