title: Liquid-phase exfoliation of expanded graphites into graphene nanoplatelets using amphiphilic organic molecules.
abstract: Graphenes with a two-dimensional lattice of carbons have been widely employed in diverse applications owing to their excellent electrical, thermal, mechanical, and gas-barrier properties. However, the frequently-used reduced graphene oxide (rGO), which is synthesized from natural graphites by strong oxidation and subsequent reduction via highly toxic components, exhibits imperfect characteristics because of remaining defect sites on its basal planes. Therefore, in this work, we present a convenient way to prepare graphene nanoplatelets (GNPs) with minimized defect sites on their basal planes employing liquid-phase exfoliation of edge-functionalized expanded graphites (EGs) with amphiphilic organic molecules. Exfoliated GNPs revealed approximately sub-7-nm-thickness and showed stable dispersibility in an organic media during 9 months. Furthermore, spray-coated GNP films presented homogeneously stacked morphologies without noticeable agglomerations.
authors.affiliation: Energy Nano Materials Research Center, Korea Electronics Technology Institute (KETI), Seongnam 463-816, Republic of Korea. Electronic address: jisun.park@keti.re.kr.
authors.forename: Ji Sun
authors.initials: JS
authors.lastname: Park
authors.affiliation: Energy Nano Materials Research Center, Korea Electronics Technology Institute (KETI), Seongnam 463-816, Republic of Korea.
authors.forename: Lan
authors.initials: L
authors.lastname: Yu
authors.affiliation: Energy Nano Materials Research Center, Korea Electronics Technology Institute (KETI), Seongnam 463-816, Republic of Korea.
authors.forename: Churl Seung
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Energy Nano Materials Research Center, Korea Electronics Technology Institute (KETI), Seongnam 463-816, Republic of Korea.
authors.forename: Kwonwoo
authors.initials: K
authors.lastname: Shin
authors.affiliation: School of Applied Chemical Engineering, Chonnam National University, Gwangju 500-757, Republic of Korea. Electronic address: jhhan@chonnam.ac.kr.
authors.forename: Jong Hun
authors.initials: JH
authors.lastname: Han
keywords: Dispersion; Expanded graphite; Functionalization; Graphene