Type

Journal Article

Authors

Jonathan N Coleman
Peter May
Khalid Nawaz
Arlene O'Neill
Harshit Porwal
Umar Khan

Subjects

Chemistry

Topics
filtration dispersion graphene solvents centrifugation graphite layers solvent

Solvent-exfoliated graphene at extremely high concentration. (2011)

Abstract We describe three related methods to disperse graphene in solvents with concentrations from 2 to 63 mg/mL. Simply sonicating graphite in N-methyl-2-pyrrolidinone, followed by centrifugation, gives dispersed graphene at concentrations of up to 2 mg/mL. Filtration of a sonicated but uncentrifuged dispersion gives a partially exfoliated powder that can be redispersed at concentrations of up to 20 mg/mL. However, this process can be significantly improved by removing any unexfolaited graphite from the starting dispersion by centrifugation. The centrifuged dispersion can be filtered to give a powder of exfoliated few-layer graphene. This powder can be redispersed at concentrations of at least 63 mg/mL. The dispersed flakes are ~1 μm long and ~3 to 4 layers thick on average. Although some sedimentation occurs, ~26-28 mg/mL of the dispersed graphene appears to be indefinitely stable.
Collections Ireland -> Trinity College Dublin -> PubMed

Full list of authors on original publication

Jonathan N Coleman, Peter May, Khalid Nawaz, Arlene O'Neill, Harshit Porwal, Umar Khan

Experts in our system

1
Jonathan Coleman
Trinity College Dublin
Total Publications: 217
 
2
Peter May
Trinity College Dublin
Total Publications: 27
 
3
Arlene O'Neill
Trinity College Dublin
Total Publications: 25
 
4
Umar Khan
Trinity College Dublin
Total Publications: 37