TY - JOUR
T1 - High-concentration solvent exfoliation of graphene
AU - Khan, Umar
AU - O'Neill, Arlene
AU - Lotya, Mustafa
AU - De, Sukanta
AU - Coleman, Jonathan N.
PY - 2010/4/9
Y1 - 2010/4/9
N2 - A method is demonstrated to prepare graphene dispersions at high concentrations, up to 1.2mg mL-1, with yields of up to 4 wt% monolayers. This process relies on low-power sonication for long times, up to 460 h. Transmission electron microscopy shows the sonication to reduce the flake size, with flake dimensions scaling as t-1/2. However, the mean flake length remains above 1 μm for all sonication times studied. Raman spectroscopy shows defects are introduced by the sonication process. However, detailed analysis suggests that predominately edge, rather than basal-plane, defects are introduced. These dispersions are used to prepare high-quality freestanding graphene films. The dispersions can be heavily diluted by water without sedimentation or aggregation. This method facilitates graphene processing for a range of applications.
AB - A method is demonstrated to prepare graphene dispersions at high concentrations, up to 1.2mg mL-1, with yields of up to 4 wt% monolayers. This process relies on low-power sonication for long times, up to 460 h. Transmission electron microscopy shows the sonication to reduce the flake size, with flake dimensions scaling as t-1/2. However, the mean flake length remains above 1 μm for all sonication times studied. Raman spectroscopy shows defects are introduced by the sonication process. However, detailed analysis suggests that predominately edge, rather than basal-plane, defects are introduced. These dispersions are used to prepare high-quality freestanding graphene films. The dispersions can be heavily diluted by water without sedimentation or aggregation. This method facilitates graphene processing for a range of applications.
KW - Films
KW - Graphene dispersions
KW - Solvent exfoliation
UR - http://www.scopus.com/inward/record.url?scp=77950606228&partnerID=8YFLogxK
U2 - 10.1002/smll.200902066
DO - 10.1002/smll.200902066
M3 - Article
C2 - 20209652
AN - SCOPUS:77950606228
SN - 1613-6810
VL - 6
SP - 864
EP - 871
JO - Small
JF - Small
IS - 7
ER -