Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Probing nanoscale graphene-liquid interfacial interactions via Ultrasonic Force Spectroscopy
AU - Robinson, Benjamin
AU - Kolosov, Oleg
PY - 2014/9/21
Y1 - 2014/9/21
N2 - We probe the interfacial forces in graphene-air and graphene-liquid environments with nanoscale resolution. Experimentally, probe ‘snap-in’ to contact, in scanning probe microscopy, is overcome by combining the ultrasonic force spectroscopy (UFS) approach and MHz frequency range harmonic oscillation of the sample thereby sweeping the tip-surface dynamically from separated to indented state across the region of intimate interface contact. We measured the force interaction between nanoscale probe tip and graphene, graphite and reference SiO2 surface in ambient, polar and non-polar liquid environments. Via modelling we estimated the decay length of the force interaction in water to be 0.25 – 0.75 nm, equivalent to 1-3 monolayers, and interfacial effective stiffness at these distances associated with the liquid layer was an order of magnitude greater for non-polar than for polar liquid environment. During the elastic indentation at increased forces, the effective Young modulus of graphene was shown only to be slightly reduced in ambient environment while experiencing significant reduction by a factor of 3 in non-polar dodecane environment.
AB - We probe the interfacial forces in graphene-air and graphene-liquid environments with nanoscale resolution. Experimentally, probe ‘snap-in’ to contact, in scanning probe microscopy, is overcome by combining the ultrasonic force spectroscopy (UFS) approach and MHz frequency range harmonic oscillation of the sample thereby sweeping the tip-surface dynamically from separated to indented state across the region of intimate interface contact. We measured the force interaction between nanoscale probe tip and graphene, graphite and reference SiO2 surface in ambient, polar and non-polar liquid environments. Via modelling we estimated the decay length of the force interaction in water to be 0.25 – 0.75 nm, equivalent to 1-3 monolayers, and interfacial effective stiffness at these distances associated with the liquid layer was an order of magnitude greater for non-polar than for polar liquid environment. During the elastic indentation at increased forces, the effective Young modulus of graphene was shown only to be slightly reduced in ambient environment while experiencing significant reduction by a factor of 3 in non-polar dodecane environment.
U2 - 10.1039/C4NR01348D
DO - 10.1039/C4NR01348D
M3 - Journal article
VL - 6
SP - 10806
EP - 10816
JO - Nanoscale
JF - Nanoscale
SN - 2040-3364
IS - 18
ER -