posted on 2016-03-28, 00:00authored byI-Cheng Chen, Ming Zhang, Younjin Min, Mustafa Akbulut
Numerous
applications of graphene oxide (GO) thin films have emerged
after the discovery of their intriguing electrical, mechanical, and
thermal properties. Function and performance of such GO films tend
to depend on their homogeneity, morphology, and nanostructure, which
are influenced by their deposition kinetics. This study investigates
the kinetics of GO deposition on substrates of systematically varying
surface potentials via systematic quartz crystal microbalance with
dissipation and atomic force microscopy techniques. While the substrates
with a positive surface potential yielded high deposition rates but
wrinkled GO films, the substrates with a negative surface potential
lead to low deposition rates but smooth GO films. For the repulsive
interactions, the deposition rate was found to roughly exponentially
decay with the product of surface potentials of GO and the substrate.
Also, building upon the Gouy–Chapman theory and the additivity
of van der Waals interactions, expressions for electrostatic double-layer
and van der Waals interactions between a nanoplatelet (e.g., GO) and
a planar wall under parallel, perpendicular, and inclined configurations
were derived to explain the observed deposition trends. We anticipate
that these findings will provide useful guidelines for manipulating
and controlling the aqueous deposition of GO and structural properties
of resultant GO films.