Chemistry Reference
In-Depth Information
technical arena. Nature has provided and optimised, through
evolution, a large number of surfaces with rather unique
characteristics. In this chapter, we particularly focussed on the
wetting property of such surfaces and elaborately discussed the
theoretical basis of super-hydrophobicity, self-cleaning, super-
hydrophilic, and anti-fogging phenomenon as expressed by these
natural surfaces. In addition, we bring in the latest in the efforts of
copying those designs in the laboratories around the world with a
focus on plasma processes. The role of micro- and nanopatterned
surfaces on their wetting properties were studied by analysing
the roughness factor and static CA in light of the existing theories.
It has been found that with increasing roughness factor on a
hydrophilic micro- or nanostructured surface becomes more
hydrophilic, whereas increasing roughness on a hydrophobic micro-
or nanostructured surface become more hydrophobic. Plasma
treatment have been regarded as a versatile and effective method
for modifying the surface roughness by creating structures whose
morphology, including length, shape, pitch, and aspect ratio, could be
tuned to express tuneable wetting properties. Plasma processes can
also introduce desired chemical groups at the surface of a material
to alter, and sometime switch, the behaviour of the material, to a
regime vastly different than when in the bulk. Plasma plays a vital
and effective role in surface modification since apart from the etching
gas chemistry, we have at our disposal other parameters, such as
plasma power, electron density, etching time, substrate temperature,
and pressure, to effect accurate and reproducible changes in
substrate morphology. In this chapter, we mostly discussed about
the preparation of super-hydrophobic and hydrophilic surfaces by
plasma processing. Plasma treatment provides an excellent tool for
delicately regulating and constructing nanostructured surface on
different types of materials, due to which it can be effectively applied
to many practical applications, where surfaces with extreme wetting
properties could be exploited.
Acknowledgement
This work was carried out with support from National Science
Council, Taiwan, grant # NSC-101-2112-M-010-003-MY3.
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