Page 38 - Gas Wettability of Reservoir Rock Surfaces with Porous Media

22 Gas Wettability of Reservoir Rock Surfaces with Porous Media

surface was obtained. It is worth mentioning that chemical bath deposi-
tion (CBD) was used while constructing the nano structural surface. For
instance, Hosono et al., constructed a brucite-type cobalt hydroxide
(BCH) film and modified it with lauric acid (LA) to finally obtain a
super-hydrophobic surface with a CA of 178 degrees.
3. Sol-gel processing
Many materials are treated by the sol gel combination to obtain a
super-hydrophobic surface. Most studies have shown that sol-gel treat-
ment does not require hydrophobization posttreatment because of the
low free surface energy material used during the sol-gel process.
Takahara’s research group used colloidal silica and fluoroalkylsilane
(FAS) to produce a sol-gel film possessing super-hydrophobic proper-
ties. They achieved this through hydrolysis and concentration of alkoxy
silane. Cho’s research group constructed a super-hydrophobic surface
through a simple sol-gel processing technique using a super-molecular
organic silicon with four hydrogen bonds at room temperature.
4. Etching and lithography
Etching and lithography are a direct and effective method to produce
a rough surface. It mainly includes plasma etching, laser etching, and
chemical etching. Shen’s research group describes a simple method
through dislocation of chemical etching in malleable metals, like alumi-
num, copper, and zinc. Then fluorine alkyl siloxane was used for chemi-
cal modification to finally obtain a super-hydrophobic metal surface.
Sugimura’s research group prepared a transparent super-hydrophobic
surface using a plasma-assisted chemical vapor deposition method
based on selective oxygen plasma etching and using tetramethylsilane
(TMS) as a precursor.
Printing (such as light printing, electron beam printing, X-ray print-
ing, soft printing, and nanosphere printing) is a good technique for the
construction of large-scale periodic micro/nano patterns. Riehle’s
research group produced orderly nano indentations and nanorods with
electron beam printing and plasma etching. It was then chemically
modified by Octadecyltrichlorosilane (OTS) to obtain a super-
hydrophobic surface. CA of water and surface was 164 degrees, and the
lag angle was l degrees.
5. Template method
Yao’s research group in Jilin University moved a single-layer of silica
spheres on the surface of polydimethylsiloxane (PDMS) template with a
micro contact printing method. Then a chemical reduction method was
used to cover silver nanoparticles on the outside surface of the micro-
spheres, and surface hydrophobization treatment was conducted. After
treatment, the CA was around 152 degrees, and the roll angle was only
4 degrees.
6. Chemical or physical vapor deposition method (CVD or PVD)
Professor Jiang Lei’s research group produced various patterns on the
base of quartz with a chemical vapor deposition method (CVD), such