Potential concerns related to using octadecyltrichlorosilane (OTS) in rendering soils and porous ceramics hydrophobic.
The treatment of hydrophilic porous ceramics to render them hydrophobic and wetting to non-aqueous phase liquids (NAPLs) is frequently needed in multiphase flow experiments to control the flow or to measure the pressure of the NAPL. In addition, research dealing with soil wettability implies a need for hydrophobic or NAPL-wet soils. The traditional procedure, which has been widely used in literature, to render hydrophilic porous ceramics and soils hydrophobic is achieved by placing the hydrophilic solid in a 5% (by volume) octadecyltrichlorosilane (OTS) solution in ethanol followed by rinsing in ethanol. This research assesses the use of this procedure as it was found that this treatment procedure resulted in excess OTS on the surface of treated hydrophobic solids which can dissolve in an organic phase and in turn alter the wettability condition of adjacent hydrophilic soils. A modified procedure, which results in hydrophobic solids free of excess OTS, is presented.
Department of Civil and Environmental Engineering, Carleton University, Ottawa, Canada. mahmed4@connect.carleton.ca
Mustafa E
ME
Ahmed
Paul J
PJ
Van Geel
D002516:Ceramics / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D016062:Porosity; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D012987:Soil / Q000032:analysis*; D017155:Wettability
D012821:Silanes; D012987:Soil; C061189:octadecyltrichlorosilane; D012822:Silicon Dioxide