Adsorption of alkylsulphinylalkanols on Graphon

Abstract

The adsorption of a series of alkylsulphinylalkanols from aqueous solution on Graphon has been studied. The results are consistent with a two-stage adsorption model. The first stage involves replacement of solvent molecules at the solid surface by a monolayer of solute molecules lying flat. The differential enthalpy changes associated with this process are large. Subsequent adsorption involves a change to a perpendicular orientation of the adsorbed solute. It is accompanied by only a small differential heat change since the enthalpy from the elimination of alkyl chain/water interface is compensated by that due to solvent reorientation as the head groups become close packed. The close-packed vertical monolayer produces a hydrophilic surface on the Graphon particles and aqueous suspensions are then stable.