Kinetics of Fatty Acid Adsorption from Non-aqueous Solutions onto Metal Surfaces Part 2.—Dilinoleic Acid

Abstract

The kinetics of adsorption ofthe thermal dimer oflinoleic acid from dodecane onto three metal surfaces have been examined. The rate of desorption of the surface species into pure dodecane has also been investigated. A general rate equation previously formulated to explain the behaviour oflinoleic acid has been applied to the dimer acid adsorption kinetics. The existence ofsurface-coverage-dependent activation energies for adsorption and desorption has been postulated to explain the kinetic behaviour. Activation energies for adsorption were lower than for the monomer. The overall adsorption process is exothermic at zero coverage but adsorption entropies are positive as for the monomer. These results are discussed in relation to the overall adsorption process.