Browsing by Author "Wheeler, Phillip A"

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    Kinetics of Fatty Acid Adsorption from Non-aqueous Solutions onto Metal Surfaces Part 1.—Linoleic Acid
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1981, 77 (06), 1981) Dacre, Brian; Wheeler, Phillip A
    The kinetics of adsorption of linoleic acid from dodecane onto three metal surfaces have been examined. Desorption into pure solvent has also been investigated. A Langmuir and a more general model have been formulated to describe the kinetics. The values obtained for activation energies and enthalpies suggest that the adsorption which occurs in the first few seconds/minutes is physical in nature. Adsorption closely follows Langmuir kinetics but a variable activation energy is used to explain the desorption process. Entropy of desorption is smaller than that for adsorption. At zero coverage adsorption is endothermic on steel and aluminium bronze but exothermic on cadmium.
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    Kinetics of Fatty Acid Adsorption from Non-aqueous Solutions onto Metal Surfaces Part 2.—Dilinoleic Acid
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1981, 77 (06), 1981) Dacre, Brian; Savory, Barbara; Wheeler, Phillip A
    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.