Browsing by Author "Aveyard, Robert"

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Desorption of Electrolytes at Liquid-Vapour and Liquid-Liquid Interfaces
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1977, 73 (1), 1977) Aveyard, Robert; Saleem, Syed M.; Heselden, Roy
The desorption of various simple inorganic salts at the decanol-water interface has been studied, and analysed together with previously obtained results for the air-electrolyte and dodecane-electrolyte interfaces. The desorption of the salts is much more dependent on the nature of the anion, at all three interface types, than it is on the cation and the results are discussed in terms of the possible interaction between anions and hydration layers at the interfaces. The dependence of free energies of adsorption of alkanols, both from alkane and from electrolyte, on the alkane-electrolyte interface has also been investigated and it is concluded that the chemical potential of the alkanol at the surface is not much affected by the salts, but the influence is greater the less the desorption of the salt.
Salting-in of Alcohols by Symmetrical Tetra-alkylammonium Bromides
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (11), 1974) Aveyard, Robert; Heselden, Roy
The changes in free energy, enthalpy and entropy associated with the transfer of several alkanols at high dilution from water to aqueous solutions of some symmetrical tetra-alkylammonium bromides (R4NBr) have been determined at 20°C. The enthalpies were determined calorimetrically for several salt concentrations. The treatment of salt effects based on the scaled particle theory has been applied to the salting-in of butanol by solutions of R4NBr. For this purpose it was necessary to obtain the cation diameter indirectly by fitting experimental salting-in data for alkanes to the theory. It is concluded that the theory is as successful for butanol as it is for the alkanes. The thermodynamic parameters of transfer are consistent with the assumption that the salting-in of alkanols (and alkanes) by R4N+ ions is caused by the formation of short-lived cation-solute “pairs” and the resultant disruption of water structure surrounding both the cation and non-electrolyte.
Work and entropy of adhesion at liquid–liquid interfaces and the relationship to salt desorption
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1977, 73 (06), 1977) Aveyard, Robert; Saleem, Syed M.
Works of adhesion of cyclohexane, toluene, chloro-octane and nonan-2-one, with water, have been determined as a function of temperature. From these results, and others in the literature, it is shown that a rectilinear relationship exists between the work and entropy of adhesion. Results for systems where water is replaced by ethan-1,2-diol do not conform to this relationship, and it is concluded that the linearity observed for the aqueous systems is a result of the promotion, by the organic liquids, of interfacial water structure. It is also found that the desorption of NaCl at the aqueous electrolyte–organic liquid interface is less the greater the work of adhesion between water and the organic liquid.