Corrected Debye-Hückel analysis of surface complexation. II. A theory of surface charging.

A theory of surface charging of colloidal particles suspended in an electrolyte solution is presented. The charging at the particle surface is assumed to originate from the adsorption and desorption of protons and is therefore strongly dependent on the acidity of the solution. The surface binding of protons occurs locally at sites of occupancy zero or one that are described by a binding energy u(0) and a three-dimensional vibration of frequency nu.

Descriptions of pain in elderly patients following orthopaedic surgery.

The aims of this study were to investigate what words elderly patients, who had undergone hip surgery, used to describe their experience of pain in spoken language and to compare these words with those used in the Short-Form McGill Pain Questionnaire (SF-MPQ) and Pain-O-Meter (POM). The study was carried out at two orthopaedic and two geriatric clinical departments at a large university hospital in Sweden. Altogether, 60 patients (mean age =77) who had undergone orthopaedic surgery took part in the study.

Corrected Debye-Hückel analysis of surface complexation; III. Spherical particle charging including ion condensation.

Statistical mechanics has been used to derive a model for the charging of a spherical particle in a salt solution to complement our experimental studies and gain a deeper understanding of the processes involved in surface complexation. Our chosen model goes beyond the equilibrium constants and the Gouy-Chapmann theory currently used in surface complexation models. The proton adsorption is taken to occur at a harmonic potential well on the surface characterized by a frequency v and a well depth u(0).

Electroacoustic and Potentiometric Studies of the Hematite/Water Interface.

The basic charging properties of nearly spherical hematite particles were studied by using potentiometric titration and the electroacoustic technique. Both the pH and the ionic strength dependence of the surface charge and the zeta-potential were studied in detail. For calculating the zeta-potential from mobility data a few different theories were used and obtained differences are discussed.