вторник, 4 сентября 2007 г.

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Interfacial and colloid science deals with the behavior of fine-particle dispersions, fibers and thin films, and other systems strongly influenced by the properties of their interfaces. Our group engages in research attempting to acquire fundamental understanding of systems of this type and their application to situations of current practical interest. CURRENT RESEARCH THRUSTS INCLUDE:

  • Dynamic surface tension and interaction of surfactant solutions with print media. The success of ink-jet printing lies in the appropriate interaction of the ink with the print medium over the time involved in the printing process. Ink-jet inks are complex formulations of dyes and surfactants in a carrier medium, while printing surfaces may be varieous types of treated or untreated paper or porous or swellable layers coated onto various backings. The dynamic interaction, inlcuding diffusion adsorption, wicking and spreading as a function of system composition and morphology is under investigation.

  • Mixed colloids. Here we are investigating the aggregation stability behavior of and floc structure evolution in colloids which consist of more than one dispersed species. One focus is on systems containing mineral pigments together with emulsion droplets (representative of resin binder) in aqueous media. These systems represent one type of water-based coatings which may ultimately replace solvent-based coatings, with both environmental and economic advantages.

  • Gel-trapping of colloidal dispersions. The behavior of colloidal and supra-colloidal dispersions in vosco-elastic media is under investigation. The objectives are to observae and predict sedimentation, diffusion and aggreation behavior in terms od dispersion type and the rheological properties of the medium.

  • Surface energetics and adhesion. Surface energy characterization, in particular acid-base characteristics, of solids is being conducted through capillary measurements, inverse gas chromatography and atomic force microscopy. In particular, micro- and nano-patterned primer layers are being produced and characterized using the pulsed-force mode of AFM. The objective is produce primers which produce strong adhesion between polymers and mineral surfaces while simultaneously promoting moisture resistance and corrosion inhibition. The data characterizing the primer surfaces are being used to correlate with adhesive performance and the mechanical properties of composite materials.