(98bg) Surface Wetting and Contamination On Alumina Ceramic

Surface energy quantifies the chemical interactions on a surface which are available for coating and adhesion.  At a basic level, a liquid will coat a surface if the surface energy is greater than the liquid’s surface tension.  At a more complex level, the types of intermolecular interactions, such as dispersion forces or hydrogen bonding, at the surface are important for determining the degree of wetting.  The surface energy of 94% alumina ceramic will be presented, including the relative influence of polar and non-polar interactions at the surface.  These measurements will be used to identify factors which may influence the quality of an epoxy adhesive joint on the ceramic.  The effect of cleaning method, heat treatment, aging and several contaminants at the surface will be examined.  Finally we will demonstrate that for this 94% alumina ceramic, the contact angle of water correlates very well with the total surface energy and can be used as a quick method for analyzing surface cleanliness.