Surface properties of slates used as filler in composite materials

This work studies the surface using nitrogen and organic vapour adsorption. Nitrogen adsorption has been used to stablish the fractal constant, D-S, o f the slate surface. We have obtained values for D-S between 2,62 and 2,77, showing an important roughness in micro and nanometric scales of the slate surface. The adsorption of organic vapours of neutral, acidic, anphoteric and basic characteristics have been used for determining the London compone nt of the surface free energy and the acid and basic constants of the surfa ce. London component gave a value corresponding to a high energy surface. T he acid and basic constants have shown the anphoteric character of the slat e surface. A first approach to establish the degree of influence of pyrite content of slates in the physicochemical characteristics of the surface.