ABSTRACT
The surface area measurement of a dry powder provides information on the properties of the powder as the starting material, but the surface area of dispersed particles is likely going to be quite different. The most important methods for surface area determination are gas adsorption, adsorption from solution, calorimetry, nuclear magnetic resonance, and permeametry. The most reliable method for measuring the surface area of particles is gas adsorption, augmented by electron microscopy to make allowances for crystal shape. The Brunauer-Emmett-Teller (BET) gas adsorption method is the most widely used procedure for the determination of surface areas of solid particles. The interpretation of adsorption data is simplified by using a dilute solution and confirming that the adsorbate is adsorbed much more strongly than the solvent. The surface areas determined by mercury porosimetry and those obtained by the BET adsorption method have been compared.
