Determining the contact angle of a nonwetting liquid in pores by liquid intrusion calorimetry

A microcalorimetric method is proposed to determine the contact angle of a nonwetting liquid within a mesoporous solid. It is based on the simultaneou s measurement of the heat and work of wetting,as the pressure is raised. Th e method simply requires a previous determination of the surface area to be wetted. It allows one to carry out liquid intrusion porosimetry without an y a priori assumption on the contact angle. This method is, in principle, a pplicable to mercury porosimetry. Its feasibility is shown here for water i n porous hydrophobic silicas.