The interactions at the carbon fiber surfaces are of fundamental importance for the reinforcement of polymers with carbon fibres. A modified sessile drop technique is proposed for the determination of the surface free energy of carbons and the interactions at carbon surfaces (work of adhesion). The method is based on the advancing contact angle (film-free surface) of aqueous solutions with pH values ranging from 1 to 14. The works of adhesion calculated from the advancing contact angle show a distinct dependence on the pH value. This dependence allows the determination of the dispersion component of the surface free energy and the acid-base interaction energies. The method was tested with high-temperature polymers and successfully applied to carbons. © 1991.
Hüttinger, K. J., Höhmann, S., & Seiferling, M. (1991). A modified sessile drop technique for the determination of the interactions at carbon-liquid interfaces. Carbon, 29(3), 449–455. https://doi.org/10.1016/0008-6223(91)90214-4