CORRELATION BETWEEN THE SURFACE FREE-ENERGY OF MODIFIED AND NON-MODIFIED GLASSES WITH CONTROLLED POROSITY AND THEIR SORPTION PROPERTIES

Contact angles for water and diiodomethane drops were measured on the surface of thermally and chemically (by Carbowax 20M bonding) modified porous glasses and on the surface of naphthalene, diphenyl and anthracene. Using the obtained results to a modified Young equation, dispersion and nondispersion components of the surface free energy of these glasses and organic substances were calculated. The work of adhesion (WA) for benzene, naphthalene, diphenyl, anthracene, nitrobenzene was estimated and correlated with the capacity factors, (k′) of these substances. On the basis of experimental and calculated data it can be stated that the thermal treatment of porous glasses increases, their hydrophobicity but the Carbowax layer causes hydrophilicity. There is a linear relationship between k′ and WA which can be helpful for predicting retention data of chromatographed substances on the base of surface free energy which can be calculated from contact angle measurements. © 1990 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.