Adsorption isotherms of n-octane and toluene were determined on thermally treated and rehydroxylated controlled porosity glasses. Based on the film pressure values which were obtained from these isotherms the dispersion and polar components of surface free energy were calculated. It was found that the dispersive interactions do not change significantly, however, they are always higher for the dehydroxylated surface. The rehydroxylation with water vapor seems to provide only the hydrolysis of surface B-O-B and B-O-Si groups, as well as those Si-O-si bridges which are influenced by B atoms. The rehydroxylation with NaOH solution leads to values of the polar component comparable to that of bare glass. The possibility of surface rehydroxylation appeared affected by the presence of both boron and sodium atoms.