Binary Adsolubilization of Organic Compounds in a Fluorocarbon Surfactant Adsorbed Layer Formed on Titanium Dioxide

The binary adsolubilization behaviors of 2-naphthol +biphenyl and 2-naphthol +1, 3-dichlorobenzene in a cationic fluorocarbon surfactant adsorbed layer formed on TiO2 have been investigated as a function of pH. In the binary adsolubilization of 2-naphthol+biphenyl, the adsolubilized amount of 2-naphthol increases gradually until pH 7 and then sharply with a further increase of pH, whereas the adsolubilization of biphenyl is not observed in the wide pH region. In the binary adsolubilization of 2-naphthol + 1, 3-dichlorobenzene, the adsolubilization behavior of 2-naphthol shows a similar trend as that of 2-naphthol +biphenyl system, while the adsolubilized amount of 1, 3-dichlorobenzene increases gradually with pH from 3 to 10. The enhancement in the adsolubilization of 2-naphthol at high pH is attributed to the interaction between deprotonated 2-naphthol and the cationic surfactant as well as the increase of interaction between negatively charged TiO2 and the surfactant. The adsolubilized sites for binary adsolubilization of 2-naphthol +1, 3-dichlorobenzene are also discussed from the admicellar partitioning coefficients. Keywords : Binary adsolubilization, 2-Naphthol, TiO2 particles, Fluorocarbon surfactant