NOTE
Cationic Surfactant Adsolubilization of 2-Naphthol and Naphthalene with Titanium Dioxide Having Dodecyl Chain tetrasiloxane (TMCTS) vapor obtained from Shin-Etsu Chemicals Co., Ltd. at 80ะC for 16 h. Then Si-H groups on the titanium dioxide were reacted Adsolubilization of 2-naphthol and naphthalene by cationic surwith 1-dodecene in ethanol in the presence of H 2 PtCl 6 as catalyst at 60ะC
factant-adsorbed layers formed on titanium dioxides with or withfor 4 h. After reaction with 1-dodecene, the surface-modified samples were out a dodecyl chain was investigated. The cationic surfactants filtered, were washed with ethanol, and then dried at 110ะC for 16 h in used were dodecyltrimethylammonium bromide and 1,2-bis(dodevacuo. The identity and content of the dodecyl chain anchor on the surfacecyldimethylammonio) ethane dibromide (2RenQ). It was found modified samples were determined by elemental analysis and infrared spec- that the adsolubilized amounts of 2-naphthol and naphthalene troscopy. The surface coverages with TMCTS were obtained from the calcu- increase and reach a maximum and then decrease for both surfaclation of density and molecular area of TMCTS. In this study, titanium tants and titanium dioxides with or without the dodecyl chain, dioxide with 47.2 mmol dodecyl chain groups per gram (95% TMCTS where in the absence of surfactants the incorporated amount of coverage) was used and this sample will be referred to as D-40 as well as naphthalene on the titanium dioxide with the dodecyl chain is D-0 (bare sample).
As surfactants, dodecyltrimethylammonium bromide (1RQ) and 1,2-bis-markedly large. The adsolubilized amounts of 2-naphthol and
(dodecyldimethylammonio) ethane dibromide (2RenQ) were used. 1RQ
naphthalene were enhanced with the titanium dioxide with the was obtained from Tokyo Kasei Co. and was used after crystallization from dodecyl chain by adsorption of surfactants, in particular 2RenQ.
acetone. 2RenQ was synthesized (10) and was used after purification. 2-
The admicellar partitioning coefficients also showed that naphtha-Naphthol and naphthalene were obtained from Tokyo Kasei Co. and were lene is adsolubilized preferentially rather than 2-naphthol and the used as received. The water used in all experiments was purified through surface treatment with the dodecyl chain enhances the adsolubilia Milli-Q system. The other chemicals were of guaranteed grade. zation for two adsolubilizates.