SURFACTANT EFFECTS IN VANADIUM ALKOXIDE-DERIVED GELS

Vanadium oxide xerogels (V2O5.nH(2)O) were synthesized by hydrolysis o f alkoxides. A surfactant of the nonylphenol family was added to the w ater-alkoxide mixture. The method was used to achieve better control o f the deposition of the thin films by limiting gelation rate. The rate can be greatly modified in this way and control seems to be due to th e encapsulation of the alkoxide by the surfactant as shown by V-51 NMR spectroscopy. After thermal treatment, xerogels have high porosity wh ich was greater than that of classical V2O5 xerogels (60 m(2)/g instea d of 2 m(2)/g) and the pore distribution is very homogeneous. (C) 1998 Elsevier Science B.V. All rights reserved.