Titania sols and gels synthesized from reverse micelles

TiO nanoparticles are synthesized in water/AOT/isooctane reverse micelles by hydrolysis of titanium (IV) n-butoxide. The molar ratios of the three components defines the size of nanoparticles as determined from the uv-visible absorption onset of the disperse system. Depending on the relative content of each component this sol undergoes a gel phase. The kinetics of sol-gel process is monitored for different Ti(BuO)./ water/AOT molar ratios, and as a function of temperature by static viscosity, and by the optical density of the system in the spectral range where light scattering is the dominant optical process. The water content of the system and the Ti(BuO)/water molar ratio have great influence on the kinetics of the gelation process. An activation energy of (91 ± 9) kJmol was obtained from Arrhenius plots.