Anatase and rutile TiO2 macrocellular foams:: Air-liquid foaming sol-gel process towards controlling cell sizes, morphologies, and topologies

Titania foams (see Figure) can be produced using a non-static air-liquid foaming sol-gel process where nitrogen is bubbled through a mixture of a surfactant and a sol-gel precursor. Either anatase or rutile phase mesoporous titania foams are produced upon thermal treatment. Macroscopic cell morphologies can be tuned by changing the air-to-liquid-foam ratios and the size of the nitrogen bubbles, while wall topologies can be varied by changing surfactant.