Single-walled carbon nanotube-facilitated dispersion of particulate TiO2 on ZrO2 ceramic membrane filters

We report that SWCNTs substantially improve the uniformity and coverage of TiO(2) coatings on porous ZrO(2) ceramic membrane filters. The ZrO(2) filters were dip coated with 100 nm anatase TiO(2), TiO(2)/SWCNT composites, a TiO(2)+SWCNT mixture, and a TiO(2)/MWCNT composite at pH 3, 5, and 8. Whereas the TiO(2)+SWCNT mixture and the TiO(2)/MWCNT composite promote better coverage and less clumping than TiO(2) alone, the TiO(2)/SWCNT composite forms a complete uniform coating without cracking at pH 5 (similar to 100% coverage). A combination of chemical and electrostatic effects between TiO(2) and SWCNTs forming the composite as well as between the composite and the ZrO(2) surface explains these observations.