Dispersions of anatase in ambient temperature ionic liquids

1-Ethyl-3-methylimidazolium (EMI) tetrachloroaluminate ("basic melt," AlCl3 : EMICl ratio 0.94) and EMIBF4 were studied as two examples of ambient temp erature ionic liquids (salts that are liquid at room temperature). Dispersi ons of graphite and anatase (300 nm in diameter particles) in these media a re surprisingly stable considering the high (about 4 mol dm(-3)) ionic stre ngth. Electrostatic interactions play a rather insignificant role in the st ability of anatase in EMIBF4, with the absolute value of electrophoretic mo bility of the particles not exceeding 3 x 10(-10) m(2)V(-1) s(-1). The sign of electrophoretic mobility depends on the presence of traces of water in EMIBF4. The particles carry a positive electrokinetic charge in dehydrated EMIBF4, and in the presence of 1% water (added as liquid water or absorbed from the atmosphere) the sign is reversed to negative. (C) 2001 Academic Pr ess.