Dye sensitised solar cells, based around colloids of the wide bandgap semiconductor TiO2 with bound dyes have potential to provide a cheap,sustainable source of solar energy conversion to electricity. Currently these cells use an organic solvent to dissolve the electrolyte which is a critical component of the cells. The solvent is environmentally toxic so we are investigating water as an alternate solvent in the cells. However efficiencies in water-based cells are lower than those using the organic solvent, and it has been suggested this is due to formation of a gel layer on the TiO2 surface. Here we propose to use SANS to compare the surface structures of the TiO2 colloids used in solar cell preparation in aqueous and organic solutions, with and without the electrolyte, to determine whether the solvent alters the surface structure of the colloid.