Figure 1

TEM images and size distribution of particles. Particles were suspended and prepared for TEM measurements in deionized water. (A) ufTiO2 and (B) fTiO2 are regular and spherical particles in contrast to (C) crystalline silica DQ12 particles that display a very irregular shape. (D) Particle size histograms are derived from the appropriate TEM analysis for primary particles of ufTiO2 and fTiO2 .