Figure 1.

Representative scanning electron microscopic images of fractionated TiO₂ in distilled water. TiO₂ suspension in deionized water was fractionated to three different hydrodynamic sizes by differential speed of centrifugation. The supernatant was carefully taken and designated as TiO₂^P25–300 (A), TiO₂^P25–130 (B), or TiO₂^P25–70 (C) after centrifugation for 20 minutes at 0 rpm, 4000 rpm (6570 g), or 8000 rpm (9870 g), respectively.

Note: Scale bars indicate 500 nm (upper) and 100 nm (lower).