Formation of titanium hydroxide nanoparticles in supercritical carbon dioxide

Abstract

Titanium isopropoxide [TIP, C(12)H(28)O(4)Ti] hydrolysis in supercritical carbon dioxide (SCCO(2)) was performed using an aerosol solvent extraction system (ASES). The experiments were conducted at a pressure of 80-150 bar and a fixed temperature of 35 degrees C, with a nozzle size diameter that ranged from 0.007 inch (0.18 mm) to 0.04 inch (1.02 mm). The TIP concentration in the liquid solution was varied from 0.1 to 2 wt.%. In situ formation of titanium hydroxide (Ti(OH(4)) nanoparticles was found during the ASES process. The effect of pressure, TIP concentration in the liquid solution, and nozzle size diameter on Ti(OH)(4) particle size was investigated. Based on scanning electron microscope and electrophoretic light scattering analyses for particle size, non-faceted titanium hydroxide particles were obtained in the range 132-356 nm.