Charpentier Research GroupWestern Engineering

Research Highlights

TiO2 aerogels were produced in Supercritical carbon dioxide (scCO2) solvent using hexamer building blocks withthe morphology and porosity of the products found to be functions of reactant ratios and reactor temperature and pressure. [Link]

Zr-TiO2 nanotubes were synthesized viaa new surfactant-free sol-gel route in supercritical CO2. The morphology of the Zr-TiO2 nanotubes can be tailored by changing either the concentration of the starting materials or the acid-to-metal-alkoxide ratio. This synthesis procedure is simple and scaleable, using mild reaction conditions and a green solvent, and provides a high yield and high-quality nanotubes. [Link]

Effect of solvent on the crystal growth of one-dimensional ZrO2-TiO2 nanostructures was examined for several common sol−gel solvents, including scCO2, hexane, xylenes, isopropanol, and ethanol. After synthesis, all materials were dried similarly in scCO2 to remove the effect of synthesis from drying. Formation of nanotubular structure was found with scCO2, whereas the other solvents gave primarily nanorod structures. [Link]

Polymer chains of PMMA were grown from nano titania (n-TiO2) spherical surfaces by the Reversible Addition Fragmentation Chain Transfer Polymerization process (RAFT) using the green solvent, supercritical carbon dioxide (scCO2). [Link]

A new approach to synthesize titania nanofibers with nanocrystallites via a sol−gel route in supercritical CO2. The nanofibers were formed by the esterification and condensation of titanium alkoxides using acetic acid as the polymerization agent in supercritical CO2 from 40 to 70 °C and 2500 to 8000 psia. [Link]