Summary	Photodissociation of near critical CO₂. High pressure from ncCO₂ is photoionized for dissociation.
Owner	Shannon A. Fiume
Status	CLOSED

Description

Coherent light can be used to seed a chamber such as a cylinder filled with CO2. Ultra Violet light at 213 and 266 nm wavelength at high pressure 7.38MPa will dissociate near critical CO2, U. Brighton.

Background

Dissociation of carbon dioxide and creation of carbon particles and films at room temperature (UV)

http://iopscience.iop.org/article/10.1088/1367-2630/9/9/321/meta

Ray Whitby

U. Brighton

Carbon was generated at 213nm and 266nm wavelength at 7.38 MPa and 31.0ºC from Near Critical CO₂
Broadening and shifting of the D and G peaks on obtained sample, ID as highly disordered carbon (D => 1380 compared to 1350 cm^-1 for graphene (two TO phonons near K point)), G peak, 1600 vs graphene G => 1580 cm^-1 (double degenerate TO ^ LO phonon mode, at gamma point)
Opalescence didn’t correlate to generating solid carbon, only lowering the wavelength acting on ncCO₂. Opalescence would indicate the CO₂molecule would vibrate down to a specific resonant state, yet it was the wavelength at the same pressure and temp that appeared to govern solidification. Would higher pressure force the molecules to a smaller space where more laser light would be more likely to ionize to ultimately break bonds?

Next Steps

Experiments

Theories

Results

Project closed due to lack of resources. Newer experiments involving forming nanocarbons should also include test plans for testing the experiment under near critical to super critical pressures, and verify efficiency at high rates forming carbon. Dissociation experiments should test if and record the extent of any effect pressure has on the experiment. Wavelengths and other CO2 data will be aggregated by the Chemical Dissociation Meta Analysis study project.

Photoionization

UV Photoionization