Viewing the cybotactic structure in gas-expanded liquids (GXLs)

I&EC 78

Rigoberto Hernandez, hernandez@chemistry.gatech.edu1, John L. Gohres, john.gohres@chbe.gatech.edu2, Charles L. Liotta1, and Charles A. Eckert, cae@gatech.edu3. (1) School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, NW, Atlanta, GA 30332-0400, (2) Department of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332, (3) School of Chemical and Biomolecular Engineering and Specialty Separations Center, Georgia Institute of Technology, 311 Ferst Drive, NW, Atlanta, GA 30332-0100
A synergistic collaboration between experiment and microscopic molecular dynamics simulations has provided a view of the heterogeneous environments surrounding solutes in GXLs. The former are essential in validating the computational model which relies on the metastability of the liquid phase in contact with a CO2-rich phase. The cybotactic structure of CO2-expanded methanol and acetone has been seen to be sensitive to CO2 overpressure. In particular, solutes are preferentially solvated in solvent-rich regions. This is consistent with the corresponding solvatochromic measurements of dissolved chromophores, though only the molecular dynamics simulations reveal the typical structure of the solvent around the probe.
 

Green Chemistry and Engineering with Gas Expanded Liquids and Near-Critical Media
8:00 AM-11:25 AM, Wednesday, August 22, 2007 Boston Park Plaza -- Clarendon Rm, Oral

Division of Industrial & Engineering Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007