Ultrafast Nonlinear Optical Investigations of Supercritical Fluids
Abstract
Both experimental and theoretical methods were employed to gain a molecular level understanding of vibrational energy flow and solute-solvent interactions in supercritical fluids (SCF) as a function of temperature and pressure. Infrared (IR) Ps pump-probe experiments and vibrational absorption spectroscopy were employed to study the vibrational dynamics of solutes in a variety of supercritical fluids. The SCF solvents were ethane, fluoroform, and carbon dioxide. Pump-probe (transient absorption) experiments were used to directly follow the relaxation of vibrational energy as a function of the density at fixed temperature and the temperature at fixed density in SCF solvents. Vibrational spectra were used to observe the spectroscopic shifts of vibrational peaks as a function of density and temperature. Detailed theory was developed to describe the density and temperature dependence of vibrational relaxation. The theory was able to reproduce the experimental results with considerable accuracy using a minimal number of parameters.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 08, 2001
- Accession Number
- ADA395545
Entities
People
- Michael D. Fayer
Organizations
- Stanford University