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| Properties for Separations |
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| Objective: |
| Provide the critical physical, chemical, and process information and measurement infrastructure required to effectively design and evaluate physical and chemical separation technologies. |
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| Description: |
| Physical and chemical separation technologies play an enormous role throughout chemicals and materials manufacture, effluent control, environmental remediation, and water utilization. The project seeks to develop measurement techniques, rooted in sound physical and chemical understanding, that provide the property and process information required to design and evaluate large scale separations technologies. The project includes research tasks focused on: supercritical fluid extraction, properties of alternative solvents, properties data key to separations - enthalpies of absorption, ranges of miscibility, etc. - for key industrial compounds, and benchmark measurements of the transport of gases, liquids and vapors in membranes and films. The tasks included in this project are: “Separations” and “Membranes” |
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| Area(s) of Application: |
- Chemical and Allied Products
- Other: Forensics and Homeland Security
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| Accomplishments: |
- Explosives on Surfaces: A Sticky Problem: Explosive compounds need to be detected on a variety of surfaces - clothing, suitcases, shoes, etc. Every surface will interact with the compounds and the degree of adhesion will vary, surface to surface. By and large, detection of these compounds relies on getting the molecules off the surface and into the gas phase. The most fundamental measure of the interaction strength with a surface is an “energy quantity” termed enthalpy. For polymeric materials, similar to silicone rubber, we have determined the enthalpy of absorption, DH SOL, for TNB, TNT, and RDX (57.85 ± 0.2, 59.48 ± 0.2, and 62.36 ± 0.2 kJ/mole, respectively). These are values similar to the long chain alkanes on the same surface suggesting that the latter might serve well as surrogates in testing of instruments. We also note that the enthalpy of vaporization for pure TNT and TNB are higher (by ~ 20 kJ/mole) than the DH SOL values. This means that it takes less energy to “desorb” an explosive molecule from a silicone rubber-like material than it would to volatilize (say by heating) a molecule from a solid particle of the pure explosive.
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| Other related project work: |
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| External Collaborators: |
- Keith E. Miller, University of Denver
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| Principal Investigator:
Tom Bruno |
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