Robert Thompson Ph.D.
Dr. Thompson's research interests are in applied kinetics and reactor analysis, especially as applied to the analysis of particulate systems. One current research interest focuses on the use of population balance methodology and experimental methods to understand and analyze the molecular sieve zeolite crystallization. Other topics of interest are: oxidative degradation of the polyethylene component in orthopedic implants and removal of volatile organic compounds from water supplies. Professor Thompson is one of the regional editors of Microporous & Mesoporous Materials, and is on the editorial board of Current Opinion in Solid State & Materials Science. Current research interests are:
Water Remediation by Hydrophobic Molecular Sieves
Efforts to remove hazardous organic compounds from water by chemical means (e.g., liquid-phase oxidation) generally require such large processing volumes that it becomes impractical. Chlorination of polluted waters can stimulate formation of Chlorinated Organic Compounds, many of which are worse than the natural organic material present in drinking water aquifers. We have developed new technologies to remove some pollutants using hydrophobic molecular sieves that exclude water from their micropores. Our research suggests that some modifications to molecular sieve zeolites to enhance removal capacity should be possible. Our focus to date has been on trichloroethylene (TCE) and methyl tertiary butyl ether (MTBE) removal from water.
Regeneration of Zeolite Adsorbents
We have begun collaboration with Professor John Bergendahl in the Civil and Environmental Engineering Department to regenerate the hydrophobic molecular sieves after they have successfully removed Volatile Organic Compounds (VOCs) from drinking water. In-situ Fenton’s Oxidation is being studied to detoxify the VOCs, thereby regenerating the zeolites for subsequent use. The processing volume is much smaller and more economical, the regeneration conditions are much milder than typical high-temperature gasification, and the harmful organics are not released into the atmosphere as in typical gasification or oxidation processes.
Equation of State for Confined Water
Theoretical aspects of the topics summarized above involve the analysis of water in the micropores of the hydrophobic adsorbents of interest. These analyses thus far have shown that the formation of a condensed liquid phase in "hydrophobic" micropores is quite sensitive to the fluid-wall interaction energy and the pore dimensions. Quite small changes in either parameter can make extraordinary differences in the state of confined water molecules. Additional follow-up work is in progress, using both the equation of state model and more recent Molecular Dynamics calculations.
Self-Assembly of silicalite-1 NanoParticles
We recently have collaborated with a colleague in Taiwan, Republic of China to isolate and manipulate nano-particulates of the hydrophobic zeolite, silicalite-1. The harvesting technique involves terminating a standard synthesis when the particulates are still nanometers in dimension, flocculating them with a surfactant, then steaming them to facilitate “zeolitization,” resulting in aggregates of the nano-particulates. Work is under way to develop larger aggregates which might be suitable for fixed bed applications.
Oxididative Degradation of UHMWPE
The plastic component of orthopedic implants is typically Ultra High Molecular Weight Polyethylene, which provides cushioning and ease of movement. These parts are made in myriad sizes, and are selected for implant only after the surgeon has determined the best fit for each individual patient. Sterilized components may require a shelf life of up to eight years prior to being implanted. In some cases the sterilization technique can initiate free radical formation, which, in the presence of atmospheric oxygen, can trigger a sequence of oxidation reactions that ultimately lead to degradation of the component, both chemically and mechanically. This degradation can lead to required replacement surgery. Our experimental and theoretical research seeks to understand the oxidative degradation process, develop reliable model simulations of the chemical reactions, and propose and investigate alternative sterilization strategies to minimize the degradation. The ultimate objective is to extend the useful life of components before replacement is suggested.
EducationB.Sc. (Ch.E); 1971 - Clarkson College of Technology; M Sc. (Ch.E); 1973 - Clarkson College of Technology; Ph.D. (Ch.E); 1975 - Iowa State University
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