Detection and Characterization of Chemicals Present in Tank Waste - Final Report - 09/15/1998 - 09/14/2001

Datskos, Panos G. ; Sepaniak, Michael J.

The University of Tennessee, Knoxville, TN (United States)

关键词: Oxidizers;    Organic Chemicals;    Nitrates;    Cantilever Surfaces;    Analytes;   

DOI  :  10.2172/790360
RP-ID  :  DOE/ER/62718
RP-ID  :  FG07-98ER62718
RP-ID  :  790360

美国|英语

来源: UNT Digital Library

【 摘 要 】

DOE has a strong commitment to the efficient and safe remediation of waste (high level radioactive waste, mixed waste, and hazardous waste) present in underground waste storage tanks. Safety issues arise from the presence of organic chemicals and oxidizers and concerns are raised about the flammability, explosivity, and the possible corrosion of storage tanks due to presence of nitrates and nitrites. Knowledge of the physical parameters and chemical and radioactive composition of waste is necessary for effective and safe tank remediation. New and improved characterization and monitoring of waste present in storage tanks is necessary. The overall goal of this project has been to develop and demonstrate novel multi-parameter micro-electro-mechanical system (MEMS) sensors based on Si and SiNx microcantilever (MC) structures that are robust and can be used to simultaneously detect the presence of target chemicals (analytes) in a mixture, radiation emitted from radioactive materials, an d the heat generated by the absorption of photons of specific wavelength by the target analytes. The mechanisms by which adsorption, photophysical, photothermal processes cause stress in MC surfaces are better understood. Methods of applying a wide variety of chemically selective coatings have been developed specifically for miniaturized MC surfaces, and the response characteristic of the cantilever were shown to be altered dramatically and predictably through incorporation of these phases on the surfaces. By addressing sensitivity and liquid matrix issues, the spectroscopic approach promises to provide an essential element of specificity for integrated sensors. We discovered early in these studies that fundamental limitations exist regarding the degree to which adsorption of analytes on smooth surfaces cause stress and this significantly limits chemi-mechanical response. To circumvent this limitation a concerted effort was made to devise and test ways to nanostructure cantilever surfaces, thereby creating new mechanisms of analyte-induced stress. Substantial improvement in chemi-mechanical response resulted from this work.