Microsensors for In-situ Chemical, Physical and Radiological Characterization of Mixed Waste (73808)

Thundat, Thomas G.

Oak Ridge National Laboratory

关键词: Research Programs;    46 Instrumentation Related To Nuclear Science And Technology;    Monitoring;    Ground Water;    Wastes;   

DOI  :  10.2172/838996
RP-ID  :  EMSP-73808--2004
RP-ID  :  838996

美国|英语

来源: UNT Digital Library

【 摘 要 】

Portable, real-time, in-situ chemical, physical, and radiological sensors for the characterization and monitoring of transuranic waste, mixed waste, ground water, contaminated soil, and process streams are needed within the DOE complex. A continuation of this basic research program is proposed to study the influence of control of the electrochemical potential of a metallic coating on a microcantilever as a means of developing specific and highly sensitive sensors. Basic research will be needed to understand the influence of variation of electrochemical potential on the bending of cantilevers in an electrolyte solution. Changes in the chemical potential of a metal-electrolyte interface, affected by changing the applied potential, leads to a change in the depletion or accumulation of substances at the interface. This change in the surface excess at the interface is reflected in a change in the interfacial tension, which is sensitively detected as cantilever deflection. Deposition of electroactive heavy metals as well as the adsorption of metal oxide species will be detectable as a cantilever bending. We plan to continue field-testing cantilever sensors at DOE sites as appropriate. Practical sensors for Hg and CrO4 -2 have been developed, and the former has been field tested. A sensor for large poorly hydrated anions (ClO4 -, ReO4 -, TcO4 -) based on a quarternary ammonium SAM coating is under development and will be field tested when appropriate. The advantage of cantilever sensors is that once the basic platform is developed, it can be the basis for a plethora of inexpensive, miniature sensors. This program will take advantage of advances in cantilever technology made by other programs as well.