Exploitable results Investigation of basic interface properties of advanced materials applicable to chemical sensors Chemically stable chalcogenide and chalcohalide glasses and thin films for chemical sensing of Cu2+, Cd2+ and Hg2+ ions were investigated. It was found that chalcogenide glasses appear to be promising membrane materials for chemical sensors and microsensors. Developed Cu2+ chemical sensors were applied for continuous in situ monitoring of the waste water treatment at the VITON factory (St.Petersburg, Russia). Further improvement of the sensor properties can be expected by using ion-conducting materials. 64Cu and 110Ag tracer diffusion experiments, electrical conductivity studies, 129I-Mössbauer spectroscopy and EXAFS measurements showed very promising transport characteristics and structure features of CuI-based glassy systems which can be used for this purpose. New Hg2+ chemical microsensors based on thermally evaporated AgBr-Ag2S-As2S3 thin films showed high sensitivity with a low detection limit of 10-8 M (2 ppb), excellent potential reproducibility, high selectivity and long-term stability. XPS studies and tracer measurements of ionic processes at the sensor surface showed that at least 2 different mechanisms are responsible for Hg2+ ion sensitivity of the devices. No commercially available Hg2+ sensors are presently at the market. Preliminary studies of new Cd2+ chemical sensors based on thermally evaporated CdS-AgI-Sb2S3 thin films showed high sensitivity of these materials. Investigations of bulk membrane transport and membrane local structure as well as tracer measurements of ion-exchange at the solution/membrane interface and surface spectroscopy studies of the membrane surface appear to be extremely important to understand sensing mechanism of chemical sensors, to optimize the existing and to develop new membrane materials for chemical sensors. It was found that there is a definitive correlation between membrane local structure and bulk transport properties, on the one hand, and surface ion-exchange characteristics and ionic sensitivity mechanism, on the other hand. It means that there exists a possibility to synthesize new chalcogenide glass membranes with improved ions-selective properties, better durability and response stability. Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
