Title :
Controlled microstructure oxide coatings for chemical sensors
Author :
Frye, G.C. ; Brinker, C.J. ; Bein, T. ; Ashley, C.S. ; Martinez, S.L.
Author_Institution :
Sandia Nat. Lab., Albuquerque, NM, USA
Abstract :
The use of porous oxide coatings, formed using sol-gel chemistry routes, as the discriminating elements of acoustic wave (AW) chemical sensors, is investigated. These coatings provide several unique advantages: durability, high adsorption capacity based on large surface areas, and chemical selectivity based on both molecular size and chemical interactions. The porosity of these coatings is determined by performing nitrogen adsorption isotherms using the AW device response to monitor the uptake of nitrogen at 77 K. The chemical sensitivity and selectivity obtained with this class of coatings is demonstrated using several examples: hydrous titanate ion exchange coatings, zeolite/silicate microcomposite coatings, and surface modified silicate films.<>
Keywords :
chemical variables measurement; gas sensors; sol-gel processing; surface acoustic wave devices; ultrasonic transducers; 77 K; N/sub 2/; acoustic wave sensors; adsorption capacity; chemical selectivity; chemical sensors; discriminating elements; durability; ion exchange coatings; microcomposite coatings; molecular size; nitrogen adsorption isotherms; porous oxide coatings; sol-gel chemistry routes; surface areas; Acoustic waves; Chemical elements; Chemical sensors; Chemistry; Coatings; Microstructure; Monitoring; Nitrogen; Surface acoustic wave devices; Titanium compounds;
Conference_Titel :
Solid-State Sensor and Actuator Workshop, 1990. 4th Technical Digest., IEEE
Conference_Location :
Hilton Head Island, SC, USA
DOI :
10.1109/SOLSEN.1990.109821
