Abstract
The Hard Soft Acid Base (HSAB) theory is introduced as a new tool to select or design sensitive materials for carbon dioxide detection with SAW-BAW (Surface Acoustic Waves - Bulk Acoustic Waves) devices. According to HSAB, CO 2 is hard acid, thus small organic or inorganic molecules, or polymers which can act as hard bases could be suitable candidates as sensing layers for carbon dioxide detection. As a consequence of this theory, we propose the following polymers as potential candidates for CO 2 sensing: simple polyallylamine, N-substituted polyallylamine, polydiallylamine and polyvinylamine, and mixtures of these polymers. The SAW device coated with one of the selected polymers, polyallyamine, shows good sensitivity for CO 2 concentration (in the range 500–5000 ppm), long term stability and repeatability.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
