Development of semiconductor-based adsorption-modified photosensitization (SAMP) sensors for a sensor array device for the monitoring of organic gasesстатья
Дата последнего поиска статьи во внешних источниках: 29 мая 2015 г.
Место издания:EPA Center on Airborne Organics Mass., United States
Первая страница:86
Последняя страница:91
Аннотация:http://web.mit.edu/airquality/www/AR99/7m1.htm
The goal of this research is to carry out the initial studies which will lead to the development of a small, easily fieldable instrument to measure organic vapors in air from sources, in industrial atmospheres, or in the ambient air. The SAMP sensors, in theory, offer high sensitivity and selectivity, small size, and it is simple to change their selectivity profile by employing different dyes. This makes them ideal for assembling into an array. There are well developed techniques for 'training' an array of differently sensitive sensors by exposing the system to various known sample concentrations, so that unknown samples can be characterized. An 'ozone precursor index' is an example of a possible output of this sensor array system.
The sensitivity of the sensor's response varies with the overlap of the sorbed gases' IR spectra with that of the photosensitizing dye. Initial versions of the device have been made with rhodamine dyes, which contain aromatic rings in their structures. Sensors coated with rhodamine are sensitive to such compounds as benzene, toluene, xylenes and other substituted benzenes (BTEX group). In addition, the molecular vibrations of olefinic compounds may also resonate with rhodamine, and will certainly do so with other suitable dyes. Initial work will focus on the BTEX compounds and possibly olefins, as these seem to be the most promising and are also of great environmental interest, as reactive ozone precursors. Eventually, the development of a small, rugged, portable device which can give an overall index of a particular air quality parameter is the goal of this research.