Laboratory tests on mercury emission monitoring with resonating gold-coated silicon cantilevers.

摘要: To measure extremely low concentrations of mercury vapor in gases as encountered flue coal-fired power plants, accurate and reliable online and/or portable detection systems are needed. As discussed this communication, resonating silicon-based cantilevers coated with thin films gold change their resonant frequency when exposed to vapors could serve the basis for such sensing devices. Two different types commercial AFM cantilevers, which differed by physical dimensions surface finish, were a 10 nm film tested streams argon containing mercury. The flow rates ranged from 5.7 57.4 ml/min, carrying at between 37 700 microg/m3. results show that smaller (approximately 140 microm x 40 4 microm) 270-275 kHz sensitive less than picograms mercury, whereas larger 245 50 7 155-165 have sensitivity about times lower. indicate kinetics capture coating follows simple law-correlation mass (delta m) being proportional t(n), where t is time n depends strongly on concentration gas. It also demonstrated can be stripped off heating 350 degrees C, would allowthe regenerated reused.