(Digital Presentation) Rapid Electrical Impedance Analysis to Identify Liquid Isomers Using Nanoparticle Thin Film

Abstract

A rapid noncontact analysis method to identify liquid isomers using an insulating nanoparticle thin film is outlined in this study. Rapid electrical analysis of chemical liquids is a promising technique for on-site evaluation. A silica nanoparticle thin film is utilized as a sensing layer. Headspace vapor from the liquid is condensed in the nanoscale void between nanoparticles, and an ionic conduction through the condensed vapor occurs under the application of AC voltage. The transient response of the electrical impedance depends on the vapor pressure and conductivity of the liquid isomers. A chemical liquid of structural isomers was identified by monitoring the impedance during exposure to its headspace vapor. The response time of the film impedance was 10.6, 4.7, 7.5, and 2.4 s, in 1-butanol, 2-butanol, 2-methyl-1-propanol, and tert-butyl alcohol, respectively. The isomer recovery time after the exposure to ambient air was less than 2 s for all samples. It is feasible to identify polar chemical liquids rapidly by combining this sensing mechanism and machine learning models in the future.