Nanocomposites and nanomaterials

Combined Polymer Nanostructures for Selective Gas Sensors
Bohdan Tsizh1,2, Olena Aksimentyeva3, Yuliia Horbenko3, Roman Holyaka4
1Kazimierz Wielki University in Bydgoszcz, 30, J.K. Chodkiewicza  St., 85-064 Bydgoszcz, Poland
E-mail: tsizhb@ukr.net
2Stepan Gzytskyi National University of Veterinary Medicine and Biotechnologies Lviv, 50, Pekarska St., Lviv 79010, Ukraine.
3Ivan Franko National University of Lviv, 6 Kyryla-Mefodia St., Lviv 79005, Ukraine 
4National University «Lvivska politehnika», 12, Bandery St., Lviv 79013, Ukraine

In recent years, significant progress has been made in the development of sensors for ammonia, hydrogen, chlorine, oxides of carbon and nitrogen, hydrogen sulfide, volatile organic compounds and other gases and volatile components. Gas-sensitive elements in such sensors are nanocomposite heterostructures based on polyaniline, polyacetylene, polypyrrole, polythiophene and other conducting polymers [1,2]. However, despite a large number of studies, today these structures have a relatively low selectivity, reproducibility and stability, which does not allow them to be used effectively in practice. 
It is shown that optical gas sensors have additional possibilities to ensure their selectivity in comparison with electrical sensors by comparing changes in optical properties at different wavelengths under the action of gases. The features of changes in optical absorption of combined thin-film nanostructures polymeric active elements based on a mixture of polyorthotoluidine and polyorthoanisidine, which allow to selectively identify the presence of ammonia, hydrogen sulfide and carbon dioxide, have been established. A method of selective detection of the analyte by an optical gas sensor on optoelectronic pairs with a mobile matrix of LEDs and photodiodes and the possibility of simultaneous registration of independent signals of parallel optocouplers is proposed.

1. Wang Y., Liu A., Han Y., Li T. Sensors based on conductive polymers and their composites: a review // Polymer International.-2020.-69, N 1.-P. 7–17.
2. Park S.J., Park C.S., Yoon H. Chemo-Electrical Gas Sensors Based on Conducting Polymer Hybrids // Polymers.-2017.-9.-P. 155–179.