Physicochemical Characteristics of Nanocomposites under Environmental Exposure Conditions for Space Applications

Abstract

Despite well-perceived advancements of nanotechnology for space applications, application of nanotechnology in the aerospace industry has potential challenges in the perspectives of monitoring and accurately measuring types and levels of pollution. Nanomaterials applied for chemical nanosensors should be well characterized and designed to detect contaminant levels different from Earth’s. However, a few studies have investigated the transformation and efficacy of aged nanomaterials in sensor development. The present study explored the aging effect of oxygenation, UV irradiation, and heat treatment on selected nanomaterials (i.e., GO, CNTs, ZnO nanowire, TiO2, and ZnO) in the perspective of sensing performance to detect trace contaminants. Further, GO-CNT nanocomposite thin films deposited on electrode chips were exposed to the CO2 gas contaminant, and their electrical resistance was measured. Results indicate significant changes in physicochemical properties (particle size, zeta potential, and absorbance) of the model nanomaterials under oxygenation and UV irradiation, which was further investigated on their electric resistance upon exposure to gaseous contaminants. The assessment of changes to the CO2-sensing ability of carbon-nanotube or graphene-oxide hybrid thin films suggests decreasing sensitivity under both UV irradiation and oxygenation.