(187e) Polymers Reimagined As Gas Sensing Materials

As our world grows more connected and safety-driven, gas sensing has become essential across a wide range of applications—from detecting indoor/outdoor pollutants and chemical warfare agents to monitoring biomarker gases, greenhouse emissions, and battery off-gassing. This growing demand calls for sensors that are not only highly sensitive but also miniaturized, portable, and flexible to enable integration into wearables, smart packaging, and remote systems. Traditional gas sensing techniques like gas chromatography and Raman spectroscopy, though accurate, are limited by bulky instrumentation, high costs, and slow analysis. Meanwhile, more recent semiconductor metal oxide sensors suffer from high operating temperatures, poor selectivity, and short operational lifespans. Polymeric gas sensing materials, by contrast, offer a compelling alternative as they operate at ambient conditions, are cost-effective, and possess tunable properties that allow for targeted sensing.

The performance of polymeric sensors hinges not only on the polymer backbone but also on the nature and arrangement of functional groups. Moieties such as amine, hydroxyl, carbonyl, and aromatic groups govern analyte interactions and influence key sensing parameters like sensitivity, selectivity, and stability. This study examines how functional groups affect the gas sensing behavior of both conducting and non-conducting polymers, specifically targeting volatile organic compounds (VOCs) such as formaldehyde, acetaldehyde and benzene. Materials studied include polyaniline (PANI), polypyrrole (PPy), polythiophene (PTh), and polyvinylpyrrolidone (PVP), along with modified PANI derivatives bearing different side chains to explore backbone-level modifications.

Distinct trends in sensitivity and selectivity were observed, which could be attributed to the nature of electrostatic interactions between analyte molecules and the polymer matrix, as well as the influence of polymer morphology. Altogether, this work advances the fundamental understanding of structure–property relationships and offers a framework for engineering next-generation polymeric gas sensors tailored for environmental, industrial, and biomedical applications.