Polymers for Detecting or Protecting Against Chemical Warfare Agents: Recent Advances and Future Perspectives

The persistent threat of chemical warfare agents (CWAs) drives the need for advanced detection and protective technologies. Polymers, with their tunable structures, ease of functionalization, and lightweight nature, have emerged as a versatile platform in this field. This review systematically summarizes recent progress in polymer-based materials for CWA sensing and protection, with emphasis on interaction mechanisms and structure-property relationships. In the realm of sensing, the working principles of polymer-based systems are rooted in electron transfer, hydrogen bonding, fluorescence quenching, and colorimetric response. Conductive polymers enable chemiresistive detection through charge transfer; hydrogen-bond acidic polymers provide selective recognition of organophosphorus agents; conjugated polymers exploit fluorescence quenching via the "molecular wire" effect; and polydiacetylenes offer visible color changes for naked-eye detection. Representative materials and their performance metrics are critically compared. For protection and decontamination, current polymer systems are designed around four synergistic mechanisms: barrier action, physical adsorption, filtration, and catalytic degradation. Barrier layers based on crosslinked networks or graphene/MOF composites suppress agent permeation while maintaining breathability. Porous polymers such as polymers of intrinsic microporosity (PIMs) and coordination polymers provide high-capacity adsorption through tailored surface functionality. Electrospun nanofiber membranes effectively filter aerosolized agents with low air resistance. Catalytic composites incorporating Zr-MOFs or single-atom catalysts enable hydrolysis of nerve agents and oxidation of blister agents under ambient conditions, with recent advances achieving self-buffering and solid-state operation. Despite significant advances, challenges remain in selectivity, environmental stability, and balancing protection with wearer comfort. Future directions point toward multifunctional systems that integrate detection, protection, and self-detoxification within wearable polymer platforms for next-generation chemical defense.