Highly stable, temperature- and humidity-responsive entactogens for long-term sustained release of ClO₂

Eutectogels have emerged as promising materials for disinfection applications under complex environmental conditions, owing to their remarkable stability and adaptive properties. In this study, a deep eutectic solvent (DES)-activated eutectogel (PVA/CMC-ZE@NaClO 2 ) was developed through physical cross-linking of polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) within a DES medium. The resulting gel exhibits dual-responsive behavior to both temperature (−20 to 50 °C) and humidity (55–90 % RH), enabling intelligent and sustained release of ClO₂ even under extreme environmental conditions. A key innovation lies in the role of DES as an activator, which reacts with NaClO₂ under moisture stimulation to continuously generate gaseous ClO₂. The eutectogel demonstrates high structural integrity across challenging environments—including cold, humid, and dry settings—maintaining stable ClO₂ release for over 20 days. This prolonged disinfectant delivery confers strong antibacterial efficacy, making the material suitable for broad public health applications. Additionally, the gel is readily reshapeable and reusable, while also being fully biodegradable within 20 days under ambient conditions. This work presents the first example of a eutectogel-based slow-release system for ClO₂, offering a new paradigm for designing intelligent, environmentally adaptive materials with extended release performance for disinfection in extreme settings.