Zeolite-Confined Ionic Liquid Enables On-Demand Active Bromine Generation for Thermally Robust and Reduced-Dosage Antimicrobial Materials

Abstract

The proliferation of multidrug-resistant pathogens and persistent microbial contamination in industrial settings necessitates the development of robust, processable, and highly efficient antimicrobial additives. Herein, we report HZSM-5/ionic liquid composite, constructed by confining and chemically anchoring a bromine-containing ionic liquid (IL) within the microporous channels of HZSM-5 zeolite. This unique structure imparts exceptional thermal stability, with the confined IL withstanding temperatures exceeding 330 °C and retaining full bactericidal activity after high-temperature (250 °C) processing, demonstrating its suitability for industrial meltprocessing applications. Then, a potent synergistic mechanism wherein the host-guest system catalytically activates molecular oxygen to generate reactive oxygen species (ROS), which in turn oxidizes the bromide anions (Br -) into elemental bromine (Br 2 ) in-situ is proposed. This selfenhancing cycle, confirmed by XPS, EPR, and UV-vis spectroscopy, enables the composite to achieve superior bactericidal efficacy against a range of pathogens, including MRSA, at a significantly reduced IL dosage compared to the pure IL and conventional agents. The mechanism involves a multi-pronged attack combining electrostatic adsorption, dual-action membrane disruption (IL and Br 2 ), and an intracellular ROS burst. This work presents a new design paradigm for creating thermally stable, high-performance antimicrobial materials with significant potential to address pressing industrial challenges in polymer processing, medical devices, and functional coatings.