Design and Application of Photocrosslinkable Hydrogel Films for Fast and Efficient Decontamination of Chemical Warfare Agents

This paper describes the design of photocrosslinkable interpenetrated network hydrogel peelable films, presenting the remarkable ability to successfully neutralize and safely remove from contaminated surfaces two of the most notorious highly toxic real chemical warfare agents (CWAs)─the blistering agent mustard gas (HD) and the nerve agent soman (GD). The goal of this study was to develop an innovative method for CWA decontamination that allows fast and efficient remediation of CWA-affected sites by entrapping the toxic compounds inside the polymeric matrix of the hydrogel, along with their efficient degradation using a dual route─hydrolytic and photocatalytic. With this aim, eight different formulations were developed for CWA decontamination involving aqueous blends containing the water-soluble components: a polymer (polyvinyl alcohol), monomers (acrylamide, acrylic acid, and/or 2-hydroxypropyl methacrylate in different molar ratios), a crosslinker (N,N′-methylenebisacrylamide), and a photoinitiator [2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiphenone]. Also, in four of these decontamination solutions, titanium dioxide nanoparticles were incorporated to investigate if their photoactive potential can enhance the CWA decontamination process. The outstanding ability of these materials to neutralize CWA, as well as their suitability for decontamination purposes, was demonstrated through a variety of analytical tools (scanning electron microscopy, micro-CT, Fourier transform infrared spectroscopy, thermogravimetric analysis, dynamic mechanical analysis, and shear, tensile, and compression tests), swelling investigations, and gas chromatography–mass spectrometry surveyed decontamination tests on two real warfare agents (HD and GD) and one chemical warfare simulant (dimethyl methylphosphonate, a simulant for G series nerve agents). After peeling the hydrogels from the contaminated surfaces, the decontamination efficiency was calculated, and the values obtained varied from 99.35 to 99.98%.