UC San Diego

The efficient adsorption or catalytic degradation of toxic chemicals is desired to provide effective personal protection in both industrial and possible military situations. The possibility of both chemical warfare agents (CWAs, e.g., VX) and toxic industrial chemicals (TICs, e.g., NH3) being released underscores the need for new materials capable of sequestering and/or decontaminating these chemicals. For this purpose, we developed a new composite material by conjugating an inorganic molecule with nano-sized silica support. Specifically, zirconium (oxo) hydroxy methacrylate (Zr cluster) composed of a Zr6O4(OH)4 node and methacrylate backbones is polymerized on the surface of silica (SiO2) nanoparticles upon UV irradiation, and this composite material is tested for (1) catalytic hydrolysis of a CWA simulant, dimethyl p-nitrophenyl phosphate (DMNP) and (2) adsorption of a TIC, ammonia. The composite material displays superior catalytic performance towards DMNP hydrolysis compared to the "free" Zr cluster, and it also shows greater adsorption capacity for NH3 than the bare silica nanoparticles. The advantage of the low-cost and low-complexity of the synthesis is demonstrated in a notional clothing decontamination scenario, where the Zr-silica composite catalyst is embedded in fabric swatches and evaluated for its adsorption and decontamination capabilities.