Oxime-Functionalized, Nonwoven Nanofabrics for Rapid, Inexpensive Decontamination of a Nerve Agent Simulant

Organophosphorous-based nerve agents remain one of the most toxic and accessible chemical warfare agents known to man. Herein, we report the development of novel, oxime-functionalized poly(4-vinylpyridine) (P4VP-Ox) materials as inexpensive, scalable polymeric substrates capable of rapid decontamination of nerve agents, as demonstrated using one nerve agent simulant, dimethyl-4-nitrophenyl phosphate (DMNP). The incorporated oximes adjacent to positively charged pyridinium salts remain deprotonated at neutral to slightly basic pH, providing super-nucleophilic materials to deactivate nerve agents and their simulants rapidly and irreversibly. These materials were electrospun to form nanofabrics, providing increased surface area and enhanced reactivity for degradation of DMNP. Nanofibers obtained from P4VP functionalized at 20 mol % pendants with ortho-pyridinium oximes moieties (P4VP-OOx20%) provided the fastest reaction kinetics. This substrate provided complete decomposition of DMNP within 1.5 h and calculated t1/2 = 14.4 min. The P4VP-Ox substrates were also found to be recyclable, allowing for quantitative DMNP degradation within 8 h over the course of four reaction cycles. Furthermore, to mimic real-life scenarios, we attempted solid-state DMNP degradation via applying small drops of DMNP directly on the nanofabric substrates and extracting with water for 31P NMR analysis. Overall, the P4VP-OOx20% substrate was found to retain its reactivity in the solid state, with the as-prepared nanofabric displaying >95% DMNP degradation after 6 h. When performed in different environments (i.e., 100% humidity, hexanes-rich atmosphere), the reactivity diminished slightly but still displayed >95% degradation after 24 h of reaction, establishing these materials for applications as reactive, economical, and easily scalable Chem-Bio protective materials.

Automated summary

In this study, novel oxime-functionalized poly(4-vinylpyridine) (P4VP-Ox) materials were developed as inexpensive and scalable polymeric substrates for the rapid decontamination of nerve agents. Nanofibers obtained from P4VP functionalized at 20 mol % pendants with ortho-pyridinium oximes moieties provided the fastest reaction kinetics, achieving complete decomposition of DMNP within 1.5 h. The P4VP-Ox substrates were also found to be recyclable, allowing for quantitative DMNP degradation within 8 h over the course of four reaction cycles.