In-situ detoxification of schedule-I chemical warfare agents utilizing Zr(OH)4@W-ACF functional material for the development of next generation NBC protective gears.

Chemical warfare agents (CWAs) have become a pivotal concern for the global community and spurred a wide spectrum of research for the development of new generation protective materials. Herein, a highly effective self-detoxifying filter consisting of in-situ immobilized Zirconium hydroxide [Zr(OH)4] over woven activated carbon fabric [Zr(OH)4@W-ACF] is presented for the removal of CWAs. It was prepared to harness the synergistic effect of high surface area of W-ACF, leads to high dispersion of CWAs and high phosphilicity and reactivity of [Zr(OH)4]. The synthesized materials were characterized by ATR-FTIR, EDX, SEM, TEM, XPS, TGA, and BET surface area analyzer. The kinetics of  in-situ degradation of CWAs over Zr(OH)4@W-ACF were studied and found to be following the first-order reaction kinetics. The rate constant was found to be 0.244 min-1 and 2.31 × 10-2 min-1 for sarin and soman, respectively over Zr(OH)4@W-ACF. The potential practical applicability of this work was established by fabricating Zr(OH)4@W-ACF as reactive adsorbent layer for protective suit, and found to be meeting the specified criteria in terms of air permeability, tearing strength and nerve agent permeation as per TOP-08-2-501A:2013 and IS-17380:2020. The degradation products of CWAs were analyzed with NMR and GC-MS. The combined properties of dual functional textile with reactive material are expected to open up new exciting avenues in the field of CWAs protective clothing and thus find diverse application in defence and environmental sector.

Screening of core filter layer for the development of respiratory mask to combat COVID-19.

The severe outbreak of respiratory coronavirus disease 2019 has increased the significant demand of respiratory mask and its use become ubiquitous worldwide to control this unprecedented respiratory pandemic. The performance of a respiratory mask depends on the efficiency of the filter layer which is mostly made of polypropylene melt blown non-woven (PP-MB-NW). So far, very limited characterization data are available for the PPE-MB-NW in terms to achieve desired particulate filtration efficiency (PFE) against 0.3 µm size, which are imperative in order to facilitate the right selection of PP-MB-NW fabric for the development of mask. In present study, eight different kinds of PP-MB-NW fabrics (Sample A-H) of varied structural morphology are chosen. The different PP-MB-NW were characterized for its pore size and distribution by mercury porosimeter and BET surface area analyzer was explored first time to understand the importance of blind pore in PFE. The PP-MB-NW samples were characterized using scanning electron microscopy so as to know the surface morphology. The filtration efficiency, pressure drop and breathing resistance of various PP-MB-NW fabric samples are investigated in single and double layers combination against the particle size of 0.3, 0.5 and 1 µm. The samples which are having low pore dia, high solid fraction volume, and low air permeability has high filtration efficiency (> 90%) against 0.3 µm particle with high pressure drop (16.3-21.3 mm WC) and breathing resistance (1.42-1.92 mbar) when compared to rest of the samples. This study will pave the way for the judicial selection of right kind of filter layer i.e., PP-MB-NW fabric for the development of mask and it will be greatly helpful in manufacturing of mask in this present pandemic with desired PFE indicating considerable promise for defense against respiratory pandemic.

Photoelectrocatalytic degradation of vesicant agent using Eu/ZnO/pPy nanocomposite.

Herein, we demonstrate a nanocomposite material Eu/ZnO/pPy for enhanced performance in photoelectrocatalytic degradation of chemical warfare agent sulphur mustard (SM) at ambient conditions which is growing concern of the Scientific Community amidst the current climate of terrorism. Eu/ZnO/pPy was electrochemically prepared on Au electrode at ambient conditions and was used for electrocatalytic reductive elimination of chloride from SM and results indicated one electron involvement process for the cleavage of the carbon-chloride bond. Surface morphology of Eu/pPy, ZnO/pPy and Eu/ZnO/pPy composites were characterized by SEM and confirmed the formation of the nanoparticles and nanorods on the modified electrode which leads to provide more surface area for the reductive elimination reaction. The elemental composition, functional groups and phase of materials on the modified electrode were deduced using EDX, Raman spectroscopy and XRD, respectively. Eu/ZnO/pPy/Au electrode was utilized for the photoelectrocatalytic degradation of SM as it exhibit excellent electrocatalytic activity and degradation products were analyzed by GC-MS. In the reductive elimination of SM, the following parameters were deduced (i) heterogeneous rate constant (0.127 s-1), (ii) transfer coefficient (0.32) and (iii) number of electron involved (1.0). The enhanced photoelectrocatalytic capability of this nanocomposite could serve as a novel and promising catalyst in defence and environmental applications.