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Abstract: High surface area (887.3m2/g) silica nanoparticles were synthesized using aerogel route and thereafter, characterized by N2-Brunauer–Emmet–Teller (BET), SEM and TEM techniques. The data indicated the formation of nanoparticles of silica in the size range of 24–75nm with mesoporous characteristics. Later, these were impregnated with reactive chemicals such as N-chloro compounds, oxaziridines, polyoxometalates, etc., which have already been proven to be effective against sulphur mustard (HD). Thus, developed novel mesoporous reactive sorbents were tested for their self-decontaminating feature by conducting studies on kinetics of adsorptive removal of HD from solution. Trichloroisocyanuric acid impregnated silica nanoparticles (10%, w/w)-based system was found to be the best with least half-life value (t 1/2 =2.8min) among prepared systems to remove and detoxify HD into nontoxic degradation products. Hydrolysis, dehydrohalogenation and oxidation reactions were found to be the route of degradation of HD over prepared sorbents. The study also inferred that 10% loading of impregnants over high surface area and low density silica nanoparticles enhances the rate of reaction kinetics and seems to be useful in the field of heterogeneous reaction kinetics. [Copyright &y& Elsevier]

Abstract: Nanoparticles of AP–Al2O3 (aerogel produced alumina) have been produced by an alkoxide based synthesis involving aluminum powder, methanol, toluene and water. Thus produced alumina nanoparticles were characterized by N2-BET, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transformed infra-red spectroscopy and thermogravimetry techniques. The data indicated the formation of nanoparticles of alumina in the size range of 2–30nm with high surface area (375m2/g) and microporous–mesoporous characteristics. Thereafter, these nanoparticles were impregnated with polyoxometalates and other reactive chemicals, which have already proven to be effective against sulphur mustard (HD). Adsorptive removal kinetics for HD was monitored by GC–FID (gas chromatograph coupled with flame ionization detector) technique and found to be following pseudo first order reaction kinetics. Among polyoxometalates impregnated alumina nanoparticles based novel mesoporous reactive sorbent systems AP–Al2O3 impregnated with 9-molybdo-3-vanadophosphoric acid (10%, w/w) was found to be the most reactive with least half life value (214min). In addition to this, degradation products of sulphur mustard on prepared mesoporous reactive sorbents were identified using GC/MS technique. Hydrolysis, dehydrohalogenation and oxidation reactions were found to be the route of degradation of sulphur mustard. [Copyright &y& Elsevier]