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This investigation includes the synthesis and characterization of a new series of ionic liquids (ILs) based on the tetraalkylammonium dication for the absorption of CO2, a step towards the development of more efficient and sustainable technologies. It was possible to synthesize amine-substituted PEG diacrylate by modifying poly(ethylene glycol) (PEG), which was then quaternized with 1-bromopentane to produce the IL PDBr. The other IL products, PDNTf2, PDBF4 and PDPF6, were synthesized via the metathesis of PDBr with the appropriate salt. The synthesized products were characterized using various techniques, such as FTIR, 1H and 13C NMR, elemental analysis, and density and viscosity meters, and evaluated as potential sorbents for CO2 capture. DSC and TGA were used to examine the thermal properties of the ILs. As observed from their thermal degradation behavior, the ILs exhibited two-stage disintegration with thermal stability up to 150 °C. The pressure drop method was used to study the sorption capacity of the ILs towards CO2. The sorption investigation showed that when the pressure is increased, the CO2 absorption increases. Equilibrium is reached in 40 minutes, demonstrating a rapid absorption rate. The IL with the [BF4]− anion (PDBF4) demonstrated a maximum sorption capacity of 0.577 mole fraction of CO2, and can be regenerated and reused efficiently with less than 0.5% variation from its original absorption capacity. The CO2 absorption capacity for the ILs with other anions follows the trend: Br ≈ NTf2 < PF6 < BF4. This work shows that tetraalkylammonium-based dicationic ILs are adaptable, making them a suitable material for many applications, including sustainable CO2 capture technology. [ABSTRACT FROM AUTHOR]

The current demilitarization processes employ open burning/open detonation which is not permitted by the environmental protection agency. Therefore, a systematic study has been carried out to convert waste/rejected nitramine propellant (NP) and fuel-rich-based propellant (FRP) into liquid fertilizer by digesting in dilute nitric acid followed by neutralization with potassium hydroxide and phosphoric acid. The obtained liquid fertilizers were fully characterized for nitrate, phosphate and ammonium ions along with potassium. Further, the effect of liquid fertilizers of NP and FRP on cluster bean plants was studied by taking different concentrations from 25 to 150 mL, and their effects on germination pattern, shoot growth, thickness of stem, size and number of leaves, number of pods and length over a full-grown period of plants were investigated. The results reveal that the germination index increases as the content of liquid fertilizer increases and the same trend was observed with respect to root and shoot growth. Also, broadness and the number of leaves showed an encouraging effect as concentration increases. Further, the final product, i.e. the number of pods of cluster bean and length in each pod was found to be more for liquid fertilizer of NP compared to FRP-based liquid fertilizer. [ABSTRACT FROM AUTHOR]

The next-generation energy economy relies heavily on hydrogen. Handling hydrogen during production, storage, and transportation requires risk mitigation. In this regard, the application of halide-free additives is very crucial. The present study experimentally and theoretically investigates the individual and combined inhibiting effect of propane and propene on hydrogen-air explosions. The experiments are carried out at 298 K and 1 bar, with additives ranging from 0.5 to 5% for the individual and 1–2% each for the combined effect in the 20–50% hydrogen-air mixture. Experimentally, the additive content in the stoichiometric and rich mixture decreases the explosion pressure, maximum pressure rise (MPR) rate, laminar burning velocity (LBV), and flame temperature, while increasing minimum ignition energy. For instance, the addition of 2% propane in a 50% hydrogen-air mixture, reduces the MPR rate by 98%, whereas such an effect is observed with 2.5% propene. Theoretical study shows that 3% equivalent additive augments inhibiting reactions, countering the main flame-promoting reaction R1 (H + O 2 O + OH) and thereby reducing LBV. Due to its low activation energy, propene consumes the active radicals twice the rate of propane, while propane not only scavenges the active radicals but also promotes oxygen consumption in the prior phase of combustion, weakening flame propagation. Overall, this approach exhibits a significant step forward in harnessing the potential of hydrogen while mitigating the safety risks associated with its use. [Display omitted] • The effect of C 3 -Hydrocarbons and their Mixtures on H2-air explosion is explored. • The additives decrease explosion pressure, MPR rate and LBV while increasing MIE. • Propene increases the consumption rate of active radicals in the additive mixtures. • Propane promotes oxygen consumption in the prior phase of combustion, countering R1. [ABSTRACT FROM AUTHOR]