selective solid- liquid separation of rdx and hmx explosive using deep eutectic solvent based on zinc acetate/diethylene glycol

A des is a fluid generally composed of two or three cheap and safe components that are capable of self-association, often through hydrogen bond interactions, to form a eutectic mixture with a melting point lower than that of each individual component. these dess exhibit similar physico-chemical properties to the traditionally used ionic liquids, while being much cheaper and environmentally friendlier. these solvents have been used in adsorption and separation processes as a substitute for conventional solvents [1,2]. in this study, deep eutectic solvent (des) based on zinc acetate and diethylene glycol (deg) was introduced for selective separation and purification of hmx explosive from rdx. the electrical conductivity and dielectric constant of different des solutions were investigated by lcr meter (inductance-capacitance-resistance) in the range of 100 hz - 1 mhz solubility parameters such as activity coefficient, dissolution enthalpy and mixing enthalpy for rdx and hmx in the proposed solvent were also calculated. using central composite design (ccd) in minitab software, the solubility of two substances in des with two parameters of temperature and zinc acetate concentration was modeled and optimized. analysis of variance (anova) showed that the experimental results of solubility have a good correlation with the predicted results. experimental results also show that the solubility ratio of rdx to hmx varies in the range of 12 to 30 times, which makes it possible to provide a selective separation method for two substances that have similar chemical properties with a separation efficiency of more than 98% and a purity of hmx of more than provides 99.5%. x-ray diffraction (xrd), high performance liquid chromatography (hplc), laser-induced failure spectroscopy (libs) and ft-ir analysis were used to evaluate the product quality. according to the obtained results, this method can be used for selective, safe and green separation of hmx and rdx explosives.