Crystal structure of ball-milled mixture of sodium chloride and magnesium chloride–ethanol adduct

NaCl doped MgCl2·nEtOH adducts were prepared by ball-milling MgCl2·2.5EtOH with NaCl. Both the ball-milled MgCl2·nEtOH/NaCl mixture and pure MgCl2·2.5EtOH adducts were analyzed by X-ray diffraction (XRD), transmission electron microscope (TEM), thermogravimetry (TG) and differencial scanning calorimetry (DSC). A simple MgCl2·nEtOH/NaCl mixture without ball-milling treatment was also studied for comparison. Two kinds of mixed crystals, Na2MgCl4 and NaMgCl3, were found to be formed in a ball-milled mixture that contained 16 mol.% NaCl. TG and DSC analysis of the samples also provided indirect evidences supporting the presence of the mixed crystals in the ball-milled mixture. Adding certain amounts of NaCl in MgCl2·2.5EtOH adduct, either by co-milling or by simple mixing, greatly increased the thermal stability of the adduct, but thermal decomposition behaviour of the ball-milled mixture was still different from that of a simple mixture.