Solid Extractants Based on Tetraoctyldiglycolamide and Hypercrosslinked Polystyrene: Production in Supercritical Carbon Dioxide

Adsorption isotherms of N , N , N ’, N ’-tetraoctyldiglycolamide (TODGA) on three brands of hypercrosslinked polystyrene (HCP) in a medium of supercritical CO 2 were constructed using the gravimetric analysis method. It was shown that, under similar conditions ( T = 313 K, P = 20 MPa), HCP marks MN200 and MN202 adsorb up to 0.55 and 0.59 mmol/g TODGA, respectively, which allows their use as a carrier of the ligand under consideration. The adsorption of TODGA on MN270 under similar conditions did not exceed 0.07 mmol/g. The effect of temperature and density of the medium on the adsorption of TODGA on MN200 was assessed. It was shown that a decrease in CO 2 density under isothermal conditions leads to an increase in the maximum adsorption of TODGA. The solid extractant obtained on the basis of MN200 and TODGA showed noticeable extraction properties for Nd 3+ compounds. The solid extractant based on MN202 turned out to be inactive in extraction, which is probably because the pore size of the matrix is too small for the complex to form.