Facile preparation of hierarchical porous poly(vinyl amidoxime) membranes as efficient gallium adsorbents

Gallium has important applications in new energy, semiconductor, and many other fields. Although a lot of work has been done in the field of preparing amidoxime resin to obtain gallium, there are still problems such as low adsorption capacity and relatively slow adsorption rate. In this paper, we report several high-performance porous amidoxime membranes (HPAOM). (Theoretical maximum adsorption capacity of gallium is 88.339 mg/g at 25 oC, and the fastest adsorption equilibrium time is only 16.9 min which prepared by non-solvent-induced phase separation.) We studied the effect of pore structure on the adsorption properties of porous amidoxime membranes. The comparative analysis of the adsorption kinetics of the porous amidoxime membrane prepared by adding different contents of pore-forming agent PMMA and spray method shows that the surface through-hole structure is very important for the improvement in the adsorption rate. The amidoxime film prepared by spraying also showed good selective adsorption. It is also found that it has good adsorption performance in a wide temperature range via the analysis of adsorption isotherm curve of amidoxime porous membrane. It provides a new method for the preparation of gallium adsorption materials with large adsorption capacity, fast adsorption speed, good selective adsorption of Ga and V, and wide adsorption temperature range.

Automated summary

This study reports on the research results of porous amidoxime membranes in gallium adsorption, identifying key structures that enhance adsorption rate and demonstrating good selective adsorption performance.