A novel adsorptive membrane for rare earth recovery prepared by facile UV grafting using 3,3′, 4,4′-benzophenone tetracarboxylic acid (BTA)

Abstract

We propose a facile method for preparing polyvinylidene fluoride (PVDF) membranes with exceptional selectivity for rare earth ions and stability by UV irradiation technology using 3,3′, 4,4′-benzophenone tetracarboxylic acid (BTA) as the grafted materials. The grafting of BTA onto the membrane surface was confirmed through Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The selection factors of PVDF-g-BTA membranes for Dy³⁺ over Na⁺, K⁺, Ca²⁺, and Mg²⁺ were 140.57, 114.16, 74.23, and 86.25, respectively. The adsorption capacity of the PVDF-g-BTA membranes remained above 80 % following five adsorption–desorption cycles, and the contact angle remained stable throughout the 30 days of immersion.