The separation of the rare and precious metal rubidium is still a challenge to hydrometallurgy and material science. A novel ammonium molybdophosphate (AMP)/polysulfone (PSf) mixed matrix membrane for rubidium adsorption and separation was prepared successfully by NIPs method via immobilizing AMP into the PSf porous membrane. FTIR, XRD, SEM tests indicate that AMP is embedded into the PSf matrix, and its crystalline structure remains intact. WCA tests show that the membrane surfaces are more and more hydrophilicity with the AMP blending content increasing. The fluxes increase approximately linearly from 210.2 to 370.2 L m À2 h À1 with the AMP content while the bovine serum albu rejections decrease from 97.8% to 88.5%. The Rb + adsorption capacities of the membranes studied as a function of contact time, pH, Rb + concentration, temperature, presence of various interference ions, and the Rb + capacity is up to 98.4 mg g À1 at the optimal adsorption conditions. The Rb + adsorption on the AMP/PSf porous membrane complies with Langmuir adsorption isotherms and pseudo-second-order kinetic model. Finally, the reusability in Rb + adsorption of the AMP/PSf porous membrane is investigated, and the recovery rate can still be maintained above 95% after five adsorption-desorption recycles.

Novel microspheres (CPs) composited by rigid and flexible polymers are synthesized and embedded in the supporting membranes to enhance both the skin–substrate adhesion and compaction resistance of the thin‐film composite (TFC) nanofiltration membranes. The CPs are in situ formed in the casting solution after the rigid poly(p‐phenylene terephthamide) (PPTA) is produced in the flexible poly(m‐phenylene isophthalamide) (PMIA) solution. Then the PPTA/PMIA in situ blending membranes are prepared by using the NIPs method, and the TFC NF membranes are fabricated via interfacial polymerization on them. The CPs are characterized via polarizing microscopy and TEM. The surface morphology and chemical composition of the blended membranes are characterized by using FESEM, AFM, FTIR, and WCA, respectively. As the results show, the supporting membrane with higher PPTA content exhibits higher permeability, thermal stability, and compaction resistance. Moreover, the adhesion strength between the TFC functional layer and the supporting membrane is improved significantly. It is proposed that this improvement can be attributed to the CPs that are exposed on the top surface of the supporting membrane, which leads to a great enhancement because of the anchoring effect between the functional layer and the CPs.

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