The development of efficient separation and enrichment methods for rare and precious metal rubidium (Rb) has attracted more and more attention the hydrometallurgy. Here, based on the phenolic hydroxyl-rich copolymer poly(styrene-co-4-hydroxylstyrene) (P(S-co-VPh)), the Rb+ imprinting nanofiber membrane (P(S-co-VPh)-(IIP)) was prepared using electrostatic spinning. NMR, FTIR, XPS, FESEM and EDS were used to comprehensively characterize the composition and structure of the copolymer and nanofiber membranes. Batch adsorption results indicated that the optimal adsorption conditions were pH = 9 at room temperature, and the process of Rb+ adsorption was spontaneous exothermic reaction. Ion imprinting technology not only enhanced adsorption capacity and recycling performance of the P(S-co-VPh20)-(IIP) membrane, but more importantly, significantly improved its selectivity, so that the selectivity coefficient (beta) of Rb+/Mn+ for the interfering ions Na+, Mg2+, Ca2+, and K+ were 1438.17, 864.38, 434.6, and 307.25, respectively. The adsorption kinetics fitted well to the pseudo-second-order rate expression, and the maximum theoretical adsorption capacity (qm) could reach 140.00 mg/g from the Langmuir model fitting. The dynamic filtration experiment of the stacked membranes chromatography indicated that the breakthrough times were significantly affected by the different operation conditions (Flow rate, initial Rb+ concentration and membrane dosage). Among the four typical models of Thomas, YoonNelson, EXY and BJP, the breakthrough curves can be well described by the EXY model.

A novel Rb+ imprinted membrane was fabricated via non-solvent inversion phase separation method by blending template RbCl, poly(styrene-co-4-hydroxylstyrene) (P(S-co-VPh)) and polysulfone, where the phenolic hydroxyl groups of P(S-co-VPh)) spontaneously coordinated with template Rb+ in the casting solution to form an imprinted Rb+ site. Gel permeation chromatography, FTIR and 1H NMR results indicated that the (P(S-co-VPh) had been synthesized successfully. The characterization of water contact angle, scanning electron microscope and membrane performance tests indicated that the blending membranes had better hydrophilicity, more porous structure and higher pure water flux. The adsorption behaviors of Rb+ on the blending membranes were investigated depending on the parameters of solution pH, temperature, ions interference, Rb+ concentration and contact time. The results indicated that the maximum Rb+ adsorption capacity can be obtained when the solution pH is 9.0, and low temperature is favorable for adsorption because it is an exothermic process. As compared to Na+, Ca2+, and Mg2+, K+ has the greatest ion interference effect, causing up to 58.1% decline in Rb+ adsorption capacity for non-imprinted membranes but only 7.4% for imprinted membranes. The adsorption process conforms to Langmuir isothermal model and pseudo-second-order kinetic model, and the theoretical maximum adsorption of Rb+ is 70.12 mg/g. Furthermore, the Rb+ imprinted membrane can be reused at least five times using 0.1 M HCl solution as the eluent, indicating that membrane has potential application value in the separation and extraction of rubidium.

本文以对苯二甲酸和ZrC14为原料,采用溶剂热法制备了UiO-66吸附剂,将UiO-66与PES共混后,通过浸没沉淀相转化法制备UiO-66/PES吸附功能膜,对水中的苯酚进行吸附研究.采用FT-IR、XRD、SEM对UiO-66及UiO-66/PES吸附功能膜进行表征分析.该膜对苯酚进行静态吸附实验、吸附动力学实验以及动态穿透实验,结果表明,吸附机理符合Langmuir等温吸附模型,吸附动力学符合拟二级动力学模型,该吸附主要为化学吸附.吸附-脱附实验表明,UiO-66/PES吸附功能膜经3次循环仍对苯酚具有较为稳定的吸附容量.

Thin film composite (TFC) reverse osmosis (RO) membranes with high permeability have been prepared by interfacial polymerization based on tailoring the polysulfone (PSf) substrate structure by in situ embedded poly(p-phenylene terephthamide) (PPTA) star-like rigid supports. The star-like rigid supports were observed by the polarizing optical microscopy (POM) and transmission electron microscope (TEM). The surface properties of the substrates were investigated by FTIR, the water contact angle (WCA), FESEM and AFM. The WCA was decreased from 88.5 degrees to 72.3 degrees with the PPTA increasing from 0% to 8%, and the surface roughness increased from 24.2, 25.1, 33.5 and 58.6 nm, respectively. Furthermore, numerous interconnect micro-structures were constructed in the substrate when the PPTA content was up to 8%. The pure water flux of 8% PPTA/92%PSf substrate was up to 377.0 L m(-2)h(-1)and the flux decline rate was lowest (64%) after compacted at 5.5 MPa for 30 min. Otherwise, increasing the PPTA contents in the substrate enhanced the roughness, encouraged nanosheet formation and improved the permeability of TFC RO membranes. The pure water flux of the TFC RO membranes increased from 36.32 to 58.42 L m(-2)h(-1), where the NaCl rejection was about 99.5% at 5.5 MPa.

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.