A surface-grafted imprinted ceramic membrane (IIP-PVI/CM) for recognizing molybdate (Mo(VI)) anion was prepared by surface-initiated graft-polymerization. Firstly, raw alumina ceramic membrane (CM) was deposited with SiO 2 active layer by situ hydrolysis deposition method. Subsequently, γ-methacryloxy propyl trimethoxyl silane (MPS) was used as a coupling agent to introduce double bonds onto the SiO 2 layer (MPS-CM). Then, 1-vinylimidazole (VI) was employed as a functional monomer to graft-polymerization onto the MPS-CM (PVI-CM). During the graft-polymerization, the influence factors of grafting degree of PVI were investigated in detail. Under optimum conditions (monomer concentration 20 wt%, temperature 70 °C, initiator amount 1.1 wt% and reaction time 8 h), the grafting degree of 20.39 g/100 g was obtained. Further, Mo(VI) anion was used as a template to imprint in the PVI-CM by employing 1,6-dibromohexane as a cross-linking agent, and then Mo(VI) was removed, obtaining the IIP-PVI/CM with many imprinted cavities for Mo(VI). Thereafter, static adsorption and dynamic separation properties of IIP-PVI/CM for Mo(VI) were studied. Results indicate that IIP-PVI/CM shows a specific selectivity for Mo(VI) with the adsorption capacity of 0.69 mmol/100 g, and the selectivity coefficient of IIP-PVI/CM is 7.48 for molybdate to tungstate anions. During the dynamic separation, IIP-PVI/CM has also good selectivity for separation of Mo(VI) and W(VI) anions.
Herein, excellent UV-absorbing poly(vinylidene fluoride) (PVDF) membranes were fabricated through the pre-irradiation induced graft polymerization method. The PVDF chains irradiated with 60 Co γ -ray were modified with the polymerizable UV absorber 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2 H -benzotriazole (RUVA-93). The influences of irradiation dose and monomer concentration on the prepared PVDF-g-PRUVA-93 membranes were investigated, and the optimal condition was eventually obtained. The chemical structures of the films were studied by 1 H-NMR, FTIR, and XRD. UV light transmittance and DSC tests were used to characterize the UV-absorbing performance and thermal property of the PVDF films before and after modification. The results proved that the PRUVA-93 side chains were successfully incorporated into the PVDF main chains and the obtained PVDF- g -PRUVA-93 films possessed remarkable UV-absorbing property. The modified membrane made under the optimized experiment condition could completely block the UV light in the range of 200−387 nm. Additionally, the transmittance of the PVDF- g -PRUVA-93 film could be reduced to 0.04% in 280−320 nm, where the light irradiation could damage polymer materials most seriously.