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Information × Registration Number 0211U009497, 0111U004601 , R & D reports Title A new generation of membranes obtained by sol-gel method for the selective extraction of heavy metal ions popup.stage_title Head Zub Yuriy Leonidovych, Registration Date 23-12-2011 Organization Institute of Surface Chemistry of the National Academy of Sciences of Ukraine popup.description2 It was shown, that sol-gel method on the basis of the reaction of hydrolytic polycondensation of tetra- and trifunctional silanes can be used to form polysiloxane layers containing 3-mercaptopropyl complexing groups on the inner surfaces of tubular ceramic membranes (made of ?-Al2O3). The first stage of the developed approach includes obtaining superfine sol by acid hydrolysis of 3-mercaptopropyltrimethoxysilane and tetraethoxysilane. It was determined, that membranes with optimal performance of active layer can be received when the sol contact time with membrane surface is 5 minutes. SEM microphotographs confirming the formation of polysiloxane layer on the surface of membranes with initial pore sizes of about 5 microns. The IR spectroscopy data also confirm the formation of polysiloxane network ?Si-O-Si? (1000-1100 cm-1) and the presence of surface 3-mercaptopropyl groups, as evident from the absorption band of their valence vibrations at 2565 cm-1. Such hybrid organic-inorganic functional layer can selectively remove metal ions, including silver (I) ions, from aqueous solutions due to the formation of complexes between mercapto groups and silver (I) ions. Meanwhile, functionalized samples retain high performance typical for highly efficient microfiltration membranes (320-690 l/m2h). It was also found, that the concentration of the original sol affects the selectivity of the obtained membranes. It appeared, that the dilution of initial sol with ethanol produces thinner and more uniform polysiloxane layer with more active centers available for Ag+ ions sorption. Thus, with the dilution of original sol 4 times, Ag+ ions sorption calculated per mass of functionalized layer increases 10 times (from 23,5 mg/g to 203,2 mg/g). Product Description popup.authors Демченко В.Я. Кочкодан В.М. Мельник І.В. popup.nrat_date 2020-04-02 Close