| As all or most of the imprinted sites located at the surface of the imprinting polymer prepared by the surface imprinted technique, it always possesses higher adsorption capacity together with faster mass transfer rate and becomes the research focus of molecular imprinting technique. Ruthenium has widely value of practical application, but it often exists dispersedly in ore at a low content, so it’s very significant to study the separation and enrichment technique for ruthenium. Based on a large number of literature consulted, Ru(Ⅲ) ion-imprinted polymers was considered to be prepared as a material for separation and enrichment of ruthenium because ion-imprinted polymer has ability of specific adsorption to the target ion. The works of this thesis were summarized as follows:1. Studies on the interaction between Ru(Ⅲ) and functional monomers in prepolymerization systemThe interaction between Ru(Ⅲ) and functional monomer (acrylamide (AM), methacrylic acid (MAA),2-allyl thiol nicotinic acid (ANA), N-Allylurea (NAU),2-acetyl amino acid (AAA),4-vinyl pyridine (4-VP) and chitosan) in prepolymerization system was studied by UV-visible and Fourier transform infared (FT-IR) spectrum. The binding constant and coordination molar ratio between Ru(Ⅲ) and functional monomer were calculated and the groups of functional monomer participated in the coordination to Ru(Ⅲ) were forecasted. The results showed that4-VP, ANA and chitosan could bind to Ru(Ⅲ) with high coordination molar ratio (3:1) and maximum binding constant as1.93×1011,3.69×1010and3.94×1010, respectively. Therefore,4-VP, ANA and chitosan may be the favorable functional monomers for the preparation of Ru(Ⅲ) ion-imprinted polymer.2. Studies on the preparation of Ru(Ⅲ) ion-imprinted polymer by precipitation polymerizationBased on the comparation of the adsorption properties among the Ru(Ⅲ) ion-imprinted polymers prepared with different polymerization methods and conditions, a Ru(Ⅲ) ion-imprinted polymer (ⅡP43), which was prepared by precipitation polymerization using ANA as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker, azodiisobutyronitrile (AIBN) as initiator under the mole ratio of Ru(Ⅲ), ANA and EGDMA as1:4:40, was selected as the material for separation and enrichment of Ru(Ⅲ). At the initial concentration of Ru(Ⅲ) as0.5mmol/L, IIP43possessesed a static adsorption capacity to Ru (Ⅲ) of9.45mg/g and the imprinting factor of1.51. The maximum adsorption capacity of the high-affinity sites of IIP43to Ru (Ⅲ) was obtained as64.91mg/g by Scatchard analysis according to the equilibrium adsorption isotherm. The results obtained from the adsorption kinetics experiment showed that the adsorption equilibrium could reach within2h and fitted the pseudo-second-order model, suggesting a chemical adsorption procedure with the rate-limiting step was occurred in the adsorption of Ru(Ⅲ) on IIP43. The structure and surface topography of the polymers were characterized by FT-IR, BET nitrogen adsorption experiment and scanning electron microscope (SEM), respectively. And IIP43was used as adsorbent for solid phase extraction of Ru(Ⅲ). At the optimizational extraction conditions, the solid phase extraction based ion-imprinted polymers (IIP-SPE) possessed the advantages as high selectivity of Ru(Ⅲ) over other platinum group metal and could be used for separation and enrichment of Ru(Ⅲ) from the real sample with the extraction percentage of77.6%(1#) and80.2%(2#).3. Studies on the preparation of Ru(Ⅲ) ion-imprinted polymer by chitosan surface imprinted techniqueA Ru(Ⅲ) ion-imprinted polymer was prepared by using chitosan as support and functional monomer together with formaldehyde and epichlorohydrin as crosslinker under the mass fraction of HAc for dissolving of chitosan as2.0%and the mole ratio of Ru(Ⅲ) to chitosan, formaldehyde as well as to epichlorohydrin as1:12,1:6and1:6, respectively. The static adsorption capacity of Ru(Ⅲ) on this ion-imprinted polymer is11.52mg/g together with the imprinting factor of1.81at the initial concentration of Ru(Ⅲ) as0.5mmol/L. The results obtained from the Scatchard analysis and adsorption kinetics experiment showed that the obtained IIP possessed a maximum adsorption capacity of the high-affinity sites of61.27mg/g and the adsorption equilibrium time of about1h with the pseudo second-order model. Moreover, FT-IR and SEM were used to reveal the structure and surface topography of the imprinted polymer, and the static adsorption experiment was used to evaluate its practicability. The results indicated that the ion-imprinted polymers had uniquely selectivity for Ru(Ⅲ) and could be used repeatly at least eight times when using1.0mol/L HC1as desorption agents.4. Studies on the preparation of Ru(Ⅲ) ion-imprinted polymer by using nano-TiO2as sacrificial supportAfter the polymerization conditions was optimized, a novel Ru(Ⅲ) ion-imprinted polymer was prepared by using vinylation chitosan and ANA as functional monomers, nano-TiO2as sacrificial support, EGDMA as crosslinker and AIBN as initiator under the mole ratio of Ru(Ⅲ), ANA, vinylation chitosan and EGDMA as1:4:2:60. The static adsorption capacity of Ru(Ⅲ) on this imprinted polymer was15.44mg/g and imprinting factor was2.78at the initial concentration of Ru(Ⅲ) as0.5mmol/L. The results obtained from Scatchard analysis and adsorption kinetics experiment showed the IIP possessed a high-affinity adsorption capacity of125.09mg/g and adsorption equilibrium time of about1h. The adsorption prodecure of this IIP to Ru(Ⅲ) is also controlled by chemical adsorption step. The structure and surface topography of the polymers were characterized by FT-IR, BET and SEM, respectively. And the obtained ion-imprinted polymer was used as adsorbent to develop a IIP-SPE method for separation of Ru(Ⅲ). After the extraction conditions was optimized, the IIP-SPE method exhibited excellent selectivity to Ru(Ⅲ) and could be used for separation of Ru(Ⅲ) from the standard mixture of platinum group metal and the real sample. The extraction percentage can reach to84.3%(1#) and85.8%(2#). |
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