Preparation Of Selective Adsorbent Materials And Their Identification Properties For Gallium

In recent years,gallium has been widely used in production and life,but due to the scarcity of gallium and the characteristics of no independent ore,taking effective measures to extract gallium has become the focus of attention.The graft material D301-g-PAA was prepared by using D301 resin as the base material,acrylic acid AA as the functional monomer,and using surface graft polymerization technology.The materials D301-g-PAA with the best adsorption properties had been fabricated when AA was used 7ml,w（APS）was 1.8%,reaction temperature was 55°C and reaction time was 11 h.At 25°C,p H=10,the adsorption equilibrium was reached after 22 h,and the adsorption capacity reached 365.43 mg·g^-1.The adsorption process followed the Lagergren-first-order kinetic model and belonged to the Frundlich monolayer adsorption.The selectivity coefficient k of D301-g-PAA to Ga（OH）₄^-was 8.60 in the binary mixed solution of Ga（OH）₄^-and Zn（OH）₄^2-.D301-g-PAA also has good recycle property.The grafted material D301-g-PAN was prepared by grafting functional monomer acrylonitrile（AN）on the surface of D301 resin by the method of surface grafting polymerization,which was characterized by FTIR and SEM.The materials D301-g-PAN with the highest percent grafting（19.77%）had been fabricated when AN was used 18 ml,w（APS）was 2.0%,reaction temperature was 45°C and reaction time was 16 h.The amidoxime was modified in a mixed solution of 1.0 mol·L^-1 NH₂OH·HCl and 1.0 mol·L^-1 Na₂CO₃ to obtain the amidoxime material D301-g-PAO.At 25°C,p H=10,the adsorption equilibrium was reached after 26 h,and the adsorption of Ga reached 383.3 mg·g^-1.The adsorption process followed the Lagergren-first-order kinetic model and belonged to the Langmuir monolayer adsorption.Comparing with adsorption of Zn（OH）₄^2-,the selectivity coefficient k of D301-g-PAO to Ga（OH）₄^-was 16.82.Besides,D301-g-PAO also has good recycle property.The surface ion imprinted material D301-g-IIPAA was prepared when using surface grafting and imprinted method with Ga（OH）₄^-as the template,AA as a monomer,and MBA as the crosslinker.The materials D301-g-IIPAA with the best adsorption properties to Ga had been fabricated when AA was used 3 ml,w（APS）was 2.5%,n（Ga（OH）₄^-）:n（AA）was 0.5%,MBA was 5%and D301 was 0.3 g.At 25°C,p H=10,the adsorption equilibrium was reached after 20 h,and the adsorption of Ga（OH）₄^-reached 426.6 mg·g^-1,which was much larger than that of the non-imprinted material（D301-g-NIPAA）(170.8 mg·g^-1).In the Ga（OH）₄^-/Zn（OH）₄^2-and Ga（III）/Cd（II）binary solutions,the adsorption selectivity coefficient k of D301-g-IIPAA reached 118.24 and 56.78,respectively.D301-g-IIPAA showed excellent adsorption selectivity to Ga.The adsorption process followed the Pseudo-second-order model and belonged to the Langmuir single-molecular layer adsorption,which indicated a Ga molecule occupies an imprint hole and was spontaneous and endothermic.Besides,the D301-g-IIPAA also has good recycle properties.The imprinted material D301-g-IIPAO was prepared by surface ion imprinting method using gallium as template and glutaraldehyde as cross-linking agent.The imprinted materials D301-g-IIPAO with the best adsorption properties to Ga（OH）₄^-had been fabricated when p H was 10,glutaraldehyde was 0.8 m L,temperature was 298 K and the reaction time was 22 h.The dynamic adsorption experiment showed that the adsorption equilibrium of materials D301-g-IIPAO was reached after 20 h,temperature was 25°C and p H=10,and the equilibration adsorption of Ga（OH）₄^-reached 488.06 mg·g^-1 which had a significant improvement than non-imprinted material D301-g-NIPAO(189.6 mg·g^-1).The selective adsorption experiments showed that the selectivity coefficient k of D301-g-IIPAO to Ga（OH）₄^-reached 108.71 and 72.88,which was much larger than the selectivity coefficient k of non-imprinted material in the Ga（OH）₄^-/Zn（OH）₄^2-、Ga（III）/Cd（II）binary mixed solution,respectively.Therefore,the selective adsorption of material D301-g-IIPAO had excellent adsorption selection character to Ga（OH）₄^-.The kinetic fitting results indicated that the adsorption process followed the Lagergren-first-order model.The isothermal adsorption experiments showed that the adsorption process can be described by the Langmuir adsorption model,which belonged to the single-molecular layer adsorption because of the imprinted hole matched with Ga（OH）₄^-on the surface of material D301-g-IIPAO.Besides,imprinted material D301-g-IIPAO also has good recycle properties.