Preparation And Performance Of Ce(Ⅲ)molecularly Imprinted Supported Liquid Membrane

Rare earth resources was abundant,but with the exploitation of rare earth metals and lacking of environment awareness,environment pollution is becoming serious.Traditional separation methods of rare earth metal ion were mature,but the process was long,low efficiency,large reagent consumption and so on.Supported liquid membrane separation got the attention of the people more and more because it had high separation efficiency,low operating cost,good selectivity,economic and energy saving,but selectivity was low.To improve the selectivity and permeability of supported liquid membrane,this paper mainly modified PVDF surface,prepared and researched performance of Ce（Ⅲ）molecular imprinted membrane.1.Response surface optimization method was used to optimize the process of Ce（Ⅲ）migrated through supporting membrane,the analysis conditions of Ce（Ⅲ）were discussed by spectrophotometric method,and extractant and extraction conditions were discussed.P507 was intended to be extractant,extraction time was 20 min,phase separation time was 15min,extraction temperature 25℃and concentration of extractant was 0.15mol/L.The optimal migrate conditions were determined as follows:concentration of carrier was 11%,p H of feed phase was 4.5,concentration of Ce（Ⅲ）was 8.5×10^-4mol/L and concentration of H₂SO₄was 2mol/L.Theoretically predicted value was 90%,value of measured migration rate was 85.41%,the relative error was 5.1%.Verification experiments verified the model can be used to analyze and predict the actual value of migration rate.2.Ce（Ⅲ）molecular imprinted membrane modified by alkali was prepared,the effect of different factors on prepared membrane were discussed.Obtained the best polymerization condition were as follow:polymerization time was 3h,molar of template molecule,function monomer and cross-linking agent was 1:4:16,photosensitizer was 2%.Characterizations declaredα-MAA was grafted to membrane surface successfully,modification was on the surface of membrane,membrane mainly oritented wasβ,exothermic peak was high than PVDF membrane after modified,pure water flux and permeability coefficient changed,stranded phenomenon of Ce（Ⅲ）through Ce（Ⅲ）molecularly imprinted membrane modified by alkali was occurred,but the membrane had good selectivity.3.Ce（Ⅲ）molecular imprinted membrane modified by acid was prepared,the effect of polymerization time,molar of template molecule,function monomer and cross-linking agent,and the amount of photosensitizer on preparation condition were discussed.Got the best polymerization condition were as follow:polymerization time was 2h,molar of template molecule,function monomer and cross-linking agent was 1:4:16,photosensitizer was 2%.A lot of methods were used to character Ce（Ⅲ）molecular imprinted membrane modified by acid.Characterizations declaredα-MAA was grafted to membrane surface,polymerization was mainly on membrane surface,membrane mainly oritented wasβ,Ce（Ⅲ）molecularly imprinted membrane modified by acid had good chemical stability,pure water flux and permeability coefficient increased,there had stranded phenomenon when Ce（Ⅲ）migration through Ce（Ⅲ）molecularly imprinted membrane modified by acid,and Ce（Ⅲ）molecularly imprinted membrane modified by acid had specific selectivity to Ce（Ⅲ）.