Preparation And Application Of The Copper Ion Imprinted Materials

Copper,as a kind of common heavy metal,is widely used in battery manufacturing,metal coating and chemical industries.However,copper pollution which derived from these industries is serious.The waste water that factory and farmland exhaust is also main pollution source of the copper pollution to water.Cu(Ⅱ)ion in the contaminated water is harmful to animals,plants and human nervous system.Thus,the preparation of materials is imminent to remove Cu(Ⅱ)ion.Among numerous materials,the copper ion imprinted materials is an eye-catching and promising adsorbents due to its specific recognition and selectivity.Cu(Ⅱ)-ion imprinted polymer was prepared by bulk polymerization using methanol,azodiisobutyronitrile and ethylene glycol dimethyl acrylate as the solvent,initiator and crosslinking agent,respectively.Diphenylcarbazide(DPC)as a N-containing multidentate lidand was introduced to improve the adsorption performance of polymer,because a large number of nitrogen atoms are introduced to chelate with Cu(Ⅱ)ions and then form more specific binding sites.Besides that,Methylacrylic acid was selected as functional monomer.The pH of solution has significantly effect on the adsorption capacity of adsorbent due to the protonation.The increase of solution concentration can obviously improve the adsorption quantity by increasing the mass transfer driving force,and the maximum adsorption is 59.0mg·g-1.Anion in the template and solution have significantly influences on the polymerization and adsorption processes,especially in the formation of imprinted cavities.In addition,adsorption equilibrium is reached within 10min,and the polymer can be reused.In order to achieve the rapid separation of the adsorbent and solution and simplify the operating conditions,a composite membrane is fabricated by layer-by-layer self assembly technology supported on a microporous polyether sulfone substrate,using polyacrylic acid,chitosan,Disodium 4,4’-Diazidostilbene-2,2’-disulfonate and acetic acid as anionic polyelectrolyte,cationic polyelectrolyte,cross-linking agent and eluent,respectively.The maximum adsorption is 48.0mg g-1.The chemisorption was proved by using adsorption kinetics theory.Moreover,this composite membrane was reused at least six times without a significant decrease of adsorption capacity,and can be utilized for separation of Cu(Ⅱ)ion even in the presence of Zn(Ⅱ),Co(Ⅱ)and Ni(Ⅱ)ions.