The Dynamic Adsorption Of Li~+ From Seawater By Lithium Ion Imprinted Calixarene Polymers Using SOL-GEL Method

The metal ion imprinting technology was one of the hot research in recent years. The metal ions imprinted materials were corresponding to 3D pore structure with the target metal ions had specificity adsorption effect, and it had extensive application value in the aspect of extraction, concentration and adsorption of metal ions.By the ion imprinting technology as the background, this paper takes the tert-butyl calix [4] arene acetic acid as functional monomer, Li+ as a template ion imprinted, the tetrabutyl titanate as the crosslinking agent and HCl solution as the eluent and anhydrous ethanol as the solvent, get the molecularly lithium ions imprinted calix[4]arene polymer by applying the methods of the bulk polymerization. We investigates the synthesis of functional monomer monomers tert-butyl calix[4]arene acetic acid mole ratio of reactants, reaction time and reaction temperature under the factors to get the best preparation conditions and influence factors. Through the single variable method dynamic adsorption test, get the Li+ penetration curve of molecularly imprinted polymer(LiIPs) and non molecularly imprinted polymer(nLi IPs), investigates the equilibrium adsorption capacity and adsorption factors such as pH value, flow velocity, height of packed column, and repeated use, and selectivity, etc. Last the polymeric material were characterized by using fourier infrared spectrometer and electron scanning microscope. Through the extracting lithium adsorption experiment, the contrast LiIPs and nLiIPs situations ions in seawater and artificial seawater was researched, The Li+ dynamic adsorption model was get by the the best conditions, and performance of the molecularly imprinted polymer adsorption, influence factor were researched.Through thoron spectrophotometer method for determining the dynamic adsorption effect of lithium in the solution after the absorbance conversion into concentration. In the liquid into the initial concentration of Li+: C0=500 mg·L-1, velocity v=1.0 mL·min-1, pH=6 and adsorption column height h=5.0 mm, LiIPs average adsorption capacity of Li+ is 14.90 mg/g. Using the Yoon-Nelson model to calculate the corresponding model parameters: τ=24.7min,kYN=0.108 min-1 and q0-YN=16.87 mg·g-1, the LiIPs column dynamic adsorption behavior can be well described. By comparing to participate in the adsorption competition of Na+, K+, the adsorption rate of decline is not obvious, LiIPs for Li+ have higher selectivity and stability. After repeat 5 times, molecularly imprinted polymer adsorption rate to an average of 61%, thus it can concluded that the molecularly imprinted polymer not only has good stability, the renewable performance is better, and it also has good research prospect.