Preparation Of Bioinspired Ion Imprinted Nanocomposite Membranes And Study On Their Adsorption Performance Of Lithium

Lithium in waste lithium batteries has great interest with the rapidly increasing demand in diverse applications.However,because of unique chemical and physical properties,the separation of lithium in solution is difficult.Due to high selectivity,good permeability,low energy consumption,membrane separation technology become the key technology of separation science in chemical as a unique separation technology.This thesis focused on ion imprinted membrane technology and bionic dopamine self-polymerization-composite modification technology,with the surface modification process of the nanocomposite materials,puts forward the preparation of bioinspired ion imprinted nanocomposite membranes,which were used in the study of selective purification and separation lithium after consulted a large number of literature.The main studies were summarized as follows:?1?The preparation of biomimetic ion imprinted nanocomposity membranes for selective adsorption separation lithium.The IIMs were prepared via modified from PDA aggregation and KH-570 based on porous PVDF membrane with Li⁺as template ion by precipitation polymerization.The maximum adsorption amount of IIMs was 22.57 mg g^-1.Selective permeation experiments showed that the IIMs for Li⁺permeability was higher than that of NIMs,selective separation factors were than 7.0,and relative selectivity coefficients were than 15,that explained the IIMs had specificity and selectivity for Li⁺.In addition,the IIMs can be refreshed by simple washed with aqueous HCl solution,and there were no significant decrease in adsorption capacity after six cycles,demonstrated that the IIMs were stable and reusable.These provided a good foundations for the industral application.?2?The preparation of biomimetic multilayer ion imprinted nanocomposity membranes for selective adsorption separation lithium.In order to enhance the fouling resistance of membranes,the surface of the membranes were loaded a layer of uniform dispersion and size uniformity of SiO₂inorganic nanomaterials,and then the Li-IIMs were prepared via surface imprinting polymerization.Langmuir isotherm model revealed the Li-IIMs of Li⁺adsorption process was the monolayer adsorption,and the maximum adsorption amount was22.33 mg g^-1.Kinetics studies showed that contained physical adsorption and chemical adsorption,adsorption behavior mainly chemical adsorption.Selective permeation experiments showed the Li-IIMs for Li⁺permeability was higher than that of Li-NIMs,selective separation factors were than 8.0,and relative selectivity coefficients were than 20,which explained the Li-IIMs had greatly specificity and selectivity for Li⁺.Contact Angle experiments showed water contact Angle of Li-IIMs to 23±0.8°?Compared to IIMs,both hydrophilic and selective permeability had improved greatly.Besides,the regeneration experiments demonstrated the well durability of Li-IIMs favoring long-term use,demonstrated that the Li-IIMs were stable and reusable.The results show that Li-IIMs has a great application prospect.?3?Fabrication of biomimetic ion imprinted hybrid membranes for selective recovery of lithiumIn present work,antifouling LIHMs were fabricated through a hydrolysis polymerization using PVDF/GO hybrid membrane as basement membrane.The antifouling experiments demonstrated LIHMs had the underwater oil contact angle of152±0.8°with excellent resistance to fouling.The maximum adsorption amount of LIHMs was 27.18 mg g^-11 by Langmuir isotherm model,and revealed the LIHMs of Li⁺adsorption process was the monolayer adsorption.Kinetics studies show that the adsorption behavior of LIHMs was chemical adsorption.Selective permeability experiment showed the LIHMs for Li⁺permeability was higher than that of NIHMs,selective separation factors were than 5.0,which explained the LIHMs has specificity and selectivity for Li⁺.At the same time,the regeneration experiments demonstrated the well durability of LIHMs favoring long-term use.Also,mechanical properties testing calculation LIHMs tensile strength and young's modulus were 0.286 MPa and5.151 MPa,meet the requirement of industry,and has a great application prospect.