Construction Of Anionic Micro/Nano Adsorbents Based On Sulfonic Groups And Their Efficient Extraction Of Lithium

Lithium and its compounds play an important role in various fields,such as national and national defense.Especially with the energy shortage and the increasingly serious environmental pollution problems,the development of new energy sources has attracted more and more attention of human beings.Lithium batteries have become one of the hot research directions.Lithium needs a huge market in the future,and the research on the development and utilization of salt lake brine rich in lithium resources is developing rapidly.In this paper,lithium ion was adsorbed and separated from salt lake brine by adsorption separation method based on the electrostatic effect of sulfonic acid group.The adsorption and separation properties of target ions Li⁺by adsorption materials HNTs-NH-CO-SS,PHIPE-SS-Ag and PHIPEs-RAFT-SS were investigated by using kinetic and thermodynamic models.The main contents are summarized as follows:?1?Halloysite nanotubes were used as matrix materials to modify amino groups on their surfaces by layer-by-layer assembly.S-?thiobenzoyl?thioacetic acid was modified by the reaction of amino groups with carboxyl groups.A large number of p-styrene sulfonic groups were introduced into the synthesis of hollow sulfonic anionic nanoadsorbents?HNTs-NH-CO-SS?.The adsorption capacity of HNTs-NH-CO-SS for Li⁺was 10.81 mg g^-1in 6 h.The results showed that the adsorbent had multi-site modified sulfonic acid group and was easy to adsorb lithium ions.?2?Porous materials were prepared by Pickering O/W HIPEs using halloysite nanotubes and Tween 80 as stabilizers,AM and SS mixed aqueous solution as water phase and liquid paraffin as oil phase.Silver particles were in situ modified by AgNO₃ solution and NaBH₄ redox reaction on the surface of porous polymers,and sulfonic anionic porous micron adsorbent?PHIPEs-SS-Ag?modified by nanosilver was obtained.The porosities of micron-scale porous polymer adsorbents,a large number of sulfonic acid groups and uniformly fixed silver particles,have the ability to improve mass transfer,increase binding binding to Li⁺and resist microbial contamination.The adsorption kinetics and thermodynamics of static mode were studied by adsorption experiments.The adsorption selectivity and recycling performance of PHIPE-SS-Ag for Li+were investigated.The antimicrobial properties were also discussed.The results showed that at 288 K,the adsorption capacity was 27.364 mg g^-1.After seven regeneration cycles,the adsorption capacity of the material remained 85.71%of the initial value,and the bacteriostasis circle was obvious,which proved that the antimicrobial performance was good.?3?Combining the advantages of nanometer adsorbent with micrometer adsorbent,surface modification of nanotubes was carried out first,and a large number of styrene sulfonate monomers were grafted by controlled polymerization.Then,halloysite nanotubes modified with amino group and S-?thiobenzoyl?thioacetic acid and Tween 80 were used as stable particles,AM and SS as disperse phases.Liquid paraffin is a continuous phase.Pickering O/W HIPEs is used to prepare sulfonated anion micro/nano hybrid adsorbent?PHIPEs-RAFT-SS?,which makes PHIPEs-RAFT-SS have double recognition sites and can be used to adsorb Li⁺.The adsorption experiment of Li⁺was studied.The results showed that the adsorption of Li⁺was multi-molecular layer at 288 K,and the adsorption capacity was 56.458 mg g^-1.In addition,after four cycles of adsorption,the adsorbent still retains the initial adsorption capacity of 84.07%,which has potential advantages in the field of adsorption and separation.