Synthesis Of Titanium Oxide And Manganese Oxide Lithium Ion Sieve And Study Of Its Exchange Property

Polystyrene （PS） microspheres were preparated by emulsion polymerizationmethod, using styrene as monomer, Sodium dodecyl sulfonate （SDS） as emulsifierand potassium persulfate （KPS） as initiator. The effects of concentration of thestyrene, SDS and KPS and polymerization temperature on the particle size and itsdistribution were studied. PS colloidalcrystal template was achieved by adoptinghigh speed centrifugal precipitation, constant temperature heated evaporationrevulsion and natural settlement method to assemble single scattered PS microspheres.By using corresponding lithium salts and titanium salt or lithium salts andmanganese salt precursors solution filling the colloidal crystal templates, aftersuction filter, drying and two paragraphs thermostatic roasting,3DOM lithiumion-sieve precursors Li4Ti5O12and Li4Mn5O12were synthesized. After acid retrofitand drying at low temperature of precursors,3DOM lithium ion-sieve H4Ti5O12（marked LiTi-H） and H₄Mn₅O₁₂（marked LiMn-H） were achieved. SEM, XRD,Saturated exchange capacity test and pH titration curve test were used to characterizethe appearance, structure and ion exchange performance of the oxide. The resultsshowed that: With the content of styrene and KPS and the reaction tempratureincreasing, the particle size of PS microspheres was increased and with the contentof SDS increasing, the particle size of PS microspheres was decreased. PScolloidalcrystal template with microspheres particle size uniform is fcc accumulatingand three-dimensional ordered. The optimum roasting condition of preparing lithiumion-sieve precursors were found as follows, heating rate at2min/℃,300℃roasting4h and800℃or850℃roasting8-10h.3DOM lithium ion-sieve precursors Li₄Ti₅O₁₂and Li₄Mn₅O₁₂and3DOM lithium ion-sieve with three-dimensionalcrosslinking interlinked space network structure are orderly arrangement, pore wallperfectly and spinel structure. The optimum acid retrofit agent are （NH4）2S2O8of0.6mol·L^-1and HCl of1.0mol·L^-1respectively.3DOM lithium ion-sieve showed goodacid stability and a high selectivity for Li⁺.The adsorption kinetic curve of LiTi-H in the system H⁺-Li⁺were measured at25℃and ion exchange kinetics data of LiTi-H for0.05mol·L^-1Li⁺were related withLangmuir,Bangham and Elovich adsorption model. The exchange isothermal of Li⁺on lithium ion-sieve LiMn-H at different temperatures was measured and theexchange isothermal diagrams of H⁺-Li⁺switching hierarchy were drawed.Theaverage activity coefficients of the electrolyte was calculated by using Pitzerelectrolyte solution theory, then the thermodynamic constants such asK Lia H, G0,H0and S0during the H⁺-Li⁺exchange process were computed,and then thedirection of reaction and the heat exchangers with that extracted were judged.