项目以高镁锂比青海盐湖卤水锂离子提取为目标，以TBP/煤油为萃取体系，针对新型锂离子膜萃取提取技术的核心耐溶剂膜材料材料，研究嵌段高分子膜结构的调控与锂离子扩散性能之间定量关系。以聚乙烯-乙烯醇（EVAL）共聚物为核心材料，采用浸没沉淀法，通过高分子溶液微观分析、相分离热力学和动力学等手段，研究亲水-疏水柔性链段在成膜过程中介观（链段尺度）和宏观（液-液和液-固相分离）的相互关联, 为调控孔结构提供理论依据；通过将EVAL磺化、EVAL与磺化聚醚醚酮、二维磺化氧化石墨烯材料杂化，研究均匀荷负电膜和有机-无机杂化二维荷负电纳米材料对膜结构、离子扩散的影响机制；建立稳态传质模型，定量分析膜萃取过程锂离子在膜材料中扩散对传质过程的影响，提供量化扩散阻力的工具。项目研究将为高镁锂比青海盐湖卤水中锂离子提取提供低能耗、高效率的膜技术，为突破青海盐湖卤水锂提取的世界性难题提供新的思路和技术。

We aim to develop a novel solvent resistant, high lithium ion flux block copolymer based membrane material for the extraction of lithium ions from the salt lake brine with high magnesium/lithium ratio. The main target is to unravel the relationship between the membrane porous structure and the ion diffusion performance in the membrane extraction process. Based on ethylene vinyl alcohol block copolymer (EVAL), immersion precipitation technology will be selected for membrane preparation. Due to the high flexibility, the meso-scale demixing of the hydrophilic and hydrophobic chains of EVAL will be investigated in relating to the macro-scale liquid-liquid/solid-liquid phase separation; the phase separation thermodynamic and kinetic behaviors of EVAL solution will be analyzed. The porous structure will be analyzed and pore formation mechanism will be described. To increase the lithium ion diffusion rate, sulfonated EVAL will be synthesized; sulfonated polyether ether ketone and sulfonated graphene oxide (SGO) will be added into EVAL. Effect of the anion charges in the membrane porous structure will be related to the lithium ion diffusion rate. Special focus will be the effect of two dimensional SGO on the membrane structure and performance of the membrane for lithium ion diffusion in membrane extraction. The transport model of lithium based on a stable operation will be used for comparing the mass transport resistant of the membrane in relating to the extraction reaction and external concentration polarization. The results and fundamental understanding in this proposal will result in a smart solution to the lithium extraction from salt lake brine of high Mg/Li ratio, leading to a breakthrough in production of high purity lithium salt and provide solid theoretical and technical basis for highly efficient exploitation of the resources from The Salt Lake of Qinghai.