超临界二氧化碳法制备高性能磺化聚醚醚酮电解质膜及性能研究

Preparation of High-Performance Sulfonated Polyether Ether Ketone Electrolyte Membrane by Supercritical Carbon Dioxide Method and Investigation of Its Properties

以磺化聚醚醚酮(SPEEK)为原料,辅以超临界二氧化碳萃取工艺,制备具有高离子导电率、高吸水性和低甲醇渗透率的复合电解质薄膜。磺化工艺能够有效地改善聚醚醚酮(PEEK)解质薄膜的吸水性,并且有助于形成良好的离子传输通路。结果表明:当磺化时间从3 h提高至12 h,SPEEK复合电解质薄膜的离子交换容量(IEC)值增至1.38 meq/g,磺化度增至46%。磺化处理后,电解质薄膜的热分解温度有所下降,热分解温度约为420℃。随着磺化时间增加,离子导电率从1.37×10^(-10)S/cm增至1.16×10^(-4)S/cm,甲醇扩散系数低至2.183×10^(-7) cm^(2)/s。研究表明,采用磺化工艺和超临界二氧化碳流体萃取工艺可以制备具有高离子导电性和低甲醇渗透率的SPEEK电解质薄膜。

The composite electrolyte membranes were fabricated using sulfonated polyether ether ketone(SPEEK) as the precursor material and supercritical carbon dioxide extraction technology,resulting in enhanced ionic conductivity,water absorption,and low methanol permeability.The water absorption of polyether ether ketone(PEEK) electrolyte membranes was enhanced by the sulfonation process,attributed to the formation of efficient ion pathways.The results showed that the ion exchange capacity(IEC) value of the SPEEK electrolyte membrane increased to 1.38 meq/g as the sulfonation time was extended from 3 h to 12 h,concurrently resulting in an increase in the degree of sulfonation to 46%.After sulfonation,the decomposition temperature of the electrolyte membrane decreased,reaching a lower value of 420 ℃.As the sulfonation time increased,the ionic conductivity exhibited an increase from 1.37×10^(-10) S/cm to 1.16×10^(-4) S/cm,meanwhile the methanol diffusion coefficient demonstrated a decrease to 2.183×10^(-7) cm^(2)/s.The study indicates that using sulfonation and supercritical carbon dioxide fluid extraction processes can prepare SPEEK electrolyte membrane with high ionic conductivity and low methanol permeability.