磨浆诱导纤维活化与部分溶解再生协同构筑高性能纤维素隔膜

Synergistic Construction of High Performance Cellulose Separators via Refining-Induced Fiber Activation and Partial Dissolution Regeneration

关键词:  天丝  碱硫脲溶剂  部分溶解  磨浆作用

Key Words:Tencel fiber  NaOH/Urea/Thiourea aqueous solvent system  Partial dissolution  Refining effect

摘要:本文以天丝纤维素为原料，采用氢氧化钠/尿素/硫脲水溶液体系结合非溶剂诱导相分离法制备再生纤维素隔膜，系统研究了PFI磨浆处理、部分溶解后保留的未溶解纤维骨架，以及完全溶解后复合外源细菌纤维素（BC）纳米骨架对膜结构与性能的影响。结果表明，PFI磨浆预处理与部分溶解制膜可显著提升纤维素膜的力学性能，其拉伸强度最高达62.5 MPa，明显优于未磨浆膜。在完全溶解纤维素溶液中引入2% BC后，所得再生纤维素复合膜（RC/BC复合膜）拉伸强度进一步提高至75.2 MPa，在水润状态下，平均孔径为89.2 nm，离子电导率达1.02 mS·cm-1，表现出良好的锂电池隔膜应用潜力。

Abstract:In this study, regenerated cellulose separators were prepared from Tencel cellulose using a NaOH/urea/thiourea aqueous solution system combined with a non-solvent-induced phase separation method. The effects of PFI beating treatment, residual undissolved fiber skeletons retained during partial dissolution, and exogenously introduced bacterial cellulose (BC) nanofiber skeletons after complete dissolution on the structure and properties of the membranes were systematically investigated. The results demonstrated that PFI beating pretreatment and partial dissolution membrane fabrication significantly improved the mechanical properties of cellulose membranes, with the maximum tensile strength reaching 62.5 MPa, which was substantially higher than that of the unbeaten membrane. After introducing 2% BC into the completely dissolved cellulose solution, the tensile strength of the regenerated cellulose composite membrane (RC/BC composite membrane) was further increased to 75.2 MPa. The RC/BC composite membrane exhibited an average pore size of 89.2 nm in the hydrated state and an ionic conductivity of 1.02 mS cm-1, demonstrating promising potential as a separator material for lithium-ion batteries.