多功能纳米碳纤维毡的加压离心纺丝制备技术及性能调控

Aiming at the urgent needs of high performance to high-temperature corrosion resistance insulation materials used in high-temperature furnace as well the problems of mass production and high cost of carbon nanofibers (CNFs), this project is to develop a novel CNF by using pressurized centrifugal-spinning and subsequent carbonization with polyacrylonitrile and ultra-fine quartz powders etc., as main raw materials. The proposal focuses on studying the influences of pressurized centrifugal-spinning and carbonization parameters on the fiber diameters, morphologies, and phases of the composite CNFs. Moreover, the present project will investigate the mechanical property and the oxidation resistance, including the influences of fiber diameters, phase composition, and crystallinity on the tensile strength and weight loss of the CNFs. The growth mechanism of SiC inside and on the surface of the CNFs is to be discussed and the mechanism of reinforcement in situ and anti-oxidation of the composite CNFs will be revealed. An optimized fabrication technology of the novel high-performance CNFs with low cost and in a large scale is to be obtained. Based on this result, CNF felt will be fabricated and the thermal insulation of the felt is to be studied. The corrosion behavior and interaction mechanism of hydrogen fluoride produced in the heat treatment of high temperature and non-oxygen atmosphere to recover waste lithium ion battery will be investigated. Also, the effect of hydrogen-fluoride corrosion on fiber strength and in-situ strengthening mechanism will be clarified. The research work of this project will lay an innovative foundation for the technical progress of high-performance CNFs in a large scale with low cost, is of great theoretical and application significance.

本项目针对目前高温炉用耐高温抗腐蚀隔热材料高性能的迫切需求及纳米碳纤维制备成本高且难以规模化生产的瓶颈问题，提出以聚丙烯腈及超细石英为主要原料，通过加压离心纺丝及后续碳化工艺研究复合纳米碳纤维的制备技术。重点研究加压离心纺丝和碳化工艺对复合纳米碳纤维的直径、形貌和物相的影响规律，研究复合纳米碳纤维的力学性能和抗氧化性能，包括研究纤维直径、物相组成、结晶度对纤维强度和氧化失重率的影响规律，探讨纤维内部和表面SiC原位生长机理及纳米碳纤维的强化机理和抗氧化机制。获得新型高性能纳米碳纤维规模化低成本的优化制备技术。在此基础上研究制备纳米碳纤维毡及其隔热性能，研究纤维毡抗废旧锂离子电池回收高温非氧热处理中产生的氟化氢的腐蚀行为和作用机理，探讨氟化氢腐蚀对纤维材料强度影响及原位强化机制。本项目研究将为开发规模化低成本纳米碳纤维制备技术奠定创新性基础，研究工作具有重要理论意义和实际应用价值。

本项目针对目前高温炉用耐高温抗腐蚀隔热材料高性能的迫切需求，提出以聚丙烯腈为主要原料，通过加压离心纺丝、涂层改性及后续碳化工艺研究复合纳米碳纤维的制备技术。重点研究复合纳米碳纤维的强化机理和抗氧化机制。并在此基础上研究纤维毡抗氟化氢的腐蚀行为和作用机理。本项目研究将为开发规模化低成本纳米碳纤维制备技术奠定创新性基础。 .研究结果表明，随着碳化温度的升高，纤维外层凝胶裂解程度增大，复合纤维中碳的有序程度提高，乱层石墨结构更完全；涂层最佳硅源配比（正硅酸乙酯/二甲基二甲氧基硅烷）为1:4；醇水配比（无水乙醇/去离子水）为8:1。抗氧化涂层能有效提高碳纤维在有氧环境中的抗氧化能力；隔热性能研究发现，所制备的微纳米级纤维有效消光系数远大于常规碳纤维。随着纤维直径逐渐增大，纤维的热导率先增大后减小；随着碳化温度的升高，纤维的热导率下降。抗氢氟酸腐蚀研究发现，随着温度的升高，纤维腐蚀程度逐渐增大，初始腐蚀速率也逐渐加快，碳纤维的拉伸强度总体呈现下降趋势，质量损失率也逐渐增大，并在60℃时24小时后的强度损失率达到最高17.86%，质量损失率达到1.867%。氢氟酸溶液浓度影响研究表明，浓度为30%时，质量损失率和拉伸强度损失率都最低，分别为0.579%、1.03%；而40%浓度中的纤维质量损失率和强度损失率都最高，为1.46%和13.13%。.本项目获得了多功能纳米碳纤维毡的加压离心纺丝的优化制备技术，并对碳纳米纤维的抗氧化性能、高温隔热性能、耐酸腐蚀性能进行研究分析。本项目所研究制备的碳纳米纤维相对于现有碳纤维而言，将具有直径更加细小、抗氧化性能更佳等特点。本项目研究将为新型高性能耐高温抗腐蚀材料的制备技术进步奠定重要理论基础，对新型高温炉的发展具有重要推动作用和实际应用价值。