天然贝壳具有独特的多层次叠层结构和卓越的韧性，为人工设计制备轻量化、高韧性复合材料提供了一流结构模型。过去几年，相关研究集中在基于无机片和聚合物构建单层次叠层薄膜，但仍面临着制备效率低、拉伸韧性不足的问题；目前，仿贝壳复合材料正在从单层次叠层薄膜向着多层次叠层块体材料的趋势发展。针对单层次叠层薄膜存在的问题，基于申请者过去十年的研究基础，本项目以耐高低温聚对苯撑苯并二噁唑纳米纤维（PBONF）为基体，开发新型溶胶-凝胶-薄膜-还原工艺，连续制备宽温域高拉伸韧性石墨烯-PBONF叠层薄膜；在此基础上，结合多层次叠层块体材料的发展趋势，通过涂覆-裁剪-堆叠-热压工艺，设计构筑多层次叠层板材，实现宽温域（从-150℃到400℃）高断裂韧性，通过原位观测裂纹扩展和非线性有限元模拟，从多个尺度分析变形过程，揭示增韧机理，为发展航空航天用新一代轻量化、宽温域、高韧性块体复合材料提供理论指导和技术支持。

Natural nacre has a unique multi-level layered structure, which impart it with outstanding toughness. It provides high-class structural model for the design and preparation of lightweight, high-toughness composite materials. In the past several years, relative researches focus on one-level layered film consisting of inorganic nanoplatelets and polymers. However, it is still faced with low preparation efficiency and insufficient tensile toughness. At present, nacre-inspired composite materials are being developed from one-level layered film to multi-level layered bulk composite materials. Aiming at the existing problems in layered film and based on applicant’s research foundation over past ten years, this project will use high/low temperature-resistant poly-p-phenylene benzobisoxazole nanofiber (PBONF) as matrix and develop new sol-gel-film-reduction procedure to continuously prepare high-tensile-toughness graphene-PBONF layered film with wide temperature range. On this basis, combined with the development trend of multi-level layered bulk composite materials, this project will further design and construct multi-level layered board materials through coating-cutting-stacking-heat pressing procedure for achieving high fracture toughness over wide temperature range (from -150 ℃ to 400 ℃). Its deformation process and toughening mechanism will be analyzed and revealed from multiple scales through in situ observation of crack propagation and nonlinear finite element modeling. The applicant believed that this project would provide theoretical direction and technical assistance for developing next-generation lightweight, wide-temperature-range, high-toughness bulk composite materials in the field of aviation and aerospace industry.