The application prospects of carbon/carbon composites are greatly limited by interfacial cracks and pores caused by binder pitch displacement and cracking during high-temperature carbonization. In this study, silane coupling agent was coated on the surface of oxygen plasma-treated carbon fibers (CFs) and subsequently electrostatically self-assembled with sulfonated graphene (SG) to improve the interfacial bonding between filler and CTP. The results indicate that the tensile strength of carbon fiber treated with silane coupling agent increased by 19 % compared to untreated CF. This increase in strength may be related to the layer of silane coupling agent that repaired the grooves and imperfections on the CF surface. The addition of SG not only improves the distribution characteristics of the fibers, allowing the silane-treated CF to play a greater role in the matrix, but also creates a three-dimensional hydrogen-bonded cross-linking between the SG and the coal tar pitch (CTP) on the surface of the fibers. This inhibits CTP displacement and pyrolysis, achieving a tight bonding of the fiber to the matrix. The composites' structural integrity and mechanical properties were significantly improved due to the synergistic effect of silane-treated CF and SG. The compressive strength was 216.98 MPa, with a flexural strength of 54.78 MPa, 250 % higher than the untreated carbon fiber-reinforced composites. Additionally, the porosity decreased by 31.5 %, and the antioxidant properties increased. The study presents a potential solution to improve the performance of carbon/carbon composites by using the silane-treated CF-SG multiscale reinforced phase.

中文翻译：

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通过磺化石墨烯与硅烷处理碳纤维的自组装来多尺度增强碳/碳复合材料性能


高温碳化过程中粘结剂沥青位移和开裂导致的界面裂纹和气孔极大地限制了碳/碳复合材料的应用前景。在这项研究中，将硅烷偶联剂涂覆在氧等离子体处理的碳纤维（CF）表面，随后与磺化石墨烯（SG）进行静电自组装，以改善填料和CTP之间的界面结合。结果表明，经过硅烷偶联剂处理的碳纤维的拉伸强度比未经处理的CF提高了19%。这种强度的增加可能与修复CF表面凹槽和缺陷的硅烷偶联剂层有关。 SG的加入不仅改善了纤维的分布特性，使硅烷处理的CF在基体中发挥更大的作用，而且在SG和煤焦油沥青之间产生了三维氢键交联（CTP）在纤维表面。这抑制了 CTP 位移和热解，实现纤维与基体的紧密粘合。由于硅烷处理的CF和SG的协同作用，复合材料的结构完整性和机械性能得到显着改善。压缩强度为216.98 MPa，弯曲强度为54.78 MPa，比未经处理的碳纤维增强复合材料高250%。此外，孔隙率降低了 31.5%，抗氧化性能提高。该研究提出了一种通过使用硅烷处理的 CF-SG 多尺度增强相来提高碳/碳复合材料性能的潜在解决方案。