Abstract: Carbon nanotube (CNT)‑reinforced silk fibroin (SF) composites are limited by weak interfacial bonding, which restricts their application in impact‑resistant protective systems. This study aims to address interfacial incompatibility through chlorosulfonic acid (CSA)‑assisted densification combined with surface modification strategies, so as to construct a reliable design system for bio‑inspired nanocomposites under extreme dynamic loads. Three interfacial engineering strategies‑oxygen plasma etching, nitric acid oxidation and polydopamine (PDA) coating‑were applied to CSA‑densified CNT films pre‑treated with CSA for structural alignment before hot‑pressing impregnation with SF solution. CSA densification ensured uniform CNT alignment prior to surface modification, which is critical for enhancing interfacial bonding. PDA‑coated densified CNT / SF films exhibited optimal performance, achieving a dynamic fracture strength of 2138.74 MPa and a specific energy absorption of 104.01 MJ/m³, representing 150.14% and 128.26% improvements over CNT/SF films respectively. Plasma‑treated densified CNT/SF films showed corresponding values of 1491.56 MPa and 94.75 MJ/m³. XPS analysis revealed that PDA‑treated CNTs achieved a nitrogen content of 3.52%, compared to 2.11% for plasma‑treated samples, confirming selective functionalization. Dynamic tensile fracture morphology indicated that PDA composites maintained smooth surfaces with tightly aligned CNT bundles. Strain‑rate sensitivity analysis showed that the strength of PDA composites increased by 43.4% from quasi‑static to dynamic loading (1491.56 MPa to 2138.74 MPa), while that of plasma‑treated composites only increased by 12.7%. PDA coating uniquely enables simultaneous CNT surface functionalization (13.61% O‑content and 3.52% N‑content) and SF matrix infiltration without fiber damage, outperforming plasma‑induced fragmentation and acid‑mediated purification. Moreover, PDA composites exhibit a 43.4% strength enhancement at 1900 s⁻¹ compared to quasi‑static conditions, demonstrating interfacial activation under dynamic loading. The optimized composite achieves a specific energy absorption of 104.01 MJ/m³ that surpasses commercial polycarbonate (35‑50 MJ/m³) while maintaining biocompatibility.

Key words: carbon nanotube, silk fibroin, surface functionalization, composite materials, dynamic mechanical property

摘要： 碳纳米管(CNT)增强丝素蛋白(SF)复合材料因界面结合较弱,限制了其在高应变率抗冲击防护领域的应用。 为此,提出一种氯磺酸(CSA)辅助致密化与表面修饰协同的策略,通过氧等离子体刻蚀、硝酸氧化及聚多巴胺(PDA)包覆三种界面工程方法对 CSA 预处理后的 CNT 薄膜进行修饰,再经 SF 溶液浸渍与热压处理,制备得到复合薄膜,并采用分离式霍普金森拉杆系统评价其动态力学性能。 结果表明:经 PDA 包覆 的丝素蛋白/ 致密化碳纳米管薄膜(CNT/ SF)动态断裂强度最高达 2138. 74 MPa,比吸能值为 104. 01 MJ/ m3,较未修饰 CNT/ SF 薄膜分别提升 150. 14%和 128. 26%。 与其他两种改性方法相比,PDA 包覆可显著增强 CNT 与SF 基体间的界面结合,有效改善载荷传递效率与动态力学响应。 该研究结果为高性能 CNT/ SF 复合材料的可控制备及其在高应变率条件下的工程应用提供了理论依据与技术参考。

关键词: 碳纳米管, 丝素蛋白, 表面改性, 复合材料, 动态力学性能