表面改性致密碳纳米管/丝素蛋白复合薄膜的制备及性能OA

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.PDA-coated 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(104.01 MJ/m3)that surpasses commercial polycarbonate(35-50 MJ/m3)while maintaining biocompatibility.