Enhanced mechanical strength and antibacterial properties of Chitosan/Graphene oxide composite fibres

In this study, micron-sized two-dimensional graphene oxide (GO) was combined with chitosan fibres, followed by immersion into dopamine lye (DA lye) through a solution complex to increase the tensile strength of fibre from 252.22 to 411.62 MPa and Young’s modulus from 18.95 to 25.67 GPa. GO sheets endue an effective stress transmission mechanism to chitosan fibre when such composite fibres are subjected to external forces. Self-polymerised poly-dopamine (PDA) formed a coating on the chitosan fibre surface, crosslinking the chitosan molecular, and thereby effectively offsetting the influence of intramolecular hydrogen bonds. Furthermore, the composite fibre exhibited an excellent antibacterial rate of > 99.9% and negligible toxicity to human fibroblasts, indicating its superior biocompatibility. The multiple van der Waals forces enhanced interfacial interactions between the GO surface and chitosan matrix, and the crosslinking and adhesion effect of the PDA coating to the chitosan fibre considerably improved the mechanical properties of the composite fibre. The results of this study can provide a guideline for bulk preparation and replication for synthesising high mechanical performance and multiple functional GO/natural polymer composite fibres, which can be used in many applications, such as biomedical and medical materials.