High strength graphene oxide/chitosan composite screws with a steel-concrete structure.

Due to the biocompatibility, biodegradability and numerous resources of chitosan (CS), CS screws attract much more attention, as a new generation of internal fixation devices. Herein, a facile solution-casting method was utilized to fabricate CS composite screws with a steel-concrete structure by combining graphene oxide (GO) and CS fiber bundles. The embedding GO endowed CS screws with a Honeycomb-Cobweb network. And CS screws reinforced with CS fiber bundles of four arrangement sequences could endure different degrees of external force. The optimal arrangement type of CS fiber bundles (the linear type) and addition amount of GO (0.15 wt%) was utilized to construct the steel-concrete structure. Due to the mechanical interlocking between the GO/CS matrices and CS fiber bundles, the bending strength of CS composite screws, with such an unusual structure, could reach high up to 378 MPa, approximately 1.88 times the blank control group was. The findings stand out as a new tool to prepare high bending strength screws and the steel-concrete structure might be used effectively in more critical load-bearing situations.