Preparation and mechanical properties of nano-iron-graphene oxide/chitosan composites

Nano-iron and graphene oxide (GO)-modified chitosan (CS) composites have the superior adsorption performance to heavy metals in water, which is environmentally friendly. The field has good application prospects. However, the effects of different contents of nano-iron and/or GO modified CS on the mechanical properties of composite materials are very limited. Therefore, CS was used as the polymer matrix, GO and FeCl₃·6H₂O were used as nanofillers, different ratios of nano-iron-graphene oxide/chitosan (Fe-GO/CS) composites were prepared by the solution mixing evaporation method material. By using the FTIR, XRD, SEM, TGA and mechanical property testing, the structure, thermal stability and mechanical properties of the composite material were studied. The research results show that nano-iron and GO are well dispersed in the CS matrix, and there is a strong molecular interaction force, and no agglomeration and amorphous structure of iron complex is formed. An appropriate mixture of nano-iron and GO can enhance the hydrogen bonding between CS and fillers, thereby improving the thermal stability and mechanical properties of Fe-GO/CS composites. The results of mechanical properties test show that the tensile strength and elastic modulus of Fe-GO/CS composites increase from 27.5 MPa to 65.4 MPa and 925.8 MPa to 2141.4 MPa, respectively, which are 58% and 57% higher than those of pure CS. But excessive nano-iron reduces the tensile strength, elastic modulus, breaking elongation and thermal stability. TG analysis shows that 1wt% nano-iron modification is beneficial to improve the stability of Fe-GO/CS composite film.