Ultrastrong composite film of Chitosan and silica-coated graphene oxide sheets

Chitosan (CS) has attracted significant interest in various fields due to its outstanding functional properties (especially, its chain with positive charge). However, wide-range applications of CS are severely limited because of its poor mechanical properties. Ultrastrong composite film of CS and silica-coated graphene oxide sheets (GO@SiO₂) were prepared by a simple solution casting method in this article. GO@SiO₂ was prepared by the hydrolysis of tetraethyl orthosilicate (TEOS) in GO ethanol solution. Compared with the pure CS film, the tensile strength of the CS/GO@SiO₂ composite film with incorporation of 1.75 wt% GO@SiO₂ fillers was significantly increased 158% from 55 ± 4 to 142 ± 24 MPa. Such high tensile strength may be caused synergistically by strong interaction between two components and high crystallinity of the CS matrix. CS based composite with ultrastrong strength may have more potential applications in biomedical fields.