Mechanical properties of bioinspired composites

Abstract

Most biological composites have structures that directly enhance their mechanical properties but cannot be easily reproduced synthetically. To overcome this, this project looks into the optimisation of procedures for the fabrication of a gelatin-based biocomposite with magnetically-controllable alignment. In achieving this, calcium phosphate (CaP) microplatelets were used. The CaP microplatelets were incorporated in the soft gelatin matrix to create biocomposites with anisotropic reinforcement. Anisotropy in the structure and mechanical properties were explored following magnetic functionalisation of the platelets and their magnetic orientation in the gelatin matrix before setting. In addition to adding reinforcing particles, gelatin was also strengthened by chemical crosslinking with tannic acid in the presence of an oxidising agent. This strategy mimicked the strengthening by catechols found in many organic materials in plants and animals. 1 h treatment time with tannic acid and the addition of sodium periodate was found to lead to the most desirable mechanical properties upon evaluation by tensile testing. The results in this report could be later applied to build more complex orientation patterns and for higher concentrations of CaP. The applications of the bioinspired materials processed with these methods could then have interesting applications in healthcare due to its biocompatibility.