Development of chitosan-clay nanocomposite films from Hermetia illucens: analysis of chemical, physical, and mechanical properties

Abstract

Chitosan has gained great attention due to its properties. In this study, chitosan obtained from an innovative and sustainable source, the bioconverter insect Hermetia illucens, known as Black Soldier Fly (BSF), was used for the development of Chitosan-Clay Nanocomposite Films. Sepiolite and montmorillonite clays were used to produce the membranes. The interaction between insect-derived chitosan and clays was studied and the chemical, thermal, mechanical, and adhesive properties of the films were assessed. The incorporation of clays enhanced thermal stability and hydrophobicity of all formulations. Films prepared with chitosan from H. illucens exhibited greater hydrophobicity than those made with commercial chitosan, particularly in unbleached samples. However, chitosan from H. illucens displayed lower elasticity and tensile strength. Despite this, the addition of clays to pupal exuviae and adult unbleached samples resulted in mechanical properties comparable to commercial chitosan. Adhesive properties of BSF chitosan consistently outperformed commercial chitosan. Unbleached samples demonstrated better performance, suggesting that the bleaching process is unnecessary for film production. Based on the results obtained, insect chitosan could be particularly advantageous in applications requiring improved adhesiveness and enhanced thermal resistance and hydrophobicity, such as in wound dressings for exudative wounds.