Biohybrid chitosan/silica self-supported films by soft chemistry in aqueous media: Biomimetic mineralization of Diatoms exoskeleton

• Published in: Surfaces and interfaces 2024-08, Vol.51, p.104675, Article 104675
• Main Authors: Larrieu, Axelle, Marcasuzaa, Pierre, Courreges, Cécile, Billon, Laurent
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Bio-Inspired material; Chemical Sciences; Chitosan; Diatoms; Hybrid material; Material chemistry; or physical chemistry; Polymers; Silica; Theoretical and
• ISSN: 2468-0230; 2468-0230
• DOI: 10.1016/j.surfin.2024.104675

Herein, we present a biomimetic approach mimicking the composition of the diatom frustule to create biohybrid chitosan/silica self-supported films. To mimic the composition of this exoskeleton, the bio-sourced chitosan polymer has been considered to replace the silaffins, proteins bearing many amino groups able to complex the silica dissolved in seawater and at the origin of the biosilification process. The sol-gel process on soft and mild conditions was used with TetraEthoxyOrthoSilicate TEOS as a silica precursor. Functional hybrid chitosan-silica self-supported films were then elaborated with different chitosan/TEOS compositions and characterized by surface (FTIR/ATR, XPS, ToF-SIMS, contact angle, SEM) and bulk (UV–visible spectroscopy, SAXS, water uptake) techniques. The chemical interaction between the chitosan and the TEOS during the film formation was demonstrated, leading to the formation of a durable interconnected structure that remains cohesive and resistant in a 2 wt% acetic acid solution. Moreover, the films exhibit ultraviolet light absorption characteristics, which could be valuable for the achievement of materials for sun protection. [Display omitted]