Poriferan chitin as a template for hydrothermal zirconia deposition

Abstract

Chitin is a thermostable biopolymer found in various inorganic--organic skeletal structures of numerous invertebrates including sponges (Porifera). The occurrence of chitin within calcium- and silica-based biominerals in organisms living in extreme natural conditions has inspired development of new (extreme biomimetic) synthesis route of chitin-based hybrid materials in vitro. Here, we show for the first time that 3D-α-chitin scaffolds isolated from skeletons of the marine sponge Aplysina aerophoba can be effectively mineralized under hydrothermal conditions (150°C) using ammonium zirconium(IV) carbonate as a precursor of zirconia. Obtained chitin--ZrO₂ hybrid materials were characterized by FT-IR, SEM, HRTEM, as well as light and confocal laser microscopy. We suggest that formation of chitin--ZrO₂ hybrids occurs due to hydrogen bonds between chitin and ZrO₂.

Keywords

chitin / biocomposite / zirconia / hydrothermal synthesis / ammonium zirconium carbonate