Preparation of monolithic silica–chitin composite under extreme biomimetic conditions

Chitin is a widespread renewable biopolymer that is extensively distributed in the natural world. The high thermal stability of chitin provides an opportunity to develop novel inorganic–organic composites under hydrothermal synthesis conditions in vitro. For the first time, in this work we prepared monolithic silica–chitin composite under extreme biomimetic conditions (80 °C and pH 1.5) using three dimensional chitinous matrices isolated from the marine sponge Aplysina cauliformis. The resulting material was studied using light and fluorescence microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy. A mechanism for the silica–chitin interaction after exposure to these hydrothermal conditions is proposed and discussed.