Synthesis of nanostructured chitin–hematite composites under extreme biomimetic conditions

Abstract

Chitin of poriferan origin is a unique and thermostable biological material. It also represents an example of a renewable materials source due to the high regeneration ability of Aplysina sponges under marine ranching conditions. Chitinous scaffolds isolated from the skeleton of the marine sponge Aplysina aerophoba were used as a template for the in vitro formation of Fe 2 O 3 under conditions (pH $ 1.5, 90 C) which are extreme for biological materials. Novel chitin-Fe 2 O 3 three dimensional composites, which have been prepared for the first time using hydrothermal synthesis, were thoroughly characterized using numerous analytical methods including Raman spectroscopy, XPS, XRD, electron diffraction and HR-TEM. We demonstrate the growth of uniform Fe 2 O 3 nanocrystals into the nanostructured chitin substrate and propose a possible mechanism of chitin-hematite interactions. Moreover, we show that composites made of sponge chitin-Fe 2 O 3 hybrid materials with active carbon can be successfully used as electrode materials for electrochemical capacitors.

Extreme biomimetic approach for developing novel chitin-GeO2 nanocomposites with photoluminescent properties

“…As Verongida sponges can be grown in marine ranching stations [5], their scaffolds may provide a natural renewable source for such materials with applications in fields such as biomedicine and technology.…”

“…Extreme biomimetics is a novel scientific direction of modern biomimetics proposed for the first time in 2010 [1] and has recently shown several successful advancements [2][3][4][5][6][7]. This powerful approach is a milestone for modern chemistry inspired by biological materials.…”

“…The exceptional thermal stability of chitin (up to 360 °C ) [11][12][13][14] is the key factor for the practical application of this biopolymer in hydrothermal synthesis [15]. For example, chitin has been recently reported as a template for the hydrothermal synthesis of nanocrystals of ZnO, ZrO 2 , SiO 2 , and Fe 2 O 3 (hematite) at temperatures between 70 and 150 °C [2][3][4][5][6][7]. Although nanostructured Stöber silica can be obtained using chitin at pH 14.0 and 120 °C [6,7], to our knowledge, there are no reports concerning the hydrothermal synthesis of germanium oxides using chitin.…”

Solvothermal synthesis of hydrophobic chitin–polyhedral oligomeric silsesquioxane (POSS) nanocomposites

“…There are many well described methods for chitin modification, including: acetylation [17,19], tosylation [20], phthaloylation [16], phosphorylation [21], and graft polymerization [16,22]. Moreover, a number of reports have been published on the modification of chitin properties by incorporation of inorganic compounds into a polymer matrix [23,24].…”

Preparation of monolithic silica–chitin composite under extreme biomimetic conditions

“…In contrast to traditional aspects of biomimetic synthesis of biocomposites, Extreme Biomimetics is based on metallization and mineralization of specific biomolecules [2] under conditions which mimic extreme aquatic niches like hydrothermal vents, geothermal pipelines or hot springs (see for review [3][4][5][6]). Therefore, the basic principle of this concept is to use biopolymers, which are chemically and thermally stable under these specific conditions in vitro.…”