Biomimetic approach to forming chitin/aragonite composites

Abstract

Biomimetic materials which display the complexity of biominerals like nacre are synthetically difficult to prepare. The formation of chitin/calcium carbonate composites, where CaCO(3) is present as aragonite, was achieved via reacetylation of preformed chitosan scaffolds followed by the combination of presoaking of chitin templates with mineral solutions in the presence of poly(acrylic acid). The as-synthesised composites are comprised of well-ordered ribbons of aragonite crystals held within an organic matrix, mimicking the structure of nacre.

Nacre‐Inspired Mineralized Films with High Transparency and Mechanically Robust Underwater Superoleophobicity

“…Mater. 2020, 32,1907413 4500 nm by regulating the volume or concentration of the CSMA solution ( Figure S4, Supporting Information).…”

“…It is worth noting that the biomineralization time in our work is significantly shorter than that in the traditional methods, which usually required weeks to complete the biomineralization process. [32,33] In comparison, our ACC-mediated biomineralization process only takes a few hours to finish the preparation of the transparent NIM film (Figure 3c), because we provide calcium and carbonate not in the form of ions but as amorphous intermediate nanoparticles as found in natural nacre. [26,34] These precursors can easily allow for high mass fluxes and increase of crystallization speed, independent of gas diffusion and evaporation, which are major factors to hinder the speed of traditional mineralization process.…”

“…With increasing mineralization time, a Voronoi pattern was eventually formed by the lateral growth of aragonite platelets (Figure c). It is worth noting that the biomineralization time in our work is significantly shorter than that in the traditional methods, which usually required weeks to complete the biomineralization process . In comparison, our ACC‐mediated biomineralization process only takes a few hours to finish the preparation of the transparent NIM film (Figure c), because we provide calcium and carbonate not in the form of ions but as amorphous intermediate nanoparticles as found in natural nacre .…”

Crystallization of Calcium Carbonate in Alginate and Xanthan Hydrogels

“…Biocompatible polysaccharide hydrogels have been recognized as suitable models for investigation of CaCO 3 precipitation (crystallization), particularly for clarifying the role of basic processes (nucleation, crystal growth, dissolution or aging) [7,10,[12][13][14]. However, a more explicit connection between calcium carbonates and gels is related to their possible biomedical or pharmaceutical application.…”

“…Thus for example, CaCO 3 precipitation has been initiated by alternating a soaking of poly(acrylic acid) grafted poly(ethylene) films into Ca 2+ or CO 3 2− solutions. Similar protocols have been applied for agarose or chitosan gels [14,[31][32][33]. A diffusion of one component (CO 2 ) into the agarose gel preloaded with Ca 2+ and modified with self-assembled monolayer, has been investigated as a model of biomineralization of protein-based hydrogels.…”