Alginate hydrogel-mediated crystallization of calcium carbonate

We documented a specific method for combining calcium ions and alginate molecules slowly and continuously in the mineralization system for the purpose of understanding the mediating function of alginate on the crystallization of calcium carbonate. The alginate was involved in the nucleation and the growth process of CaCO3. The crystal size, morphology and roughness of crystal surface were significantly influenced by the type of the alginate, which could be accounted for by the length of the G blocks in alginate. A combination of Fourier transform infrared spectroscopy and thermogravimetric analysis showed that there were the chemical interactions between the alginate and the mineral phase. This strategic approach revealed the biologically controlled CaCO3 mineralization within calcium alginate hydrogels via the selective nucleation and the confined crystallization of CaCO3. The results presented here could contribute to the understanding of the mineralization process in hydrogel systems.

Schematic illustration of the growth of calcite aggregates with different morphologies obtained from (a) Low G alginate gels and (b) High G alginate gels. Figure optionsDownload as PowerPoint slideHighlights
► We use a specific method for combining calcium ions and alginate molecules slowly and continuously in the mineralization system to understand the mediating function of alginate on the crystallization of CaCO3 crystals.
► The crystal size, morphology and crystal surface roughness are influenced by the length of G blocks in alginate. There are chemical interactions between the alginate and the mineral phase.
► We propose a potential mechanism of CaCO3 crystallization within High G and Low G calcium alginate hydrogel.