Control of calcium carbonate polymorphism and morphology by high molecular weight alginate and well defined alginate oligomers

摘要

Calcium carbonate precipitation was studied at controlled conditions, by seeded- and unseeded experiments, with various alginates and oligomers of alginate present. In unseeded experiments with low concentrations of a-L-guluronic acid oligomers (G-blocks), strong polymorph-selection of calcite was seen. The effect was explained by doing calcite- and vaterite-seeded growth experiments, which showed that growth of vaterite was strongly inhibited by G-blocks, while the growth rate of calcite was not affected significantly by G-blocks.