The effect of the presence of ions on the aggregation behavior of natural polymer alginate in aqueous media was investigated. Through self-assembly of alginate in aqueous solutions containing Ca<sup>2+</sup> and CO<inf>3</inf> <sup>2-</sup> ions under very mild conditions, nanosized aggregates with four different morphologies, i.e., nanosphere, vesicle, nanoparticle, and nanorod, could be obtained under different ion concentrations. This study provides a simple approach to prepare organic/inorganic (O/I) hybrid natural polymer based aggregates with different morphologies. ©2009 American Chemical Society.
