title: Biomimetic synthesis of multilayered aragonite aggregates using alginate as crystal growth modifier.
abstract: Polysaccharides were believed to play an important role in the mineralization process of many organisms. As the source of continuously and uniformly releasing alginate molecules and Ca(2+), alginate/Ca nanospherical gel was employed in the solution to induce the nucleation and growth of CaCO(3). Time-resolved transmission electron microscopy (TEM) was applied to study the crystallization at a very early stage. It was found that the initially formed lens-like vaterite particles gradually dissolved from the middle of the particle and released alginate molecules and Ca(2+) back into the system. As reaction time increased, the released substances were involved in the next stage of crystallization of CaCO(3), in the form of needle-like and shuttle-like aragonite particles sequentially depending on the concentration of alginate molecules and Ca(2+). "Egg-box" conformation of alginate and Ca(2+) was considered a skeleton for the growth of such aragonite particles. Notably, shuttle-like aragonite particles were composed of "bricks" of several hundred nanometers in size, which were very similar to biogenetic nacreous layers in shells.
authors.affiliation: Key Laboratory of Molecular Engineering of Polymers of Ministry of Education, Department of Macromolecular Science, Fudan University, Shanghai, 200433, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.forename: Boxun
authors.initials: B
authors.lastname: Leng
authors.forename: Renchao
authors.initials: R
authors.lastname: Che
authors.forename: Zhengzhong
authors.initials: Z
authors.lastname: Shao
mesh_terms: D000464:Alginates / Q000737:chemistry*; D032701:Biomimetics / Q000379:methods*; D002119:Calcium Carbonate / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D054118:Nanospheres / Q000737:chemistry / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D002119:Calcium Carbonate