title: pH-induced self-assembly and capsules of sodium alginate.
abstract: In this investigation, we used a kind of polyelectrolyte, sodium alginate, as a model biomacromolecule to investigate the aggregation behaviors in aqueous solution after partial protonation of carboxylate groups in the alginate molecules. It is demonstrated that the alginate assemblies with core-shell structure can be generated by the partial protonation of carboxylate groups in sodium alginate chains using the protons released gradually from the reaction of K(2)S(2)O(8) with water at 70 degrees C in aqueous solution. The partial cross-linked alginate assemblies are pH sensitive and can change to hollow structure in the medium with relatively high pH value. This approach avoids use of block or grafted copolymers as the precursors or any other template to prepare assemblies and capsules, and provides a functional surface for subsequent chemical reaction at the surface (e.g., for binding biomolecules and for surface grafting). Such unique assemblies are also expected to be useful in biomedical fields.
authors: Laboratory of Mesoscopic Chemistry and Department of Polymer Science and Engineering, College of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors: Yi
authors: Y
authors: Cao
authors: Xiaochen
authors: X
authors: Shen
authors: Ying
authors: Y
authors: Chen
authors: Jian
authors: J
authors: Guo
authors: Qi
authors: Q
authors: Chen
authors: Xiqun
authors: X
authors: Jiang
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002214:Capsules; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D046529:Microscopy, Electron, Transmission
chemical_list: D000464:Alginates; D002214:Capsules; D006603:Hexuronic Acids; D020723:Glucuronic Acid