title: The crystallization of Hydroxyapatite in the presence of sodium alginate.
abstract: The effect of sodium alginate on the crystal growth of hydroxyapatite (HAP) was investigated at sustained supersaturation by the constant composition technique. Sodium alginate was found to inhibit HAP crystal growth at low concentrations and reduced the crystal growth rates by 42-86% for inhibitor concentrations of 2.1x10(-7)-12.6x10(-7) mol/l. The inhibition effect on the crystal growth rate may be explained possibly through adsorption onto the active growth sites. A detailed kinetics analysis suggested a Langmuir-type adsorption of the alginate on HAP surface and a value of 1.63x10(7) l/mol was obtained for the affinity constant of sodium alginate for the surface of HAP. The apparent order for the crystallization reaction was determined to be approximately 2, thus suggesting a surface diffusion controlled spiral growth mechanism.
authors.affiliation: Department of Chemistry, University of Patras, GR-26504, Patras, Greece.
authors.forename: P
authors.initials: P
authors.lastname: Malkaj
authors.forename: E
authors.initials: E
authors.lastname: Pierri
authors.forename: E
authors.initials: E
authors.lastname: Dalas
mesh_terms: D000464:Alginates / Q000032:analysis / Q000737:chemistry*; D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry; D018786:Bone Substitutes / Q000032:analysis / Q000737:chemistry*; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D017886:Durapatite / Q000032:analysis / Q000737:chemistry*; D020723:Glucuronic Acid / Q000032:analysis / Q000737:chemistry; D006603:Hexuronic Acids / Q000032:analysis / Q000737:chemistry; D007700:Kinetics; D008422:Materials Testing; D008956:Models, Chemical; D013499:Surface Properties
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D018786:Bone Substitutes; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D017886:Durapatite