Malkaj P, Pierri E, Dalas E
Department of Chemistry, University of Patras, GR-26504, Patras, Greece.
J Mater Sci Mater Med. 2005 Aug;16(8):733-7. doi: 10.1007/s10856-005-2610-9.
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.
采用恒组成技术，在持续过饱和条件下研究了海藻酸钠对羟基磷灰石（HAP）晶体生长的影响。发现海藻酸钠在低浓度时能抑制HAP晶体生长，当抑制剂浓度为2.1×10⁻⁷ - 12.6×10⁻⁷ mol/L时，晶体生长速率降低了42% - 86%。对晶体生长速率的抑制作用可能是通过吸附在活性生长位点上来解释的。详细的动力学分析表明，海藻酸钠在HAP表面的吸附为朗缪尔型吸附，海藻酸钠对HAP表面的亲和常数为1.63×10⁷ L/mol。确定结晶反应的表观级数约为2，这表明其生长机制为表面扩散控制的螺旋生长机制。
