粒径、形貌对羟基磷灰石及其牙膏吸附Zn2+的影响

摘要

Objective To study the influence of particle size and morphology on zinc cation adsorption by hydroxyapatite (HA) and dentifrice containing HA. Methods Four HAs with different particle sizes and morphologies, HA-containing dentifrice and blank dentifrice were prepared into suspensions of serial concentrations. Zinc ion solutions with an initial concentration of 10 mg/L was mixed with the suspensions and kept for 24 h for adsorption reaction. The zinc ion concentration in the supernatant was measured by inductively coupled plasma emission spectrometer and the sorption rate of zinc ion was calculated. Results HA and HA-containing dentifrice with various particle sizes and morphologies were all capable of absorbing zinc ions from simulated waste water, and the adsorption rate of HA-containing dentifrice was 3%-10%higher than that of HA. HA with a particle size of 12μm and a spherical morphology showed the strongest adsorption ability, followed by short bar-shaped HA with a particle size of 30 μm. Both Langmuir and Freundlich equation could simulate the sorption processes of HA dentifrice, while only Langmuir equation could simulate the sorption processes of HA. Conclusion Incorporation of HA in dentifrice can enhance zinc ion adsorption capacity of the material. The particle size and morphology of HA both affect the adsorption of zinc ions, and 12-μm HA particle with a spherical morphology has the best adsorption ability.%目的：研究羟基磷灰石的粒径、形貌对HA及其牙膏吸附水溶液中Zn2+的影响。方法取不同粒径、形貌的四种HA及其牙膏和空白对照牙膏分别配成9组系列浓度的悬液，分别加入初始浓度为10 mg/L的锌离子溶液，静置反应24 h后取上清液用电感耦合等离子发射光谱仪测定残余锌离子浓度，计算吸附率和吸附能力。结果 HA及掺HA牙膏对锌离子有一定的吸附能力，掺HA牙膏较纯HA的吸附率提高了3%~10%。12μm球形HA对锌离子的吸附能力最强，其次为30 nm短棒状的HA。掺HA牙膏对锌离子的吸附符合Langmuir和Freundlish等温模型，纯HA的吸附仅符合Langmuir等温模型。结论在牙膏中加入HA可获得良好的锌离子吸附效果。HA的粒径、形貌对其吸附Zn2+的能力均有一定的影响，其中以12μm球形HA对锌离子的吸附效果最优。