关键词: 羟基磷灰石, 磷酸缓冲液, 快速洗涤

Abstract: Synthetic nano-sized hydroxyapatite, which is widely used in biomedical engineering, is commonly prepared at pH>10, leading to long time and large amounts of water to wash the fabricated hydroxyapatite so as to remove its alkaline before further processing. In this paper, we developed a method for rapid washing hydroxyapatite by using neutral phosphate buffer (PBS) as the washing solution. Firstly, hydroxyapatite (HA) was prepared by precipitation using calcium nitrate and trisodium phosphate as raw materials. Then the hydroxyapatite was quickly washed with the formulated PBS to neutral, while another hydroxyapatite sample was neutralized by washing with deionized water based on the conventional washing procedure. The morphology, particle size and chemical composition of the samples washed by the two methods were analyzed by transmission electron microscope, X-ray diffraction, infrared spectroscopy and thermogravimetry. The results showed that the above-mentioned properties of the products obtained by the two methods did not show significant difference, although the HA crystals washed with PBS showed improved crystal integrity and thermal stability. Notably, the rapid washing method with PBS can save more than 80% of deionized water and shorten the washing cycle from 10 day to about 8 hour in comparison with the conventional washing method. The rapid washing method proposed in this paper is expected to be able to greatly increase the yield and lower the cost of nano-hydroxyapatite in laboratory and industrial production.

Key words: hydroxyapatite, phosphate buffer solution, rapid washing method