Study On Bioactivity And Adsorption Function Of Modified Nano - Hydroxyapatite

The medical engineering and environmental protection are most popular in the world, it is also the inevitable trend of development of human society. The hydroxyapatite (HA) play a key dual role in the bone implanting and drug loading for its good bio-activity and bone similar composition. Meanwhile, the Zeta potential and specific surface areas of HA crystal lead to high adsorption capacity for metal ions and organics. The HA is promising adsorbent in water treatment and protein purification for excellent adsorption capacity. So multi-functional inorganic materials in the future will attract munch attention. The main contents in this paper as follow:1. Highly crystalline carbonated hydroxyapatite (CHA) nanorods with different carbonate contents and Flower-like silicon doped hydroxyapatite (Si-HA) were synthesized by a novel hydrothermal method with soft-template. CHA nanorods and Flower-like Si-HA powders were synthesized with NH4HCO3 and TEOS respectively for carbonate and silicate source. The effects on synthesized crystal structure were investigated with different hydrothermal parameters included temperature, time and pH values. The crystallinity and chemical structure of prepared samples were studied by Fourier transform infrared spectroscopy (FTIR), X-ray photo-electronic spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), and scanning electron microscope (SEM). The specific surface area and pore size distribution were further analyzed by BET. The BET analysis results showed that the surface area of the synthesized samples was in the range of 60-80m2/g, while the pure HA with 26m2/g. Also pore size of the samples was about 26.228-30.632nm, which are belong to medium-size hole. Numerical considerable specific surface area and medium-size hole of HA results in conductive adsorption activity of pollutants.2. The cell toxicity test and alkaline phosphatase experiment were used to characterized the bio-activity and bio-compatibility, and the results demonstrate that the synthesized HA samples were promising application in bio-medical materials. Human osteosarcoma cells (MG-63 Cells) and New Zealand rabbit bone marrow mesenchymal stem cells (rBMSCs) were used in the process of biological activity analysis. The above-mentioned cells were co-cultured with different concentrations of synthetic hydroxyapatite in different days, cells attached and grew well, cell morphology and proliferation did not appear obvious change, highlighting the two materials of cells with low toxicity and high biological activity. The cells had been co-cultured with synthesized samples were dealt with phosphatase staining. And large amounts of alkaline phosphate is expressed in cytoplasm, which is indicative of osteogenesis.3. Ultra thin hydroxyapatite films were coated successfully on different substrates by hydrothermal contained glass, quartz, and CaF2 sheet. The film thickness can be controlled well by changing the concentrations of Ca, P source. Coated substrates showed high transmittance in different experiment conditions. The bio-activity and bio-compatibility of the substrates were improved, and the osteogenesis of bone cells was apparent.4. Removal of organic and heavy metal pollutants from wastewater is a very attractive research, and wastewater has been a serious threat to human. In this paper, CHA nanorods and Flower-like Si-HA were adopted for different pollutants adsorption. Adsorption studies showed that the pH values has a great effects on pollutants removal, which indicates that the the pollutants adsorption on hydroxyapatite induced by electrostatic attraction and pH environment mainly by changing the surface charge of adsorbent and pollurants. Also the experiment data for isotherm and kinetic investigations claimed that pseudo-second-order model and Langmuir model could well describe all above the adsorption behaviours. The two kinds of materials have great potential in the treatment of wastewater, which is worth further development and utilization.