Study On Synthesis Of Peanut Nano - Hydroxyapatite By Ethanol Template

Hydroxyapatite (HA) nanopeanut, hierarchical nanorods covered with nanopits on surface, was successfully synthesized via a novel ethanol induced and stabilized route combine with the reflux-solvothermal method. Ca(NO3)2, H3PO4, and NaOH were used as calcium source, phosphorus source, and pH adjusting agent, respectively. Ethanol as the sole functional organic molecule. We compared the structure of hydroxyapatite prepared by reflux method, solvothermal method, and reflux-solvothermal method. The ethanol-assisted synthesis mechanism of HA nanopeanut was proposed and discussed in thermodynamics. In the process of experiment, the XRD、TEM、SEM and isothermal nitrogen adsorption method were used to characterize the samples.The results proved that hierarchical nanorods synthesized by the reflux-solvothermal method are well crystallized and present a pure hexagonal Ca10(PO4)6(OH)2. Transmission electron microscopy (TEM) exhibited that the nanorods are of 50～210 nm in length and 22～52 nm in width. The nanopits of 3～ 12 nm in diameter in the surface were also confirmed and calculated by nitrogen adsorption/desorption isotherms, which is well consistent with TEM observation. By studying the effect of the template, the preparation methods, the reflux time, solvothermal temperature, and template agent on the influence of the structure of hierarchical nanorods, we obtained the process conditions optimized:reflux 2 hours, solvothermal temperature 160 ℃, ethanol/H2O=1/1, sodium hydroxide/Calcium nitrate=2/1; Ethanol as the sole functional organic molecule played the roles of improving the HA crystallization, inducing the nucleation and growth of HA nanorods, as well as inducing and stablizing the nanopits in surface. Different structure of hierarchical nanorods was synthesized using the optimal process for the preparation of hierarchical nanorods, with acetic acid, dioxane, tetrahydrofuran, isopropanol as template agent. Compared with ethanol, these samples were poorly-crystallized, poorly-ordered and the holes size was too small.