Conversion of waste eggshells to mesoporous hydroxyapatite nanoparticles with high surface area
- OAPS－大学生创新计划项目 
The objective of this work was to convert waste eggshells to mesoporous hydroxyapatte(HAp) with high surface area by using a simple and inexpensive protocol without complexes. The eggshells were initially dissolved in concentrated nitric acid under vigorous agitation to form Ca(NO3)2 solution, followed by the production of HAp nanoparticles through the addition of dilute phosphoric acid solution to the calcium solution at room temperature with a syringepump. The HAp product possessed high surface area (212.4m2/g), large pore size(16.8nm) and small particle size(o10nm)as shown by BET and small angle XRD analyses.Moreover,only about 8% of the HAp phase was converted to whitlockite at high temperature(950 1C), indicating its stability.