Table 1.
Experimental parameters and their levels.
Table 2.
Ion concentrations of prepared SBF (Simulated Body Fluid) and human blood plasma.
Fig 1.
FTIR spectra of HAp powders at different condition based on RSM design.
A) Alkaline condition; B) Normal condition; C) Acidic condition.
Fig 2.
TEM images for HAp samples in alkaline conditions (pH = 10).
Fig 3.
TEM images for HAp samples in normal conditions (pH = 7).
Fig 4.
TEM images for HAp samples in acidic conditions (pH = 4).
Fig 5.
XRD pattern hydroxyapatite standard [29] and XRD pattern at different condition based on RSM design.
Table 3.
XRD results for 17 sample HAp.
Table 4.
Design of Central Composite Design (CCD) and its actual values.
Table 5.
ANOVA table for yield (quadratic model).
Fig 6.
Effect of process parameters on reaction yield.
A: Hydrothermal temperature, B: hydrothermal reaction time, C: pH.
Fig 7.
Residual plots for yield of HAp nano powder, based on Central Composite Design (CCD).
A: normal probability; B: residuals.
Table 6.
ANOVA table for crystallinity (quadratic model).
Fig 8.
Effect of process parameters on degree of crystallinity.
A: Hydrothermal temperature, B: hydrothermal reaction time, C: pH.
Fig 9.
A: 2D contour plots and B: 3D surface plots for the effects of pH and temperature on the degree of crystallinity at time 10 h.
Fig 10.
The residual plots for degree of crystallinity of HAp nano powder using hydrothermal method, based on CCD.
A: normal probability; B: residuals versus predicted.
Fig 11.
Perturbation chart for crystallinity response.
Table 7.
ANOVA table for crystal size, quadratic model.
Fig 12.
Effect of process parameter on crystal size.
A: Hydrothermal temperature, B: hydrothermal reaction time, C: pH.
Fig 13.
A: 2D contour plots and B: 3D surface plots for the effects of pH and temperature on the percent of crystal size at time 10 h.
Fig 14.
Residual plots for particle size of HAp nano powder, according to CCD.
A: Normal probability; B: residuals versus predicted.
Fig 15.
Perturbation chart for crystal size response.
Fig 16.
Desirability bar graph.
Fig 17.
XRD pattern at optimum conditions (time = 10 h, temperature: = 130°C, pH = 10).
Table 8.
Design optimization parameter.
Fig 18.
TEM result for HAp powder at optimal conditions (time = 10 h, pH = 10, temperature = 130°C).
Fig 19.
FTIR spectrum of HAp powder at optimal conditions (time = 10 h, pH = 10, temperature = 130°C).
Fig 20.
EDX result for HAp powder at optimal conditions (time = 10 h, pH = 10, temperature = 130°C).
Fig 21.
SEM images of HAp powder a) before and b) after immersion in SBF c) growth of apatite layer after immersion in SBF.
Fig 22.
a) before, and b) after immersion in SBF.