Advanced Statistical Optimization of Parameters of Synthesis Process of Oxygenated Carbonated Apatite

Abstract

The synthesis process of oxygenated carbonated apatite was optimized by an advanced statistical planning of experiments. Full factorial design of 24 experiments was used to find the effects of five principal parameters: pH of the reaction medium, atomic ratio Ca/P of the reagents, concentration of the calcium solution (Ca²⁺), temperature of the reaction medium (T) and duration of the reaction (D), with fixing the H₂O₂ composition at 30% and stirring to 600 turns/min. Studied responses were the atomic ratio Ca/P, % O₂, % O₂ ²⁻ and % CO_{3 2−}. Optimum synthesis parameters were found to be pH = 7.38, Ca/P = 1.647, [Ca2+] = 0.636 M, T = 40°C and D = 1 h. The prediction responses were Ca/P = 1.575, % O₂ = 0.76, % O₂ ²⁻ = 0.50 and % CO₃ ²⁻= 1.84. The actual experimental results were in agreement with the prediction.

Keywords:

• Optimisation
• oxygenated carbonated apatites
• statistical analysis
• synthesis

Notes

***: Significant on a level of 0.1% (F_0.001(1.5) = 47.18)

**: significant on a level of 1% (F_0.01(1.5) = 16.26) NS: nonsignificant.

****: Very significant

***: significant on a level of 0.1% (F_0.001(1.5) = 47.18)

**: significant on a level of 1% (F_0.01(1.5) = 16.26); NS: nonsignificant.

****: Very significant

***: significant on a level of 0.1% (F_0.001(1.5) = 47.18)

**: significant on a level of 1% (F_0.01(1.5) = 16.26); NS: nonsignificant.

****: very significant

***: significant on a level of 99.9%

**: significant on a level of 99%.

****: Very significant

***: significant on a level of 0.1% (F_0.001(1.5) = 47.18)

**: significant on a level of 1% (F_0.01(1.5) = 16.26); NS: nonsignificant

* : Value outside of the experimental field (Table II).