Synthesis of nano-structured sphene and optimization of the mechanical properties of its scaffold via response surface methodology

Nano-structured sphene (CaTiSiO5) powder was synthesized via mechanical activation and heat treatment. The synthesized powder was characterized by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), and simultaneous thermal analysis (STA). The sphene scaffolds were then fabricated via porogen method (using citric acid). Response surface methodology was used to determine the effects of d (particle size) and %V porogen (volume percent of porogen) on the mechanical behavior of the prepared sphene scaffolds. Moreover, a suitable mathematical model for describing the relationship between the factors (d and %V porogen) and the response (compressive strength) was statistically developed. The use of porogen in the synthesis procedure can change the porosity value of the final scaffold; thus, the compressive strength of the sphene scaffolds varied widely. The statistical analysis results predicted that the maximum value of the compressive strength can be obtained if %V = 25% and d = 250 μm. Under these conditions, the prepared scaffolds possess a compressive strength value as high as 7 MPa.