SYNTHESIS AND CHARACTERISATION OF PHOSPHORUS-DOPED AKERMANITE-BASED BIOCERAMICS

Abstract

Synthetic akermanite (Ca₂MgSi₂O₇) ceramics are viewed as promising candidates for bone implants due to their superior mechanical and bioactive properties compared to CaP-based ceramics. This paper investigates the effect of substituting phosphorus (P⁵⁺) ions on the physical, chemical/elemental, and morphological characteristics of akermanite-based powders produced at ambient conditions. To make the composition closer to our native bone, phosphate ions (P⁵⁺) were introduced into the akermanite host structure within controlled amounts, Ca₂MgSi_2-xP_xO₇ (where x = 1, 1.5, 2.5, and 3.5 mol%). The powders were synthesised using planetary ball milling at 400 rpm for 4 hours, and the slurry was heated in the electric oven at 100 ℃ for 10 hours. X-ray diffraction pattern of the as-milled powders revealed no distinct akermanite phase, likely due to the poor crystallinity of the samples, as the synthesis was conducted at low temperature. However, a slight shift of the broad peaks toward higher angles was observed with increasing P⁵⁺ substitution, suggesting structural changes in the short-range of the material. No apparent changes were observed in the functional groups detected, as the amount of dopant was relatively small. The elemental analysis confirmed the partial substitution of P⁵⁺ into the akermanite structure, with the amount of phosphorus increasing with increasing Phosphorus Pentoxide (P₂O₅). Despite the varying compositions, all the powders formed agglomerated particles due to the Van der Waals attractive forces between the particles. Based on physicochemical analyses, the optimum concentration of P⁵⁺ was found at 3.5 mol%. These findings indicate that P-doped akermanite-based materials provide valuable insights for use in orthopaedic applications.