Coagulated concentrated anatase slurry leads to improved strength of ceramic TiO2 bone scaffolds

Slurry behaviour has an important influence on the properties of ceramic scaffolds produced by the polymer sponge method. By adding chloride salts to the TiO2 slurry, the viscosity was increased depending on the chloride concentration at low pH and high particle concentration. Slurries with higher viscosity led to closed and dense scaffold struts combined with high porosity, resulting in a compressive strength over 1.6 MPa. Furthermore, scaffold prepared with 0.1 M CaCl2 and SrCl2 showed the formation of Ca- and Sr-rich phases at the grain boundaries. These ions were also shown to reduce the activation energy for grain growth in the TiO2 scaffold as indicated by the significantly larger grain size. Ca2+-doped scaffolds had the highest compressive strength, while the strength of Sr2+-doped scaffolds was reduced by the formation of a solid solution phase below the sintering temperature.