Processing of highly porous bioglass monoliths by hydrothermal hot pressing

B. Degraeve (1) , B. Lefeuvre (1) , N. Rocton (1) , N. Herbert (1) , N. Hamrouni (1) , Grégory Hauss (2) , Alain Largeteau (3) , Mythili Prakasam (3) , Hassane Oudadesse (1) , Odile Merdrignac-Conanec (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 PLACAMAT - Plateforme Aquitaine de Caractérisation des Matériaux
3 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Porous bioglass monoliths have been processed by hydrothermal hot pressing (HyHP) from sol-gel and melt-derived bioglass powders of composition (in mol %): SiO2–CaO–P2O5 (55.0-40.0-5.0) and SiO2–CaO–Na2O–P2O5 (47.2-26.4-23.8-2.6), respectively. An open porosity of >70% ever reached in 3D structures is reported for monoliths issued from sol-gel powders. Dissolution studies were performed in simulated body fluid (SBF) for 1–30 days. The monoliths were analysed using X-Ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) to observe the formation of an apatite-like layer and elemental concentration of SBF was evaluated using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). A higher kinetics in the development of apatite layer was observed for sol-gel derived monoliths. This result is explained by the high surface areas of the nanosized sol-gel powders and the possibility of HyHP to create large porosity (mesoporous monoliths) and retain large surface areas. HyHP is also effective in processing 3D-bioglass structures with porosity gradient by co-sintering powders of different size.

Mots clés: Hydrothermal hot pressing; Sol-gel derived bioglass; Highly porous monolith; Melt-derived bioglass; Sintering

Domaines: Chimie

B. Degraeve, B. Lefeuvre, N. Rocton, N. Herbert, N. Hamrouni, et al.. Processing of highly porous bioglass monoliths by hydrothermal hot pressing. Ceramics International, 2022, 48 (13), pp.18190-18198. ⟨10.1016/j.ceramint.2022.03.078⟩. ⟨hal-03643101⟩