- Surface and porous textural properties of silica–wollastonite composites prepared by sol–gel process doi link

Auteur(s): Larreal de Hernandez Lismarihen, Anez-Borges Liz, Woignier Thierry, Alaoui Adil, Etienne-Calas S., Despetis F., Bonnet L., Colaiocco B., Tahir S., Dieudonne-George P.

(Article) Publié: Journal Of Sol-Gel Science And Technology, vol. 90 p.113–125 (2019)
Texte intégral en Openaccess : openaccess

Ref HAL: hal-02464294_v2
DOI: 10.1007/s10971-018-4874-9
WoS: 000466160600013
Exporter : BibTex | endNote

Silica–wollastonite xerogel composites (xerocomposites) with different wollastonite filler content were obtained after classical drying of silica–wollastonite gels. Two different silica precursors were used, TEOS and colloidal LUDOX, for composites named TW and LW, respectively. We utilized SAXS experiments, N2 adsorption–desorption, and SEM techniques to determine the textural and structural properties of these porous materials. For both the TW and LW composites, it was shown that a macroporosity and a mesoporosity coexist. We argue that the proportion of macroporosity directly depends on the proportion of wollastonite fillers in the composite. We propose a unique two-stage drying mechanism to explain the formation of macropores. We additionally found that the surface of wollastonite fillers was covered by a dense multilayer packing of silica colloids in LUDOX LW xerocomposites. We believe that these surface-modified wollastonite fillers could improve the carbonation kinetics of wollastonite when used as a precursor for aqueous mineral carbonation, a promising route for safe and durable carbon sequestration.