Structure and morphology of propylthiol-functionalised mesoporous silicas templated by non-ionic triblock copolymers

• Published in: Microporous and mesoporous materials Vol. 79; no. 1; pp. 241 - 252
• Main Authors: Hodgkins, Robert P., Garcia-Bennett, Alfonso E., Wright, Paul A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.04.2005; Elsevier
• Subjects: Chemistry; Colloidal state and disperse state; Ellman’s reagent; Exact sciences and technology; FDU-12; General and physical chemistry; Mesoporous solids; Porous materials; SBA-15; Thiol contents; Mesoporous solids; Thiol contents; Ellman’s reagent; SBA-15; FDU-12; Thiol; Porous material; Silica; Mesoporosity; Solid; Triblock copolymer; Morphology; Reagents; Ellman's reagent; Structure
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2004.10.036

The effect of the co-condensation of 3-mercaptopropyltriethoxysilane (MPTES) in the preparation of mesoporous silicas has been examined for levels of MPTES of 0–10 mol% (based on silicon) in reported syntheses using the block co-polymers P123 and F127. In syntheses using P123, SBA-15 (p6mm) forms with 0–5 mol% MPTES whereas addition of 7 mol% of the silane results in highly ordered Ia 3 ¯ d silica. Using F127, synthesis in the absence of MPTES gives the reported cubic Fm3m FDU-12 structure, based on the cubic close packing of surfactant micelles, whereas addition of MPTES results in the introduction of a high concentration of stacking defects in the close packing sequences and changes in particle morphology. At 5 mol% MPTES, tapered hexagonal prismatic particles with nano-domains of the hexagonally close packed structure (space group P6 3/mmc) are obtained. The accessible thiol contents in the members of these two series of solids have been determined using Ellman’s reagent (5,5′-dithiobis-(2-nitrobenzoic acid)): values of 50–70% of the thiols incorporated in the solid have been measured as being accessible to this reactant.