Enlargement of mesopores of 2-D orthorhombic KSW-2 type silica by the addition of poly(oxyethylene) alkyl ether during the mesostructural formation

• Published in: Solid state sciences 2011-04, Vol.13 (4), p.714-720
• Main Authors: Takahashi, Nobuyuki, Kimura, Tatsuo, Kuroda, Kazuyuki
• Format: Article
• Language: English
• Subjects: Adsorbents; Brij56; Chemistry; Condensed matter: structure, mechanical and thermal properties; Enlargement; Ethers; Exact sciences and technology; Expansion; General and physical chemistry; Hexadecyltrimethylammonium; Inorganic compounds; Kanemite; KSW-2; Mesoporous silica; Orthorhombic phase; Physics; Porosity; Precursors; Silicates; Silicon dioxide; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Surface physical chemistry; Transformations
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2010.06.023

The size of mesopores in 2-D orthorhombic KSW-2 type silica, derived from a layered silicate kanemite, can be enlarged by the addition of poly(oxyethylene) alkyl ether (C 16EO 10) during the mesostructural transformation from a lamellar phase to a 2-D orthorhombic one. Precursors for pore-expanded KSW-2 type silica were prepared by an acid treatment of lamellar hexadecyltrimethylammonium-intercalated kanemite (C 16TMA-kanemite) in the presence of C 16EO 10. The acid treatment induces simultaneous reactions of (1) intercalation of C 16EO 10, (2) deintercalation of C 16TMA cations, and (3) mesostructural transformation into a 2-D orthorhombic phase. Depending on the concentration of C 16EO 10, the d 11 spacing of the products after the acid treatment but before calcination varied from 4.0 to 5.4 nm and that of the calcined products varied from 3.5 nm to 4.8 nm. The method provides a precise control in a certain range of the pore size of KSW-2 type mesoporous silica. [Display omitted]