Morphology Variations of Plugged Hexagonal Templated Silica

• Published in: Journal of porous materials 2005-01, Vol.12 (1), p.65-69
• Main Authors: Van Bavel, E, Cool, P, Aerts, K, Vansant, E F
• Format: Article
• Language: English
• Subjects: Channels; Deposition; Morphology; Nanoparticles; Porous materials; Rods; Silicon dioxide; Stirring
• ISSN: 1380-2224; 1573-4854
• DOI: 10.1007/s10934-005-5235-y

PHTS materials with combined micro- and mesoporosity and with different morphologies were synthesized. PHTS or Plugged Hexagonal Templated Silica is a plugged variant of SBA-15 containing extra silica nanoparticles ('plugs') inside the mesoporous channels. Utilising a low amount of TEOS and high stirring and aging temperatures, PHTS-particles with spherical morphology were synthesized for the first time. It was observed that the morphology changed gradually with increasing stirring temperature. It evolved from smooth rods (60^sup ^C) to rough rods with a deposition of small particles on the surface (70^sup ^C) and finally to spheres (80^sup ^C). However, synthesis of materials at a stirring and aging temperature of 80^sup ^C using larger amounts of silica source (TEOS) did not result in particles with spherical morphology. This demonstrates the profound impact of the amount of silica source, as well as the temperature. The results are explained by means of the cloud point of the surfactant and the balance between the rate of polymerization of the silica source and the rate of mesostructure formation. The prepared PHTS materials were characterized by XRD, N^sub 2^ sorption and SEM.[PUBLICATION ABSTRACT]