On the Formation Mechanism of Pluronic-Templated Mesostructured Silica
Journal article, 2010

The synthesis of mesostructured silica formed at mildly acidic conditions using the nonionic surfactant Pluronic P123 has been studied with the aim of showing the importance of the degree of condensation of the silica source. The experimental investigation employed was ill situ small-angle X-ray scattering (SAXS) in combination with all advanced model. The results are further supported by dynamic light scattering (DLS) and transmission electron microscope (TEM) analyses. Tetraethyl orthosilicate (TEOS) has been used as silica source, using a two step procedure involving a prehydrolysis of the TEOS, so that the degree of condensation of the silica at the start of the reaction could be varied. The results obtained demonstrated that, by controlling the degree of condensation of the silica at the start of the synthesis, it is possible to control the formation rate and the degree of order of the final material. The findings are summarized in a formation mechanism comprising three steps: Entropy driven surfactant-silica attraction that results in Cylindrical silica containing micelles, particle formation induced by micelle-micelle association caused by the surfactant-silica interaction, and finally rearrangement of the internal particle structure into a hexagonal arrangement that also affects the morphology of the entire particle, creating elongated particles.

copolymer

phase-separation

mesoporous silica

control

aggregation

x-ray-scattering

poly(ethylene oxide)

size

water-soluble silicates

sba-15

nonionic triblock

Author

Andreas Sundblom

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

C. L. P. Oliveira

Aarhus University

J. S. Pedersen

Aarhus University

Anders Palmqvist

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 114 8 3483-3492

Subject Categories

Physical Chemistry

DOI

10.1021/jp100087z

More information

Latest update

2/28/2018