Self-Assembly of Pluronic F127-Silica Spherical Core-Shell Nanoparticles in Cubic Close-Packed Structures.
A new ordered mesoporous silica material (COK-19) with cubic symmetry is synthesized by silicate polycondensation in a citric acid/citrate buffered micellar solution of Pluronic F127 triblock copolymer near neutral pH. SAXS, nitrogen adsorption, TEM, and electron tomography reveal the final material has a cubic close packed symmetry (Fm3̅m) with isolated spherical mesopores interconnected through micropores. Heating of the synthesis medium from room temperature to 70 °C results in a mesopore size increase from 7.0 to 11.2 nm. Stepwise addition of the silicate source allows isolation of a sequence of intermediates that upon characterization with small-angle X-ray scattering uncovers the formation process via formation and aggregation of individual silica-covered Pluronic micelles.
Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23, 3001 Leuven, Belgium.
Stef
S
Kerkhofs
Electron Microscopy for Materials Science (EMAT), University of Antwerp , Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
Tom
T
Willhammar
Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23, 3001 Leuven, Belgium.
Heleen
H
Van Den Noortgate
Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23, 3001 Leuven, Belgium.
Christine E A
CE
Kirschhock
Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23, 3001 Leuven, Belgium.
Eric
E
Breynaert
Electron Microscopy for Materials Science (EMAT), University of Antwerp , Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
Gustaaf
G
Van Tendeloo
Electron Microscopy for Materials Science (EMAT), University of Antwerp , Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
Sara
S
Bals
Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23, 3001 Leuven, Belgium.
Johan A
JA
Martens