Self-Assembly of Pluronic F127鈥擲ilica Spherical Core鈥揝hell Nanoparticles in Cubic Close-Packed Structures
详细信息 查看全文
- 作者：Stef Kerkhofs ; Tom Willhammar ; Heleen Van Den Noortgate ; Christine E. A. Kirschhock ; Eric Breynaert ; Gustaaf Van Tendeloo ; Sara Bals ; Johan A. Martens
- 刊名：Chemistry of Materials
- 出版年：2015
- 出版时间：August 11, 2015
- 年：2015
- 卷：27
- 期：15
- 页码：5161-5169
- 全文大小：517K
- ISSN：1520-5002
文摘
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 (Fm3虆m) with isolated spherical mesopores interconnected through micropores. Heating of the synthesis medium from room temperature to 70 掳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.