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Silica Nanotubes with Widely Adjustable Inner Diameter and Ordered Silicas with Ultralarge Cylindrical Mesopores Templated by Swollen Micelles of Mixed Pluronic Triblock Copolymers

Mixtures of commercially available Pluronic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers combined with appropriate swelling agents are proposed as templates for silica nanotubes and ordered silicas with very large cylindrical mesopores. In particular, swollen micelles of Pluronic F127 (EO106PO70EO106) with long poly(ethylene oxide) (PEO) chains and low poly(propylene oxide) (PPO) content (30 wt %) mixed with a Pluronic with a higher PPO content (60–70 wt %) and short PEO chains were found at 11 °C to template two-dimensional hexagonal SBA-15 silicas with ultralarge (100) interplanar spacings up to ∼30 nm. Moreover, when the ratio of the silica precursor to the triblock copolymer mixture was appropriately lowered, silica nanotubes were readily obtained. While the addition of the high-PPO-content Pluronic facilitated the uptake of the swelling agent (toluene), allowing one to achieve very large inner tube diameters (∼35 nm), smaller diameters down to ∼10 ...

Autoren:   George Farid; Michal Kruk
Journal:   Chemistry of Materials
Jahrgang:   2017
DOI:   10.1021/acs.chemmater.6b05504
Erscheinungsdatum:   18.05.2017
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