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Your search keyword '"Kourkoutis, Lena F."' showing total 11 results
Start Over Author "Kourkoutis, Lena F." Journal nano letters
11 results on '"Kourkoutis, Lena F."'

11. Stimuli-Responsive Shapeshifting Mesoporous Silica Nanoparticles.

Author

Sun Y, Sai H, Spoth KA, Tan KW, Werner-Zwanziger U, Zwanziger J, Gruner SM, Kourkoutis LF, and Wiesner U

Subjects
Humans, Humidity, Magnetic Resonance Spectroscopy, Porosity, Drug Delivery Systems, Nanoparticles chemistry, Silicon Dioxide chemistry
Abstract

Stimuli-responsive materials have attracted great interest in catalysis, sensing, and drug delivery applications and are typically constituted by soft components. We present a one-pot synthetic method for a type of inorganic silica-based shape change material that is responsive to water vapor exposure. After the wetting treatment, the cross-sectional shape of aminated mesoporous silica nanoparticles (MSNs) with hexagonal pore lattice changed from hexagonal to six-angle-star, accompanied by the loss of periodic mesostructural order. Nitrogen sorption measurements suggested that the wetting treatment induced a shrinkage of mesopores resulting in a broad size distribution and decreased mesopore volume. Solid-state (29)Si nuclear magnetic resonance (NMR) spectroscopy of samples after wetting treatment displayed a higher degree of silica condensation, indicating that the shape change was associated with the formation of more siloxane bonds within the silica matrix. On the basis of material characterization results, a mechanism for the observed anisotropic shrinkage is suggested based on a buckling deformation induced by capillary forces in the presence of a threshold amount of water vapor available beyond a humidity of about 50%. The work presented here may open a path toward novel stimuli-responsive materials based on inorganic components.

Published
2016
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