TY  - JOUR
A1  - Wang, Weijia
A1  - Kaune, Gunar
A1  - Perlich, Jan
A1  - Paradakis, Christine M.
A1  - Bivigou Koumba, Achille Mayelle
A1  - Laschewsky, André
A1  - Schlage, K.
A1  - Röhlsberger, Ralf
A1  - Roth, Stephan V.
A1  - Cubitt, Robert
A1  - Müller-Buschbaum, Peter
T1  - Swelling and switching kinetics of gold coated end-capped poly(N-isopropylacrylamide) thin films
N2  - Thin thermoresponsive hydrogel films of poly(N-isopropylacrylamide) end-capped with n-butyltrithiocarbonate(nbc- PNIPAM) oil si I icon supports with a gold layer on top, causing an asymmetric confinement, are investigated. For two different gold layer thicknesses (nominally 0.4 and 5 rim), the swelling and switching kinetics are probed with in situ neutron reflectivity. With a temperature jump from 23 to 40 degrees C the film is switched from a swollen into a collapsed state. For the thin gold layer this switching is faster as compared to the thick gold layer. The switching is a two-step process of water release and a subsequent structural relaxation. fit swelling and deswelling cycles, aging of the films is probed. After five cycles, the film exhibits enhanced water storage capacity. Grazing-incidence small-angle X-ray scattering (GISAXS) shows that these gold coated nbc-PNIPAM films do not age with respect to the inner structure but slightly roughen at the gold surface. As revealed by atomic force microscopy, the morphology of the gold layer is changed by the water uptake and release.
Y1  - 2010
UR  - http://pubs.acs.org/journal/mamobx
U6  - https://doi.org/10.1021/Ma902637a
SN  - 0024-9297
ER  -