Thin thermoresponsive hydrogel films of poly(N-isopropylacrylamide) end-capped with n-butyltrithiocarbonate (nbc-PNIPAM) on silicon supports with a gold layer on top, causing an asymmetric confinement, are investigated. For two different gold layer thicknesses (nominally 0.4 and 5 nm), the swelling and switching kinetics are probed with in situ neutron reflectivity. With a temperature jump from 23 to 40°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. In 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.

The thermal behavior of a poly(styrene-b-N-isopropyl acrylamide) diblock copolymer was studied in aqueous solution as well as in thick and in thin films. The polymer was synthesized using reversible addition-fragmentation chain transfer. The critical micelle concentration in aqueous solution was determined using fluorescence correlation spectroscopy. The lower critical solution temperature (LCST) of micellar solutions was detected using microcalorimetry and turbidimetry at 31 °C. Using dynamic light scattering, the collapse of the micelles at the LCST as well as their clustering above was observed. These findings were corroborated with small-angle X-ray scattering. In thick films immersed in water, similar findings were made. In a thin film, however, the LCST is depressed and is found at 26-27 °C

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We have studied the thermal behavior of an ABA triblock copolymer having short, deuterated polystyrene end‐blocks and a longer poly(N‐isopropyl acrylamide) middle block, the latter exhibiting a lower critical solution temperature. The collapse of the micelles was investigated using dynamic light scattering. Small‐angle neutron scattering with contrast matching allowed us to quantify the core‐shell structure of the micelles as well as their correlations as a function of temperature.

Due to a processing error the presentation of Fig. 7 was incorrect. The correct figure is given below.