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Gewählte Publikation:

Pirani, F; Sharma, N; Moreno-Cencerrado, A; Fossati, S; Petri, C; Descrovi, E; Toca-Herrera, JL; Jonas, U; Dostalek, J.
(2017): Optical Waveguide-Enhanced Diffraction for Observation of Responsive Hydrogel Nanostructures
MACROMOL CHEM PHYS. 2017; 218(6): FullText FullText_BOKU

Optical diffraction measurements are reported for in situ observation of swelling and collapsing of responsive hydrogel nanostructures. The optical signal is enhanced by probing the surface carrying periodic arrays of hydrogel nanostructures by resonantly excited optical waveguide modes. UV-nanoimprint lithography is employed for the preparation of the arrays of nanopillars from photo-crosslinked N-isopropylacrylamide (pNIPAAm)-based hydrogel that are covalently tethered to a gold surface. The thermo-responsive properties of such pNIPAAm nano-pillars that swell in 3D are compared to those of a thin film prepared from the identical material and that is allowed to swell predominantly in 1D. The nanopillars with a diameter of approximate to 100 nm and aspect ratio of 2 swell by a factor of approximate to 6 as determined by optical measurements supported by simulations that are compared to morphological characteristics obtained from atomic force microscopy. Bending of nanopillars above the lower critical solution temperature (LCST), erasure of the topographic structure by drying at temperature below the LCST, and recovery by subsequent swelling below the LCST and drying at temperature above the LCST are observed.
Autor*innen der BOKU Wien:
Moreno Cencerrado Alberto
Toca-Herrera José Luis
BOKU Gendermonitor:

Find related publications in this database (Keywords)
nanoimprint lithography
optical waveguide spectroscopy

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