In situ study of the thermoresponsive behavior of micropatterned hydrogel films by imaging ellipsometry.
A patterned hydrogel was immobilized on a polymer substrate by low-pressure argon plasma treatment using a masking technique. The polymer sample showed a thermoresponsive aggregation behavior in the region of 35-37 degrees C. The micropatterned, thermoresponsive hydrogel film has been characterized with imaging ellipsometry. The characterization was carried out on the dry film as well as on a swollen sample in water. The thermoresponsive behavior was studied in deionized water by temperature-dependent measurements in a solid-liquid cell. Through imaging ellipsometry, it was possible to distinguish the different regions of interest on a micrometer scale and to follow the swelling of the hydrogel part as a function of the temperature. It was possible to visualize the swelling as 3D profiles of Delta at various temperatures. Long-term changes of the sample could also be detected, which cannot be picked up by conventional ellipsometry.
Schmaljohann
Dirk
D
Welsh School of Pharmacy, Cardiff University & Cardiff Institute of Tissue Engineering and Repair (CITER), Redwood Building, King Edward VII Avenue, Cardiff CF10 3XF, Wales, U.K. dchmaljohannd@cf.ac.uk
Nitschke
Mirko
M
Schulze
Roland
R
Eing
Andreas
A
Werner
Carsten
C
Eichhorn
Klaus-Jochen
KJ