TY  - JOUR
A1  - Buller, Jens
A1  - Laschewsky, André
A1  - Wischerhoff, Erik
T1  - Photoreactive oligoethylene glycol polymers - versatile compounds for surface modification by thin hydrogel films
T2  - Soft matter
N2  - Solid surfaces are modified using photo-crosslinkable copolymers based on oligo(ethylene glycol) methacrylate (OEGMA) bearing 2-(4-benzoylphenoxy) ethyl methacrylate (BPEM) as a photosensitive crosslinking unit. Thin films of about 100 nm are formed by spin-coating these a priori highly biocompatible copolymers onto silicon substrates. Subsequent UV-irradiation assures immobilization and crosslinking of the hydrogel films. Their stability is controlled by the number of crosslinker units per chain and the molar mass of the copolymers. The swelling of the hydrogel layers, as investigated by ellipsometry, can be tuned by the crosslinker content in the copolymer. If films are built from the ternary copolymers of OEGMA, BPEM and 2-(2-methoxyethoxy) ethyl methacrylate (MEO(2)MA), the hydrogel films exhibit a swelling/deswelling transition of the lower critical solution temperature (LCST) type. The observed thermally induced hydrogel collapse is fully reversible and the onset temperature of the transition can be tuned at will by the copolymer composition. Different from analogously prepared thermo-responsive hydrogel films of photocrosslinked poly(N-isopropylacrylamide), the swelling-deswelling transition occurs more gradually, but shows no hysteresis.
Y1  - 2013
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/35429
SN  - 1744-683X
VL  - 9
IS  - 3
SP  - 929
EP  - 937
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -