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Photocrosslinking of thin polymer films – materials for sensors and actuators
Author(s) -
Kuckling Dirk,
Adler HansJürgen,
Arndt KarlFriedrich,
Wolff Thomas,
Hoffmann Jan,
Fischer WolfJoachim
Publication year - 1999
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19991420112
Subject(s) - lower critical solution temperature , polymer , materials science , swelling , thin film , chromophore , aqueous solution , polymer chemistry , irradiation , chemical engineering , copolymer , atmospheric temperature range , composite material , nanotechnology , photochemistry , organic chemistry , chemistry , physics , nuclear physics , engineering , meteorology
Polymers with temperature dependent degrees of swelling, especially polymers which exhibit lower critical solution temperature (LCST) behaviour in aqueous solutions, are of interest for applications in microsystems. For these applications it is necessary to form and pattern thin films in the μm‐range. This has been achieved through photocrosslinking of linear prepolymers. Copolymers based on N‐isopropylacrylamide (NIPAAm) were modified with a stilbazolium salt chromophore to yield photocrosslinkable temperature sensitive polymers. The chromophore reacts via a [2+2]‐cycloaddition under irradiation, this can be used to crosslink the polymer. The photocrosslinking properties were studied by UV irradiation of thin films and measuring the changes in UV absorption spectra. Through irradiation of thin films through a mask it was possible to obtain patterned networks in the μm‐range (20 μm space width and > 50 μm line width). The polymers exhibited LCST behaviour, which was measured using DSC. The resulting patterned networks had temperature dependent swelling properties in aqueous media.