Photocrosslinking of thin films of temperature-sensitive polymers

The use of polymeric materials with temperature-dependent degrees of swelling (especially polymers that exhibit lower critical solution temperature (LCST) behaviour in aqueous solutions) in microsystems requires the preparation and patterning of layers in the µm range. Copolymers based on N-isopropylacrylamide were modi-fied with a stilbazolium salt chromophore to yield photocrosslinkable temperature-sensitive polymers. The chromophore and the polymers were characterized by UV, IR, 1H-NMR (nuclear magnetic resonance) and 13C-NMR spectra. The resulting polymers showed LCST behaviour, which was measured by differential scanning calorimetry. The photocrosslinking properties were studied by UV irradiation of the thin films and measurement of the changes in the UV absorption spectra. By 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 resulting patterned networks showed temperature-dependent swelling properties in aqueous media. Copyright © 1999 John Wiley & Sons, Ltd.

[1]  K. Subramanian,et al.  Synthesis and characterization of copolymers with a photosensitive group , 2001 .

[2]  Yoshihiro Ito,et al.  Photolithographic Synthesis of Hydrogels , 1998 .

[3]  Yoshihiro Ito,et al.  Micropattern immobilization of a pH-sensitive polymer , 1997 .

[4]  Yoshihiro Ito,et al.  Patterned immobilization of thermoresponsive polymer , 1997 .

[5]  K. Ichimura.  Photocrosslinkable Poly(vinyl alcohols): Preparation, Properties and Applications , 1996 .

[6]  Norman F. Sheppard,et al.  Adhesion of polymer films to oxidized silicon and its effect on performance of a conductometric pH sensor , 1996 .

[7]  T. Wolff,et al.  Interactions of AOT lyotropic liquid crystals and photochemical reactions of hydroxystilbazolium bromides : Steering reactions and switching phases , 1996 .

[8]  Yun Chen,et al.  Copolymers derived from 7-acryloyloxy-4-methylcoumarin and acrylates: 2. Reversible photocrosslinking and photocleavage , 1996 .

[9]  T. Ebisuno,et al.  Network formation and swelling behavior of photosensitive poly(vinyl alcohol) gels prepared by photogenerated crosslinking , 1996 .

[10]  Chi Wu,et al.  In-Situ Interferometry Studies of the Drying and Swelling Kinetics of an Ultrathin Poly(N-isopropylacrylamide) Gel Film below and above Its Volume Phase Transition Temperature , 1996 .

[11]  R. S. Davidson,et al.  The photocrosslinking of styrylpyridinium salts via a [2 + 2]-cycloaddition reaction , 1996 .

[12]  A S Hoffman,et al.  "Intelligent" polymers in medicine and biotechnology. , 1995, Artificial organs.

[13]  A. Hoffman,et al.  A new temperature- and pH-responsive copolymer for possible use in protein conjugation , 1995 .

[14]  M. Mikami,et al.  Preparation of thermoresponsive surfaces using polyvinylchloride-graft-poly(N-isopropylacrylamide) , 1993 .

[15]  Y. Nakayama,et al.  Preparation and characteristics of photocrosslinkable hydrophilic polymer having cinnamate moiety , 1992 .

[16]  T. Saegusa,et al.  Polyoxazoline having a coumarin moiety as a pendant group. Synthesis and photogelation , 1990 .

[17]  Masahiro Irie,et al.  Photoresponsive polymers. Photocontrol of the phase separation temperature of aqueous solutions of poly-[N-isopropylacrylamide-co-N-(4-phenylazophenyl)acrylamide] , 1988 .

[18]  S. S. Shah,et al.  Merocyanin dye preparation for the introductory organic laboratory , 1977 .

[19]  D. Whitten,et al.  Photochemical reactions in organized monolayer assemblies. 4. Photodimerization, photoisomerization, and excimer formation with surfactant olefins and dienes in monolayer assemblies, crystals, and micelles , 1977 .

[20]  Jack L. R. Williams,et al.  The preparation and properties of photoreactive polymers I. 2-(arylvinyl)-N-vinylpyridinium arylsulfonate polymers , 1964 .

[21]  Toyoichi Tanaka,et al.  Volume phase transition and related phenomena of polymer gels , 1993 .

[22]  S. Hirotsu.  Coexistence of phases and the nature of first-order phase transition in poly-N-isopropylacrylamide gels , 1993 .

[23]  S. Gehrke.  Synthesis, equilibrium swelling, kinetics, permeability and applications of environmentally responsive gels , 1993 .

[24]  Jan Feijen,et al.  Effect of comonomer hydrophilicity and ionization on the lower critical solution temperature of N-isopropylacrylamide copolymers , 1993 .

[25]  H. G. Schild.  Poly(N-isopropylacrylamide): experiment, theory and application , 1992 .