4.6 Article

Azobenzene-Based Light-Responsive Hydrogel System

Journal

LANGMUIR
Volume 25, Issue 15, Pages 8442-8446

Publisher

AMER CHEMICAL SOC
DOI: 10.1021/la804316u

Keywords

-

Funding

  1. Microelectronics Advanced Research Corporation (MARCO)
  2. Focus Center Research Program (FCRP)
  3. Center on Functional Engineered NanoArchitectonics (FENA)

Ask authors/readers for more resources

A deoxycholic acid-modified beta-cyclodextrin derivative (2) and an azobenzene-branched poly(acrylic acid) copolymer (3) were prepared, and the association and dissociation of 2 with the trans/cis-azobenzene units in 3 were characterized by UV/vis spectroscopy, induced circular dichroism, and H-1 NMR spectroscopy. The experimental results indicate that the trans-azobenzene units are bound strongly within the cavities of 2 whereas the cis-azobenzene is not bound at all. A supramolecular inclusion complex (1), formed by 2 and 3, is accompanied by the formation of a hydrogel. The light-responsive gel-to-sol and sol-to-gel phase transitions of the hydrogel, induced by trans-cis photoisomerization of the azobenzene units, were investigated. In the hydrogel system, the trans-azobenzene units in 3 are included inside the hydrophobic cavity of 2. Upon photoirradiation with UV light of 355 nm, the hydrogel is converted efficiently to the sol phase because the trans-azobenzene units are converted photochemically to their cis configurations, whereupon the resulting cis-azobenzene units dissociate from 2. The hydrogel can be recovered from the sol phase by photoirradiation with visible light of 450 nm. The swelling ratio for fresh hydrogel samples, which was found to be 8.7 +/- 0.7, was measured for a number of gel-to-sol and sol-to-gel phase-transition cycles.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available