Reversible Light-Triggered Transition of Amphiphilic Random Copolymers

Ke Feng, Nan Xie, Bin Chen, Li-Ping Zhang, Chen-Ho Tung, and Li-Zhu Wu
Macromolecules

http://pubs.acs.org/doi/full/10.1021/ma300734z

The authors prepared an amphiphilic random copolymer using ROMP. One of the monomers, the spiropyran, undergoes an ultraviolet-initiated change from hydrophobic to hydrophilic. This transition is reversible on irradiation with visible light. The authors found that in solution these polymers for micelles which shrink in size (and solution changes color) upon uv irradiation. They also studied the encapsulation and release of the hydrophobic dye Nile Red, which is used as a model for drug delivery.