In conclusion, the negative solvatochromism upon the increasing polarity of the solvents was observed, and the polarity of comonomer had an effect on the photo-responsive behavior of spiropyran.
The strong polarity could result in the shift of lmax to low wavelength in UVeVIS spectra. The amphiphilic random copolymer exhibited a good reversible behavior in aqueous solution: the addition of strong acid promoted the isomerization from spiropyran (SP) to merocyanine (MC), and the inverse process was achieved by the introduction of strong base.
Finally, a significant blueshift and an obvious color from purple to claretred were observed upon the introduction of Co2þ into the amphiphilic copolymer after UV irradiation, which may exploit the potential application of the amphiphilic spiropyran-based random copolymer in the selective recognition for Co2þ ions.