Near-Infrared Two-Wavelength-Selective Response Of Thermosensitive Gels Modified With Rare-Earth Ions

Near-infrared two-wavelength-selective responses of thermosensitive hydrogels consisting of acrylic acid/N-isopropylacrylamide (NIPAAm) copolymers coordinated with rare-earth ions Nd3+ and Yb3+ were demonstrated. The transparency of the gels coordinated independently with Nd3+ and Yb3+ was reversibly changed by on/off switching of 808- and 980-nm light irradiation, respectively, because of the volume phase transition of the gels induced by photothermal conversion.