Figure 2 : Expansion of αCD–Azo gels immersed in aqueous solutions of competitive molecules.

From: Expansion–contraction of photoresponsive artificial muscle regulated by host–guest interactions

Figure 2

(a) Weight ratio change of the αCD–Azo gel(1, 2) immersed in aqueous solutions of competitive molecules such as 1,4-butane diol (C4 diol), 1,5-pentane diol (C5 diol), 1,6-hexane diol (C6 diol), 1,7-heptane diol (C7 diol) and competitive hosts (CDs). Concentration of competitive molecules in water was changed from 0 to 1,000 mM. Data for 1,000 mM of αCD and γCD are not collected because they become saturated at 100 mM. Saturated concentration of βCD is 10 mM. Error bars, standard deviation for 5 measurements. (b) Weight ratio change of αCD–Azo gel(1, 4) immersed in competitive molecules. Error bars, standard deviation for 5 measurements. (c) Photographs of the volume change of αCD–Azo gel(1, 2) immersed in aqueous solutions of C7 diol. Scale bar, 5mm. (d) Photographs of the volume change of αCD–Azo gel(1, 2) immersed in aqueous solutions of αCD. Scale bar, 5mm. (e) Schematic illustration of the expansion of αCD–Azo gels immersed in aqueous solutions of competitive molecules. Azo unit on the polymer chain is ejected from the αCD cavity by competitive guests. Added CDs competitively form inclusion complexes with the Azo units. Av., average.