Fig. 5. (a) PL emission spectra of NP4C aqueous solution measured at different temperatures ranging from 4 to 80 °C; (b) PL emission spectra of NP4C aqueous solution at different volume fractions of H2O (fw, from 0 to 100%) and MeOH, the intensity of the blue light band was unified to the same level; (c) PL emission spectra of NP4C aqueous solution when added with different amounts of the β-CD host molecules (from 0 to 20 eq.). The yellow/blue (Y/B) emission intensity ratio as a function of (d) temperature, (e) water fraction fw and (f) the amount of β-CD. All the measurements were taken using aqueous NP4C solutions with a unified concentration ([NP4C] = 25 μM) and excited at 400 nm.
