Interaction of the excited state intramolecular proton transfer probe 3-hydroxy-2-naphthoic acid with poly N-vinyl-2-pyrrolidone polymer in water: An insight into the water structure in the binding region

The change in excited-state proton transfer kinetics of 1-naphthol in micelles upon the binding of polymers: The influence of hyaluronan hydration

“…The fluorescence intensity ratio in hyaluronan was significantly different from that of bulk water. The increase in proton transfer efficiency suggests the adsorption of 1-naphthol in the hyaluronan-bound water region, as similarly reported for poly (N-vinyl-2-pyrrolidone) (PVP) (Pal et al, 2010). The fluorescence spectrum of 1-naphthol in the 80% water-methanol mixture depicts an example of the effective inhibition of ESPT.…”

“…The fluorescence decay suggests influence from the adsorption of 1-naphthol onto hyaluronan, because the deprotonation rate is influenced by polymer bound water, not by bulk water. Also, the average fluorescence lifetime increased two times in the presence of hyaluronan, which was also the case with PVP, resulting from adsorption of the probe onto polymer bound water (Pal et al, 2010). The significant change in the relative amplitudes of the two slow decay components, when compared to water, also suggests that the fluorescence decay of NpOH does not belong to 1-naphthol in bulk water but to adsorbed 1-naphthol.…”

“…When an ESPT (excited state proton transfer) fluorescence probe adsorbs onto a polymer, the proton transfer rate changes as well as the fluorescence intensity of its emission peaks. This phenomenon was used to study the hydration of some polymers such as poly N-vinyl-2-pyrrolidone (Pal, Sundar Maity, Samanta, Saha Sardar, & Ghosh, 2010) and polyvinyl alcohol (Kumar & Mishra, 2007). Spry et al (2007) used proton transfer dynamics as a tool to study the water environment in nafion fuel cell membranes and in the anionic surfactant aerosol OT in heptane as a solvent.…”

Fluorescence properties of 3-hydroxy-2-naphthoic acid-doped poly(methyl methacrylate) composites

“…*) transition from an E tautomer generated by the ESIPT from hydroxyl groups to the carbonyl oxygen of the 3HNA as shown in Figure 7. 18,19 As shown in Figure 6, with the increase in the concentration of 3HNA from 0.5% to 2.0%, the intensity of the violet band decreases, while the green band changes little in intensity. The violet band emission peak shifts from 413 nm to 426 nm.…”

“…Pal et al studied the enhancement of the ESIPT emission of 3HNA in the presence of poly(N-vinyl-2-pyrrolidone). 18 Mishra et al studied the spectral and photophysical properties of 3HNA and revealed that 3HNA seemed to form different emitting species in different media. 19 Poly(methyl methacrylate) (PMMA) has been widely studied in the last decades due to its outstanding mechanical and chemicophysical properties.…”