Research / 2021 / Article / Fig 2

Research Article

Simple Vanilla Derivatives for Long-Lived Room-Temperature Polymer Phosphorescence as Invisible Security Inks

Figure 2

Schematic illustration and spectral studies. (a, b) Schematic illustration of the RTPP process and hydrogen bonding in vanilla-doped PVA films. Fluo.: fluorescence; Nonrad.: nonradiative transition. (c) Fluorescence spectra () of M1-M4-doped PVA at 0.3 mg mL-1 doping concentration. (d) UV-Vis absorption spectra of M1-doped PVA films at 0.1 mg, 0.3 mg, 0.5 mg, 1.0 mg, and 3.0 mg mL-1. (e) Phosphorescence spectra of M1-0.3 mg PVA film with 250 nm-360 nm excitation wavelength. (f) Phosphorescence spectra () of vanilla-doped PVA films at 0.3 mg mL-1 doping concentration.