Research / 2021 / Article / Fig 1

Research Article

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

Figure 1

Chemical structures and long-lived phosphorescence photographs. (a) Chemical structures of M1, M1-acid, M2, M2-acid, M3, M3-acid, M4, and M4-acid. (b) Long-lived phosphorescence photographs of M-doped PVA films under 254 nm excitation.