Unique Photoluminescence of Diacetylene Containing Dendrimer Self-Assemblies: Application in Positive and Negative Luminescence Patterning

A series of poly(benzyl ether) dendrimers with two benzene-1,3,5-tricarboxamide (BTA) units bridged by diacetylene were synthesized. The formation of hydrogen bonds between BTA units to form the supramolecular self-assembly was confirmed by FT-IR and AFM measurements. When the dendrimers in CH2Cl2 was excited with 280 nm irradiation, the dendrimers exhibited an unexpected strong photoluminescence (PL) around 450 nm in addition to 310 nm fluorescence upon excitation at 280 nm. The PL intensity of each dendrimers has shown generation dependency. With the continuous irradiation of 280 nm UV light, dendrimers exhibited decreased PL emission at both 310 and 450 nm by photopolymerization of diaceytlene units. A poly(vinylidene fluoride) (PVDF) membrane saturated with dendrimer solution were prepared to obtain a patterned PL image. Utilizing a photomask, a negative PL pattern was successfully obtained. When the membrane was annealed to 100 °C, new anomalous PL was generated and opposite type PL-patterned image could be obtained.