Photophysical properties and photostability of novel 2-amino-3-benzothiazole thiophene-based azo disperse dyes

The design, synthesis, and use of four new thiophene-based dispersed azo dyes with salicylic and carboxylic acid acceptors are shown in this work. The produced dyes exhibit a wide range of light absorption characteristics, including near UV–visible, and deep red wavelengths. PG9 and PG12, which are thiophene disperse azo dyes with carboxylic acid acceptor, showed red-shifted absorption, but PG10 and PG11, which are azo dyes with salicylic acid, showed blue-shifted absorption. The synthesized dyes exhibited good photostability in solvents. The experimental results are supported by theoretical results from Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT).

Furthermore, the dyes exhibit outstanding dyeability with percentage exhaustion characteristics of 90% when applied to acrylic, nylon, and polyester fabrics. Rich shades ranging from deep orange to black are seen in the dyed fabrics. Salicylic acid acceptor-dyed materials have higher K/S values when applied to nylon-dyed fabrics, while acrylic and polyester-dyed fabrics respond better to carboxylic acid acceptor dyes. The fabrics that have been colored display exceptional light, wash, and rubbing fastness. In light and wash fastness, polyester-dyed fabrics performed better than acrylic and nylon-dyed fabrics. Studies on UV protection show that fabrics with high UPF ratings can block damaging UV-A and UV-B radiation efficiently. All synthetic dyes have their antibacterial activity assessed using the AATCC 100 test method, which is associated with the HOMO-LUMO energy gap.