Progressive applications of synthesized isatin-based reactive dye: fabrics dyeing, corrosion inhibition, and antimicrobial activity

Abstract

A new heterobis- reactive dye, monochlorotriazine/sulphatoethylsulphone bearing an isatin moiety (MCT-SES dye), was synthesized and identified using NMR, mass spectra, and elemental analysis. The prepared reactive dye showed an absorption band at 543 nm. The dyeing properties on cotton and wool fabrics were investigated at different concentrations and pH levels, showing excellent dye affinity toward both fabrics. The dyed fabrics exhibited excellent wash fastness, rubbing fastness, perspiration fastness, and good light stability. In 1.0 M hydrochloric acid solution, the isatin-based MCT-SES dye exhibited unique corrosion inhibition performance for carbon steel (CS). Energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) were the methods used to assess the inhibitory efficacy and development of a protective film on the steel surface. With increasing dye concentration, the corrosion inhibition efficiency increased, reaching a maximum of 98.64% at 500 ppm. The excellent performance was attributed to strong adsorption and the formation of a dense, protective barrier film on the steel surface. The MCT-SES dye demonstrated strong antibacterial action against P. aeruginosa (23 ± 0.23 mm) and E. coli (20 ± 0.34 mm). The inhibition of the bacteria growing on the surface of the dyed fabrics was investigated by scanning electron microscope (SEM), which proves the high affinity of the dyed fabric against bacteria growth. Molecular docking simulations and the binding interaction of the dye structure with the bacteria protein were investigated.