Gemini cationic surfactant based 4-(dimethylamino)benzaldehyde: surface characteristics and biological activity, a straightforward one-step synthesis

Abstract

A novel three Gemini cationic surfactants was created in this study by one step of alkylating 4-(dimethylamino)benzaldehyde with 1,6-dibromohexane, 1,8-dibromooctane, and 1,10-dibromo-decane in acetone. The chemical structures of the generated cationic surfactants were examined using Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance ( 1 H NMR). After measuring the surface tension at various temperatures, the surface parameters, including the critical micelle concentration (CMC), effectiveness (π CMC ), maximum surface excess (Γ max ), efficiency (Pc 20 ), and minimum surface area ( A min ), were calculated. Adsorption and micellization’s thermodynamic characteristics were calculated, and the results revealed that both processes are sponta-neous. It is clear that the Gemini surfactants created have a high tendency to adsorb at the interfaces as well as micellize in the majority of their solutions. The antibacterial activity of the generated surfactants against Gram-negative, Gram-positive, and fungus was examined. The Gemini surfac-tants’ antibacterial effectiveness was enhanced from 22 to 36 mm by an increase in their hydrophobicity and spacer length.