Preparation of organophilic montmorillonite-based dimethylamino benzaldehyde-Schiff-base as antibacterial agents

AbstractNew antibacterial composites were synthesized by modification and functionalization of montmorillonite (MMT). The antibacterial composites were synthesized by the reaction of MMT clay with the quaternary salt of p-N,N-dimethylamino benzaldehyde which produced modified functionalized montmorillonite composite in the form of Schiff bases. The Schiff bases (4–11) were obtained by the reaction of functionalized montmorillonite with various amines namely o-anisidine, anthranilic acid, p-carboxy aniline, p-methyl aniline, p-methoxy aniline, p-hydroxy aniline, p-nitro aniline and p-phenylene diamine. The structures of the newly prepared composites were elucidated by Fourier transform infra red (FT-IR), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). The antibacterial activities of these composites were investigated by the ‘cut plug’ method against Gram-negative bacteria such as Escherichia coli, Serratia marcescens, Enterobacter cloacae, Shigella dysenteriae, Salmonella enterica and Proteus vulgaris, and Gram-positive such as Bacillus subtilis and Staphylococcus aureus which showed high antimicrobial activities at relatively low concentrations (2.5–20mg/mL). These promising results pave the way in the future to use the newly synthesized composites as antibacterial agents for water treatment against pathogenic bacteria which exist in polluted water courses