Intercalation of 2-mercaptobenzimidazole into magadiite and bentonite: preparation pathway, characterization, and antibacterial assessment

Layered materials bentonite (BENT) and Na-magadiite (MAG) have been used as the host solids for the intercalation of different amounts of 2-mercaptobezimidazole (MBI) molecule. This process was carried out in ethanol solutions with percentages of 30, 50, and 70% of MBI and while adjusting the pH of the reaction medium. The intercalated materials have been evaluated against gram-positive and gram-negative bacteria for the purpose to determine the suitable antibacterial material between them. The intercalation of MBI molecules between the interfoliar spaces of solids was confirmed via the X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), the Fourier transform infrared (FTIR) spectroscopy, the UV–visible absorbance spectroscopy (UV–vis), the scanning electron microscopy (SEM) and the X-ray photoelectron spectroscopy (XPS). Consequently, the appreciable change in the basal spacing with the decrease in intensities justified the intercalation of the MBI molecules in the interfoliar spaces of MAG and BENT materials. The basal spacing of the MBI-70@BENT material has increased to up to 15.76 Å, for the MBI-70@MAG material it has been reduced to 13.60 Å. Antibacterial properties of the layered materials were evaluated against gram-positive bacteria Staphylococcus aureus (staph) and gram-negative bacteria Pseudomonas aeruginosa (pseudo). A satisfactory antibacterial activity was observed, for the intercalated bentonite materials against Pseudomonas aeruginosa compared to the intercalated magadiite material which is presented no activity.