Evaluation of thermal and antimicrobial behavior of Montmorillonite nanoclay modified with 2-Mercaptobenzothiazole

Abstract

Thermal and antimicrobial properties of hybrid synthesized compounds were evaluated in the<br />present study. Hybrid structures were synthesized via two main organic and inorganic components,<br />namely: 2-Mercaptobenzothiazole (MBT) and sodium Montmorillonite clay (Na+-<br />MMT). The synthesis process took place in a direct reaction, intercalation; and the resulting<br />material was characterized. Results of scanning electron microscope (SEM), Energy dispersive<br />X-ray spectroscopy (EDS), transmission electron microscope (TEM), and small-angle X-ray scattering<br />(SAXS) and Fourier transform infrared spectroscopy (FTIR) confirmed MBT penetration<br />of particles into the inner space of the clay layers and interaction between the two organic<br />and inorganic phases. Also, thermal properties of the resulting compounds were evaluated by<br />thermo gravimetric analysis (TGA) and differential thermalgravimetric (DTG). It was found that<br />while MBT sample had relatively low degradation temperature (about 250°C), the MBT-modified<br />clay compound showed superior thermal stability, and in high temperatures, less weight<br />loss as compared to MBT. Antimicrobial properties of the hybrid nano compound against five<br />types of bacteria, two types of fungus and one type of yeast were examined using well diffusion<br />agar method and minimum inhibitory concentration (MIC). The diameter of inhibition<br />zone was measured and their antimicrobial potential was compared with two common antibiotics:<br />gentamicin and rifampin. The concentration of about 1000 μg/mL of MBT-MMT showed<br />antibacterial performance equal to 250 μg/mL of rifampin. Also, 1000 μg/mL of this material<br />was required to inhibit the growth of important bacteria.