Comparative Evaluation of Synthetic Routes and Antibacterial/Antifungal Properties of Zn-Al Layered Double Hydroxides Containing Benzoate Anion

Abstract

With variation in synthetic routes, properties of the as-obtained products also vary. Three synthetic routes are opted such as coprecipitation (CP), ion exchange (IE), and rehydration (RH) to form an antibacterial/antifungal composite of Zn-Al layered double hydroxide with benzoate (BZ) anion in the interlayer space. X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectrum, and thermogravimetric analyses are used to characterize the samples. In case of composite obtained by CP route, the molecular arrangement of the BZ anion is bilayer with both the molecules are arranged along their y-axis. Similarly, in case of IE route, the arrangement is also bilayer but the molecules are arranged along the y-axis of one molecule and along the x-axis of another. In the RH route, the arrangement is monolayer. The three novel nanocomposites showed different performance in terms of liberation factor and antibacterial activity toward both Gram-positive (Staphylococcus aureus MTCC 96) and Gram-negative (Escherichia coli MTCC 739) bacterial strains as well as fungicidal effect toward the fungal strain, Fusarium oxysporum MTCC 3075.