Antimicrobial Applications of Transition Metal Complexes of Benzothiazole Based Terpolymer: Synthesis, Characterization, and Effect on Bacterial and Fungal Strains

Terpolymer of 2-amino-6-nitro-benzothiazole-ethylenediamine-formaldehyde (BEF) has been synthesized and characterized by elemental analysis and various spectral techniques like FTIR, UV-Visible, and 1H and 13C-NMR. The terpolymer metal complexes were prepared with Cu2+, Ni2+, and Zn2+ metal ions using BEF terpolymer as a ligand. The complexes have been characterized by elemental analysis and IR, UV-Visible, ESR, 1H-NMR, and 13C-NMR spectral studies. Gel permeation chromatography was used to determine the molecular weight of the ligand. The surface features and crystalline behavior of the ligand and its complexes were analyzed by scanning electron microscope and X-ray diffraction methods. Thermogravimetric analysis was used to analyze the thermal stability of the ligand and its metal complexes. Kinetic parameters such as activation energy (Ea) and order of reaction (n) and thermodynamic parameters, namely, ΔS, ΔF, S*, and Z, were calculated using Freeman-Carroll (FC), Sharp-Wentworth (SW), and Phadnis-Deshpande (PD) methods. Thermal degradation model of the terpolymer and its metal complexes was also proposed using PD method. Biological activities of the ligand and its complexes were tested against Shigella sonnei, Escherichia coli, Klebsiella species, Staphylococcus aureus, Bacillus subtilis, and Salmonella typhimurium bacteria and Aspergillus flavus, Aspergillus niger, Penicillium species, Candida albicans, Cryptococcus neoformans, Mucor species fungi

Thermal degradation kinetics and antimicrobial studies of terpolymer resins

The terpolymer (ASF) was synthesized by condensation of anthranilic acid and salicylic acid with formaldehyde in the presence of glacial acetic acid as a catalyst at 140 ± 2 °C for 6 h with varying proportions of reactants. The terpolymer ASF-I was characterized by elemental analysis, FTIR, 1H NMR and 13C NMR spectroscopy. The thermal decomposition behavior of ASF-I, II and III terpolymers was studied using thermogravimetric analysis (TGA) in a static nitrogen atmosphere at a heating rate of 20 °C/min. Freeman–Carroll, Sharp–Wentworth and Phadnis–Deshpande methods were used to calculate the thermal activation energy (Ea) the order of reaction (n), entropy change (ΔS), free energy change (ΔF), apparent entropy (S∗) and frequency factor (Z). Phadnis–Deshpande method was used to propose the thermal degradation model for the decomposition pattern of ASF-I terpolymer resin. The order of the decomposition reaction was found to be 0.901. The thermal activation energy determined with the help of these methods was in good agreement with each other. The ASF-I, II and III resins were tested for their inhibitory action against pathogenic bacteria and fungi. The resins show potent inhibitory action against bacteria, such as Escherichia coli, Klebsiella, Staphylococcus aureus and Pseudomonas aeruginosa and fungi viz. Aspergillus flavus, Aspergillus niger, Penicillium sp., Candida albicans, Cryptococcus neoformans and Mucor sp

Novel hexamethylene diamine-functionalized macroporous copolymer for chromium removal from aqueous solutions

Macroporous copolymers of poly[(glycidyl methacrylate)-co-(ethylene glycol dimethacrylate)] (PGME) with various crosslinker (ethylene glycol dimethacrylate) concentrations and porosity parameters and additionally functionalized with hexamethylene diamine (PGME-HD) were tested as potential Cr(VI) oxyanion sorbents from aqueous solutions. Kinetics of Cr(VI) sorption was investigated in the temperature range 298-343 K and the results were fitted to chemical reaction and particle diffusion models. The Cr(VI) sorption obeys the pseudo-second-order model with definite influence of pore diffusion. A temperature rise promotes chromium removal, with a maximum experimental uptake capacity of 4.21 mmol g(-1) at 343 K for the sample with the highest amino group concentration. Equilibrium data were analysed with Langmuir, Freundlich and Temkin adsorption isotherm models. Thermodynamic parameters, i.e. Gibbs free energy (G(0)), enthalpy (H-0) and entropy change (S-0) and activation energy of sorption (E-a), were calculated. The Cr(VI) adsorption onto PGME-HD was found to be spontaneous and endothermic, with increased randomness in the system. Desorption experiments show that chromium anion sorption was reversible and the PGME-HD sample GMA 60 HD was easily regenerated with 0.1 mol L-1 NaOH up to 90% recovery in the fourth sorption/desorption cycle. In the fifth cycle, a substantial sorption loss of 37% was observed