Application of FTIR-ATR spectroscopy to confirm the microwave assisted synthesis and curing of Cashew nut shell liquid derived nanostructured materials

The present work reports the development of nanostructured material from Cashew nut shell liquid (CNSL, an agro byproduct of cashew industry, 87% cardanol) to evaluate their potential in antibacterial applications as a substitute of petroleum feedstock via an energy-efficient method. The nanostructured material was synthesized by coordination polymerization reaction of cardanol and divalent Mn(II) salt with the aid of microwave irradiations. FTIR spectroscopy was used to confirm the proposed structure of the synthesized materials. FTIR-ATR spectroscopy was employed to verify the curing of material by comparing the spectra of the cured samples with the frequencies of uncured samples. Magnetic moment and UV-visible spectroscopy were used to confirm the proposed structure of the material further. Morphology of the synthesized material was investigated by XRD, optical microscopy, SEM and TEM and thermal behaviour by TGA/DTG/DSC technique. Agar diffusion method was utilized to investigate the antibacterial activity of the synthesized material against bacterial strains E. coli, K. pneumoniae, B. subtilis and S. aureus. N₂ adsorption-desorption was investigated to check BET specific surface area and BJH pore size distribution of the same. The results revealed that the synthesized materials were obtained as semicrystalline, porous, thermally stable and nanostructured film forming materials with moderate to good antibacterial activity against different nosocomial bacteria. They can be used as thermally stable antibacterial agents in the field of films/coatings for health care applications.

Biogenic synthesis of iron oxide nanoparticles using Agrewia optiva and Prunus persica phyto species: Characterization, antibacterial and antioxidant activity

A phytoextract mediated synthesis of iron oxide nanoparticles using Agrewia optiva (Dhaman or Biul) and Prunus persica (Peach) leaf extract as capping and stabilizing agent without using hazardous toxic chemicals via biogenic route has been studied. The biogenic method of synthesis is convenient, rapid, cost effective and ecofriendly. The green synthesized nanoparticles were characterized by Ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, Attenuated total reflectance spectroscopy, X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy and dynamic light scattering measurements. The antibacterial study was determined by agar well diffusion method to measure the efficiency of both phyto species extract and its mediated iron oxide nanoparticles against five gram positive bacterial stains such as Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Streptococcus pyrogenes (S. pyrogenes), Corynebacterium diphtheriae (C. diphtheriae) and Corynebacterium xerosis (C. xerosis) and three gram negative bacterial stains such as Escherichia coli (E. coli), Klebsiella pneuomoniae (K. pneuomoniae) and Pseudomonas aeruginosa (P. aeruginosa). The antibiotic Ciprofloxacin and Gentamicin have been used as reference standard drugs for gram positive and gram negative bacterial stains, respectively. The antioxidant activity of the phyto extracts and prepared nanoparticles have been performed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay employing l-ascorbic acid as a standard.

Synthesis, vibrational spectrometry and thermal characterizations of coordination polymers derived from divalent metal ions and hydroxyl terminated polyurethane as ligand

A series of novel coordination polyurethanes [HTPU-M, where M=Mn(II) 'd⁵', Ni(II) 'd⁸', and Zn(II) 'd¹⁰'] have been synthesized to investigate the effect of divalent metal ions coordination on structure, thermal and adsorption properties of low molecular weight hydroxyl terminated polyurethane (HTPU). HTPU-M have been synthesized in situ where, OH group of HTPU (synthesized by the condensation polymerization reaction of ethylene glycol (EG) and toluene diisocyanate (TDI) in presence of catalyst) on condensation polymerization with metal acetate in presence of acid catalyst synthesized HTPU-M followed by coordination of metal ions with hetero atoms. The structure, composition and geometry of HTPU-M have been confirmed by vibrational spectrometry (FTIR), ¹H NMR, elemental analysis and UV-Visible spectroscopy. Morphological structures of HTPU-M were analyzed by X-Ray Diffraction analysis (XRD), Field Emission Scanning Electron Microscope (FE-SEM) with Energy Dispersive X-ray spectroscopy (EDX) and High Resolution Transmission Electron Microscope (HR-TEM) techniques. The thermal degradation pattern and thermal stability of HTPU-M in comparison to HTPU was investigated by thermal-gravimetric (TG)/differential thermal (DT), analyses along with Integral procedure decomposition temperature (IPDT) by Doyle method. The molecular weight of HTPU was determined by gel permeation chromatography (GPC). The preliminary adsorption/desorption studies of HTPU-M for Congo red (CR) was studied by batch adsorption techniques. The results indicated that HTPU-M have amorphous, layered morphology with higher number of nano-sized grooves in comparison to HTPU. Coordination of metal to HTPU plays a key role in enhancing the thermal stability [HTPU-Ni(II)>HTPU-Mn(II)>HTPU-Zn(II)>HTPU]. The HTPU-M can be utilized for industrial waste water treatment by removing environmental pollutants.