Papers by Keyword: FT-IR Spectroscopy

Abstract: Poly (methyl methacrylate) (PMMA) and chitosan composites were synthesized by means of the mechanochemical method. In addition, PMMA–chitosan films were obtained in polar (water) and non-polar (benzene) solvents. Obtained polymer composites were analyzed by the Fourier transform infrared spectroscopy method using the ATR attachment with diamond crystal. The presence of intermolecular hydrogen bonds in formation of PMMA and chitosan polymer composites was shown. С=О group of PMMA and OH and NH₂ groups of chitosan molecule take part in the formation of hydrogen bonds.

Abstract: A series of glasses with composition of xPbO-(50-x)ZnO-yB₂O₃-(50-y)P₂O₅ with 0 x 50 mol% and 10 y 20 mol% were prepared by melt quenching technique, with 30 minutes pre-heating and 10 minutes for melting. The structural properties of prepared samples were studied using Fourier Transform-Infrared spectroscopy. The glasses were mainly based on PO₂, BOP and BO₃ unit. In order to obtain luminescence properties, another series of sample at composition 20PbO-30ZnO-10B₂O₃-40P₂O₅ doped with Fe²⁺, Ti²⁺, Y²⁺ and Nd²⁺ were prepared. These samples were investigated using Photoluminescence Spectroscopy with different excitation wavelength to compare results. Results showed that with the presence of rare earth and transition metal ions as activator in lead zinc borophosphate glass system give rise to luminescence of visible light.

Abstract: In this work the syntheses of covalently grafted Ni(II)-complexes formed with various N- or C-protected amino acid ligands (L-histidine, L-tyrosine, L-cysteine and L-cystine) inspired by the active site of the Ni-SOD enzyme are presented. Merrifield’s resin was used as support to mimic the proteomic skeleton of the enzyme. Conditions of the syntheses were altered and the structural features of the substances obtained were studied by infrared spectroscopy. It was found that the preparation of covalently anchored Ni(II)−amino acid complexes was successful in all cases. In many cases the structures of the anchored complexes and the coordinating groups substantially varied upon changing the conditions of the syntheses. The obtained materials were studied by energy dispersive X-ray fluorescence coupled to scanning electron microscope (SEM−EDX). All the covalently anchored materials displayed superoxide dismutase (SOD) activity and some proved to be exceptionally efficient in the biochemical test reaction.

Abstract: Crosslinking of cotton with polycarboxylic acid, applied with catalysts based on phosphorus-containing inorganic acids, produces fabrics with excellent smooth-drying properties, which release no formaldehyde at any stage of preparation or on storage. If polycarboxylic acid has three or more carboxylic acid groups, the formation of such an anhydride can occur more than once and crosslinking of the cellulose molecule occurs. In our research work the use of an unsaturated bifunctional acid (maleic acid) and a phosphorus-containing inorganic compound (sodium hydroxyphosphinite) to obtain durable press finishing properties and flame retardant properties was studied.

Abstract: In this paper, conducting polypyrrole (PPy) films doped with p-toluene solfonate (pTS) was electrochemically synthesized. The chemical groups of the sample were analysed by FT-IR, an in situ nanotribolab system together with the four-probe instrument were employed to investigate the mechanical and conductivity of the prepared films. The surface morphology was studied by scanning electron microscopy (SEM). It demonstrates that the dopant anion was doped into the PPy while the overoxidation did not occur during the polymerization. The conductivity of PPy film is stable, during indentation, different loads were applied and hardness, elastic modulus were obtained. SEM images showed that the film is uniform. The characteristic microstructure of polypyrrole, the cauliflower-like, is appeared and the film is compact and homogeneous.

Abstract: Kaolinite/formamide intercalation materials are characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy(FT-IR), Raman spectroscopy and 1H magic angle spinning nuclear magnetic resonance spectroscopy (1H MAS NMR). The d(001) spacing of kaolinite treated with formamide is 1.020nm, which is larger than that of the original clay. The 1H MAS NMR graphs show that the proton chemical shifts of the inner hydroxyl and inner surface hydroxyl of kaolinte are δ-1.3 and δ2.4 respectively. After formamide intercalation, the proton peaks of the inner surface hydroxyls shifted to high-field with δ2.3, the proton peak of the inner hydroxyl shifted to δ-0.3 toward low-field. In the hydroxyl stretching vibration region of Raman spectrum, the formamide intercalation resulted in the decrease of the intensities of kaolinite inner surface hydroxyl bands at 3699cm-1,3682cm-1, 3665cm-1 and 3642cm-1, and the appearance of additional bands at 3610cm-1,3628cm-1. In the NH stretching region of FT-IR spectrum, two bands are observed at 3336cm-1 and 3466cm-1 corresponding to the two types of the hydrogen bonds between formamide and kaolinite. In the carboxyl stretching region, an additional band at 1667cm-1 is assigned to C=O group that bonded to the inner surface hydroxyl of kaolinite.

Abstract: Our previous study has demonstrated that industrial waste biomasses of Penicillium oxalicum var. Armeniaca and Tolypocladium sp., could be used for biosorption of Cd, Pb, Hg and Cr(VI). The objective of the present study was to investigate the biosorption mechanisms, while using FT-IR spectroscopy and SEM technique. SEM microscopic observations (coupled with EDX analysis) confirmed the presence of the target metals on the biosorbents surface. Carboxyl groups were identified by FT-IR spectra analysis on the surface of Tolypocladium sample, while the alkaline treated Penicillium sample was characterized by the presence of amine groups. It was proved that the metal biosorption slightly modified the FT-IR spectra, while the mentioned functional groups were involved in the uptake mechanism (chelation on nitrogen containing groups and ion exchange on carboxyl groups).