Papers by Keyword: Infrared Spectroscopy

Abstract: In recent years biopolymer fillers are widely used to development of composite materials for various purposes. In this respect collagen hydrolysate (HC) is one of the most promising biopolymer for modification of synthetic polymers to produce different types of item. In this work, a new source of collagen has been tested - collagen hydrolysate obtained from a swim bladder of northern fishes. The cure characteristics, mechanical and relaxation properties, abrasion resistance of the Butadiene–acrylonitrile rubber composites containing the collagen hydrolysate have been discussed. The chemical compositions, properties, morphology of collagen hydrolysates have been studied. It was shown by means of IR spectroscopy that the bands of Amide I, Amide II, Amide III, Amide A, which is related to the vibrations of the polypeptide bond of the protein, are recorded in the infrared spectra of the samples. The morphological structure of collagen was investigated by scanning electron microscope JSM-7800F ("JEOL", Japan). The size and the zeta potential of collagen hydrolysate were investigated by Dynamic Light Scattering (DLS) on the Zetasizer nanoZS instruments (Malvern Instruments Ltd., UK).

Abstract: This research addresses the challenges of sustainable use of natural polymers, including in technical fields. One of the leading trends in science and industry headway today lies in designing advanced functional materials, e.g. for manufacturing medical items, technical devices, food-processing tools et al. For this purpose, universally applicable technological processes are being developed, including in biotechnology. One of the main goals of this research is to explore ways to consolidate living systems, by instilling in them desirable physical and chemical properties so as to diversify their applications, including in technical fields. Polymers structure and properties have been investigated via raster electron microscopy, spectral analysis, et al.

Abstract: Infrared (IR) absorption and polarized Raman spectra were measured in BaSi₂ epitaxial films to investigate the vibrational modes and the symmetry of Si₄ cluster in BaSi₂. By an analysis based on Raman and/or IR activity in the spectra, the symmetry of Si₄ cluster was determined as T_h-symmetry and the observed Raman lines and IR peaks were assigned to A_g, E_g, F_g, and F_u, respectively. In the three Raman lines of F_g-mode, one LO phonon line and two TO phonon lines were classified by the depolarization ratio of polarized Raman intensities.

Abstract: The optical response of graphene on 6H-SiC was investigated by means of IR-reflectance measurements. Thereby, the anisotropy of the substrate is considered and its influence was studied by performing measurements with s- and p-polarized light. The anisotropy causes a splitting of the reststrahlen band in p-polarization, but does not affect spectra recorded with s-polarization. In both cases a thin film approximation was used to simulate the reflectance spectra. A model consisting of SiC, graphene and air enables the extraction of the graphene layer count.

Abstract: Nowadays alkali activated binders are one of alternative materials to Portland cement. Alkaline activation is a process when the material hardens in medium at pH>12. This paper presents the study of stability of different polymer admixtures (polypropylene glycol, polyvinyl alcohol, polyethylene glycol with different molecular weight, different modifications of commercial polymer admixtures VINNAPAS^® and shrinkage-reducing Peramin SRA) in alkaline media NaOH at pH=12.42. The influence of the alkaline medium on the properties of polymer admixtures was examined by infrared spectroscopy. All types of VINNAPAS^®, Peramin SRA are unstable in high alkaline media.

Abstract: In this paper we report an approach for the structural analysis of mineral-collector interfaces of (bio) flotation systems by means of attenuated total reflection Fourier-transform infrared spectroscopy (ATR FT-IR). The extraction of rare earth metals from electronic waste materials is an important challenge for the recycling industry. In a current project bacteriophage are used as biocollectors to develop a bioflotation model system for the separation of lanthanum phosphate doped with cerium and terbium (LaPO₄:Ce³⁺,Tb³⁺) from mixed fluorescent phosphors. As an initial analytical concept fluorescence microscopy was successfully applied to investigate particles of spent fluorescent lamp powders and to visualize the bacteriophage on the surface of the waste material. However, due to the restrictions of this technique we are not able to identify the molecular interactions of the bacteriophage with the recycled material. ATR FT-IR was found to be an effective tool to detect the major coat protein of the bacteriophage biocollectors on the surface of the LaPO₄:Ce³⁺,Tb³⁺ and sense their specific bonding interaction opening the gates for the high level chemical characterization of the interface.

Abstract: Tb (AUFA)₃2H₂O, a rare earth terbium complex,was synthesized by introducing 4-(11-azobenzene-undecyloxy) ferrocene acid (AUFA) as the ligand. This complex was characterized by elemental analysis, MS, IR, Raman, UV spectroscopy and fluorescence spectrophotometry. The complex exhibited ligand-sensitized green emission, and Tb (AUFA)₃2H₂O had a higher sensitized luminescence efficiency and a longer lifetime than the other terbium complexes (DPC: 2, 6-Pyridinedicarboxylic acid, Aspirin: 2-ethanoylhydroxybenzoic acid). The organic-inorganic thin film of complexe Tb (AUFA)₃2H₂O in nanoTiO₂ was fabricated, and the nanoTiO₂ has been used in the luminescence layer to change the luminescence property of complexes Tb (AUFA)₃2H₂O. It was found that there was an efficient energy transfer process between the ligands and metal ions. Moreover, In an ITO/PVK/Tb (AUFA)₃2H₂O/Al device, Tb³⁺ may be excited by intramolecular energy transfer from the ligand, as observed by electroluminescence. The main emitting peak at 545 nm can be attributed to the ⁵D₄→⁷F₅ transition of the Tb³⁺ ion, and this process results in the enhancement of the green emission from the electroluminescence device.

Abstract: Epitaxial graphene on semiinsulating silicon carbide was grown using a high temperature method at atmospheric pressure in argon atmosphere. The temperature dependence of the layer quality was analysed using Raman and infrared spectroscopy. It is demonstrated that infrared spectroscopy can be used as a versatile tool to access the layer count and the quality of the epitaxial grown graphene on silicon carbide. The results obtained by infrared spectroscopy correlate with the Raman measurements.

Abstract: The paper deals with analyses of composition and structure of historic plasters from the convent building of the Želiv Monastery (Czech Republic). Composition and microstructure of plaster samples taken from the historic object have been assessed using both traditional and advanced analytical methods. The following techniques have been used for the assessment of binders and fine aggregates in plasters: optical microscopy of thin sections, mineralogical and petrographic analysis of separated components, infrared spectroscopy, and thermal analysis. Presented results show significant differences in character of the studied materials of varying age and demonstrate the effectiveness of the taken analytical approach.

Abstract: This paper summarizes research on infrared absorption spectrum of gum Arabica, a Bio-material. The frequency shift due to deuterium exchange in gum Arabica molecule and rotational spectrum of bio-molecules are estimated from the measured data of FTIR spectra. The obtained shift of the characteristics frequency caused due to deuterium exchange in the –OH bond of gum Arabica. Normally two major region in the IR spectrum of a molecule are the functional group region ( 7000 cm^-1 to 1500 cm^-1) it includes the X-H stretching region and finger print region ( 1500 cm^-1 to 350 cm^-1). The mentioned region is very important in bio-molecular dynamics and it may provide much relevant information about the internal motion of the molecule and is related bio-molecular function in living systems. The change in molecular structure, of the constituent bio-molecules of Gum Arabica, due deuterium exchange is directly determined from analysis of FTIR spectrum in functional group region. The rotational constants as well as the ground state rotational energy levels are estimated from analysis of FTIR spectrum of the experimental specimens. A map of quantum energy levels of the bio-molecule has been extracted from this present FTIR analysis.