Fourier Transform Infrared Spectra Studies Research Articles

Eu3+-ion doped LnF3 NPs: Comparative study of the crystallographic, and photophysical properties

The thermal co-precipitation approach was employed for the synthesis of the Eu3+-ion doped YF3, LaF3, and GdF3 nanoparticles (NPs) and compared their photophysical properties. Ammonium fluorite was used as a fluorine source for the synthesis of metal fluorides at lower temperatures. Luminescent lanthanide fluoride (LnF3) NPs were characterized by different techniques containing X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), FT-Raman, UV/Visible absorption spectra, and photoluminescence spectroscopic procedures to investigate the crystal structural, thermal, Raman effect, surface, optical, and luminescent properties. XRD study shows two types of crystal phase orthorhombic in YF3:Eu & GdF3:Eu and hexagonal in LaF3:Eu NPs. TGA, FTIR, and absorption spectra studies show the exterior adsorbed –OH molecules, which assist in the development of colloidal solution in aqueous media. Raman vibrations were strongly affected which were correlated with the XRD reflection planes. In comparative photo-physical properties, the excitation and emission spectra exhibited remarkable intensities of the Eu3+-ion transitions. Similarly, the emission spectra of all three samples exhibited the highest emission efficiency of the magnetically-dipole(5D0→7F2) transition in comparison to the electric-dipole 5D0→7F1 transition, which reflected the transformation of the crystal symmetry. Comparative analysis was presented to investigate the role of the host lattice on crystallinity, thermal stability, and luminescent properties. These findings are highly fruitful in designing photonic-based applications including optical biosensors, fingermark detection, security systems, etc.

PREPARATION OF ORAL CURCUMIN DELIVERY FROM 3D-NANO-CELLULOSE NETWORKS MATERIAL PRODUCED BY ACETOBACTER XYLINUM USING OPTIMIZATION TECHNIQUE

Objective: To prepare oral curcumin delivery and optimize curcumin loading of 3D-nano-cellulose networks material (3DCM) by looking into the impact of process variables on the response utilizing response surface methodology (RSM) and Box-Behnken design.
 Methods: Optimization of curcumin loading of 3DCM was conducted using RSM and Box-Behnken model. Impact of four independent variables, including, the concentration of curcumin (X1), temperature (X2), shaking speed (X3), and time of loading (X4), was studied on one dependent response, that is, an amount of loaded curcumin (Y). Characterization of optimized 3DCM including curcumin was examined by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) analysis .
 Results: R2 value for Y was approximately 0.94. X1 possessed the biggest positive impact compared to X2, X3 and X4. Optimized conditions for curcumin loading of 3DCM were X1 at 3 mg/ml, X2 at 40 °C, X3 at 120 rpm and X4 at 120 min. SEM photograph of 3DCM surfaces were found including fibers creating a 3D network structure. FTIR spectra studies depicted that there was no interaction between curcumin and 3DCM.
 Conclusion: The data obtained in this study thus suggest that curcumin loaded 3DCM was successfully fabricated to give a potential oral delivery system of curcumin.

Synthesis, Optical, and Structural Studies of Iron Sulphide Nanoparticles and Iron Sulphide Hydroxyethyl Cellulose Nanocomposites from Bis-(Dithiocarbamato)Iron(II) Single-Source Precursors.

In this study, Fe(II) complexes of phenyldithiocarbamate, dimethyldithiocarbamate and imidazolyldithiocarbamate were used as single-source precursors to prepare iron sulphide nanoparticles by thermolysis in oleic acid/octadecylamine (ODA) at 180 °C. The nanoparticles were dispersed into hydroxyethyl cellulose (HEC) to prepare iron sulphide/HEC nanocomposites. Ultraviolet-Visible (UV-Vis), Photoluminescence (PL), Fourier Transform Infrared (FTIR), powder X-ray diffraction (pXRD), high-resolution transmission electron microscopy (HRTEM), Field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDS) were used to characterize the iron sulphide nanoparticles and corresponding HEC nanocomposites. The absorption spectra studies revealed that the nanoparticles were blue shifted due to quantum confinement and the optical band gaps of the nanoparticles are 4.85 eV for FeS1, 4.36 eV for FeS2, and 4.77 eV for FeS3. The emission maxima are red-shifted and broader for the nanoparticles prepared from phenyldithiocarbamate. Rod-like and spherically shaped iron sulphide particles were observed from the HRTEM images. The crystallite sizes from the HRTEM images are 23.90–38.89 nm for FeS1, 4.50–10.50 nm for FeS2, and 6.05–6.19 nm for FeS3 iron sulphide nanoparticles, respectively. pXRD diffraction patterns confirmed that FeS1 is in the pyrrhotite-4M crystalline phase, FeS2 is in the pyrrhotite phase, and FeS3 is in the troilite phase of iron sulphide. The phases of the iron sulphide nanoparticles indicate that the nature of the precursor complex affects the obtained crystalline phase. FTIR spectra studies confirmed the incorporation of the nanoparticles in the HEC matrix by the slight shift of the O–H and C–O bonds and the intense peaks on the nanoparticles. FESEM images of the iron sulphide nanoparticles showed flake-like or leaf-like morphologies with some hollow spheres. The EDS confirmed the formation of iron sulphide nanoparticles by showing the peaks of Fe and S.

The study of electrodeposition of hydroxyapatite-ZrO2-TiO2 nanocomposite coatings on 316 stainless steel

In this research pure HA and HA-ZrO2-TiO2 nanocomposite coatings (named HZT coatings) were successfully synthesized by merging two usual electroplating methods. In order to deposit pure HA coating a particular saline solution of Calcium and Phosphate was prepared with pH = 4.2, thermodynamically rich of hydroxyapatite. XRD and FTIR studies prove the synthesis of hydroxyapatite during electrodeposition process. To synthesize composite coatings with rational molar ratios of composite agents to matrix, two different concentrations of ZrO2-TiO2 suspensions were added to Ca-P solution at the pH = 4.2 and electrodeposition process done similar to pure HA sample. XRD, FTIR and FESEM (EDS) analyses prove that composite coatings electrodeposited successfully too. The effect of ZrO2-TiO2 composite agents on the characteristics of the coatings were investigated using X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), Field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy. Polarization test was carried out to evaluate corrosion behavior of the coatings. In-vitro test was done in SBF solution and bioactivity of coatings was evaluated using FESEM observation.Adding ZrO2-TiO2 nanoparticles makes different changes in the coating specifications. In composite coatings hydroxyapatite has higher crystallinity (92%) rather than pure HA (80%). FESEM observations reveal new morphologies of electrodeposited HA, such as micro-nanorods of HA formed in composite coatings that are not mentioned before in the literature. EDS results show that adding more nanoparticles to the solution results in more nanoparticles deposition in composite coating.The minimum corrosion current density (icorr.) of coatings was for HZT2 composite coating equal to 0.01 μA/cm2 while icorr. of bare substrate was 1.5 μA/cm2 (it means that icorr. of composite coating is 0.007 icorr. of bare substrate.). As a result of nanoparticles addition, porosity is decreased from 46% for HA coating to 6% for HZT2 coating. EIS results show that corrosion resistance of coating increased as a result of adding nanoparticles and HZT2 coating has largest charge transfer resistance among the prepared coatings.The FE-SEM observations suggest that the coatings would demonstrate bioactive behavior because natural hydroxyapatite (deposits formed during immersion) is formed during immersion.

X-ray diffraction, rheological and FT-IR spectra studies of processed amaranth (Amaranthus hypochondriacus)

The X-ray diffraction pattern, rheological properties, particle size distribution and Fourier transform-infrared (FT-IR) spectra of native and processed (cooked, germinated and fermented) amaranth were determined using different techniques. The data revealed that the native and processed amaranth flour showed major peak values of the 2θ at 15°, 18° and 23° resembling an A-type X-ray diffraction pattern. The percent crystallinity of fermented and germinated amaranth flour was higher than the native amaranth flour whereas loss in crystallinity was observed for cooked amaranth flour. Fermented amaranth flour showed the highest value while cooked amaranth flour showed the lowest value for storage (G′) and loss modulus (G″). The value of tan∂ was lower than 1 for native and processed amaranth dough. Native amaranth flour showed unimodal size distribution and the size of flour granules were ranged from 0.67 to 98.1 µm in diameter while the germinated and fermented amaranth flour showed bimodal distribution. The FT-IR spectroscopy provides the information about the product composition in the form of peaks. The peak for starch was obtained in the range of 994–1144 cm−1. The proteins bands of native amaranth flour were reported at 1644 and 1545 cm−1. The changes observed in physicochemical properties of amaranth flour after processing treatments provided a crucial basis for its potential applications on industrial scale.

A flexible, wave-shaped P(VDF-TrFE)/metglas piezoelectric composite for wearable applications

In this work, a wave-shaped piezoelectric composite (WSPC) made of fine β-phase vinylidene fluoride trifluoroethylene copolymer (P(VDF-TrFE)) polymer and high-elastic FeSiB amorphous alloy (metglas) ribbon has been successfully fabricated for wearable device applications. X-ray diffraction and the Fourier Transform Infrared Spectrum studies reveal P(VDF-TrFE) exhibiting the fine β-phase. Both theoretical analysis and experimental results show that unique wave-shaped structure enhances the electromechanical coupling significantly, because of the combination piezoelectric effects of d33 and d31 modes in P(VDF-TrFE) polymer, as well as the enhanced effective piezoelectric coefficient caused by the pre-stretch in P(VDF-TrFE) film. Two application examples of WSPC, (i) mechanical force sensor or energy harvester, and (ii) the medical blood-pressure pulse sensor, have been investigated, which show that the WSPC is a promising candidate for future wearable device applications.

Probing the binding mode of psoralen to calf thymus DNA

The binding properties between psoralen (PSO) and calf thymus DNA (ctDNA) were predicted by molecular docking, and then determined with the use of UV–vis absorption, fluorescence, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy, coupled with DNA melting and viscosity measurements. The data matrix obtained from UV–vis spectra was resolved by multivariate curve resolution–alternating least squares (MCR–ALS) approach. The pure spectra and the equilibrium concentration profiles for PSO, ctDNA and PSO–ctDNA complex extracted from the highly overlapping composite response were obtained simultaneously to evaluate the PSO–ctDNA interaction. The intercalation mode of PSO binding to ctDNA was supported by the results from the melting studies, viscosity measurements, iodide quenching and fluorescence polarization experiments, competitive binding investigations and CD analysis. The molecular docking prediction showed that the specific binding most likely occurred between PSO and adenine bases of ctDNA. FT-IR spectra studies further confirmed that PSO preferentially bound to adenine bases, and this binding decreased right-handed helicity of ctDNA and enhanced the degree of base stacking with the preservation of native B-conformation. The calculated thermodynamic parameters indicated that hydrogen bonds and van der Waals forces played a major role in the binding process.

Genetic and environmental information in goat milk Fourier transform infrared spectra

Fourier transform infrared (FTIR) spectroscopy is often used in prediction of major milk components in genetic evaluation of dairy animals. Until now genetic variability of goat milk FTIR spectra has only been known indirectly through their contribution to the major milk components. In this study, genetic and environmental components of goat milk FTIR spectra were examined directly. A data set containing 83,858 milk FTIR spectral observations belonging to 29,320 Norwegian dairy goats of 271 herds was used for the study. Principal components analysis was applied on both unprocessed and preprocessed spectral data, and new traits (latent traits) were defined because a multitrait analysis of all spectral variables for variance components could not be done. Eight and 7 latent variables, explaining approximately 99% of the total unprocessed and preprocessed spectral variation, respectively, were kept from the principal components analysis for genetic analysis. Genetic and environmental variance components were estimated for the latent traits using restricted maximum likelihood. Genetic-to-total phenotypic variance ratios (heritabilities) of the latent traits were between 0.011 and 0.285 for the unprocessed spectra and between 0.135 and 0.262 for the preprocessed spectra. The estimated variance components for the latent traits were back transformed to the spectral variables. Heritabilities of these spectral variables ranged from 0.018 to 0.408 and variance ratios of the permanent environmental effects of goats were between 0.002 and 0.184 of the phenotypic spectral variation. High-to-moderate heritabilities were observed in particular in spectral regions related to major milk components (fat, lactose, and protein): between 1,030 and 1,300cm−1, 1,500 and 1,600cm−1, 1,700 and 1,800cm−1, and 2,800 and 3,000cm−1. Our results confirmed that a substantial amount of genetic variation exists in goat milk FTIR spectra. Not all spectral variations are of genetic origin; some FTIR regions are highly influenced by herd test-day variation. The study also pointed out the possibility of using FTIR spectra as a monitoring tool in herd management.

Spectroscopic studies on the interaction between EcoRI and CdS QDs and conformation of EcoRI in EcoRI-CdS QDs bioconjugates

Water-soluble fluorescent quantum dots (QDs) have been widely used in biological and biomedical fields, and the interaction between QDs and proteins and the conformational structure of the protein in the bioconjugate has attracted increasing attention. In this study, UV-Vis spectroscopy, fluorescence quenching, CD spectra, gel electrophoresis and Fourier transform infrared (FTIR) spectroscopic techniques were used to systematically investigate the interaction between type II restriction endonuclease (EcoRI) and CdS QDs and the conformational structure of EcoRI in the EcoRI-CdS QDs bioconjugates. The results indicated that electrostatic interactions played a major role in the binding reaction at pH 6.0, and the nature of quenching was static, resulting in forming CdS QDs-EcoRI bioconjugates. FTIR and CD spectra studies indicated a decrease of α-helical and turn structures accompanied by the increase of β-sheet structures of EcoRI in the bioconjugates. This study showed that the interaction between EcoRI and CdS QDs resulted in a change in the secondary structure of EcoRI after it was conjugated with CdS QDs, but the enzyme activity was maintained.

High temperature and low current density synthesis of Mn 3O 4 porous nano spheres: Characterization and electrochemical properties

Uniform and single-crystalline Mn 3O 4 nano-spheres were synthesized by cathodic electrodeposition at high temperature (80 °C) and low current density (0.25 mA cm −1) on steel electrode. Further the annealed samples were characterized for their structural and morphological properties by means of X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) studies. TEM and SEM images showed that particles have spherical shapes and the average diameter size was about 50 nm. Formation of Mn 3O 4 compound was confirmed from FTIR studies. The XRD pattern showed that the Mn 3O 4 exhibit tetragonal hausmannite structure. The results of N 2 adsorption-desorption analysis indicated that Mn 3O 4 nano–sphere has BET surface area of about 177.6 m 2 g −1 and average pore diameters of 3 and 4 nm. The possible formation mechanism of Mn 3O 4 nanostructures has been discussed. The supercapacitive properties of Mn 3O 4 sample in 0.5 M Na 2SO 4 electrolyte showed maximum supercapacitance of 235.4 Fg −1 at scan rate 10 mV s −1. Coulumbic efficiency could be kept about 90% during 1000 cycles at 10 mV s −1.

Thermal and dielectric studies of self-assembly systems formed by hydroquinone and alkyloxy benzoic acids

Self-assembly systems formed by hydroquinone and alkyloxy benzoic acids are isolated and characterized. Hydroquinone formed double hydrogen bonds with p- n-alkyloxy benzoic acids. Various hydrogen bonded complexes have been synthesized with hydroquinone and pentyloxy to dodecyloxy benzoic acid, respectively. FTIR studies confirm the hydrogen bond formation in the complex. Polarizing Optical Microscopic (POM) studies revealed the textural information while the transition and enthalpy values are experimentally deduced from Differential Scanning Calorimetry (DSC) studies. Phase diagram has been constructed from the POM and DSC data. The members of the present homologous complexes are characterized by POM, DSC, optical tilt angle and dielectric studies. Odd–even effect has been evinced in enthalpy values and transition temperatures corresponding to the isotropic to nematic phase transition. Optical tilt angle in Smectic C phase data has been fitted to a power law and it has been observed that the temperature variation of the tilt angle follows Mean Field theory prediction. Results of Fourier Transform Infrared Spectra (FTIR), POM, DSC, tilt angle and dielectric studies are discussed.

Infrared spectra study of Nd 1.85−xR xCe 0.15CuO 4±δ ( R = Gd and Sm) single crystals

The X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, and resistivity ρ are measured on Nd 1.85− xR x Ce 0.15CuO 4± δ ( R = Gd and Sm) single crystals. From the XRD and FTIR spectra studies, the lattice constant c are found to decrease faster for Gd doping than that for Sm doping with increasing doping concentration x. Upon Gd doping, all the transmission peaks shift to high frequency but nearly unchanged with increasing Sm doping content. The volume of the unit cell observed through XRD and FTIR spectra decreases faster for Gd doping than that for Sm doping. Furthermore, for Gd doping the superconducting T c decreases rapidly with increasing the doping concentration, while the T c decreases slowly for Sm doping with increasing Sm content, which is found to be very well consistent with the evolution of the volume of the unit cell for two series.

Chemical synthesis and characterization of Mn3O4 thin films for supercapacitor application

A facile chemical bath deposition (CBD) technique has been used for the preparation of Mn3O4 thin films at room temperature. The structural, morphological, optical, wettability and electrical characterizations have been carried out by means of X-ray diffraction (XRD), Scanning electron micrograph (SEM), Fourier transform infrared spectrum (FTIR), optical absorption, contact angle and electrical resistivity studies of deposited films. The XRD pattern shows the tetragonal hausmannite structure of Mn3O4 thin film. The Mn3O4 formation was also confirmed from FTIR studies. SEM images showed that the substrate surface is uniformly covered with spherical beads-like architecture. The Mn3O4 film showed a direct optical band gap with energy 2.51 eV and hydrophilicity with water contact angle of 53°. The room temperature electrical resistivity of Mn3O4 thin film was found to be 1.6 × 102 Ω cm. Mn3O4 films when used in supercapacitor exhibited specific capacitance of 284 F g-1 in 1 M Na2SO4 electrolyte.

A novel chemical synthesis and characterization of Mn 3O 4 thin films for supercapacitor application

Mn 3O 4 thin films have been prepared by novel chemical successive ionic layer adsorption and reaction (SILAR) method. Further these films were characterized for their structural, morphological and optical properties by means of X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), field emission scanning electron microscopy (FESEM), wettability test and optical absorption studies. The XRD pattern showed that the Mn 3O 4 films exhibit tetragonal hausmannite structure. Formation of manganese oxide compound was confirmed from FTIR studies. The optical absorption showed existence of direct optical band gap of energy 2.30 eV. Mn 3O 4 film surface showed hydrophilic nature with water contact angle of 55°. The supercapacitive properties of Mn 3O 4 thin film investigated in 1 M Na 2SO 4 electrolyte showed maximum supercapacitance of 314 F g −1 at scan rate 5 mV s −1.

Fabrication of copper oxide multilayer nanosheets for supercapacitor application

Copper oxide multilayer nanosheets thin films have been formed using simple and inexpensive chemical bath deposition (CBD) method. These films were characterized using X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Fourier transform infrared spectrum (FTIR), optical absorption and wettability test. The XRD pattern revealed that the copper oxide films are amorphous. Formation of copper oxide compound was confirmed from the FTIR studies. The FESEM images revealed the development of hierarchical multilayer nanosheets which covered the substrate surface. Surface wettability with liquid interface showed hydrophilic nature with water contact angle 53°. The optical absorption showed existence of direct optical band gap of energy 2.18 eV. The supercapacitive properties of copper oxide thin film investigated in 1 M Na2SO4 electrolyte showed supercapacitance of 43 F g-1 at scan rate 10 mV s-1.

FTIR spectra studies on the secondary structures of 7S and 11S globulins from soybean proteins using AOT reverse micellar extraction

Fourier transform infrared (FTIR) method was used to study the secondary structures of 7S and 11S globulins from soybean proteins using aqueous buffer and reverse micelles extraction method for the first time. The Fourier second derivative was applied to all spectra, revealing that the amideband of 7S and 11S globulins with two extraction methods consisted of eight bands. The I band frequencies were assigned to α-helix, β-sheet, unordered and turn structure. The second derivative spectra of 7S and 11S globulins had been shifted with reverse micellar extraction method compared with their spectra with aqueous buffer extraction method. The relative amount of different structure of 7S and 11S globulins could be estimated through accurate measurement of the band intensities. The results indicated that the percentage of 7S globulin α-helix and β-sheet, turn structures decreased with the reverse micelles extraction (7S globulin: 14.5% α-helix, 45.6% β-sheet, 14.4% unordered, 23.8% turn; 11S globulin: 17.0% α-helix, 47.3% β-sheet, 16.5% unordered, 19.3% turn), compared with 7S (16.5% α-helix, 47.6% β-sheet, 35.9% turn) and 11S (17.0% α-helix, 47.3% β-sheet, 35.8% turn) globulins by the aqueous buffer extraction, while the percentage of 11S globulin α-helix and β-sheet structures did not change. The percentage of unordered structure was 14.4 and 16.5, respectively. The amount change of these substructures might affect functional properties of 7S and 11S globulins.