An Overview of Common Infrared Techniques for Detecting CO Intermediates on Metal Surfaces for Hydrocarbon Products

Detection of intermediates during the catalytic process by infrared techniques has been widely implemented for many important reactions. For the reduction of CO2 into hydrocarbons on metal surfaces, CO molecule is one of the most important transient species to be followed due to its involvement in several products’ pathways, and its distinct vibrational features. Herein, basic understandings behind these utilized infrared techniques are illustrated aiming for highlighting the potential of each infrared technique and its advantages over the other ones for detecting CO molecules on metal surfaces.

Carboxyl graphene reinforced melamine-based polyamide nanocomposites

Over the years, various types of techniques have been used for the synthesis of nanocomposites. In this work, melamine-based polyamide (PA) was synthesized using a one-pot polycondensation method under mild conditions. carboxyl graphene (CG)/PA nanocomposites (CGMPA) were prepared by CG nanofiller loadings of 1, 3, and 5 wt.% via delamination/adsorption approach. The prepared CGMPA nanocomposites were characterized using different analyses, such as Fourier transform infrared techniques (FTIR), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), differential scanning calorimetric (DSC), and thermogravimetric analysis (TGA). The effects of the CG on the thermal properties of the CGMPA nanocomposites were significant. The results showed that the melting temperature (Tm) of neat PA and CGMPA were increased from 378°C to 393°C suggested better dispersion of CG in PA matrix. The decomposition temperature of PA was increased from 451°C to 463°C in CGMPA nanocomposites indicates the better thermal stability of PA matrix by addition of CG.

Electrical and optical studies on tungsten-substituted bismuth molybdates

This manuscript highlights the structural, electrical and optical properties of Bi2Mo1-xWxO6 (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) compounds. These compounds were prepared employing the citrate sol-gel method. These compositions were characterized using thermo-gravimetric and differential scanning calorimetry, X-ray diffraction and infrared techniques. The Rietveld refinements of X-ray powder diffraction data determined and confirmed the crystal structure of the compositions. DC electrical conductivity indicated the conduction behaviour and diffuse reflectance spectroscopy confirmed the semiconducting nature of the compounds. Room temperature photoluminescence results exhibited two type of emission namely blue-green and green emission in the visible region.

Magnetic tetraethylenepentamine-functionalized graphene oxide to prepare new methyl rich bisphenol-based soluble and heat-resistant polyamide ether nanocomposites: Synthesis and characterization

The new magnetic and heat-resistant polyamide ether (PAE)/graphene oxide (GO) nanocomposites were prepared by blending PAE with modified GO. Furthermore, a novel PAE containing flexible ether, methyl, and triphenylmethane moiety in the main chain of PAE was prepared by direct polycondensation reaction of a diamine and 4,4′-(butane-1,4-diylbis(oxy))dibenzoic acid (9). The prepared PAE was characterized using various techniques. The obtained PAEs were readily soluble in various aprotic polar solvents at room temperature. The incorporation of bulky aryl pendant groups and flexible ether linkage into the backbones of polyamide may provide beneficial effects for solubility, as this approach produces a separate chain of the polymer, which makes weaker of hydrogen bonds. GO, which synthesized by the Hummer method, was modified with tetraethylenepentamine (GO-TEPA) and sequentially magnetized with Fe3O4 nanoparticles via chemical coprecipitation (GO-TEPA@Fe3O4). The PAE/GO/TEPA@Fe3O4 nanocomposite films, PAE/GO-TEPA@Fe3O4, were also synthesized as a heat-resistant and superparamagnetic nanocomposites, which were characterized using different analyses, such as field emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray, thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Fourier transform infrared techniques. TGA of nanocomposites exhibit higher degradation temperature than that of neat PAE, which is an indication of high levels of interfacial interaction and dispersion.

Design and manufacture of a device using transillumination and scattering near-infrared techniques for detecting dental lesions

In dentistry, near-infrared (NIR) technology has been studied for decades that is being applied for the detection of dental damages without using ionizing radiation. Based on the interaction between dental tissue and NIR light such as transmission, absorption, and scattering, the teeth structure, and dental lesions can be observed by NIR images. The aim of this study was to build the dental diagnostic device using NIR light at 850-nm wavelength for detecting the early and hidden dental damages, that are not observed by X-rays. According to the various types of teeth samples, the transillumination and the scattering methods were designed and applied for capturing the teeth structures. The transillumination technique was used for thin teeth such as incisor and canine while the scattering system for observing the occlusal surface. The results show that the areas suspected to be the demineralized enamel are distinctly distinguished from the surrounding sound tissues and especially, the stain and pigmentation don’t appear in the NIR image. The designed device meets some requirements such as simple setup, safety, and affordable price for the purpose of replacement of imported equipment.