Search results for "fourier transform infrared spectroscopy"
showing 10 items of 394 documents
Double Step Electrochemical Process for the Deposition of Superhydrophobic Coatings for Enhanced Corrosion Resistance
2021
Superhydrophobic surface on anodized AA5083 sample was obtained by an electrochemical process. Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy analyses revealed the hierarchical structure of the coating and the presence of manganese stearate. These features were crucial for the coating superhydrophobicity, demonstrated by a measured contact angle of ~ 163° and its self-cleaning ability. Electrochemical characterization in an aqueous solution mimicking seawater proved an enhanced corrosion resistance due to the superhydrophobic coating with respect to anodized AA5083 sample that also lasted after 20 immersion days in Cl- containing electrolyte.
Design of siliceous lignins – Novel organic/inorganic hybrid sorbent materials
2009
Novel nanoporous lignin(lignocellulose)/SiO2 hybrid materials were designed using the sol–gel process. X-ray photoelectronic spectroscopy, Fourier transform infrared spectroscopy and 29Si and 13C nuclear magnetic resonance spectroscopy were applied to characterize the hybrids’ surface and bulk structure. Nitrogen and water vapor sorption were used for assessment of porous structure parameters and hydrophobization of matrices, respectively. The efficiency of the hybrid materials obtained was proved by adsorption tests with potential inorganic (Cu2+) and organic (2,4-dichlorophenoxyacetic acid) pollutants.
Protection of high-density polyethylene-silicon composites from ultraviolet-visible photodegradation
2017
[EN] The extent of the ultraviolet¿visible (UV¿vis) photoirradiation effect on high-density polyethylene (HDPE) and HDPE¿sili-con (Si) composites is reported in terms of the addition of Si microparticles at contents of 0.1, 1, and 5 wt %. A standard acceleratedUV-vis exposure was applied over 2750 h, corresponding to 22 months in Florida. Thermogravimetry, differential scanning calorimetry,and Fourier transform infrared spectroscopy were used as reliable techniques for monitoring the quality of the HDPE-Si composites. Theincreasing addition of Si microparticles delayed the photodegradation of the HDPE¿Si composites. Because of their strong light-scattering effects, Si microparticles blocked…
Simple New Method for the Preparation of La(IO3)3 Nanoparticles
2020
We present a cost- and time-efficient method for the controlled preparation of single phase La(IO3)3 nanoparticles via a simple soft-chemical route, which takes a matter of hours, thereby providing an alternative to the common hydrothermal method, which takes days. Nanoparticles of pure &alpha
Enhancing the sensitivity of nano-FTIR spectroscopy.
2017
Synchrotron radiation-based nano-FTIR spectroscopy utilizes the highly brilliant and ultra-broadband infrared (IR) radiation provided by electron storage rings for the infrared spectroscopic characterization of samples at the nanoscale. In order to exploit the full potential of this approach we investigated the influence of the properties of the radiation source, such as the electron bunch shape and spectral bandwidth of the emitted radiation, on near-field infrared spectra of silicon-carbide (SiC). The adapted configuration of the storage ring optics enables a modification of the transverse electron bunch profile allowing an increase of the measured near-field signal amplitude. Additionall…
Crystal growth of Hg1−xMnxSe for infrared detection
2007
In this work, we report on the successfully growing Hg"1"-"xMn"xSe bulk crystals using a mixed, travelling heater method and Bridgman method, two-step procedure. Firstly, and with the aim of reducing Hg high pressure related to the high temperature synthesis reaction between the components in elemental form, HgSe crystals were synthesized and grown by the cold travelling heater method. Secondly, previously sublimated Mn and Se were incorporated to complete the desired composition. Then, the Bridgman growth was carried out by heating the alloy at a temperature of about 880^oC and lowering it at rate of 1mm/h through a gradient of 25^oC/cm. The Hg"1"-"xMn"xSe crystals were characterized by sc…
Preparation and characterization of activated carbon from date stones by physical activation with steam
2008
Abstract Activated carbons are produced from wastes of Algerian date stones by pyrolysis and physical activation in the presence of water vapor into a heated fixed-bed reactor. The effect of pyrolysis temperature and activation hold time on textural and chemical surface properties of raw date stones and carbon materials produced are studied. As expected, the percentage yield decreases with increase of activation temperature and hold time. The characterization of carbon materials is performed by scanning electron microscopy (SEM). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption (BET). Results show the presence of cellulose and hemicellulose in …
Two-component self-assembly with solvent leading to "wet" and microcrystalline organogel fibers
2014
Abstract Hypothesis The microcrystalline fibers of N -(2-aminoethyl)-3α-hydroxy-5β-cholan-24-amide 1 provided a useful model system for studying the complex relationship between morphology, experimental parameters, solvent, and the phenomenon of organogelation. The presence of solvents in the solid forms of 1 along with crystallization behavior suggested solvate formation and polymorphic behavior. Experiments Forty solid state- and xerogel samples of 1 formed in organic solvents and in three categories of experimental conditions were analyzed with single crystal X-ray diffraction (XRD), powder X-ray diffraction (PXRD), Raman microscopy, and attenuated total reflection Fourier-transform infr…
FIA—FT—IR determination of ibuprofen in pharmaceuticals
1992
A method has been developed for the determination of Ibuprofen (2-[4-isobutylphenyl]-propionic acid) in pharmaceuticals by FT-IR, using the carbonyl band which this compound presents at 1710 cm(-1) in carbon tetrachloride solutions. Samples are dissolved in carbon tetrachloride. In this solvent the excipients are not soluble and so the drug can be directly determined without any additional treatment. The use of a simple FIA manifold permits one to carry out this analysis with a low consumption of reagent and the FT-IR provides a continuous monitoring of the spectral base-line which permits an accurate determination of the maximum in the absorbance band. Also, the FIA system permits easy and…
Adsorption of functionalized biomembrane vesicles on crystalline surfaces monitored by FTIR- and Surface Enhanced FTIR Spectroscopy
1997
A special class of integral membrane proteins are the ion channels. To use them for technical purposes they have to be transferred with their lipid surrounding onto artificial materials, i.e. crystals. In this study we used vesicles containing the nicotinic acetylcholine receptor (nAChR) and porin. The first allows the ligand gated flow and the second allows the voltage gated flow of cations across the membrane. We used ATR-FTIR spectroscopy and surface enhanced FTIR techniques (SEIRA) to monitor the direct contact of the vesicles with the crystal.