IR Spectroscopy Research Papers - Academia.edu (original) (raw)

Lignocelluloses industrial waste flour of olive husk powder (LCF) was utilized as reinforcement in carboxylated nitrile butadiene rubber (XNBR)/Polyamide-12 (PA-12) thermoplastic elastomer composites. To improve the bonding quality... more

Lignocelluloses industrial waste flour of olive husk powder (LCF) was utilized as reinforcement in carboxylated nitrile butadiene rubber (XNBR)/Polyamide-12 (PA-12) thermoplastic elastomer composites. To improve the bonding quality between the LCF and the blend, the powder was chemically treated by two means, the former is the treatment with toulene-2–4-diisocyanate (TDIC), and the latter is mercerization with sodium hydroxide followed by neutralization with acetic acid. The untreated and chemically treated powders were analyzed with attenuated total reflectance infrared spectroscopy (ATR-IR). The morphology of the powders before and after treatment was studied with scanning electron microscopy (SEM). The LCF reinforced composites were prepared using computerized Haake internal mixer coupled with rheometer. The processing conditions were 178°C and rotor speed of 80- round per minute for 7 min. The melt mixing process was monitored by the torque-time plastograms of the Haake internal mixer. The development of the stock temperature during the mixing process was monitored using the rheometer of Hakke internal mixer. The structural changes of the XNBR/PA-12 composites were inspected by SEM and attenuated ATR-IR spectroscopy. The influence of the modified filler on the toughness and hardness of the prepared samples are reported. The resistance of the prepared composites to water and toluene swelling are evaluated as well.

A series of titanium based gels comprising carbohydrate moieties was synthesized. The sugars used include a specific hydrazide group as complex forming agent. Additionally, this group forms stable hydrates which allow further slow water... more

A series of titanium based gels comprising carbohydrate moieties was synthesized. The sugars used include a specific hydrazide group as complex forming agent. Additionally, this group forms stable hydrates which allow further slow water release. As a result, the compounds used in this study form transparent and stable gels with titanium alkoxide without addition of external water. Interpretation of the IR-spectra reveals that some compounds form monodentate ligands and other bidentate ligands. Further Tian-Calvet calorimetric measurements confirmed our IR-based conclusions. This strategy of synthesis gives a new opportunity to obtain hybrid materials by addition of natural chelating ligands to slow down the hydrolysis/condensation reactions that occur during the sol-gel process. Therefore, carbohydrate moieties have been incorporated in the gels obtained and different type of Ti coordination was proposed based on the IR spectroscopy studies. SEM investigations show the influence of the ligand on the morphology of the xerogel. GRAPHICAL ABSTRACT

The effect of different catalysts (NaY, Cr-VPI-5, acidic kaolinite clay, clayfen, and p-toluenesulfonic acid) on the reaction between cyclohexanone and methanol-d4 was investigated using GC-MS and in situ NMR spectroscopy at room... more

The effect of different catalysts (NaY, Cr-VPI-5, acidic kaolinite clay, clayfen, and p-toluenesulfonic acid) on the reaction between cyclohexanone and methanol-d4 was investigated using GC-MS and in situ NMR spectroscopy at room temperature. An in situ IR spectroscopy analysis of pyridine adsorbed on the clay and NaY samples showed that they are both weakly acidic. Depending on the catalyst employed, acetalization, α-carbon deuteration, or both of these reactions occurred. With the clays only acetalization proceeded to yield 1,1-dimethoxycyclohexane with 90% conversion at room temperature. When zeolite Y was used, only deuteration of the cyclohexanone α-carbon was observed, while with the homogeneous p-toluenesulfonic acid catalyst, both deuteration of the α-carbons and the acetalization reaction proceeded.

The coherent time-stretch transform enables high-throughput acquisition of complex optical fields in single-shot measurements. Full-field spectra are recovered via temporal interferometry on waveforms dispersed in the temporal near... more

The coherent time-stretch transform enables high-throughput acquisition of complex optical fields in single-shot measurements. Full-field spectra are recovered via temporal interferometry on waveforms dispersed in the temporal near field. Real-time absorption spectra, including both amplitude and phase information, are acquired at 37 MHz.

Richard Crocombe of Crocombe Spectroscopic Consulting surveys the use of portable spectrometers in pharmaceutical manufacturing, with an emphasis on vibrational spectroscopy. Ideal and typical features of portable spectrometers are... more

Richard Crocombe of Crocombe Spectroscopic Consulting surveys the use of portable spectrometers in pharmaceutical manufacturing, with an emphasis on vibrational spectroscopy. Ideal and typical features of portable spectrometers are reviewed, alongside explanation of why device characteristics and sample presentation are critical to obtaining meaningful results.

X-band and high-frequency EPR spectroscopy were used for studying the manganese environment in layered Li[Mg xNi 0.5-xMn 0.5]O 2, 00.5Mn 0.5O 2 and monoclinic Li[Li 1/3Mn 2/3]O 2 oxides (containing Mn 4+ ions only) were used as EPR... more

X-band and high-frequency EPR spectroscopy were used for studying the manganese environment in layered Li[Mg xNi 0.5-xMn 0.5]O 2, 00.5Mn 0.5O 2 and monoclinic Li[Li 1/3Mn 2/3]O 2 oxides (containing Mn 4+ ions only) were used as EPR standards. The EPR study was extended to the Ni-substituted analogues, where both Ni 2+ and Mn 4+ are paramagnetic. For LiMg 0.5-xNi xMn 0.5O 2 and Li[Li (1-2x)/3Ni xMn (2-x)/3]O 2, an EPR response from Mn 4+ ions only was detected, while the Ni 2+ ions remained EPR silent in the frequency range of 9.23-285 GHz. For the diamagnetically diluted oxides, LiMg 0.25Ni 0.25Mn 0.5O 2 and Li[Li 0.10Ni 0.35Mn 0.55]O 2, two types of Mn 4+ ions located in a mixed (Mn-Ni-Li)-environment and in a Ni-Mn environment, respectively, were registered by high-field experiments. In the X-band, comparative analysis of the EPR line width of Mn 4+ ions permits to extract the composition of the first coordination sphere of Mn in layered LiMg 0.5-xNi xMn 0.5O 2 (0(1-2x)/3Ni xMn (2-x)/3]O 2 ( x>0.2). It was shown that a fraction of Mn 4+ are in an environment resembling the ordered " alpha, beta"-type arrangement in Li 1-delta1Ni delta1[Li (1-2x)/3+delta1Ni 2x/3-delta1) alpha(Mn (2-x)/3Ni x/3) beta]O 2 (where x={2}/{7} and delta1=0.06 were calculated), while the rest of Mn 4+ are in the Ni,Mn-environment corresponding to the Li 1-delta2Ni delta2[Ni 1-yMn y]O 2 ( y<{1}/{2}) composition with a statistical Ni,Mn distribution. For Li[Li (1-2x)/3Ni xMn (2-x)/3]O 2 with x1/3Mn 2/3]O 2.

Hydrothermal synthetic emeralds manufactured by Biron, Regency and Tairus have been distinguished from natural and synthetic emeralds using chemical analysis and infrared (IR) spectroscopy. Polarized IR spectra have been obtained from... more

Hydrothermal synthetic emeralds manufactured by Biron, Regency and Tairus have been distinguished from natural and synthetic emeralds using chemical analysis and infrared (IR) spectroscopy. Polarized IR spectra have been obtained from plates. Hydrothermal synthetic emeralds possess infrared absorption features not present in natural emeralds, and these features have been investigated. We infer that the system of five narrow bands in the 3000-2600 cm-1 region is related to the dimer formation of HCl molecules, which have been incorporated in the channels parallel to the c-axis during growth of Biron and Regency emeralds. In Regency emeralds, a double band with maximum at 3295 and shoulder near 3232 cm-1 and a broad band between 3000 and 2500 cm-1 are attributed to hydrogen- bonded NH4 + ions. In Russian hydrothermal synthetic emeralds the strong infrared spectral features related to molecular water are generally similar to those of some natural emeralds but there are also broad bands due to Ni2+ and Cu2+ ions in the near-infrared regions which enable one to distinguish Russian hydrothermal synthetic from natural emeralds. Other bands unrelated to water in hydrothermal synthetic emeralds are also discussed.

Modern textiles often contain cotton-polyester products which must undergo quality assurance processes. The ability to identify the mixture ratio analysis of these products for the manufacturer is a great advantage. Preferably these... more

Modern textiles often contain cotton-polyester products which must undergo quality assurance processes. The ability to identify the mixture ratio analysis of these products for the manufacturer is a great advantage. Preferably these methods should be non-destructive and calculated quickly. Infrared spectroscopy was used to identify textile products by absorption and soft independent modeling of class analogy. Mixture ratio analysis was conducted by analysis of the absorption spectrum and partial least squares regression. The accuracy of mixture ratio analysis has reached 2.4 %.