FT-IR spectra of Li(AlxCo1-x)O2 (x=0.1-0.5)

2001 ◽  
Vol 699 ◽  
Author(s):  
W. Hao ◽  
C. Li ◽  
X. Meng ◽  
G. Chen ◽  
W. Xu

AbstractFT-IR spectra from Li(AlxCo1-x)O2 (x=0.1-0.5) are reported. It was found out that there are four peaks located at 556cm−1, 601cm−1, 1438cm−1, 1498cm−1. First two peaks at 556cm−1 and 601cm−1 can be assigned to A2u and Eu vibration modes, respectively. The other two new peaks at 1438cm−1 and 1498cm−1 can not be explained clearly. With the increasing of Al concentration, all peaks position remain unchanged. However a relative change in the intensity of A2u and Eu peaks was observed.

2005 ◽  
Vol 60 (8-9) ◽  
pp. 633-636 ◽  
Author(s):  
Nuri Öztürk ◽  
Çağrı Çırak ◽  
Semiha Bahçeli

The adsorption of 1,5-pentanedithiol (1,5-PDT) and 1,6-hexanedithiol (1,6-HDT) in liquid phases on NaA (or 4A-type), CaA (or 5A-type) and NaY zeolites has been studied by using infrared spectroscopy. From the IR spectra it is found that the peak positions of the symmetric as well as the antisymmetric modes of the methylene (CH2) groups are observed at almost the same band values for the title dithiolates adsorbed on the A-type and NaY zeolites. On the other hand, the weak SH stretching vibration, observed for all samples, can be attributed to the sulphure atoms of 1,5-PDT and 1,6-HDT coordinatively adsorbed on cationic sites of the zeolites.


Author(s):  
Fumihiro Sagane ◽  
Kenta Ogi ◽  
Akinori Konno ◽  
Kiyoshi Kanamura

Abstract The effect of the coordination ability of the solvent species on the Mg plating/stripping behavior was investigated. The Mg plating reaction in Mg(N(CF3SO2)2)2/diglyme was inhibited by the equimolar of 15-crown-5 ether (15C5) to Mg2+-ion. On the other hand, Mg plating took place in the solution by reducing the amount of 15C5 less than that of Mg2+-ion. FT-IR spectra showed that 15C5 preferentially solvated Mg2+-ion in the glyme based solutions. The theoretical calculation indicated the interaction between Mg2+-ion and each O atom in 15C5 was stronger than that with diglyme or larger sized crown ether. The results showed that the coordination ability of the solvent species could be the critical for the Mg plating reaction.


2021 ◽  
Vol 882 (1) ◽  
pp. 012026
Author(s):  
E Maryani ◽  
N Sofiyaningsih ◽  
R Septawendar

Abstract Composites of Na2SO4 is promising for solid electrolyte application. In this initial study, composites of Al2O3/Na2SO4 were successfully synthesized from local kaolin through an alkaline destruction method combined with sulphatization. The composites were characterized including thermal behaviour, mineral phases, chemical composition, FT-IR spectra, and microstructures. The composites consist of a-Al2O3 and Na2SO4 phases after calcination at 1300 °C. This phenomenon is confirmed by the XRF and FT-IR result. The composite consists of Al2O3 and Na2SO4 as major components, accounting 41.98% and 47.09% of the total, respectively. Meanwhile, SiO2 is found as the impurity, accounting 2.86% of the total. The vibration modes of Al-O bonds are detected at 995.27 and 524.46 cm1, whereas the SO4 bands appear at 1111.00 and 617.22 cm1. Na2SO4 exhibits a rod-like particle that cover the alumina surface in the morphology.


2018 ◽  
Author(s):  
Koen Vercruysse ◽  
Margaret M. Whalen

<p>This report is a continuation of previous research on the H<sub>2</sub>O<sub>2</sub>-mediated synthesis of melanin-like pigments. We synthesized and characterized L-DOPA-based pigments using air- or H<sub>2</sub>O<sub>2</sub>-mediated<sub> </sub>oxidation. We compared their physic-chemical properties and evaluated their capacity to affect the interleukin release from immune cells. The use of higher concentrations of H<sub>2</sub>O<sub>2</sub> resulted in melanin-like materials with a distinct chemical signature in their FT-IR spectra and a lighter color. All pigments enhanced the interleukin release from immune cells. The possibility that lighter-colored melanins can be generated is discussed in the context of the importance of melanin-based pigmentation in human physiology.</p>


Author(s):  
Anna Wójtowicz ◽  
Agata Mitura ◽  
Renata Wietecha-Posłuszny ◽  
Rafał Kurczab ◽  
Marcin Zawadzki

AbstractVitreous humor (VH) is an alternative biological matrix with a great advantage of longer availability for analysis due to the lack of many enzymes. The use of VH in forensic toxicology may have an added benefit, however, this application requires rapid, simple, non-destructive, and relatively portable analytical analysis methods. These requirements may be met by Fourier transform infrared spectroscopy technique (FT-IR) equipped with attenuated total reflection accessory (ATR). FT-IR spectra of vitreous humor samples, deposited on glass slides, were collected and subsequent chemometric data analysis by means of Hierarchical Cluster Analysis and Principal Component Analysis was conducted. Differences between animal and human VH samples and human VH samples stored for diverse periods of time were detected. A kinetic study of changes in the VH composition up to 2 weeks showed the distinction of FT-IR spectra collected on the 1st and 14th day of storage. In addition, data obtained for the most recent human vitreous humor samples—collected 3 and 2 years before the study, presented successful discrimination of all time points studied. The method introduced was unable to detect mephedrone addition to VH in the concentration of 10 µg/cm3. Graphic abstract


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 340
Author(s):  
Kitherian Sahayaraj ◽  
Balakrishnan Saranya ◽  
Samy Sayed ◽  
Loko Yêyinou Laura Estelle ◽  
Koilraj Madasamy

The foam produced by nymphs of Poophilus costalis on eleven different host plants belonging to eight families on St. Xavier’s College campus in India was studied over five months. The chemical composition and antimicrobial activity of these biofoams were investigated. The results revealed that P. costalis preferred Theporsia purpurea and Mimosa pudica for laying their eggs and producing foam, over the other tested plants. P. costalis produce their foam on either nodes or internodes on monocotyledons (30%) (p < 0.05), whereas on dicotyledons, they produce more foam on the stems (63.8%) than on the leaves (6.2%) (p < 0.01). The number of nymphs in each piece of foam from P. costalis varied from 1 to 3 (mean = 1.8 per plant). They produced their foam (5.7 to 45.2 cm) from the ground level on a plant. The length and breadth of a piece of foam ranged from 1.0 to 3.9 cm and 0.6 to 4.7 cm, respectively. The foam tended to be cooler than the environment. Qualitative profiling showed that the foam consists of carbohydrates, including maltose; trypsin; amino acids; protease. The foam was also analyzed using a spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), gas chromatography–mass spectroscopy (GC-MS), and high-performance liquid chromatography (HPLC). The antimicrobial activity of the biofoam was the greatest against Staphylococcus aureus, the growth of which was reduced by 55.9 ± 3.9%, suggesting that the foam could be used as an antimicrobial product. However, no activities were observed against Fusarium oxysporum and Candida albicans.


2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.


Sign in / Sign up

Export Citation Format

Share Document