Papers by Keyword: IR Spectra

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Authors: Gui Xiang Wang, Xue Dong Gong, He Ming Xiao
Abstract: The derivatives of HNS are optimized to obtain their molecular geometries and electronic structures at the DFT-B3LYP/ 6-31G* level. Their IR spectra are obtained and assigned by vibrational analysis. Compared with the experimental results, all the calculated IR data are found to be reliable. Based on the frequencies scaled by 0.96 and the principle of statistic thermodynamics, the thermodynamic properties are evaluated, which are respectively linearly related with the number of methyl, azido and difluoramino groups as well as the temperature, obviously showing good group additivity.
202
Authors: Madhvesh Pathak, Blassan Samuel, Kiran Tummalapalli, Prasanth Vuppalapati Giri, Sivasankar Koppala, Rakesh Bohra, Kap Jin Kim
Abstract: Novel structural arrangements for alkoxyalkanol modified titanium tetraisopropoxide [(Ti(OPri)4, TPT] were obtained from stoichiometric reactions between TPT and alkoxyalkanols {HOCH2CH2OR,where R= Me, Et}. All the 1:1, 1:2, 1:3 and 1:4 reactions in refluxing benzene form mononuclear species [(OPri)4-nTi(OC2H4OR)n]. All these compounds can be purified by distillation under reduced pressure. On the basis of IR and NMR (1H &13C) spectral studies all the mononuclear derivatives have been obtained in tetrahedral geometry around titanium atom.
415
Authors: V. Psycharis, N. Kalamakis, N. Boukos, C. Trapalis, A. Bourlinos, M. Karakasides
759
Authors: Qiao Xia Li, Hong Min Mao, Ming Shuang Liu, Qun Jie Xu
Abstract: A new approach of spontaneous deposition was carried out to prepare the Ru/Pt film electrocatalyst for direct methanol fuel cells. This deposition method just made Pt like a ‘skin’ covered Ru films, which reduced the load of Pt but obtained a higher activity. The Pt-modified Ru films electrode was studied with the cyclic voltammetries and in-situ ATR-SEITA spectra on methanol oxidation. Compare to bare Ru and Pt, the bands of the adsorbed CO and water observed in IR spectra can be assigned. The present results give a clue for designing new electrocatalysts for DMFCs.
945
Authors: R.M. Nor, S.N.M. Halim, Mohamad Fariz Mohamad Taib, Abdel Baset M.A. Ibrahim, M. Kamil Abd-Rahman
Abstract: The aim of this study is to investigate the incorporation of Al2O3 in SiO2 glass with emphasis on reducing the phonon energy in the SiO2 matrix. Pure SiO2 glass has very high phonon energy of about 1100 cm-1, while Al2O3 has 780 cm-1. By incorporating Al2O3 into SiO2 glass structure, the relative phonon energy of the SiO2 matrix is expected to reduce. However, the composition of Al2O3 has been limited to a desired amount so as not to perturb other properties of SiO2, such as optical absorption. The Infrared (IR) spectra for a portion of SiO2 glass with the Al dopants were simulated at different molar ratio of the composition using Molecular Mechanic and Density Functional Theory (DFT). The Al2O3-SiO2 structures show a significant change in the simulated IR spectra compared to pure SiO2 glass. The Al2O3-SiO2 structures in the present work were constructed by replacing some Si atoms with Al atoms in the host lattice of SiO2 glass. In addition, some O atoms were removed from SiO2 host lattice to get the correct chemical balance. With increasing of Al2O3 content, the relative intensity of ~1100 cm-1 band associated with the asymmetrical O-Si-O/Si-O stretching vibrations is decreased. The decreasing in relative intensity of the IR spectra demonstrates that Al dopants are forming – [Al-O-Si] – linkages in the structure.
160
Authors: Bing Yang Liu, Man Xing, Yu Shu Bai, Lei Dong, Sen Wang, Xiao Dong Liu
Abstract: IR and Raman spectra of three kinds of mineral drug montmorillonite powders (brands Biqi, Smecta general, Smecta strawberry flavour) commercially available for children are obtained to tell the true from the false through checking the spectral information of the active ingredient (montmorillonite) and pharmaceutical excipients (glucose, saccharin sodium, vanillin and strawberry essence). It is found that net contents of the active ingredient in all three drugs maybe really high and even the cheapest brand is also with a high quality. From this study one can see that the IR spectroscopic method is more suitable for this kind of drug identification than the Raman one using the present Raman spectroscope because strong fluorescent signals excited by lasers on the pharmaceutical excipients can generally cover up the fingerprint signals of the active ingredient.
97
Authors: Ping Huang, Jia Chun Lu, Sheng Bo Jiang, Zhi Chao Liu
Abstract: Li/graphite fluoride (GFx) cells have been widely noticed during the past decades due to its highest theoretical capacity, high energy density, long shelf life, safety and a wide operating temperature range in primary lithium batteries. Bamboo charcoal is cheap and widely used carbon with high specific surface area and large layer spacing, which is suitable to be fluorinated to form carbon fluoride. Five products with varied fluorine and color were obtained by fluorinating bamboo charcoal under varied reaction conditions. FT-IR spectra of these FBCs were studied. The absorbance peak related to C-F band was involved into five Gaussian peaks, and the area of each peak was calculated. The specific discharge capacity of each product was measured by galvanostatic discharging at 0.01C rate. It is turned out that there is a positive linear relationship between the specific capacity and the percentage of the peak area related to semi-covalent covalent C-F, if the carbon in the products was removed. The discharge curves showed that the discharge process could be divided into three parts. The pure compound corresponding to the first part of the discharge is the target material we actually want.
789
Authors: Gao Zhang Gou, Ling Shi, Xian Lan Chen, Bo Zhou, Wei Liu, Chao Yong Mang
Abstract: The molecular structures and infrared of four meso-phenyl and 3,5-diaryl substituted BODIPY dyes, A to D, were investigated theoretically using the gradient-corrected density functional theory B3LYP method under 6-31+G* level. The vibrational and transition modes of spectra were explored in terms of their microscopic origin. According to structure analysis, the intersection angles of BODIPY core with meso-phenyl were estimated 59-61º and the angles of BODIPY ring with 3,5-diaryl groups were evaluated 38-62º. The solvation energies of four BODIPYs are −26.26, −30.39, −34.1, −27.58 KJ/mol, respectively.
113
Authors: M. Hartmanová, J. Schneider, A.A. Urusovskaya, K. Putyera, D. Tonega
263
Authors: Noraiham Mohamad, Nor Nadiah Abdul Hamid, Nor Abidah Abdul Aziz, Jeeferie Abd Razak, Umar Al Amani Azlan, Mohd Fairuz Dimin, Azizah Shaaban
Abstract: This study is to investigate the potential of ENR to be incorporated with chitosan for slow release urea fertilizer. In this research, mixture of chitosan and epoxidized natural rubber (ENR) was used as binder to take advantage of their biodegradable and polar characteristics, respectively. The effect of mixing formulation to the properties of fertilizer was studied. Firstly, the chitosan and ENR were diluted in toluene with the presence of bentonite as filler. Then, urea powder was mixed and stirred for 20 minutes before left to dry overnight in an oven at 60°C. Water absorption and water retention analysis were carried out on compressed pellets. The increase of ENR loading was observed to contribute to the increase of hydrophobic properties of the fertilizer. The findings were supported by compositional analysis using Fourier Transform Infrared spectroscopy (FTIR).
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