The characterization of Indian bituminous and subbituminous coal was performed by UVVisible– NIR spectroscopy. Chemical leaching with varying concentration of hydrofluoric acid was conducted on both the samples. Elec...The characterization of Indian bituminous and subbituminous coal was performed by UVVisible– NIR spectroscopy. Chemical leaching with varying concentration of hydrofluoric acid was conducted on both the samples. Electronic absorption at this region was higher for higher ranked coals. Chemical leaching increased electronic transitions in subbituminous coal with maximum transitions for HF (10%) leached samples. The absorption maximum of benzeneoxygen system was found between 235-270 nm and was showing a red shift with leaching. The characteristic naphthalene ring systems (220 & 280 nm) were masked by the absorption regions of monoaromatic rings;indicating the content of napthalenoid hydrocarbon was very low. The bands observed in the visible region (450nm) were attributed to SO2 in the sample and was showing a red shift. The weak band at the 680 nm was attributed to the Ⅱ-Ⅱ* electronic transitions of the polynuclear aromatic hydrocarbons which also showed red shift with leaching. It was found that the ash content is reduced by 87.5% & 76.2% in bituminous and subbituminous coal respectively with HF (30%) leaching.展开更多
A new alkali metallo-organic single crystal of Lithium Sodium Acid Phthlate (LiNaP) complex has been synthesized from aqueous solution in the equimolar ratio 3:1:2. Transparent and bulk single crystals of dimension 9 ...A new alkali metallo-organic single crystal of Lithium Sodium Acid Phthlate (LiNaP) complex has been synthesized from aqueous solution in the equimolar ratio 3:1:2. Transparent and bulk single crystals of dimension 9 × 4 ×2 mm3 have been grown from the conventional slow-cooling technique. The crystal structure of the compound has been solved from single crystal X-ray diffraction. The compound 2[C8H4O3]4-Li3+Na+ crystallizes in triclinic system with a space group of Pī having cell dimensions a = 7.5451(2) ? b = 9.8422(3) ? c = 25.2209(7) ? α = 80.299(2);β = 89.204(2);γ = 82.7770(10). FTIR measurement was carried out fo? LiNaP to study the vibrational structure of the compound. The various functional groups present in the molecule and the role of H-bonds in stabilizing the crystal structure of the compound have been explained. Optical absorption properties were studied for the grown crystal using UV-Vis-NIR spectrum. Thermal measurements were carried out for LiNaP to determine the thermal strength as well as to ascertain the hydrated nature of the crystal. Third order nonliner optical studies have also studied by Z-scan techniques. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated. The results of all studies have been discussed in detail.展开更多
We have investigated the effects of chemical treatment on Single Wall Carbon Nanotube (SWCNT) before and after being modified with HNO3/H2SO4 by Raman, FTIR and UV-Vis-NIR spectroscopy. The results show successful car...We have investigated the effects of chemical treatment on Single Wall Carbon Nanotube (SWCNT) before and after being modified with HNO3/H2SO4 by Raman, FTIR and UV-Vis-NIR spectroscopy. The results show successful carboxylation of the CNT sidewalls as observed from FTIR and UV-Vis-NIR spectroscopy. This successful functionalization is achieved in 6-8 hrs of refluxing. We also report changes in the first and second order Raman spectra of SWNTs functionalized with oxygenated groups. During the experiment, we observe some important Raman features: Radial breathing mode (RBM), Tangential mode (G-band), and Disordered mode (D-band);which are affected due to the chemical oxidation of carbon nanotubes. We found that the ratio of D- to the G-band intensity (Id/Ig), increase after functionalization and the RBM mode in acid treated SWCNTs is almost disappeared.展开更多
文摘The characterization of Indian bituminous and subbituminous coal was performed by UVVisible– NIR spectroscopy. Chemical leaching with varying concentration of hydrofluoric acid was conducted on both the samples. Electronic absorption at this region was higher for higher ranked coals. Chemical leaching increased electronic transitions in subbituminous coal with maximum transitions for HF (10%) leached samples. The absorption maximum of benzeneoxygen system was found between 235-270 nm and was showing a red shift with leaching. The characteristic naphthalene ring systems (220 & 280 nm) were masked by the absorption regions of monoaromatic rings;indicating the content of napthalenoid hydrocarbon was very low. The bands observed in the visible region (450nm) were attributed to SO2 in the sample and was showing a red shift. The weak band at the 680 nm was attributed to the Ⅱ-Ⅱ* electronic transitions of the polynuclear aromatic hydrocarbons which also showed red shift with leaching. It was found that the ash content is reduced by 87.5% & 76.2% in bituminous and subbituminous coal respectively with HF (30%) leaching.
文摘A new alkali metallo-organic single crystal of Lithium Sodium Acid Phthlate (LiNaP) complex has been synthesized from aqueous solution in the equimolar ratio 3:1:2. Transparent and bulk single crystals of dimension 9 × 4 ×2 mm3 have been grown from the conventional slow-cooling technique. The crystal structure of the compound has been solved from single crystal X-ray diffraction. The compound 2[C8H4O3]4-Li3+Na+ crystallizes in triclinic system with a space group of Pī having cell dimensions a = 7.5451(2) ? b = 9.8422(3) ? c = 25.2209(7) ? α = 80.299(2);β = 89.204(2);γ = 82.7770(10). FTIR measurement was carried out fo? LiNaP to study the vibrational structure of the compound. The various functional groups present in the molecule and the role of H-bonds in stabilizing the crystal structure of the compound have been explained. Optical absorption properties were studied for the grown crystal using UV-Vis-NIR spectrum. Thermal measurements were carried out for LiNaP to determine the thermal strength as well as to ascertain the hydrated nature of the crystal. Third order nonliner optical studies have also studied by Z-scan techniques. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated. The results of all studies have been discussed in detail.
文摘We have investigated the effects of chemical treatment on Single Wall Carbon Nanotube (SWCNT) before and after being modified with HNO3/H2SO4 by Raman, FTIR and UV-Vis-NIR spectroscopy. The results show successful carboxylation of the CNT sidewalls as observed from FTIR and UV-Vis-NIR spectroscopy. This successful functionalization is achieved in 6-8 hrs of refluxing. We also report changes in the first and second order Raman spectra of SWNTs functionalized with oxygenated groups. During the experiment, we observe some important Raman features: Radial breathing mode (RBM), Tangential mode (G-band), and Disordered mode (D-band);which are affected due to the chemical oxidation of carbon nanotubes. We found that the ratio of D- to the G-band intensity (Id/Ig), increase after functionalization and the RBM mode in acid treated SWCNTs is almost disappeared.
