JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Chen Zhou,Hui Zhang,Jianian Cheng,Hongyi Li,Sadeh Beysen
Two new isostructural lead borates , Pb 8 Mg(BO 3 ) 6 and Pb 8 Ca(BO 3 ) 6 , have been synthesized via high temperature solution method. The single crystal structures of title compounds contain ∞ [Pb 8 B 6 O 18 ] 2- double layers composed of planar BO 3 triangles, Pb(2)O 9 and distorted Pb(1)O 5 polyhedra, these layers condense in c -axis, and the MgO 6 (or CaO 6 ) polyhedra fill into the layers, forming a three-dimensional framework. The stereochemical activity of lone pair (SCALP) electrons were found in the Pb(1)O 5 polyhedra, which combine with the BO 3 units, generating strong optical anisotropy . The calculated birefringences of Pb 8 Mg(BO 3 ) 6 and Pb 8 Ca(BO 3 ) 6 using first-principles method are 0.15@1064 nm and 0.12@1064 nm, respectively, which are comparable to the commercial α -BaB 2 O 4 (α-BBO) crystal and imply that they probably can be used as birefringent materials. The electronic structures, density of states of title compounds were calculated by density functional theory (DFT). Meanwhile, the TG-DSC curves, infrared spectral and UV–Vis–NIR diffuse reflectance spectral were measured.
研究领域:
无机化学
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材料科学
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晶体工程
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非线性光学材料
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固体化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2013
·Vol. 51
·期 9
·2016-2023
·
IF 3.543
CaiFei Wang,ChunHua Zhao,JiaQin Sun,SanQing Huang,XiangDong Liu,Takeshi Endo
A fully bio-based benzoxazine, 3-furfuryl-8-methoxy-3,4-dihydro-2H-1,3-benzoxazine (Bzf), has been prepared using guaiacol, furfurylamine, and paraformaldehyde as raw materials. Its chemical structure has been characterized by 1H and 13C NMR, FTIR, and elemental analysis. The polymerization behavior of Bzf in the presence of methyl p-toluenesulfonate (PTSM) has been studied by FTIR and DSC, and the thermal stability of the cured resin has been evaluated by thermogravimetric analysis. It was found that PTSM is a good promoter that serves to avoid thermal decomposition of the bio-based monomer during the curing process at high temperature. In contrast to the situation with neat Bzf, the presence of PTSM (5 mol % for Bzf) significantly improves the polymerization behaviors, including a decrease in the polymerization temperature from 240 to 174 °C, a shortening of the time required to reach the gel point on heating at 200 °C from 47 to 20 min, and an increase in the char yield of the cured resin from 53 to 62%. Moreover, these observed experimental results on the promoting effect of PTSM are interpreted in terms of several possible mechanistic schemes, which involve a catalytic effect on the dissociation of C O bonds in both the coordination ring-opening reaction and the rearrangement from a phenoxy structure to a phenolic structure. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
研究领域:
高分子化学
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材料科学
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热分析
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绿色化学
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功能高分子
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2016
·Vol. 18
·期 29
·19731-19737
·
IF 4.449
Yingna Cui,Jingmei Yin,Changping Li,Shenmin Li,Ailing Wang,Guang Yang,Yingping Jia
The compositions and structures of amine-based functionalized protic ionic liquids (PILs), namely N,N-dimethyl(cyanoethyl)ammonium propionate (DMCEAP) and N,N-dimethyl(hydroxyethyl)ammonium propionate (DMEOAP) have been investigated systematically by IR and 1H NMR spectroscopy and density functional theory (DFT) calculations. Analysis of the IR spectra suggests that both DMCEAP and DMEOAP are composed of neutral and ionized species in the liquid phase, the former one mainly existing in the state of precursor molecules, and the latter mainly as ion-pairs. The ratio of precursor molecules to ion-pairs in the liquid phase depends on the types of precursors, especially the functional groups of cations. 1H NMR spectra indicate that there is a dynamic equilibrium between the neutral and ionized species, probably due to the formation of some intermediates in the PILs. The DFT calculations have been carried out to reveal the conformation, and obtain the corresponding IR and 1H NMR spectra of the neutral and ionized species, so that the theoretical support to the experimental results can be provided. The present study will help understand the properties of PILs and provide guidance for further applications of PILs.
研究领域:
物理化学
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离子液体化学
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光谱学
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理论化学
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分析化学
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材料化学
✓ 已验证
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2022
·Vol. 17
·期 5
·e2790
·
IF 1.777
Bingyi Zhou,Tao Ge,Xiaoman Luo,Zhaohui Wang,Yueyue Qiao,Chuanchuan Cai,Jingyao Xu
Under the two frequency microwave conditions of 915 and 2450 MHz, orthogonal tests were designed to investigate the effects of organic acid reagent, microwave irradiation time, and mixing time of additives and coal samples on the desulfurization effect of coal. Results show that the effect of irradiation time on the experimental desulfurization efficiency under frequency microwave conditions is large and is the main factor. The desulfurization effect under 915 MHz microwave condition is better than 2450 MHz microwave condition. Two sets of experimental optimal coal samples were used for characterization and analysis. Thermogravimetric analysis revealed that the combustion temperature range of the coal samples is shortened and the integrated combustion index is considerably higher after the microwave irradiation experiment. Fourier-transform infrared spectroscopy analysis showed that the overall chemical structure of the coal samples does not change significantly after the experimental treatment. X-ray photoelectron spectroscopy analysis showed that the intensity of organic sulfur in coal samples is weakened after microwave irradiation, the characteristic peaks of thiols and thioethers are reduced to a great extent, and an increase in the intensity of sulfoxide organic sulfur is observed. On the basis of the results of experimental analysis and quantum chemical simulation calculations, the mechanism of organosulfur structure removal under the action of microwave is revealed.
研究领域:
能源化学
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煤化学
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环境工程
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材料科学
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物理化学
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分析化学
·
清洁燃料技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）