共查询到20条相似文献,搜索用时 15 毫秒
1.
The ZnO films with two-dimensional ordered macroporous structure were successfully fabricated through hydrothermal crystal
growth of ZnO on the ZnO substrate covered with a monolayer of polystyrene (PS) spheres as template. The precursor solution
of hydrothermal crystal growth of ZnO were prepared by equimolar solution of Zn(NO3)2·6H2O and hexamethylenetramine (HMT). The confinement effect of the PS spheres template on the growth of ZnO nanorods and the
influence of sodium citrate on the crystal growth of ZnO had been studied. The film surface morphology and the preferential
growth of ZnO crystal were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Also,
the photoluminescence spectrum of ZnO films had been measured, and the corresponding mechanism was discussed.
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Translated from Chemistry, 2007, 70 (8): 587–592 [译自: 化学通报] 相似文献
2.
One kind of built-in silica adsorbent, which has high adsorption selectivity to rutin, was synthesized using molecular imprinting
technology by the following steps: synthesis of precursor from the reaction between water soluble rutin (as template molecule)
and the functional monomer chloropropyltriethoxysilane, co-hydrolysis of the precursor and tetraethoxysilane (TEOS), sol-gel
aging process, and removal of template molecules. The results of adsorption experiment show that this adsorbent has a high
adsorption capacity for rutin, and good adsorption selectivity towards rutin even under the interference of a flavone with
a similar structure. TEM photos suggest that nanocaves corresponding to rutin were formed inside the adsorbent while FTIR
spectra indicate that new bond was generated during the recognition process.
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Translated from Journal of Tianjin University, 2007, 40(4): 411–415 [译自: 天津大学学报] 相似文献
3.
A nano-alumina with high specific area was prepared using a homogeneous precipitation method with titanium dioxide and barium
oxide as modifying additives. Results showed that 5 wt% TiO2 or BaO added in the alumina gels can decrease the particle size and increase the specific area, but excessive TiO2 or BaO could deteriorate the properties of α-Al2O3.
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Translated from Journal of Shandong University of Technology (Natural Science Edition), 2007, 27(3): 23–26 [译自: 山东理工大学学报(自然科学版)] 相似文献
4.
Lingang Li Yu Tang Yuanming Zhang Jun Yang Biying Du 《Frontiers of Chemistry in China》2008,3(1):76-80
ZnS hollow nanospheres with holes were prepared by reacting ZnSO4 with H2S, the sulfide source formed in the reaction of CS2 with ethylenediamine, 1,3-propylenediamine, butylamine or 2-(2-aminoethylamino) ethanol, which also acted as a template agent,
at 50°C under agitation. The shape, particle size of about 100–850 nm and hole size of about 150–600 nm of ZnS hollow nanospheres
with holes were shown by SEM and TEM images. These ZnS nanospheres with β cubic ZnS phase and composed of 2–5 nm nanocrystals
were characterized by XRD and HRTEM. The blue shift of maximum absorption in UV-vis displayed the effect of quantum size.
The two amino groups of amine templates reacted favorably with Zn2+ to form uniform and relatively smooth ZnS nanospheres with holes, while hydroxyethyl played a disadvantageous role. A reasonable
mechanism of hole formation by H2S rushing out is suggested.
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Translated from Journal of Jinan University (Natural Science), 2007, 28(1): 92–95 [译自: 暨南大学学报(自然科学版)] 相似文献
5.
Huixue Ren Yanzhao Yang Jimao Lin Yinshan Qi Yeqing Zhang 《Frontiers of Chemistry in China》2008,3(2):152-156
A new synthetic method for 5-bromo-3-sec-butyl-6-methyluracil (Bromacil) using 2-bromobutane and urea as starting materials is described. The synthesis involved condensation,
cyclization and bromination with a total yield of 60%. The structure of Bromacil was determined by 1H NMR, 13C NMR and IR spectroscopy.
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Translated from Journal of Shandong University (Natural Science Edition), 2007, 42(7): 9–12 [译自: 山东大学学报(自然科学版)] 相似文献
6.
Kinetics of thermal decomposition of CeO2 nanocrystalline precursor prepared by precipitation method
Xiaolan Song Xi He Haiping Yang Dayu Xu Nan Jiang Guanzhou Qiu 《Frontiers of Chemistry in China》2008,3(2):182-185
The thermal decomposition of CeO2 nanocrystalline precursor prepared by chemical precipitation method was investigated using thermo-gravimetric/differential
scanning calorimetry (TG/DSC) and X-ray powder diffraction (XRD). In particular, the differential thermal analysis curves
for the decomposition of CeO2 nanocrystalline precursor were measured at different heating rates in air by a thermal analyzer (NETZSCH STA 449C, Germany).
The kinetic parameters of the thermal decomposition of CeO2 nanocrystalline precursor were calculated using the Kissinger method and the Coats-Redfern method. Results show that the
apparent active energy E of the reaction is 105.51 kJ/mol, the frequency factor lnA is 3.602 and the reaction order n is 2. This thermal decomposition process can be described by the anti-Jander equation and a three-dimensional diffusion mechanism.
Tanslated from Journal of Central South University (Science and Technology), 2007, 38(3): 428–432 [译自: 中南大学学报(自然科学版] 相似文献
7.
With the aim of improving the microstructures and properties of TiO2 pillared montmorillonite (MMT), a long-chain polymer (polyoxypropylenediamine, PPO-D 2000) was used as a template to synthesize
composite pillared MMT. The materials were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR)
spectrophotometer, Fourier Raman (FT-Raman) spectrophotometer, thermo-gravimeter/differential thermogravimeter (TG/DSC), transmission
electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) methods. The results show that as compared to low-molecular weight
surfactant, this polymer significantly expanded the interlayer spacing and thus more TiO2 could be intercalated into MMT. The specific surface area of polymer/TiO2 pillared MMT was increased by 13% with comparison to TiO2 pillared MMT and rose to 241.52 m2/g. Both the pore diameter and volume are doubled, and thus the pore structure is optimized markedly. The investigation on
the photo-catalytic degradation of methyl orange in aqueous solution show that the modulation of polymer molecules raise the
adsorption content of montmorillonite and improve the photo-catalytic activity. Therefore, this process provides a novel alternative
to design and prepare the advanced eco-catalytic materials with high adsorption capacity and photo-catalytic activity.
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Translated from Huaxue Tongbao, 2007, 12: 936–941 [译自: 化学通报] 相似文献
8.
Yingpin Li Xiaoquan Zhou Huijing Zhou Zhurui Shen Tiehong Chen 《Frontiers of Chemistry in China》2008,3(2):128-132
Manganese dioxides with various morphologies were prepared using a common hydrothermalmethod without any templates or additives.
The evolution of the morphology was accompanied by the gradual conversion of the polymorphic forms from γ-type to β-type. Meanwhile, MnO2 microspheres, urchin-like nanostructures and nanowires were successfully synthesized. The products were characterized by
X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscope. The
evolution process can be explained by the Ostwald Ripening mechanism.
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Translated from Chinese Journal of Chinese Universities 28(7): 1223–1226 [译自: 高等学校化学学报] 相似文献
9.
CdS semiconductor nano-films were grown on ITO glass substrates by means of chemical bath deposition (CBD), with Cd(NO3)2 as Cd ion and (NH2)2CS as S ion sources. The concentration of Cd ions, deposition temperature, deposition time and post-treatment temperature
have an impact on the formation of CdS nano-films. UV-vis absorption spectrum and atomic force microscope (AFM) images indicated
that the change of concentration and post-treatment temperature may adjust the band-gap of CdS to obtain stable, homogeneous
and compact films. Formation mechanism of the crystal nucleus and CdS film was also discussed. Active sites on the surface
of ITO are critical to the formation of the crystal nucleus and a uniform and compact CdS nano-film. The active site and crystal
nucleus are formed due to the comprehensive effect of electricity, thermodynamics and chemistry.
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Translated from Journal of Jilin University (Science Edition), 2007, 45(1): 116–120 [译自: 吉林大学学报(自然科学版)] 相似文献
10.
Guangjun Xu Wen Gu Xiaofang Ma Li Feng Shiping Yan Daizheng Liao Peng Cheng 《Frontiers of Chemistry in China》2008,3(2):138-142
The interaction between CT-DNA and a ternary copper (II) complex, [Cu(phendio)(L-Phe)(H2O)](ClO4)·H2O (CuPP, phendio = 1,10-phenanthroline-5,6-dione, L-Phe = L-phenylalanine), has been conducted by electronic spectra, fluorescence
spectroscopy and cyclic voltammetry. It has been found that the max. absorption peak from the electronic spectra is red shifted
and the intensity is weakened and that the values of peak current from cyclic voltammetry are decreased significantly in the
presence of DNA compared with that in the absence of DNA. At the same time, the complex can quench the emission intensity
of EB-DNA system. The existence of the intercalation mode between the complex and DNA was proven. By submarine gel electrophoresis,
we found that the copper(II) complex can cleave circular plasmid pBR322 DNA into nicked and linear forms in the presence of
ascorbic acid and H2O2.
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Translated from Acta Scientiarum Naturalium Universitatis Nankaiensis, 2007, 40(1): 32–36 [译自: 南开大学学报(自然科学版)] 相似文献
11.
Bitao Su Ke Wang Jie Bai Hongmei Mu Yongchun Tong Shixiong Min Shixiong She Ziqiang Lei 《Frontiers of Chemistry in China》2007,2(4):364-368
Fe3+-doped TiO2 composite nanoparticles with different doping amounts were successfully synthesized using sol-gel method and characterized
by X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultravioletvisible spectroscopy (UV-Vis) diffuse reflectance
spectra (DRS). The photocatalytic degradation of methylene blue was used as a model reaction to evaluate the photocatalytic
activity of Fe3+/TiO2 nanoparticles under visible light irradiation. The influence of doping amount of Fe3+ (ω: 0.00%–3.00%) on photocatalytic activities of TiO2 was investigated. Results show that the size of Fe3+/TiO2 particles decreases with the increase of the amount of Fe3+ and their absorption spectra are broaden and absorption intensities are also increased. Doping Fe3+ can control the conversion of TiO2 from anatase to rutile. The doping amount of Fe3+ remarkably affects the activity of the catalyst, and the optimum efficiency occurs at about the doping amount of 0.3%. The
appropriate doping of Fe3+ can markedly increase the catalytic activity of TiO2 under visible light irradiation.
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Translated from Journal of Northwest Normal University (Natural Science), 2006, 42(6): 55–56 [译自: 西北师范大学学报(自然科学版)] 相似文献
12.
Chun Yang Gongfeng Xu Bin Liu Qinglun Wang Daizheng Liao 《Frontiers of Chemistry in China》2008,3(3):294-297
The bimetallic complex of Ni2Co(TTHA)·12H2O (TTHA = triethylene tetraminehexaacetic acid) was synthesized and characterized structurally and magnetically. The title
complex crystallizes in the triclinic space group P ī with a = 0.7316(2), b = 0.8624(2), c = 1.5041(4) nm; α = 73.38(2), β = 83.97(2), γ = 70.50(2)°. The crystal structure is built up of [Ni2(TTHA)(H2O)2]2−, Co(H2O)62+ and water molecules. The variable magnetic measurement shows that there is strong antiferromagnetic interaction between two
Ni(II) ions in [Ni2(TTHA) (H2O)2]2− with J
Ni−Ni = −141.64 cm−1, g
Ni = 2.21 and that the constant of spin-orbit coupling of Co(II) ion is −134.8 cm−1.
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Translated from Acta Scientiarum Naturalium Universitatis Nankaiensis, 2007, 40(1): 6–10 [译自: 南开大学学报(自然科学版)] 相似文献
13.
Sr2CeO4/Ln3+ (Ln = Er, Ho, Tm) phosphors were synthesized with the microwave radiation method for the first time. The luminescent properties
of the samples were investigated and the up-conversion luminescence of Er3+, Ho3+ and Tm3+ doped Sr2CeO4 phosphors was observed. The spectra indicate that the energy transfer takes place from the triplet excited state of MLCT
(metal-to-ligand charge transfer) state for Sr2CeO4 (sensitizer) to the rare earth ions (activator).
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Translated from Journal of Hebei Normal University (Natural Science Edition), 2007, 31(2): 212–216 [译自: 河北师范大学学报 (自然科学版)] 相似文献
14.
Xiao Yang Youyuan Huang Henghui Zhou Jitao Chen Xinxiang Zhang 《Frontiers of Chemistry in China》2008,3(1):64-69
LiCo0.2Ni0.4Mn0.4O2, as the cathode material for lithium ion batteries, was modified by TiO2-coating. The effect of TiO2-coating on the structure and electrochemical performance of LiCo0.2Ni0.4Mn0.4O2 was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS),
and galvanostatic charge-discharge tests. The results suggest that a small amount of TiO2-coating does not change the crystalline structure, but considerably improves the electrochemical performance of LiCo0.2Ni0.4Mn0.4O2 in terms of capacity delivery and cyclability. XPS measurements confirm that the improved electrochemical performance is
most possibly attributed to a decrease in interaction between the layered material and non-aqueous electrolyte during the
charge-discharge processes.
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Translated from Chinese Journal of Inorganic Chemistry, 2007, 23(5): 753–758 [译自: 无机化学学报] 相似文献
15.
A novel compound of butyl crystal violet lactone (BCVL) has been prepared by oxidizing leuco butyl crystal violet lactone
(LBCVL), which was obtained by the mixture of N,N-dibutylaniline, p-(dibutylamino) benzaldehyde and methyl-m-(dibutylamino) benzoate. The structure of BCVL was characterized by 1H-nuclear magnetic resonance (NMR), infrared (IR), and mass spectrometry (MS). The color of BCVL can change reversibly in
some acid or alkali solvents. The result of the dissolution experiment showed that solubility of BCVL in organic solvent was
improved compared with crystal violet lactone (CVL).
Translated from Journal of Fudan University (Natural Science), 2006, 45(3): 375–379 [译自: 复旦学报(自然科学版)] 相似文献
16.
Haihong Fang Binyuan Hu Lingshen Wang Rongli Lu Cui Yang 《Frontiers of Chemistry in China》2008,3(2):193-197
Nanometer MgO was prepared via a sol-gel auto-combustion technique using magnesium nitrate as raw material and citric acid
as chelating agent. IR spectra of the dried gel were used to investigate the structure of the precursors. By studying the
different TG curves of magnesium citrate gel prepared by different methods, we found that a combustion process occurred and
the nitrate ions acted as an oxidant in the combustion process. TEM photographs of synthesized powders from the sol-gel auto-combustion
showed that the crystallites were uniform in size. In addition, the XRD pattern of this sample showed that the particle size
was 8.9 nm. The BET curves, in turn, showed that the specific surface of the sample was 26.34 m2/g. The mechanism of the frothing process in restraining agglomeration is discussed.
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Translated from Journal of East China Normal University (Natural Science), 2007, (2): 52–57 [译自: 华东师范大学学报(自然科学版)] 相似文献
17.
Controlled/living photopolymerization of methyl methacrylate (MMA) in miniemulsion mediated by 4-hydroxy-2,2,6,6-tetramethyl-piperidinyloxy
(HTEMPO) was carried out at ambient temperatures. MMA miniemulsion was prepared by using an anionic surfactant with cetylalcohol
as a co-stabilizer. The photopolymerization led to stable lattices and they were obtained with no coagulation during synthesis
and no destabilization over time. It was found that the obtained MMA homopolymers exhibited relatively narrow molecular weight
distribution (PDI = 1.27 − 1.36) which was characterized by GPC. The plots of number-average molecular weight in (M
n) vs. conversion and ln([M0]/[M]) vs. time both were linear indicating that the reaction was a controlled/living free radical polymerization.
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Translated from Chemical Journal of Chinese Universities, 2007, 28(4): 774–778 [译自: 高等学校化学学报] 相似文献
18.
The rare earth Schiff base complex Nd (H2Salen)2Cl3·2C2H5OH was synthesized by a simple and convenient method and characterized by IR and elemental analysis. The catalyst system composed
of Nd (H2Salen)2Cl3·2C2H5OH/Al(i-Bu)3/CCl4 is effective for the polymerization of styrene (St). The optimum conditions are as follows: [St]/[Nd] = 1000, [CCl4]/[Nd] = 9, [Al]/[Nd] = 30, and polymerization at 50°C for 20 h. The resulting polystyrene was characterized by NMR and GPC.
The results of NMR show that the polymer obtained had a stereoregularity with 52.3% isotacticity and 47.7% syndiotacticity
without any random structure.
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Translated from Journal of Zhejiang University (Science Edition), 2007, 34(2): 189–196 [译自: 浙江大学学报(理学版)] 相似文献
19.
Xiaolei Zhang Mingwang Pan Shengnan Xing Jingsheng Li 《Frontiers of Chemistry in China》2008,3(1):27-32
An ionomer-type of polyurethane (PU) emulsion was prepared from toluene diisocyanate (TDI), polypropylene glycol (PPG) and
dimethylol propionic acid (DMPA) following a self-emulsification process. The modified poly(vinyl chloride) (PVC) emulsion
resin was obtained by in situ emulsion copolymerization using the PU as seeds in an autoclave. The effects of PU molecular
weight on the mechanical properties and thermal stability of the PU/PVC materials were investigated. The composite latex particles
and composite materials were determined and characterized using a laser particle size analyzer, transmission electron microscopy
or scanning electron microscopy. The study results showed that the PU/PVC hybrid emulsion particles possess a core/shell structure.
When the general mechanical properties of the composite materials increase, the thermal stabilities decrease a little. The
tough fractures on the surface of the PU/PVC composite sample following impact are quite obvious.
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Translated from Journal of Hebei Normal University (Natural Science Edition), 2007, 31(2): 228–232 [译自: 河北师范大学学报(自然科学版)] 相似文献
20.
ZrWMoO8 powders with different morphologies were obtained using ammonium tungstate, molybdate tungstate and zirconium tungstate as
the starting materials by dehydrating the precursor ZrWMoO7(OH)2(H2O)2. The precursor was studied by thermo-gravimetric and differential scanning calorimetry (TG-DSC). The influence of the gelling
agents (HCl, HClO4, HNO3, H2SO4 and H3PO4) on the crystallization process and crystal morphology of the products prepared was investigated by X-ray powder diffraction
(XRD), scanning electron micrograph (SEM) and X-ray fluorescence spectrometer (XRF). Results showed that the morphology of
the ZrWMoO8 particles can be simply adjusted by changing the gelling agents, and the thermal expansion coefficients of cubic ZrWMoO8 prepared in HCl solution are −3.84 × 10−6 K−1 from 100°C to 700°C.
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Translated from Chemical Journal of Chinese University, 2007, 28(3): 397–401 [译自: 高等学校化学学报] 相似文献