Login In
2017 Volume 34 Issue 10
2017, 34(10): 1099-1109
doi: 10.11944/j.issn.1000-0518.2017.10.170120
Abstract:
Tetrazole-1-acetic acids(Htza)as a class of organic ligands with good coordination abilities and various coordination fashions have gained rapid and extensive studies in coordination chemistry. This article reviewed the research advances on the synthesis and structure characterization of tetrazole-1-acetic acid coordinated metal complexes, and discussed the fluorescent, magnetic, and catalytic applications of tetrazole-1-acetic acid-based coordination polymers. Finally, research prospects of coordination polymers based on tetrazole-1-acetic acid derivatives were discussed.
Tetrazole-1-acetic acids(Htza)as a class of organic ligands with good coordination abilities and various coordination fashions have gained rapid and extensive studies in coordination chemistry. This article reviewed the research advances on the synthesis and structure characterization of tetrazole-1-acetic acid coordinated metal complexes, and discussed the fluorescent, magnetic, and catalytic applications of tetrazole-1-acetic acid-based coordination polymers. Finally, research prospects of coordination polymers based on tetrazole-1-acetic acid derivatives were discussed.
2017, 34(10): 1110-1116
doi: 10.11944/j.issn.1000-0518.2017.10.170231
Abstract:
Microcellular polyurethane elastomers were obtained by a two-step polymerization using 1, 4-phenylene diisocyanate(PPDI), 1, 4-butanediol(BDO), water, polyethylene tetrahydrofuran ether polyol(PTMEG) and hydrogenated hydroxyl-terminated butadiene polyols(HLBH) as raw materials. Fourier reflection infrared(FTIR-ATR), dynamic mechanical analysis(DMA), differential scanning calorimetry(DSC), universal material testing machine, dynamic fatigue testing machine were used to systematically characterize the microphase separation, low temperature resistance, dynamic heat build-up of the samples. The results show that the microcellular size of the specimens based on two polyols is 100~300 μm wherein the 150 μm is the majority, indicating that the structure of polyols has little influence on the microcellular size. Due to more H-bonds between hard segments, HLBH-based microcellular polyurethane elastomers show better microphase separation than that of PTMEG. There is a wide modulus platform region at -30~150℃ in the modulus-temperature curve for HLBH-based specimens due to its proper microphase separation structure. However, due to the crystallization of the soft segments at low temperature, the modulus of PTMEG-based specimens increases dramatically under 0℃. The stiffness of HLBH-based specimens surpasses that of PTMEG-based specimens at low temperature, and the hysteresis heat production of HLBH-based specimens is less than that of PTMEG-based specimens. Therefore, the former shows better dynamic fatigue performance.
Microcellular polyurethane elastomers were obtained by a two-step polymerization using 1, 4-phenylene diisocyanate(PPDI), 1, 4-butanediol(BDO), water, polyethylene tetrahydrofuran ether polyol(PTMEG) and hydrogenated hydroxyl-terminated butadiene polyols(HLBH) as raw materials. Fourier reflection infrared(FTIR-ATR), dynamic mechanical analysis(DMA), differential scanning calorimetry(DSC), universal material testing machine, dynamic fatigue testing machine were used to systematically characterize the microphase separation, low temperature resistance, dynamic heat build-up of the samples. The results show that the microcellular size of the specimens based on two polyols is 100~300 μm wherein the 150 μm is the majority, indicating that the structure of polyols has little influence on the microcellular size. Due to more H-bonds between hard segments, HLBH-based microcellular polyurethane elastomers show better microphase separation than that of PTMEG. There is a wide modulus platform region at -30~150℃ in the modulus-temperature curve for HLBH-based specimens due to its proper microphase separation structure. However, due to the crystallization of the soft segments at low temperature, the modulus of PTMEG-based specimens increases dramatically under 0℃. The stiffness of HLBH-based specimens surpasses that of PTMEG-based specimens at low temperature, and the hysteresis heat production of HLBH-based specimens is less than that of PTMEG-based specimens. Therefore, the former shows better dynamic fatigue performance.
2017, 34(10): 1117-1126
doi: 10.11944/j.issn.1000-0518.2017.10.170026
Abstract:
A novel monomer was designed and synthesized, in which the cyano groups were distributed on three benzene rings linked by meta ether linkages. Then using this monomer and 2, 5-dichloro-3'-sulfobenzophenone as raw materials, a series of novel micro-block copolymer proton exchange membranes(middle length-sulfonated polyphenylene-co-poly aryl ether ketone 3CN(m-SPP-co-PAEK 3CN x), x represents the ion exchange capacity of the polymer) was prepared by nickel(0) catalyzed coupling copolymerization. The experimental results show that these membranes exhibit low water uptake and swelling ratio as well as methanol permeability under similar ion exchange capacity. As the ion exchange capacity is equal to 2.16 and the temperature is 80℃, the water uptake and swelling ratio of m-SPP-co-PAEK 3CN 2.16 are 29.7% and 28.2%, respectively, while the water uptake and swelling ratio of SPP-co-PAEK MO 2.33 are 80.2% and 37.2%, respectively. At 25℃, the methanol permeability of the two membranes is 2.38 and 7.20, respectively. The good dimensional stability of the as-synthesized membrane can be attributed to the introduction of the polar-CN groups into the skeleton. With these properties, the prepared membranes are promising proton exchange membrane materials in fuel cell applications.
A novel monomer was designed and synthesized, in which the cyano groups were distributed on three benzene rings linked by meta ether linkages. Then using this monomer and 2, 5-dichloro-3'-sulfobenzophenone as raw materials, a series of novel micro-block copolymer proton exchange membranes(middle length-sulfonated polyphenylene-co-poly aryl ether ketone 3CN(m-SPP-co-PAEK 3CN x), x represents the ion exchange capacity of the polymer) was prepared by nickel(0) catalyzed coupling copolymerization. The experimental results show that these membranes exhibit low water uptake and swelling ratio as well as methanol permeability under similar ion exchange capacity. As the ion exchange capacity is equal to 2.16 and the temperature is 80℃, the water uptake and swelling ratio of m-SPP-co-PAEK 3CN 2.16 are 29.7% and 28.2%, respectively, while the water uptake and swelling ratio of SPP-co-PAEK MO 2.33 are 80.2% and 37.2%, respectively. At 25℃, the methanol permeability of the two membranes is 2.38 and 7.20, respectively. The good dimensional stability of the as-synthesized membrane can be attributed to the introduction of the polar-CN groups into the skeleton. With these properties, the prepared membranes are promising proton exchange membrane materials in fuel cell applications.
2017, 34(10): 1127-1133
doi: 10.11944/j.issn.1000-0518.2017.10.170049
Abstract:
To explore the application of cisplatin-loaded thermosensitive hydrogel in the treatment of the cervical cancer in mice, cisplatin-loaded poloxamer thermosensitive hydrogel was prepared and characterized. The mouse uterine cervical cancer cell line U14 was injected into submucosa nearby the cervix in female mice. Drug-loaded hydrogel was infused into the vagina of tumor-bearing mice and the inhibitory effect was evaluated. The results show that the tumor inhibition rate is as high as 63.1% by vaginal administration of cisplatin-loaded poloxamer hydrogel, which presents a new formulation for the local drug delivery via vagina against cervical cancer.
To explore the application of cisplatin-loaded thermosensitive hydrogel in the treatment of the cervical cancer in mice, cisplatin-loaded poloxamer thermosensitive hydrogel was prepared and characterized. The mouse uterine cervical cancer cell line U14 was injected into submucosa nearby the cervix in female mice. Drug-loaded hydrogel was infused into the vagina of tumor-bearing mice and the inhibitory effect was evaluated. The results show that the tumor inhibition rate is as high as 63.1% by vaginal administration of cisplatin-loaded poloxamer hydrogel, which presents a new formulation for the local drug delivery via vagina against cervical cancer.
2017, 34(10): 1134-1139
doi: 10.11944/j.issn.1000-0518.2017.10.160513
Abstract:
Alkynyl selenides are important starting materials for the synthesis of some organic selenides. In this paper, alkynyl selenides were synthesized by the reaction between terminal alkynes and diaryl diselenides catalyzed by gold tribromide(AuBr3) in the presence of a base such as potassium carbonate in good to excellent yields(69%~98%). The reaction was performed at 80℃ in air, and all the selenium atoms of diaryl diselenides could be taken into use. Dimethyl sulfoxide is a proper solvent. The reaction does not occur when less polar tetrahydrofuran or toluene is used as the solvent. Aryl, alkenyl and alkyl alkynes can smoothly react with diaryl diselenides under the above conditions. Para-substituted phenylacetylene(such as 4-ethynyltoluene, 1-ethynyl-4-methoxybenzene, 4-fluorophenylacetylene, 4-chlorophenylacetylene, etc.) gives rise to alkynyl selenides in good to excellent yields(78%~98%) whether the substituents are electron-donating or -withdrawing. Ortho-and meta-substituted phenylacetylene leads to relatively low yields(69%~82%). Non-aryl alkynes(such as 1-nonyne and 1-ethynylcyclohexene) also afford corresponding alkynyl selenides with high yields(95%).
Alkynyl selenides are important starting materials for the synthesis of some organic selenides. In this paper, alkynyl selenides were synthesized by the reaction between terminal alkynes and diaryl diselenides catalyzed by gold tribromide(AuBr3) in the presence of a base such as potassium carbonate in good to excellent yields(69%~98%). The reaction was performed at 80℃ in air, and all the selenium atoms of diaryl diselenides could be taken into use. Dimethyl sulfoxide is a proper solvent. The reaction does not occur when less polar tetrahydrofuran or toluene is used as the solvent. Aryl, alkenyl and alkyl alkynes can smoothly react with diaryl diselenides under the above conditions. Para-substituted phenylacetylene(such as 4-ethynyltoluene, 1-ethynyl-4-methoxybenzene, 4-fluorophenylacetylene, 4-chlorophenylacetylene, etc.) gives rise to alkynyl selenides in good to excellent yields(78%~98%) whether the substituents are electron-donating or -withdrawing. Ortho-and meta-substituted phenylacetylene leads to relatively low yields(69%~82%). Non-aryl alkynes(such as 1-nonyne and 1-ethynylcyclohexene) also afford corresponding alkynyl selenides with high yields(95%).
2017, 34(10): 1140-1149
doi: 10.11944/j.issn.1000-0518.2017.10.160494
Abstract:
Three geranylated flavanones isolated from the bark of Paulownia tomentosa were synthesized from phloroacetophenone and substituted hydroxybenzaldehydes via substitution, protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection reactions. Their structures were confirmed by proton and carbon(1H and 13C) nuclear magnetic resonance(NMR) and high resolution mass spectrometry(HRMS). The inhibition assay of these flavanones against A459 cell by methyl thiazolyl tetrazolium(MTT) protocol, indicates that compound 2 exihibits the highest activity with an half maximal inhibitory concentration(IC50) value at 25.6 μmol/L. This study provides a suggestion for drug development based on geranylated flavanone scaffold.
Three geranylated flavanones isolated from the bark of Paulownia tomentosa were synthesized from phloroacetophenone and substituted hydroxybenzaldehydes via substitution, protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection reactions. Their structures were confirmed by proton and carbon(1H and 13C) nuclear magnetic resonance(NMR) and high resolution mass spectrometry(HRMS). The inhibition assay of these flavanones against A459 cell by methyl thiazolyl tetrazolium(MTT) protocol, indicates that compound 2 exihibits the highest activity with an half maximal inhibitory concentration(IC50) value at 25.6 μmol/L. This study provides a suggestion for drug development based on geranylated flavanone scaffold.
2017, 34(10): 1150-1160
doi: 10.11944/j.issn.1000-0518.2017.10.160473
Abstract:
L-Histidine has excellent affinity for biological organism. Its derivatives by structural modification may possess high pharmacological activity and bio-availability. In this work, two L-histidineamide derivatives were designed and synthesized by the reaction of L-histidine with trans-cinnamic acid and p-methoxycinnamic acid. Their structures were characterized by infrared, mass spectrometry, and nuclear magnetic resonance. The interaction mechanism of derivatives and human serum albumin(HSA) was investigated by molecular operating environment(MOE) molecular docking, fluorescence spectroscopy, synchronous fluorescence spectroscopy(SFS) and ultraviolet-visible(UV-Vis) absorption spectroscopy. The results of MOE molecular docking shows that the two derivatives exist in the hydrophobic pocket of subdomain ⅡA(site Ⅰ) of HSA under the action of van der Waals force and hydrophobic effect, with the simulation binding energy are -13.82 and -16.25 kcal/mol, respectively. The fluorescence quenching results show that the derivatives can interact with HSA and form new ground-state complexes and the fluorescence quenching process is a static quenching procedure. The binding of HSA to derivatives driven by van der Waals force was found from the thermodynamic parameters, and the binding equilibrium constants at different temperatures(300 K, 305 K, and 310 K) are 1.773×104, 6.354×103, 1.260×103, 5.314×104, 4.614×103, 1.420×103, respectively. The SFS characterization shows that the secondary structure of HSA has been changed by derivatives. Combining the results of UV-Vis spectra, it is obviously that under physiological conditions in vitro, the interaction between derivatives with HSA produces static quenching and conformational effects to the internal fluorescence of HSA through van der Waals force, which is consistent with the prediction of molecular docking, thus providing a reference for the further development of histidine amide derivatives research.
L-Histidine has excellent affinity for biological organism. Its derivatives by structural modification may possess high pharmacological activity and bio-availability. In this work, two L-histidineamide derivatives were designed and synthesized by the reaction of L-histidine with trans-cinnamic acid and p-methoxycinnamic acid. Their structures were characterized by infrared, mass spectrometry, and nuclear magnetic resonance. The interaction mechanism of derivatives and human serum albumin(HSA) was investigated by molecular operating environment(MOE) molecular docking, fluorescence spectroscopy, synchronous fluorescence spectroscopy(SFS) and ultraviolet-visible(UV-Vis) absorption spectroscopy. The results of MOE molecular docking shows that the two derivatives exist in the hydrophobic pocket of subdomain ⅡA(site Ⅰ) of HSA under the action of van der Waals force and hydrophobic effect, with the simulation binding energy are -13.82 and -16.25 kcal/mol, respectively. The fluorescence quenching results show that the derivatives can interact with HSA and form new ground-state complexes and the fluorescence quenching process is a static quenching procedure. The binding of HSA to derivatives driven by van der Waals force was found from the thermodynamic parameters, and the binding equilibrium constants at different temperatures(300 K, 305 K, and 310 K) are 1.773×104, 6.354×103, 1.260×103, 5.314×104, 4.614×103, 1.420×103, respectively. The SFS characterization shows that the secondary structure of HSA has been changed by derivatives. Combining the results of UV-Vis spectra, it is obviously that under physiological conditions in vitro, the interaction between derivatives with HSA produces static quenching and conformational effects to the internal fluorescence of HSA through van der Waals force, which is consistent with the prediction of molecular docking, thus providing a reference for the further development of histidine amide derivatives research.
2017, 34(10): 1161-1171
doi: 10.11944/j.issn.1000-0518.2017.10.170163
Abstract:
In order to explore efficient, low toxic and eco-friendly fungicides, a series of 1, 2, 4-triazole and thiadiazole derivatives containing benzenesulfonamide moieties was designed and synthesized. Their chemical structures were confirmed by nuclear magnetic resonance spectroscopy(NMR), mass spectrometry and elemental analysis. Preliminary fungicidal bioassay in vitro was carried out against seven plant pathogenic fungi and the results showed that compounds 10 exhibited moderate fungicidal activities, especially 10a, 10g and 10n demonstrated similar high inhibition rate against Fusarium moniliforme in comparison with commercial Azoxystrobin.
In order to explore efficient, low toxic and eco-friendly fungicides, a series of 1, 2, 4-triazole and thiadiazole derivatives containing benzenesulfonamide moieties was designed and synthesized. Their chemical structures were confirmed by nuclear magnetic resonance spectroscopy(NMR), mass spectrometry and elemental analysis. Preliminary fungicidal bioassay in vitro was carried out against seven plant pathogenic fungi and the results showed that compounds 10 exhibited moderate fungicidal activities, especially 10a, 10g and 10n demonstrated similar high inhibition rate against Fusarium moniliforme in comparison with commercial Azoxystrobin.
2017, 34(10): 1172-1176
doi: 10.11944/j.issn.1000-0518.2017.10.170124
Abstract:
Pyrazinedimethylformamide bridged apigenin copper(Ⅱ) complex was prepared by solvothermal method with 5, 6-dimethyl-2, 3-pyrazinedimethylformamide and apigenin as mixed ligands and copper(Ⅱ) acetate. The complex was characterized by ultra-violet and infrared spectroscopies, and thermogravimetric analysis. The DNA cleavage behavior of pyrazinedimethylformamide bridged apigenin copper(Ⅱ) complex has been investigated by agarose gel electrophoresis. The results suggest that the complex can promote the cleavage of pBR322 DNA in the absence of any reducing reagent.
Pyrazinedimethylformamide bridged apigenin copper(Ⅱ) complex was prepared by solvothermal method with 5, 6-dimethyl-2, 3-pyrazinedimethylformamide and apigenin as mixed ligands and copper(Ⅱ) acetate. The complex was characterized by ultra-violet and infrared spectroscopies, and thermogravimetric analysis. The DNA cleavage behavior of pyrazinedimethylformamide bridged apigenin copper(Ⅱ) complex has been investigated by agarose gel electrophoresis. The results suggest that the complex can promote the cleavage of pBR322 DNA in the absence of any reducing reagent.
2017, 34(10): 1177-1185
doi: 10.11944/j.issn.1000-0518.2017.10.170149
Abstract:
Thorium dioxide(ThO2), a kind of actinide metal oxides, has good performance as adsorbent, but it is necessary to extend their application scope. In the present work, we investigated the adsorption property of ThO2 nanospheres prepared by hydrothermal method in the aqueous solution of ammonium uranyl tricarbonate. In the presence of 2 mmol/L NH4HCO3 and 20 mmol/L tris(hydroxymethyl)aminomethane)-HCl, ThO2 nanospheres had an adsorption capacity of 6.52 mg/g when the initial concentration of uranium was 20 mg/L, which followed pseudo-second-order kinetic model well. In isothermal adsorption studies, Freundlich model was preferable. The desorption of ThO2 nanospheres after adsorption was achieved easily by using dilute HCl solution. In the mechanism research, it was found that ThO2 nanospheres have negative charges under the experiment conditions and adsorb UO22+ via cation adsorption mechanism. However, the uranium uptake was seriously affected by other cations, such as Ca2+, Cu2+ and Ni2+. This work will contribute to the recovery of uranium from seawater and alkaline/neutral radioactive waste by metal oxides.
Thorium dioxide(ThO2), a kind of actinide metal oxides, has good performance as adsorbent, but it is necessary to extend their application scope. In the present work, we investigated the adsorption property of ThO2 nanospheres prepared by hydrothermal method in the aqueous solution of ammonium uranyl tricarbonate. In the presence of 2 mmol/L NH4HCO3 and 20 mmol/L tris(hydroxymethyl)aminomethane)-HCl, ThO2 nanospheres had an adsorption capacity of 6.52 mg/g when the initial concentration of uranium was 20 mg/L, which followed pseudo-second-order kinetic model well. In isothermal adsorption studies, Freundlich model was preferable. The desorption of ThO2 nanospheres after adsorption was achieved easily by using dilute HCl solution. In the mechanism research, it was found that ThO2 nanospheres have negative charges under the experiment conditions and adsorb UO22+ via cation adsorption mechanism. However, the uranium uptake was seriously affected by other cations, such as Ca2+, Cu2+ and Ni2+. This work will contribute to the recovery of uranium from seawater and alkaline/neutral radioactive waste by metal oxides.
2017, 34(10): 1186-1194
doi: 10.11944/j.issn.1000-0518.2017.10.160495
Abstract:
A series of Dy3+ and/or Eu3+ doped Ba3Y(PO4)3 phosphors was prepared via a traditional high temperature solid state reaction to investigate how the luminescent properties of Dy3+ doped Ba3Y(PO4)3 phosphor can be tuned by co-doping Eu3+ ions into the host lattice. X-ray diffraction(XRD), photoluminescence and fluorescence lifetime were used to characterize the as-prepared samples. The results show that all the samples have Ba3Y(PO4)3 eulytite cubic structure. Under the excitation of near-UV light, the Ba3Y(PO4)3:Dy3+ phosphor shows cool-white emission and the Ba3Y(PO4)3:Eu3+ phosphor presents an orange-red emission. For Ba3Y(PO4)3:Dy3+, Eu3+ phosphor, warm-white emission with high color rendering index and appropriate correlated color temperature has been obtained by combining red emission of Eu3+with cool-white emission of Dy3+. The luminescence mechanism of Ba3Y(PO4)3:Dy3+, Eu3+ phosphor has been tentatively proposed and the prepared Ba3Y(PO4)3:Dy3+, Eu3+ phosphor has potential application in white-light-emitting-diodes(WLEDs) filed.
A series of Dy3+ and/or Eu3+ doped Ba3Y(PO4)3 phosphors was prepared via a traditional high temperature solid state reaction to investigate how the luminescent properties of Dy3+ doped Ba3Y(PO4)3 phosphor can be tuned by co-doping Eu3+ ions into the host lattice. X-ray diffraction(XRD), photoluminescence and fluorescence lifetime were used to characterize the as-prepared samples. The results show that all the samples have Ba3Y(PO4)3 eulytite cubic structure. Under the excitation of near-UV light, the Ba3Y(PO4)3:Dy3+ phosphor shows cool-white emission and the Ba3Y(PO4)3:Eu3+ phosphor presents an orange-red emission. For Ba3Y(PO4)3:Dy3+, Eu3+ phosphor, warm-white emission with high color rendering index and appropriate correlated color temperature has been obtained by combining red emission of Eu3+with cool-white emission of Dy3+. The luminescence mechanism of Ba3Y(PO4)3:Dy3+, Eu3+ phosphor has been tentatively proposed and the prepared Ba3Y(PO4)3:Dy3+, Eu3+ phosphor has potential application in white-light-emitting-diodes(WLEDs) filed.
2017, 34(10): 1195-1201
doi: 10.11944/j.issn.1000-0518.2017.10.160504
Abstract:
Potassium magnesium titanate with excellent mechanical properties is widely used as friction materials of various advanced brake pads. The influence of composition and morphology on braking effect is very large, but the traditional synthesis method can not effectively control it. In this paper, we successfully obtained the potassium magnesium titanate with excellent crystallinity and morphology by controlling the calcination process. Platy potassium magnesium titanate(KMTO) was synthesized by molten salt method with KCl as the molten salt and Mg(OH)2, K2CO3 and TiO2 as raw materials. The effect of calcination process(heating rate, calcination temperature and holding time) on phase composition and morphology of obtained KMTO were analyzed by X-ray diffraction and scanning electron microscopy. The mechanism of this reaction was explored preliminarily. Calcination process was found to significantly affect the composition and morphology of KMTO synthesized by molten salt method. When raw materials are calcined at 1000℃ for 2 h by heating rate at 200℃/h( > 800℃) and 100℃/h( > 800℃), platy K0.8Mg0.4Ti1.6O4 with high crystallinity and uniform morphology is obtained after washing and drying.
Potassium magnesium titanate with excellent mechanical properties is widely used as friction materials of various advanced brake pads. The influence of composition and morphology on braking effect is very large, but the traditional synthesis method can not effectively control it. In this paper, we successfully obtained the potassium magnesium titanate with excellent crystallinity and morphology by controlling the calcination process. Platy potassium magnesium titanate(KMTO) was synthesized by molten salt method with KCl as the molten salt and Mg(OH)2, K2CO3 and TiO2 as raw materials. The effect of calcination process(heating rate, calcination temperature and holding time) on phase composition and morphology of obtained KMTO were analyzed by X-ray diffraction and scanning electron microscopy. The mechanism of this reaction was explored preliminarily. Calcination process was found to significantly affect the composition and morphology of KMTO synthesized by molten salt method. When raw materials are calcined at 1000℃ for 2 h by heating rate at 200℃/h( > 800℃) and 100℃/h( > 800℃), platy K0.8Mg0.4Ti1.6O4 with high crystallinity and uniform morphology is obtained after washing and drying.
2017, 34(10): 1202-1208
doi: 10.11944/j.issn.1000-0518.2017.10.160500
Abstract:
There are debates on the influence of pressures on chemical processes of crude oil in reservoirs. To investigate the effect of pressure on the pyrolysis of crude oil into gas in the reservoir, the compositions and contents of the gas products produced by pyrolysis reactions of four components separated from the Tarim crude oil and that of liquid products from saturates of Tarim crude oil under 450℃ and 5~40 MPa were analyzed by gas chromatography(GC) and GC mass spectrometry GC/MS, respectively. The results show that more gas is obtained in pyrolysis of asphaltene than resins, aromatics and saturates. The amount of C1 in hydrocarbon gases generated by pyrolysis of the four-components is significantly higher than that of C2~C5 components. Increasing pressure decreases the yield of hydrocarbon gas generation in the pyrolysis process of asphaltene, resin and aromatics, but promotes the production of hydrocarbon gas in saturates pyrolysis. The liquid pyrolysis products transform to hydrocarbon compounds of low carbon numbers then to high carbon numbers with the pressure increase. The pyrolysis process is dominated by thermal cracking of the components in saturates under pressures less than 20 MPa. The study provides the theoretical reference for the crude oil stability and the natural gas formation in deep reservoirs.
There are debates on the influence of pressures on chemical processes of crude oil in reservoirs. To investigate the effect of pressure on the pyrolysis of crude oil into gas in the reservoir, the compositions and contents of the gas products produced by pyrolysis reactions of four components separated from the Tarim crude oil and that of liquid products from saturates of Tarim crude oil under 450℃ and 5~40 MPa were analyzed by gas chromatography(GC) and GC mass spectrometry GC/MS, respectively. The results show that more gas is obtained in pyrolysis of asphaltene than resins, aromatics and saturates. The amount of C1 in hydrocarbon gases generated by pyrolysis of the four-components is significantly higher than that of C2~C5 components. Increasing pressure decreases the yield of hydrocarbon gas generation in the pyrolysis process of asphaltene, resin and aromatics, but promotes the production of hydrocarbon gas in saturates pyrolysis. The liquid pyrolysis products transform to hydrocarbon compounds of low carbon numbers then to high carbon numbers with the pressure increase. The pyrolysis process is dominated by thermal cracking of the components in saturates under pressures less than 20 MPa. The study provides the theoretical reference for the crude oil stability and the natural gas formation in deep reservoirs.
2017, 34(10): 1209-1220
doi: 10.11944/j.issn.1000-0518.2017.10.160501
Abstract:
A series of {Reduced graphene oxide/Polyoxometalates}n({rGO/POMs }n) multilayer composite films was prepared by layer by layer assembly(LBL) combined with the light-assisted reduction in situ. The {rGO/POMs }n film was used as a carrier to support Pt nanoparticles electrodeposited by constant potential method to obtain a new type of fuel cell anode catalyst, namely Pt/{rGO/SiW12}6 multilayer composite film. The growth of the multilayer composite films and Pt nanoclusters' morphology were characterized by UV-visible absorption spectrum(UV-Vis), atomic force microscope(AFM) and scanning elecrton microscopy(SEM). The results indicate that the multilayer composite {rGO/SiW12}6 is assembled on different substrate(quartz plate, indium tin oxide(ITO), and glass carbon electrode(GC)) surfaces with a continuous and uniform state, and the Pt nanoparticles on the surface exhibit a flower-like morphology. The electrochemical experiments show that Pt/{rGO/SiW12}6 catalyst exhibits better electrocatalytic activity, electrochemical stability and superior resistance to CO poisoning in the acidic methanol solution when it is compared with Pt/{rGO/PMo12}6, Pt/{rGO/PW12}6 and Pt. The Pt/{rGO/SiW12}6 multilayer composite film is expected to be the most promising methanol oxidation reaction catalyst in fuel cell anode.
A series of {Reduced graphene oxide/Polyoxometalates}n({rGO/POMs }n) multilayer composite films was prepared by layer by layer assembly(LBL) combined with the light-assisted reduction in situ. The {rGO/POMs }n film was used as a carrier to support Pt nanoparticles electrodeposited by constant potential method to obtain a new type of fuel cell anode catalyst, namely Pt/{rGO/SiW12}6 multilayer composite film. The growth of the multilayer composite films and Pt nanoclusters' morphology were characterized by UV-visible absorption spectrum(UV-Vis), atomic force microscope(AFM) and scanning elecrton microscopy(SEM). The results indicate that the multilayer composite {rGO/SiW12}6 is assembled on different substrate(quartz plate, indium tin oxide(ITO), and glass carbon electrode(GC)) surfaces with a continuous and uniform state, and the Pt nanoparticles on the surface exhibit a flower-like morphology. The electrochemical experiments show that Pt/{rGO/SiW12}6 catalyst exhibits better electrocatalytic activity, electrochemical stability and superior resistance to CO poisoning in the acidic methanol solution when it is compared with Pt/{rGO/PMo12}6, Pt/{rGO/PW12}6 and Pt. The Pt/{rGO/SiW12}6 multilayer composite film is expected to be the most promising methanol oxidation reaction catalyst in fuel cell anode.
