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2016 Volume 79 Issue 1
2016, 79(1): 4-8
Abstract:
The structure of the catalytic center for water-splitting reaction in natural photosynthesis has been revealed recently, which provides a blueprint for the development of artificial water-splitting catalyst in artificial photosynthesis. Mimicking the natural catalyst to prepare efficient and low-cost artificial catalysts and produce electric energy and/or hydrogen energy by using sun light and water has been considered to be an ideal way to solve the energy crisis and environmental pollution of our society. This field is a well-known major scientific frontier and may be crucial for both fundamental scientific research and potential application. Here, recent advance of the water-splitting catalyst in natural and artificial photosynthesis was reviewed.
The structure of the catalytic center for water-splitting reaction in natural photosynthesis has been revealed recently, which provides a blueprint for the development of artificial water-splitting catalyst in artificial photosynthesis. Mimicking the natural catalyst to prepare efficient and low-cost artificial catalysts and produce electric energy and/or hydrogen energy by using sun light and water has been considered to be an ideal way to solve the energy crisis and environmental pollution of our society. This field is a well-known major scientific frontier and may be crucial for both fundamental scientific research and potential application. Here, recent advance of the water-splitting catalyst in natural and artificial photosynthesis was reviewed.
2016, 79(1): 9-15
Abstract:
To achieve proton exchange membrane fuel cell long-life high-performance (high power density or high current density) power generation at low cost (low platinum loading), gradient design is introduced into fabrication of MEA. Gradient MEA includes gradient of each MEA assembly:gradient PTFE content and porosity of gas diffusion layer, gradient content of catalyst and Nafion in catalyst layer, and gradient hydrophobicity and porosity of micro-porous layer. Gradient MEA has reasonable distribution of catalyst, porosity and hydrophilicity/hydrophobicity, together with good three phase boundary and multiphase mass transmission channels (e.g. proton,electron,reactant gas and water transmission channels), thus achieving stable high performance of PEMFC at circumstance of low Pt loading, low humidity and high current density. Manufacturing methods, performance and structure-activity relationship of gradient MEA are reviwed in this paper based on the latest research literatures and patents,which has guiding significance for developing of low cost, long-life and high performance MEA.
To achieve proton exchange membrane fuel cell long-life high-performance (high power density or high current density) power generation at low cost (low platinum loading), gradient design is introduced into fabrication of MEA. Gradient MEA includes gradient of each MEA assembly:gradient PTFE content and porosity of gas diffusion layer, gradient content of catalyst and Nafion in catalyst layer, and gradient hydrophobicity and porosity of micro-porous layer. Gradient MEA has reasonable distribution of catalyst, porosity and hydrophilicity/hydrophobicity, together with good three phase boundary and multiphase mass transmission channels (e.g. proton,electron,reactant gas and water transmission channels), thus achieving stable high performance of PEMFC at circumstance of low Pt loading, low humidity and high current density. Manufacturing methods, performance and structure-activity relationship of gradient MEA are reviwed in this paper based on the latest research literatures and patents,which has guiding significance for developing of low cost, long-life and high performance MEA.
2016, 79(1): 16-22
Abstract:
The immobilized ionic liquid is the combination of the ionic liquid and support material, in which two distinct parts are connected by two different interaction forces, one is the physisorption of ionic liquids to the supporting surface, such as Vander Waals, hydrogen bonding etc, and the other is chemisorption of the ionic liquids to the surface, such as covalent bonding. The immobilized ionic liquid remains the main advantages of ionic liquid, and has higher catalytic activity and better reusability. This novel catalyst can be used in many organic reactions, such as condensation reaction, coupled reaction and asymmetric synthesis. This article describes the variety of immobilized materials, interaction forces between support material and ionic liquid, and the applications of immobilized ionic liquids in organic synthesis as catalyst.
The immobilized ionic liquid is the combination of the ionic liquid and support material, in which two distinct parts are connected by two different interaction forces, one is the physisorption of ionic liquids to the supporting surface, such as Vander Waals, hydrogen bonding etc, and the other is chemisorption of the ionic liquids to the surface, such as covalent bonding. The immobilized ionic liquid remains the main advantages of ionic liquid, and has higher catalytic activity and better reusability. This novel catalyst can be used in many organic reactions, such as condensation reaction, coupled reaction and asymmetric synthesis. This article describes the variety of immobilized materials, interaction forces between support material and ionic liquid, and the applications of immobilized ionic liquids in organic synthesis as catalyst.
2016, 79(1): 23-30
Abstract:
Based on previous theories and field tests, in thermal recovery process, foam flooding is an effective way to prevent gas migration and to enhance oil recovery. In this paper the shortages in the thermal recovery foam flooding and proposed solutions are analyzed, the progress in the study of high temperature and high salinity foam agents including synthesis methods of foam agent and compounding foam system, mechanisms of bubble generation, flow and stabilization, nanoparticles increasing substantial thermal recovery efficiency of foam flooding is reviewed. At last, the direction of development for thermal recovery foam flooding is proposed.
Based on previous theories and field tests, in thermal recovery process, foam flooding is an effective way to prevent gas migration and to enhance oil recovery. In this paper the shortages in the thermal recovery foam flooding and proposed solutions are analyzed, the progress in the study of high temperature and high salinity foam agents including synthesis methods of foam agent and compounding foam system, mechanisms of bubble generation, flow and stabilization, nanoparticles increasing substantial thermal recovery efficiency of foam flooding is reviewed. At last, the direction of development for thermal recovery foam flooding is proposed.
2016, 79(1): 31-36,30
Abstract:
As one of the basic materials in organic synthesis, decene plays an indispensable role in modern chemical production. The demand of decene is increasing year by year, while there is no one process route to produce decene from ethylene oligomerization directly at present. As a long-chain alkene, decene can be prepared by ethylene oligomerization. In this paper, we focused on the reaction of decene synthesis from ethylene oligomerization. We mainly expressed the research status and the achievements in Cr catalytic system which included the effect of the structure of catalysts on the selectivity of decene and the mechanism of polymerization. At the same time, we expounded the research status in Ni catalytic system which included the relationship between the structure of catalysts and the selectivity of decene, and the relationship between the structure of dendritic molecule and the selectivity of decene. Moreover, the progresses of Fe, Ti, Zr catalytic systems in the catalytic synthesis of decene from ethylene oligomerization were also described by some, hoping to provide theory bases for the development of new catalysts for producing decene.
As one of the basic materials in organic synthesis, decene plays an indispensable role in modern chemical production. The demand of decene is increasing year by year, while there is no one process route to produce decene from ethylene oligomerization directly at present. As a long-chain alkene, decene can be prepared by ethylene oligomerization. In this paper, we focused on the reaction of decene synthesis from ethylene oligomerization. We mainly expressed the research status and the achievements in Cr catalytic system which included the effect of the structure of catalysts on the selectivity of decene and the mechanism of polymerization. At the same time, we expounded the research status in Ni catalytic system which included the relationship between the structure of catalysts and the selectivity of decene, and the relationship between the structure of dendritic molecule and the selectivity of decene. Moreover, the progresses of Fe, Ti, Zr catalytic systems in the catalytic synthesis of decene from ethylene oligomerization were also described by some, hoping to provide theory bases for the development of new catalysts for producing decene.
2016, 79(1): 37-42
Abstract:
A new antioxidant dilauric acid thiodiglycol ester is prepared in high yield starting from thiodiglycol and lauric acid catalyzed by p-toluenesulfonic acid. The optimized reaction condition is as follows:using xylene to remove water azeotropically with reaction temperature at 140℃, molar ratio of thiodiglyol to lauric acid at 2:1.5, and loading of catalyst at 2% by weight of lauric acid. The antioxidant activity of the product is investigated and compared with other commercially available antioxidants. The results show that when dilauric acid thiodiglycol ester is used as antioxidant additive, the melt flow index (MFI) of polypropylene powder decreases sharply from 5.36 g·10min-1 to 3.59 g·10min-1, and elongation at break and impact strength also reach a high level to 112.2% and 121.0kJ·m-2. The blending of dilauric acid thiodiglycol ester with commercially available antioxidant 1010 or 168 can further improve the antioxidant performance. Tensile strength of 40.2 MPa, elongation at break of 140.8% and impact strength of 124.2kJ·m-2 are obtained when dilauric acid thiodilglycol ester is combined with 168, while MFI decreases to 3.56g·10min-1 and 3.28g·10min-1 when it is combined with 1010 and 168, respectively.
A new antioxidant dilauric acid thiodiglycol ester is prepared in high yield starting from thiodiglycol and lauric acid catalyzed by p-toluenesulfonic acid. The optimized reaction condition is as follows:using xylene to remove water azeotropically with reaction temperature at 140℃, molar ratio of thiodiglyol to lauric acid at 2:1.5, and loading of catalyst at 2% by weight of lauric acid. The antioxidant activity of the product is investigated and compared with other commercially available antioxidants. The results show that when dilauric acid thiodiglycol ester is used as antioxidant additive, the melt flow index (MFI) of polypropylene powder decreases sharply from 5.36 g·10min-1 to 3.59 g·10min-1, and elongation at break and impact strength also reach a high level to 112.2% and 121.0kJ·m-2. The blending of dilauric acid thiodiglycol ester with commercially available antioxidant 1010 or 168 can further improve the antioxidant performance. Tensile strength of 40.2 MPa, elongation at break of 140.8% and impact strength of 124.2kJ·m-2 are obtained when dilauric acid thiodilglycol ester is combined with 168, while MFI decreases to 3.56g·10min-1 and 3.28g·10min-1 when it is combined with 1010 and 168, respectively.
2016, 79(1): 43-47
Abstract:
In this article, six linear molecules including 4-butyl-1,1'-biphenyl (L1), 4,4'-diisopropyl-1,1'-biphenyl (L2), 5,5'-dimethyl-2,2'-bipyridine (L3), 2-([1,1'-biphenyl]-4) thiophene (L4), 1,1'-binaphthyl (L5), and 5-phenyl-2,2'-bithiophene (L6) were synthesized. Their luminescent properties were studied by UV-Vis and fluorescence spectra. The results revealed that compound L1, L2 and L3 show AIE properties, while L4, L5, L6 show ACQ properties. We extrapolated that biphenyl-like compounds are AIE active, and restriction of intramolecular rotation (RIR) in the aggregates is the cause for the AIE effect. But linear molecules with more or larger aromatic rings show ACQ phenomena.
In this article, six linear molecules including 4-butyl-1,1'-biphenyl (L1), 4,4'-diisopropyl-1,1'-biphenyl (L2), 5,5'-dimethyl-2,2'-bipyridine (L3), 2-([1,1'-biphenyl]-4) thiophene (L4), 1,1'-binaphthyl (L5), and 5-phenyl-2,2'-bithiophene (L6) were synthesized. Their luminescent properties were studied by UV-Vis and fluorescence spectra. The results revealed that compound L1, L2 and L3 show AIE properties, while L4, L5, L6 show ACQ properties. We extrapolated that biphenyl-like compounds are AIE active, and restriction of intramolecular rotation (RIR) in the aggregates is the cause for the AIE effect. But linear molecules with more or larger aromatic rings show ACQ phenomena.
2016, 79(1): 48-55,42
Abstract:
Two bidentate Schiff base ligand-functionalized PSFs, PSF-SAN and PSF-SCA were synthesized by the substitution reaction under optimal conditions, i.e. in N,N-dimethylacetamide at 80℃ from chloromethylated polysulfone (CMPSF) as starting material and the Schiff base reaction in turn. The chemical structures of products were characterized by FT IR and 1H NMR techniques. Their binary polymer-rare earth (Tb(Ⅲ) ion and Eu(Ⅲ)) ion complexes were prepared, and their photoluminescence properties were preliminarily explored. The PSF-SAN produces strong sensitization action towards Eu(Ⅲ) ion, and the complex PSF-(SAN)3-Eu(Ⅲ) emits red fluorescence. While the PSF-SCA produce sensitization action towards Tb(Ⅲ) ion, and the complex PSF-(SCN)3-Tb(Ⅲ) emits green fluorescence.
Two bidentate Schiff base ligand-functionalized PSFs, PSF-SAN and PSF-SCA were synthesized by the substitution reaction under optimal conditions, i.e. in N,N-dimethylacetamide at 80℃ from chloromethylated polysulfone (CMPSF) as starting material and the Schiff base reaction in turn. The chemical structures of products were characterized by FT IR and 1H NMR techniques. Their binary polymer-rare earth (Tb(Ⅲ) ion and Eu(Ⅲ)) ion complexes were prepared, and their photoluminescence properties were preliminarily explored. The PSF-SAN produces strong sensitization action towards Eu(Ⅲ) ion, and the complex PSF-(SAN)3-Eu(Ⅲ) emits red fluorescence. While the PSF-SCA produce sensitization action towards Tb(Ⅲ) ion, and the complex PSF-(SCN)3-Tb(Ⅲ) emits green fluorescence.
2016, 79(1): 56-61
Abstract:
In this paper, 1-(chloromethyl)-4-vinylbenzene (C9H9Cl) as raw material, a new type quaternary ammonium salt antibacterial monomer, namely C9H9Cl-16DMA, was synthesized through nucleophilic substitution reaction with N,N-dimethylcetylamine (16DMA), and its structure was characterized by using FT IR, 1H NMR, EA, TG. Its antibacterial activities were tested for staphylococcus aureus, bacillus subtilis and escherichia coli by the inhibition zone method. Considering the future application and safety, its toxicity was evaluated. The results showed that there were no abnormal change in the physiological characteristics and the skin of rabbit, and the scope of LD50 was 3000.68(2560.57~3440.79) mg/kg calculated by Karber's method.
In this paper, 1-(chloromethyl)-4-vinylbenzene (C9H9Cl) as raw material, a new type quaternary ammonium salt antibacterial monomer, namely C9H9Cl-16DMA, was synthesized through nucleophilic substitution reaction with N,N-dimethylcetylamine (16DMA), and its structure was characterized by using FT IR, 1H NMR, EA, TG. Its antibacterial activities were tested for staphylococcus aureus, bacillus subtilis and escherichia coli by the inhibition zone method. Considering the future application and safety, its toxicity was evaluated. The results showed that there were no abnormal change in the physiological characteristics and the skin of rabbit, and the scope of LD50 was 3000.68(2560.57~3440.79) mg/kg calculated by Karber's method.
2016, 79(1): 62-65,61
Abstract:
Xinjiang is rich in saline lake resources and has a long cold winter, some researches showed that brine can be separated by using cold energy in winter. The liquid-solid phase equilibriums of Na+, K+//Cl-, SO42-, NO3--H2O and Na+, K+//Cl-, NO3--H2O systems were investigated by isothermal method at 273.15K. Based on the data of literatures and experiments, solubilities and densities of the two systems were received and the phase diagrams were plotted. The results showed that the phase diagram of the system Na+, K+//Cl-, NO3--H2O consists of two invariant points, five invariant curves and four crystallization regions corresponding to NaNO3, NaCl, KNO3 and KCl respectively. In addition, compared with the phase diagram of this quaternary system at 298.15K, the crystalline region of KNO3 becomes larger. For the system Na+, K+//Cl-, SO42-, NO3--H2O saturated with NaCl, the phase diagram consists of two invariant points, five invariant curves, four crystallization regions corresponding to NaCl+Na2SO4·10H2O, NaCl+NaNO3, NaCl+KNO3, and NaCl+KCl respectively. Compared with the phase diagram of this system at 298.15K, it was more simple, in which the crystalline regions of double salts, glaserite and darapskite, disappear, and the Na2SO4·10H2O crystalline region becomes larger.
Xinjiang is rich in saline lake resources and has a long cold winter, some researches showed that brine can be separated by using cold energy in winter. The liquid-solid phase equilibriums of Na+, K+//Cl-, SO42-, NO3--H2O and Na+, K+//Cl-, NO3--H2O systems were investigated by isothermal method at 273.15K. Based on the data of literatures and experiments, solubilities and densities of the two systems were received and the phase diagrams were plotted. The results showed that the phase diagram of the system Na+, K+//Cl-, NO3--H2O consists of two invariant points, five invariant curves and four crystallization regions corresponding to NaNO3, NaCl, KNO3 and KCl respectively. In addition, compared with the phase diagram of this quaternary system at 298.15K, the crystalline region of KNO3 becomes larger. For the system Na+, K+//Cl-, SO42-, NO3--H2O saturated with NaCl, the phase diagram consists of two invariant points, five invariant curves, four crystallization regions corresponding to NaCl+Na2SO4·10H2O, NaCl+NaNO3, NaCl+KNO3, and NaCl+KCl respectively. Compared with the phase diagram of this system at 298.15K, it was more simple, in which the crystalline regions of double salts, glaserite and darapskite, disappear, and the Na2SO4·10H2O crystalline region becomes larger.
2016, 79(1): 66-70
Abstract:
Molecular imprinting technique was used to prepare electrochemical sensor for ciprofloxacin hydrochloride (CPX) by electrochemical polymerization on the surface of graphite electrode using pyrrole as functional monomer. The effect of preparation conditions on sensor was investigated and the performances of the sensor were measured by square wave voltammetry (SWV) with ferricyanide as an electrochemical probe. The results showed that the peak current was linear to the negative logarithm of CPX concentration in the range from 1.0×10-8 to 1.0×10-4 mol/L with a detection limits (S/N=3) of 3.5×10-9 mol/L. The sensor has good selectivity, reproducibility and stability for template CPX and the peak current of the sensor did not clearly change after stored for 15 days.
Molecular imprinting technique was used to prepare electrochemical sensor for ciprofloxacin hydrochloride (CPX) by electrochemical polymerization on the surface of graphite electrode using pyrrole as functional monomer. The effect of preparation conditions on sensor was investigated and the performances of the sensor were measured by square wave voltammetry (SWV) with ferricyanide as an electrochemical probe. The results showed that the peak current was linear to the negative logarithm of CPX concentration in the range from 1.0×10-8 to 1.0×10-4 mol/L with a detection limits (S/N=3) of 3.5×10-9 mol/L. The sensor has good selectivity, reproducibility and stability for template CPX and the peak current of the sensor did not clearly change after stored for 15 days.
2016, 79(1): 71-76
Abstract:
The composite electrode material of ferroferric oxide/nitrogen doping reduction graphene (Fe3O4/N-rGO) was successfully prepared by the hydrothermal method. Its structure and morphology were characterized using XRD, XPS, FESEM and TEM, respectively. The electrochemical performance of prepared material was studied by cyclic voltammetry and ac impedance and constant current charge and discharge technology. The results showed that the Fe3O4/N-rGO has higher specific capacitance and better cycle stability. Its specific capacitance is 291.7F/g under the current density of 0.5A/g, which is higher than those of pure ferroferric oxide and pure graphene. It is clear that the addition of smaller particle size of Fe3O4 reduces the agglomeration of graphene and improves the specific capacitance of composites greatly.
The composite electrode material of ferroferric oxide/nitrogen doping reduction graphene (Fe3O4/N-rGO) was successfully prepared by the hydrothermal method. Its structure and morphology were characterized using XRD, XPS, FESEM and TEM, respectively. The electrochemical performance of prepared material was studied by cyclic voltammetry and ac impedance and constant current charge and discharge technology. The results showed that the Fe3O4/N-rGO has higher specific capacitance and better cycle stability. Its specific capacitance is 291.7F/g under the current density of 0.5A/g, which is higher than those of pure ferroferric oxide and pure graphene. It is clear that the addition of smaller particle size of Fe3O4 reduces the agglomeration of graphene and improves the specific capacitance of composites greatly.
2016, 79(1): 77-82,76
Abstract:
Twelve kinds of D-glucosamine acylthiourea derivatives were synthesized from acyl isothiocyanate and 1,3,4,6-tetra-O-acetyl-2-deoxy-β-D-glucosamine hydrochloride prepared from D-glucosamine hydrochloride by protection of amino group followed by acetylation of hydroxyl group, and deprotection of the amino group. The optimal conditions for the coupling reaction were the molar ratio of acyl isothiocyanate and 1,3,4,6-tetra-O-acetyl-2-deoxy-β-D-glucosamine 1:1.2 in dichloromethane at 40℃ for 6 hours. The products were characterized by IR, 1H NMR and 13C NMR.
Twelve kinds of D-glucosamine acylthiourea derivatives were synthesized from acyl isothiocyanate and 1,3,4,6-tetra-O-acetyl-2-deoxy-β-D-glucosamine hydrochloride prepared from D-glucosamine hydrochloride by protection of amino group followed by acetylation of hydroxyl group, and deprotection of the amino group. The optimal conditions for the coupling reaction were the molar ratio of acyl isothiocyanate and 1,3,4,6-tetra-O-acetyl-2-deoxy-β-D-glucosamine 1:1.2 in dichloromethane at 40℃ for 6 hours. The products were characterized by IR, 1H NMR and 13C NMR.
2016, 79(1): 83-87
Abstract:
The wastewater from 6-aminopenicillanic acid production factory contains high concentration of pollutants, sulfate and non biodegradable compounds and it is hard to be treated. In this work, after sulfate is removed by pretreatment and dilution for three and six times, the wastewater is non toxic to anaerobic sludge and the anaerobic sludge can assimilate to the wastewater gradually. After anaerobic treatment and later Fenton tertiary treatment, the CODCr in the raw 6-aminopenicillanic acid producing wastewater can be reduced from 45450mg/L to 255mg/L, which reaches the national discharge standards class 3 for wastewater.
The wastewater from 6-aminopenicillanic acid production factory contains high concentration of pollutants, sulfate and non biodegradable compounds and it is hard to be treated. In this work, after sulfate is removed by pretreatment and dilution for three and six times, the wastewater is non toxic to anaerobic sludge and the anaerobic sludge can assimilate to the wastewater gradually. After anaerobic treatment and later Fenton tertiary treatment, the CODCr in the raw 6-aminopenicillanic acid producing wastewater can be reduced from 45450mg/L to 255mg/L, which reaches the national discharge standards class 3 for wastewater.
Influence of Ozonation on Chlorinated Disinfection By-Products Formation Potential in Drinking Water
2016, 79(1): 88-91
Abstract:
The effect of ozonation on chlorination disinfection by-products (DBPs) formation potential in drinking water was studied. The results showed that ozonation has different effects on different chlorinated DBPs formation potential. Extracellular polymeric substances (EPS) and soluble microbial products (SMP) from biological treatment units are efficient precursors of chlorinated DBPs, and they are more efficient precursors of trihalomethans (THMs) than haloacetic acids (HAAs). The major precursors of THMs in water samples are the high molecular weight organics which can be removed by ozonation efficiently. The low molecular weight organics that produced by ozonation may be efficient precursors of monochloroacetic acid (MCAA) and monobromoacetic acid (MBAA). Trichloroacetic acid (TCAA) formation potential can be removed by ozonation efficiently, especially in high initial concentration of TCAA precursors.
The effect of ozonation on chlorination disinfection by-products (DBPs) formation potential in drinking water was studied. The results showed that ozonation has different effects on different chlorinated DBPs formation potential. Extracellular polymeric substances (EPS) and soluble microbial products (SMP) from biological treatment units are efficient precursors of chlorinated DBPs, and they are more efficient precursors of trihalomethans (THMs) than haloacetic acids (HAAs). The major precursors of THMs in water samples are the high molecular weight organics which can be removed by ozonation efficiently. The low molecular weight organics that produced by ozonation may be efficient precursors of monochloroacetic acid (MCAA) and monobromoacetic acid (MBAA). Trichloroacetic acid (TCAA) formation potential can be removed by ozonation efficiently, especially in high initial concentration of TCAA precursors.
2016, 79(1): 92-95
Abstract:
Necessity and feasibility of uncertainty calculations in fundamental chemistry experiments were discussed depending on the current situation of uncertainty application. It was recommended that main sources of error is identified according to the basis of learning error theory and calculated directly when true value was known, and the main components of uncertainty be determined when the true value was unknown. Uncertainty was calculated by considering 1~2 main components of uncertainty and ignoring minor components of uncertainty. The method for uncertainty calculation described above meets the requirements of fundamental chemistry experiment.
Necessity and feasibility of uncertainty calculations in fundamental chemistry experiments were discussed depending on the current situation of uncertainty application. It was recommended that main sources of error is identified according to the basis of learning error theory and calculated directly when true value was known, and the main components of uncertainty be determined when the true value was unknown. Uncertainty was calculated by considering 1~2 main components of uncertainty and ignoring minor components of uncertainty. The method for uncertainty calculation described above meets the requirements of fundamental chemistry experiment.
