Login In
2018 Volume 35 Issue 11
2018, 35(11): 1277-1288
doi: 10.11944/j.issn.1000-0518.2018.11.180006
Abstract:
Lithium-rich ternary layered cathode material (xLi2MnO3·(1-x)LiMO2 (0 < x < 1, M=Mn, Ni, Co)) has much higher discharge capacity than other cathode materials. Therefore, it is regarded as one of the best choice for the next generation of lithium-ion battery cathode materials. However, its commercial production and application have been limited by its poor cycle performance and low coulomb efficiency. Herein the latest research progress of lithium-rich ternary layered cathode materials is reviewed, mainly including the progresses in the aspects of material composition, preparation technology, structure tuning, doping and coating modification of the materials. Furthermore, developing trends of the materials is also prospected in this paper.
Lithium-rich ternary layered cathode material (xLi2MnO3·(1-x)LiMO2 (0 < x < 1, M=Mn, Ni, Co)) has much higher discharge capacity than other cathode materials. Therefore, it is regarded as one of the best choice for the next generation of lithium-ion battery cathode materials. However, its commercial production and application have been limited by its poor cycle performance and low coulomb efficiency. Herein the latest research progress of lithium-rich ternary layered cathode materials is reviewed, mainly including the progresses in the aspects of material composition, preparation technology, structure tuning, doping and coating modification of the materials. Furthermore, developing trends of the materials is also prospected in this paper.
2018, 35(11): 1289-1294
doi: 10.11944/j.issn.1000-0518.2018.11.170409
Abstract:
A kind of poly (aryl ether ether ketone ketone) containing phenyl phosphine oxide structure (P-PEEKK) was synthesized by polycondensation of bis (4-phenoxy phenyl) phenyl phosphine oxide (BPOPPO) synthesized from phenol, 1, 4-dibromobenzene and phenylphosphonic dichloride as raw materials and terephthaloyl chloride (TPC) with aluminum chloride (AlCl3) as the catalyst. The structure and properties of P-PEEKK resin were characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA) and wide-angle X-ray diffraction (WAXD), etc. The results show that P-PEEKK resin is amorphous with a high glass transition temperature (Tg) of 190.5℃, a thermal decomposition temperature (T5%) of 515℃, limiting oxygen index (LOI) of 42 and tensile strength of 62 MPa, and is soluble in chloroform, 1, 2-dichloroethane, N, N-dimethylacetamide and other organic solvents for coating film.
A kind of poly (aryl ether ether ketone ketone) containing phenyl phosphine oxide structure (P-PEEKK) was synthesized by polycondensation of bis (4-phenoxy phenyl) phenyl phosphine oxide (BPOPPO) synthesized from phenol, 1, 4-dibromobenzene and phenylphosphonic dichloride as raw materials and terephthaloyl chloride (TPC) with aluminum chloride (AlCl3) as the catalyst. The structure and properties of P-PEEKK resin were characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA) and wide-angle X-ray diffraction (WAXD), etc. The results show that P-PEEKK resin is amorphous with a high glass transition temperature (Tg) of 190.5℃, a thermal decomposition temperature (T5%) of 515℃, limiting oxygen index (LOI) of 42 and tensile strength of 62 MPa, and is soluble in chloroform, 1, 2-dichloroethane, N, N-dimethylacetamide and other organic solvents for coating film.
2018, 35(11): 1295-1300
doi: 10.11944/j.issn.1000-0518.2018.11.170410
Abstract:
In order to improve the temperate and salt tolerance performance of water base fracturing fluid used in fracturing and reconstruction of oil field, acrylic acid (AA), acrylamide (AM), 2-acrylamide-2-methyl propane sulfonic acid (AMPS) and cationic hydrophobic long chain monomer (DS) were used as raw materials to prepare a modified hydrophobic polymer thickener (AAAD). A new fracturing fluid system was prepared using AAAD as the thickening agent, the complex of organic borates and sodium gluconate (GS-2) as the crosslinking agent. The system rheology and viscoelasticity, temperature resistance, salt resistance and gel breaking performance were evaluated. The results show that the fracturing fluid has good rheological properties at 150℃ with the shear rate of 170 s-1. The gel can be broken within 4 h at 90℃ and the viscosity of the gel breaking liquid is 1.6 mPa·s when mass fraction of ammonium persulfate is 0.01%.
In order to improve the temperate and salt tolerance performance of water base fracturing fluid used in fracturing and reconstruction of oil field, acrylic acid (AA), acrylamide (AM), 2-acrylamide-2-methyl propane sulfonic acid (AMPS) and cationic hydrophobic long chain monomer (DS) were used as raw materials to prepare a modified hydrophobic polymer thickener (AAAD). A new fracturing fluid system was prepared using AAAD as the thickening agent, the complex of organic borates and sodium gluconate (GS-2) as the crosslinking agent. The system rheology and viscoelasticity, temperature resistance, salt resistance and gel breaking performance were evaluated. The results show that the fracturing fluid has good rheological properties at 150℃ with the shear rate of 170 s-1. The gel can be broken within 4 h at 90℃ and the viscosity of the gel breaking liquid is 1.6 mPa·s when mass fraction of ammonium persulfate is 0.01%.
2018, 35(11): 1301-1308
doi: 10.11944/j.issn.1000-0518.2018.11.180013
Abstract:
The aim of this paper is to study the relationship between the ability to combine water and the toughness of hydrogel by means of differential scanning calorimetry (DSC). N-butyl methacrylate (BMA) or 2, 2, 3, 4, 4, 4-hexafluorobutyl methacrylate (HFBMA) and allylamine were chosen as monomers to synthesize core-shell nanospheres (named BMA nanosphere or HFBMA nanosphere). Then, the two nanospheres were used as macromolecular initiators and crosslinking agents to prepare nanospherical composite hydrogels (named BMA-H hydrogel or HFBMA-H hydrogel). DSC, Fourier transform infrared spectrometer (FTIR) and transmission electron microscopy (TEM) were used to characterize the structures and properties of hydrogels. The results of mechanical performance analysis indicate that the HFBMA-H hydrogel has better mechanical properties and its tensile strength and fracture elongation are up to 280 kPa and 3960%, respectively, which are much higher than those of BMA-H hydrogel (101 kPa, 2700%). DSC was used to investigate the state and proportion of water in composite hydrogels with different kinds of nanospheres. The results show that the non-freezing water content of HFBMA-H hydrogel is far higher than that of BMA-H hydrogel under the same water content, and the plasticizing effect of non-freezing water has an important effect on the mechanical strength of the hydrogel.
The aim of this paper is to study the relationship between the ability to combine water and the toughness of hydrogel by means of differential scanning calorimetry (DSC). N-butyl methacrylate (BMA) or 2, 2, 3, 4, 4, 4-hexafluorobutyl methacrylate (HFBMA) and allylamine were chosen as monomers to synthesize core-shell nanospheres (named BMA nanosphere or HFBMA nanosphere). Then, the two nanospheres were used as macromolecular initiators and crosslinking agents to prepare nanospherical composite hydrogels (named BMA-H hydrogel or HFBMA-H hydrogel). DSC, Fourier transform infrared spectrometer (FTIR) and transmission electron microscopy (TEM) were used to characterize the structures and properties of hydrogels. The results of mechanical performance analysis indicate that the HFBMA-H hydrogel has better mechanical properties and its tensile strength and fracture elongation are up to 280 kPa and 3960%, respectively, which are much higher than those of BMA-H hydrogel (101 kPa, 2700%). DSC was used to investigate the state and proportion of water in composite hydrogels with different kinds of nanospheres. The results show that the non-freezing water content of HFBMA-H hydrogel is far higher than that of BMA-H hydrogel under the same water content, and the plasticizing effect of non-freezing water has an important effect on the mechanical strength of the hydrogel.
2018, 35(11): 1309-1316
doi: 10.11944/j.issn.1000-0518.2018.11.170371
Abstract:
This paper presented a facile method to the modification of the three-dimensionally ordered macroporous (3DOM) SiO2 hybrids with a carboxyl functionalized polymer layer on the macropore walls. Acrylic acid and glycerol 1, 3-diglycerolate diacrylate were copolymerized to form the polymer layer in the macropores. Raman spectra, scanning electron microscopy (SEM) and BET measurements show that the prepared 3DOM SiO2@polymer composites (SiO2-COOH) have an uniform interconnected macroporous structure and the macropore walls are covered by a nanoscaled compact polymer layer. Moreover, the 3DOM SiO2-COOH has an improved mechanical strength. The 3DOM SiO2-COOH was further used as the support to immobilize glucoamylase. The results show that the immobilized enzyme homogeneously distributes in the 3DOM materials. The optimum pH of immobilized and free enzymes is both at 5, and the optimal reaction temperature is at 55℃. Michaelis constants of the immobilized enzyme and free enzyme are 3.78 g/L and 3.97 g/L, respectively. The immobilized enzyme presents higher thermal, pH, storage stabilities and higher reusability compared with the free enzyme. The results indicate that 3DOM SiO2-COOH could be a novel support for the immobilization of enzymes.
This paper presented a facile method to the modification of the three-dimensionally ordered macroporous (3DOM) SiO2 hybrids with a carboxyl functionalized polymer layer on the macropore walls. Acrylic acid and glycerol 1, 3-diglycerolate diacrylate were copolymerized to form the polymer layer in the macropores. Raman spectra, scanning electron microscopy (SEM) and BET measurements show that the prepared 3DOM SiO2@polymer composites (SiO2-COOH) have an uniform interconnected macroporous structure and the macropore walls are covered by a nanoscaled compact polymer layer. Moreover, the 3DOM SiO2-COOH has an improved mechanical strength. The 3DOM SiO2-COOH was further used as the support to immobilize glucoamylase. The results show that the immobilized enzyme homogeneously distributes in the 3DOM materials. The optimum pH of immobilized and free enzymes is both at 5, and the optimal reaction temperature is at 55℃. Michaelis constants of the immobilized enzyme and free enzyme are 3.78 g/L and 3.97 g/L, respectively. The immobilized enzyme presents higher thermal, pH, storage stabilities and higher reusability compared with the free enzyme. The results indicate that 3DOM SiO2-COOH could be a novel support for the immobilization of enzymes.
2018, 35(11): 1317-1324
doi: 10.11944/j.issn.1000-0518.2018.11.170398
Abstract:
In order to build photodynamic therapy and chemotherapy synergy anticancer leading compounds, three novel nitrogen mustard-linked bis (arylmethylidene)cycloalkanone compounds 3a~3c and other three bis (arylmethylidene)-cycloalkanone compounds 3d~3f were designed and synthesized based on principle of efficacy hybridization. Their structures were characterized by nuclear magnetic resonance spectroscopy (NMR), high resolution mass spectrometry (ESI-MS), X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FTIR). Their in vitro phototoxicity were investigated by thiazolyl blue tetrazolium bromide (MTT) method against A549 (human lung adenocarcinoma) and HepG2 (human hepatoma) cell lines. The preliminary data indicates that most of these compounds exhibit moderate to potent phototoxicity against both tumor cell lines. In particular, compound 3a is worthy of further study with an IC50 of against HepG2 at 2.0 nmol/mL. Compounds 3a and 3d were simulated at B3LYP 6-311G+ level with Gaussian09 program. Their optimized geometries and the energy of frontier molecular orbitals are obtained. Furthermore, the relationship between the structural features and phototoxicity were analyzed based on the energy of frontier molecular orbitals.
In order to build photodynamic therapy and chemotherapy synergy anticancer leading compounds, three novel nitrogen mustard-linked bis (arylmethylidene)cycloalkanone compounds 3a~3c and other three bis (arylmethylidene)-cycloalkanone compounds 3d~3f were designed and synthesized based on principle of efficacy hybridization. Their structures were characterized by nuclear magnetic resonance spectroscopy (NMR), high resolution mass spectrometry (ESI-MS), X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FTIR). Their in vitro phototoxicity were investigated by thiazolyl blue tetrazolium bromide (MTT) method against A549 (human lung adenocarcinoma) and HepG2 (human hepatoma) cell lines. The preliminary data indicates that most of these compounds exhibit moderate to potent phototoxicity against both tumor cell lines. In particular, compound 3a is worthy of further study with an IC50 of against HepG2 at 2.0 nmol/mL. Compounds 3a and 3d were simulated at B3LYP 6-311G+ level with Gaussian09 program. Their optimized geometries and the energy of frontier molecular orbitals are obtained. Furthermore, the relationship between the structural features and phototoxicity were analyzed based on the energy of frontier molecular orbitals.
2018, 35(11): 1325-1330
doi: 10.11944/j.issn.1000-0518.2018.11.170421
Abstract:
1, 2, 3-Triazole compounds show a wide range of biological activities. In order to find new compounds with bactericidal activity, a series of 2-substituted-4-aryl-2H-1, 2, 3-triazoles was synthesized from benzaldehyde or substituted benzaldehyde, nitromethane and sodium azide in 51% to 91% yields. The structures of these compounds were characterized by nuclear magnetic resonance spectroscopy (NMR), mass spectra and elemental analyses. Most of these compounds show the preliminary antibacterial activity against Gibberella zeae and Phytophythora capsici in vitro, in 25 mg/L concentration. Among them, compound 3a shows 80.4% activity of against Gibberella zeae, compound 3b shows 78.2% activity of against Botrytis cinerea, compounds 3a and 3h show 70.3%, 75.9% activities of against Sclerotonia sclerotiorum, respectively.
1, 2, 3-Triazole compounds show a wide range of biological activities. In order to find new compounds with bactericidal activity, a series of 2-substituted-4-aryl-2H-1, 2, 3-triazoles was synthesized from benzaldehyde or substituted benzaldehyde, nitromethane and sodium azide in 51% to 91% yields. The structures of these compounds were characterized by nuclear magnetic resonance spectroscopy (NMR), mass spectra and elemental analyses. Most of these compounds show the preliminary antibacterial activity against Gibberella zeae and Phytophythora capsici in vitro, in 25 mg/L concentration. Among them, compound 3a shows 80.4% activity of against Gibberella zeae, compound 3b shows 78.2% activity of against Botrytis cinerea, compounds 3a and 3h show 70.3%, 75.9% activities of against Sclerotonia sclerotiorum, respectively.
2018, 35(11): 1331-1334
doi: 10.11944/j.issn.1000-0518.2018.11.170429
Abstract:
In order to overcome the shortcomings of facile production of dihydroxy diphenyl ethylene by-product in traditional method, dibenzo [d, f][1, 3] dioxepines was synthesized highly regioselectively from a broad range of terminal alkynes with Lewis acidic guanidinium ionic liquid catalyst in 39%~84% yields. The Lewis acidic guanidinium ionic liquid can be reused five times without significantly decrease in catalytic activity.
In order to overcome the shortcomings of facile production of dihydroxy diphenyl ethylene by-product in traditional method, dibenzo [d, f][1, 3] dioxepines was synthesized highly regioselectively from a broad range of terminal alkynes with Lewis acidic guanidinium ionic liquid catalyst in 39%~84% yields. The Lewis acidic guanidinium ionic liquid can be reused five times without significantly decrease in catalytic activity.
2018, 35(11): 1335-1341
doi: 10.11944/j.issn.1000-0518.2018.11.170446
Abstract:
CuI/Bipy (2, 2'-bipyridine)/TEMPO (2, 2, 6, 6-Tetramethylpiperidinooxy) catalytic oxidation process was optimized for nitriles synthesis using alcohols as starting material with aqueous ammonia as nitrogen source and molecular oxygen as the oxidant in a pressurized reactor. The effect of copper salts, catalyst loading, solvent, reaction temperature and reaction time were studied using benzyl alcohol as a model substrate. It is shown that low catalyst loading (1% molar fraction for aromatic alcohols, 5% molar fraction for aliphatic alcohols) and short reaction time (8 hours) are required for oxidizing both aromatic and aliphatic alcohols to their corresponding nitriles over 90% conversion rate and 90% yield under 40×105 Pa presure of O2 (8% volume fraction)-N2 gas mixture at 120℃.
CuI/Bipy (2, 2'-bipyridine)/TEMPO (2, 2, 6, 6-Tetramethylpiperidinooxy) catalytic oxidation process was optimized for nitriles synthesis using alcohols as starting material with aqueous ammonia as nitrogen source and molecular oxygen as the oxidant in a pressurized reactor. The effect of copper salts, catalyst loading, solvent, reaction temperature and reaction time were studied using benzyl alcohol as a model substrate. It is shown that low catalyst loading (1% molar fraction for aromatic alcohols, 5% molar fraction for aliphatic alcohols) and short reaction time (8 hours) are required for oxidizing both aromatic and aliphatic alcohols to their corresponding nitriles over 90% conversion rate and 90% yield under 40×105 Pa presure of O2 (8% volume fraction)-N2 gas mixture at 120℃.
Synthesis of Ordered Mesoporous Ru-MgZr Composite Oxide Catalysts for Isomerization of Linoleic Acid
2018, 35(11): 1342-1350
doi: 10.11944/j.issn.1000-0518.2018.11.170412
Abstract:
The preparation of highly efficient and selective catalyst is important for the isomerization of linoleic acid. Herein, ordered mesoporous Ru-MgO-ZrO2 solid base catalysts were synthesized through the evaporation-induced self-assembly sol-gel method. The effects of the basicity, pore size and specific surface area of the catalyst were investigated. The effect of catalysts surface basicity, Ru doping and its effect on catalysis activity were also investigated. The results show that the Ru-MgO-ZrO2 catalyst with n (Zr):n (Mg)=3:1 has good order and high specific surface area. The strong base sites and lattice Ru of catalyst are the two active sites of catalytic reaction. The Ru-MgO-ZrO2 catalyst with n (Zr):n (Mg)=1:1 catalyst leads to the highest 85% yield of conjugated linoleic acid (CLA) in 4 hour reaction time and the productivity of CLA is 0.099 g (CLA)·L-1 (solvent)·min-1. Furthermore, the products are mainly three kinds of isomers with biological activity. These solid base oxide catalysts with the advantages of high catalytic efficiency, simple preparation and high selectivity toward biological activity of linoleic acid products show application prospect.
The preparation of highly efficient and selective catalyst is important for the isomerization of linoleic acid. Herein, ordered mesoporous Ru-MgO-ZrO2 solid base catalysts were synthesized through the evaporation-induced self-assembly sol-gel method. The effects of the basicity, pore size and specific surface area of the catalyst were investigated. The effect of catalysts surface basicity, Ru doping and its effect on catalysis activity were also investigated. The results show that the Ru-MgO-ZrO2 catalyst with n (Zr):n (Mg)=3:1 has good order and high specific surface area. The strong base sites and lattice Ru of catalyst are the two active sites of catalytic reaction. The Ru-MgO-ZrO2 catalyst with n (Zr):n (Mg)=1:1 catalyst leads to the highest 85% yield of conjugated linoleic acid (CLA) in 4 hour reaction time and the productivity of CLA is 0.099 g (CLA)·L-1 (solvent)·min-1. Furthermore, the products are mainly three kinds of isomers with biological activity. These solid base oxide catalysts with the advantages of high catalytic efficiency, simple preparation and high selectivity toward biological activity of linoleic acid products show application prospect.
2018, 35(11): 1351-1356
doi: 10.11944/j.issn.1000-0518.2018.11.170462
Abstract:
High-performance titania-silica (TiO2-SiO2) nanocomposites were synthesized with a sol gel method. The composite catalyst was prepared by either in situ synthesis (HPMo-TiO2-SiO2-is) or the impregnation method (HPMo/TiO2-SiO2) using Keggin-structure phosphomolybdic acid and TiO2-SiO2. The structures of these catalysts were characterized by scanning electron micrographs (SEM), Fourier transform infrared spectrum (FT-IR), ultraviolet visible spectroscopy (UV-Vis), Brunauer-Emmett-Teller (BET) and X-ray powder diffraction pattern (XRD). The preservation of the Keggin structure in HPMo-TiO2-SiO2-is and HPMo/TiO2-SiO2 catalysts was confirmed. The results show that the synthesized catalysts are in nanometer size and the micropores and mesopores coexist. The catalytic oxidation desulfurization reaction was studied over synthesized catalysts with a model oil (n-octane solution of organic sulfur). Reaction conditions are listed as following:model oil/ethanol=10.0 mL/10.0 mL, catalyst 0.15 g, n (O)/n (S)=5, temperature 30~70℃ and time=3 h. It is clear that the catalytic properties of the HPMo-TiO2-SiO2-is and HPMo/TiO2-SiO2 are similar under optimized conditions. The conversion of dibenzothiophene is 96.0% and the content of sulphur is below 10 μg/g. Under the same conditions, the efficiencies of oxidative desulfurization decrease in the order of dibenzothiophene > benzothiophene > thiophene, and the result is influenced by the electron density on the sulfur atoms. The catalytic activity of the recycled HPMo-TiO2-SiO2-is catalyst is almost as the same as that of freshly prepared. The HPMo-TiO2-SiO2-is and HPMo/TiO2-SiO2 catalysts could be recycled and easily separated. These catalysts used herein are an ideal model for oxidation desulfurization of sulfur compounds.
High-performance titania-silica (TiO2-SiO2) nanocomposites were synthesized with a sol gel method. The composite catalyst was prepared by either in situ synthesis (HPMo-TiO2-SiO2-is) or the impregnation method (HPMo/TiO2-SiO2) using Keggin-structure phosphomolybdic acid and TiO2-SiO2. The structures of these catalysts were characterized by scanning electron micrographs (SEM), Fourier transform infrared spectrum (FT-IR), ultraviolet visible spectroscopy (UV-Vis), Brunauer-Emmett-Teller (BET) and X-ray powder diffraction pattern (XRD). The preservation of the Keggin structure in HPMo-TiO2-SiO2-is and HPMo/TiO2-SiO2 catalysts was confirmed. The results show that the synthesized catalysts are in nanometer size and the micropores and mesopores coexist. The catalytic oxidation desulfurization reaction was studied over synthesized catalysts with a model oil (n-octane solution of organic sulfur). Reaction conditions are listed as following:model oil/ethanol=10.0 mL/10.0 mL, catalyst 0.15 g, n (O)/n (S)=5, temperature 30~70℃ and time=3 h. It is clear that the catalytic properties of the HPMo-TiO2-SiO2-is and HPMo/TiO2-SiO2 are similar under optimized conditions. The conversion of dibenzothiophene is 96.0% and the content of sulphur is below 10 μg/g. Under the same conditions, the efficiencies of oxidative desulfurization decrease in the order of dibenzothiophene > benzothiophene > thiophene, and the result is influenced by the electron density on the sulfur atoms. The catalytic activity of the recycled HPMo-TiO2-SiO2-is catalyst is almost as the same as that of freshly prepared. The HPMo-TiO2-SiO2-is and HPMo/TiO2-SiO2 catalysts could be recycled and easily separated. These catalysts used herein are an ideal model for oxidation desulfurization of sulfur compounds.
2018, 35(11): 1357-1363
doi: 10.11944/j.issn.1000-0518.2018.11.180235
Abstract:
To prepare catalysts with high activity in the Fenton reaction toward the decomposition of pollutants in water, SiO2 coated polyacrylate and manganese dioxide composite colloids (PAA-Mn@SiO2) were carbonized under N2 atmosphere. The synthesis process is very facile and effective. The as-prepared manganese oxides-carbon@SiO2 core shell type catalyst (MnOX-C@SiO2) was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and the specific surface area analysis. The results indicate that low-valenced manganese oxides (Mn3O4 and MnO) are formed in the MnOX-C@SiO2 due to the reductive atmosphere formed by the pyrolysis of PAA, which is beneficial for the enhancement of the catalytic performance in the Fenton reaction. In addition, the SiO2 shell not only effectively prevents the inside manganese oxide nanoparticles from getting larger but also stops the product from aggregating during carbonation. The carbon component in the core can further stabilize the manganese oxide nanoparticles and promote the enrichment of organic pollutants. The specific surface area of the MnOX-C@SiO2 is 317.3 m2/g, which is well dispersed in water. For the catalytic degradation of methylene blue (MB) solution via the Fenton process, the degradation rate of MB can reach ~96.8% only after 40 min.
To prepare catalysts with high activity in the Fenton reaction toward the decomposition of pollutants in water, SiO2 coated polyacrylate and manganese dioxide composite colloids (PAA-Mn@SiO2) were carbonized under N2 atmosphere. The synthesis process is very facile and effective. The as-prepared manganese oxides-carbon@SiO2 core shell type catalyst (MnOX-C@SiO2) was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and the specific surface area analysis. The results indicate that low-valenced manganese oxides (Mn3O4 and MnO) are formed in the MnOX-C@SiO2 due to the reductive atmosphere formed by the pyrolysis of PAA, which is beneficial for the enhancement of the catalytic performance in the Fenton reaction. In addition, the SiO2 shell not only effectively prevents the inside manganese oxide nanoparticles from getting larger but also stops the product from aggregating during carbonation. The carbon component in the core can further stabilize the manganese oxide nanoparticles and promote the enrichment of organic pollutants. The specific surface area of the MnOX-C@SiO2 is 317.3 m2/g, which is well dispersed in water. For the catalytic degradation of methylene blue (MB) solution via the Fenton process, the degradation rate of MB can reach ~96.8% only after 40 min.
2018, 35(11): 1364-1371
doi: 10.11944/j.issn.1000-0518.2018.11.170414
Abstract:
Silicon nitride was prepared through nitriding the diamond-wire cutting waste, which not only recycles the diamond-wire cutting waste but also improves the environment. The influence of HCl and HF on the phase composition, component content and microtopography of nitride products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that the phases in nitride samples fabricated from the HCl-soaked cutting waste are mainly Si2N2O and Si3N4. However, the phases in nitride samples fabricated from the HF-soaked cutting waste is mostly Si3N4. Si2N2O in nitride samples is related to the mass fraction of SiO2 in cutting waste, and the precondition of producing Si3N4 from cutting waste by high temperature nitriding is to reduce the mass fraction of SiO2 in cutting waste.
Silicon nitride was prepared through nitriding the diamond-wire cutting waste, which not only recycles the diamond-wire cutting waste but also improves the environment. The influence of HCl and HF on the phase composition, component content and microtopography of nitride products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that the phases in nitride samples fabricated from the HCl-soaked cutting waste are mainly Si2N2O and Si3N4. However, the phases in nitride samples fabricated from the HF-soaked cutting waste is mostly Si3N4. Si2N2O in nitride samples is related to the mass fraction of SiO2 in cutting waste, and the precondition of producing Si3N4 from cutting waste by high temperature nitriding is to reduce the mass fraction of SiO2 in cutting waste.
2018, 35(11): 1372-1377
doi: 10.11944/j.issn.1000-0518.2018.11.170464
Abstract:
A zinc complex based on the one-dimensional (1D) double-helical chains was hydrothermally self-assembled by selecting the organic ligand N, N'-bis (3-pyridyl)malonamide (3-bpma), 1, 4-phenylenediacetic acid (H2 pda) and zinc nitrate, [Zn (3-bpma) (pda)]n (1), then structurally characterized by infrared spectroscopy (IR), element analysis, thermogravimetry (TG) and X-ray single-crystal diffraction. The single-crystal structural analysis reveals that this zinc complex is an orthorhombic system with space group Pna21, its cell parameters are:a=1.62512 (11) nm, b=1.15947 (8) nm, c=1.19282 (8) nm, α=90°, β=90°, γ=90°, V=2.2476 (3) nm3, Mr=513.80, Dc=1.518 g/cm3, Z=4, F (000)=1056, R1=0.0381, wR2=0.0669. The zinc ions are bridged by two kinds of ligands 3-bpma and pda to form a 1D double-helical chain, then the adjacent chains are extended into the 3D supramolecular network through the hydrogen bonding interactions. The title zinc complex shows a strong fluorescence emission characteristic. Moreover, this complex possesses remarkable fluorescent sensing behaviors for organic solvent molecules and metal ions, which may be a potential fluorescent sensing material for detecting nitrobenzene.
A zinc complex based on the one-dimensional (1D) double-helical chains was hydrothermally self-assembled by selecting the organic ligand N, N'-bis (3-pyridyl)malonamide (3-bpma), 1, 4-phenylenediacetic acid (H2 pda) and zinc nitrate, [Zn (3-bpma) (pda)]n (1), then structurally characterized by infrared spectroscopy (IR), element analysis, thermogravimetry (TG) and X-ray single-crystal diffraction. The single-crystal structural analysis reveals that this zinc complex is an orthorhombic system with space group Pna21, its cell parameters are:a=1.62512 (11) nm, b=1.15947 (8) nm, c=1.19282 (8) nm, α=90°, β=90°, γ=90°, V=2.2476 (3) nm3, Mr=513.80, Dc=1.518 g/cm3, Z=4, F (000)=1056, R1=0.0381, wR2=0.0669. The zinc ions are bridged by two kinds of ligands 3-bpma and pda to form a 1D double-helical chain, then the adjacent chains are extended into the 3D supramolecular network through the hydrogen bonding interactions. The title zinc complex shows a strong fluorescence emission characteristic. Moreover, this complex possesses remarkable fluorescent sensing behaviors for organic solvent molecules and metal ions, which may be a potential fluorescent sensing material for detecting nitrobenzene.
2018, 35(11): 1378-1383
doi: 10.11944/j.issn.1000-0518.2018.11.170450
Abstract:
In order to effectively reduce the turn-on voltage of the liquid crystal device and low power consumption characteristics. Gold nanoparticles with an average particle diameter of about 5 nm were prepared by using polyhedral oligomeric silsesquioxanes (POSS) as the modification ligand and NaBH4 as the reductant to reduce the chloroauric acid. Gold nanoparticles were doped into nematic liquid crystal 4-n-pentyl-4'-cyanobiphenyl (5CB) with different mass fractions to study its effect on the viscosity, the threshold voltage and the phase transition temperature. The results show that the viscosity and the threshold voltage of 5CB are decreased by doping with POSS modified gold nanoparticles. Moreover, the phase transition temperature range of 5CB is broadened by addition of the gold nanoparticles.
In order to effectively reduce the turn-on voltage of the liquid crystal device and low power consumption characteristics. Gold nanoparticles with an average particle diameter of about 5 nm were prepared by using polyhedral oligomeric silsesquioxanes (POSS) as the modification ligand and NaBH4 as the reductant to reduce the chloroauric acid. Gold nanoparticles were doped into nematic liquid crystal 4-n-pentyl-4'-cyanobiphenyl (5CB) with different mass fractions to study its effect on the viscosity, the threshold voltage and the phase transition temperature. The results show that the viscosity and the threshold voltage of 5CB are decreased by doping with POSS modified gold nanoparticles. Moreover, the phase transition temperature range of 5CB is broadened by addition of the gold nanoparticles.
2018, 35(11): 1384-1390
doi: 10.11944/j.issn.1000-0518.2018.11.170407
Abstract:
Spinel LiMn2O4 octahedral nanoparticles were prepared by template-directed and high temperature solid-phase methods as cathode materials for lithium-ion batteries. Their structure and electrochemical performances were investigated. The electrochemical performance results show that LiMn2O4 as lithium-ion batteries cathode displays excellent cycling stability, rate capability and high specific capacity. The initial charge-discharge specific capacities are 147 mA·h/g and 179 mA·h/g at a current density of 100 mA/g and the voltage of 2.5~4.5 V, respectively. The cathode materials retain reversible charge-discharge capacities of 180 mA·h/g and 181 mA·h/g after 50 cycles, respectively. Excellent electrochemical properties may be attributed to the octahedral LiMn2O4 structure. This method is instructive for fabrication and design of excellent electrode materials for lithium ion batteries.
Spinel LiMn2O4 octahedral nanoparticles were prepared by template-directed and high temperature solid-phase methods as cathode materials for lithium-ion batteries. Their structure and electrochemical performances were investigated. The electrochemical performance results show that LiMn2O4 as lithium-ion batteries cathode displays excellent cycling stability, rate capability and high specific capacity. The initial charge-discharge specific capacities are 147 mA·h/g and 179 mA·h/g at a current density of 100 mA/g and the voltage of 2.5~4.5 V, respectively. The cathode materials retain reversible charge-discharge capacities of 180 mA·h/g and 181 mA·h/g after 50 cycles, respectively. Excellent electrochemical properties may be attributed to the octahedral LiMn2O4 structure. This method is instructive for fabrication and design of excellent electrode materials for lithium ion batteries.
2018, 35(11): 1391-1398
doi: 10.11944/j.issn.1000-0518.2018.11.180051
Abstract:
In recent years, studies on the extraction and analysis of the components contained in fig leaves have focused on the analysis of the same type or the whole group of single compounds, and there are few qualitative and quantitative studies on single effective substances in various types. In this study, solvent extraction-ultrasonic-assisted extraction was used to extract the active ingredients of fig leaves, and the active ingredients were identified by gas chromatography-mass spectrometry and ultrahigh performance liquid chromatography-ion trap-mass spectrometry. The results show that the main components of fig leaves are chlorogenic acid, rutin, psoralen and bergapten. The single factor experiments were used to determine the best extraction process for the four components. A quantitative method for the determination of chlorogenic acid, rutin, psoralen and bergapten was established by high performance liquid chromatography. The linear relationship is obtained for chlorogenic acid in the range of 1.84~9.2 μg (R2=0.9991) with recovery rate of 95.2%, rutin in the range of 1.84~9.2 μg (R2=0.9981) with a recovery rate of 96.8%, bergapten in the range of 4~20 μg (R2=0.9998) with a recovery rate of 89.5%, and psoralen in the range of 4~20 μg (R2=0.9963) with a recovery rate of 87.1%, respectively.
In recent years, studies on the extraction and analysis of the components contained in fig leaves have focused on the analysis of the same type or the whole group of single compounds, and there are few qualitative and quantitative studies on single effective substances in various types. In this study, solvent extraction-ultrasonic-assisted extraction was used to extract the active ingredients of fig leaves, and the active ingredients were identified by gas chromatography-mass spectrometry and ultrahigh performance liquid chromatography-ion trap-mass spectrometry. The results show that the main components of fig leaves are chlorogenic acid, rutin, psoralen and bergapten. The single factor experiments were used to determine the best extraction process for the four components. A quantitative method for the determination of chlorogenic acid, rutin, psoralen and bergapten was established by high performance liquid chromatography. The linear relationship is obtained for chlorogenic acid in the range of 1.84~9.2 μg (R2=0.9991) with recovery rate of 95.2%, rutin in the range of 1.84~9.2 μg (R2=0.9981) with a recovery rate of 96.8%, bergapten in the range of 4~20 μg (R2=0.9998) with a recovery rate of 89.5%, and psoralen in the range of 4~20 μg (R2=0.9963) with a recovery rate of 87.1%, respectively.
