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2017 Volume 80 Issue 2
2017, 80(2): 123-131
Abstract:
Near infrared light sensors have shown great potentials in the fields of military guard, space exploration, scientific detection and medical diagnosis. Conventional NIR sensing materials routinely turn the photon of NIR light into electrical signals based on photoelectric effect, with the help of semimetal-like inorganic materials that have narrow band gap. Though providing high sensitivity, these inorganic materials are meeting a bottleneck in consideration of cumbersome process, non-flexibility, high cost and difficult degradation. Emerging conjugated polymer materials with low band gap provide an alternative strategy to design novel NIR sensors. These polymer materials possess tunable energy level and are able to respond to NIR light rapidly. The enhanced sensitivity to NIR light is attributed to photothermal conversion or photoelectric effect. Taking advantages of flexibility, eco-friendliness, facile fabrication, doping convenience and high sensitivity, conjugated polymer materials afford great opportunity for developing new generation of NIR sensors with high popularization.
Near infrared light sensors have shown great potentials in the fields of military guard, space exploration, scientific detection and medical diagnosis. Conventional NIR sensing materials routinely turn the photon of NIR light into electrical signals based on photoelectric effect, with the help of semimetal-like inorganic materials that have narrow band gap. Though providing high sensitivity, these inorganic materials are meeting a bottleneck in consideration of cumbersome process, non-flexibility, high cost and difficult degradation. Emerging conjugated polymer materials with low band gap provide an alternative strategy to design novel NIR sensors. These polymer materials possess tunable energy level and are able to respond to NIR light rapidly. The enhanced sensitivity to NIR light is attributed to photothermal conversion or photoelectric effect. Taking advantages of flexibility, eco-friendliness, facile fabrication, doping convenience and high sensitivity, conjugated polymer materials afford great opportunity for developing new generation of NIR sensors with high popularization.
2017, 80(2): 132-138
Abstract:
Covalent organic frameworks (COFs) represent an emerging class of crystalline polymeric material with porous structures. COFs have shown interesting applications in molecular storage and separation, catalysis and energy conversion. In this review, we will introduce a series of porphyrin-based COFs and summarize their research progress in synthesis and application.
Covalent organic frameworks (COFs) represent an emerging class of crystalline polymeric material with porous structures. COFs have shown interesting applications in molecular storage and separation, catalysis and energy conversion. In this review, we will introduce a series of porphyrin-based COFs and summarize their research progress in synthesis and application.
2017, 80(2): 139-145
Abstract:
New high-energy oxidizers occupy a large mass proportion in solid propellants and are one of key materials for improving the energy properties of solid propellants. The latest research progresses on synthesis, physicochemical, explosive properties and modification ADN, HNF, TNAZ, and HNFX were summarized in this paper. The development directions and application prospects of these four oxidizers in solid propellants were expected.
New high-energy oxidizers occupy a large mass proportion in solid propellants and are one of key materials for improving the energy properties of solid propellants. The latest research progresses on synthesis, physicochemical, explosive properties and modification ADN, HNF, TNAZ, and HNFX were summarized in this paper. The development directions and application prospects of these four oxidizers in solid propellants were expected.
2017, 80(2): 146-150, 138
Abstract:
Pyrazole derivatives are important intermediates in pharmaceutical synthesis and play significant roles in anticancer, antiviral, and antidepression. Progress in syntheses of pyrazole derivatives, including cyclocondensation of 1, 3-dielectrophilic compounds with hydrazines and 1, 3-dipolar cycloadditions methods are summarized.
Pyrazole derivatives are important intermediates in pharmaceutical synthesis and play significant roles in anticancer, antiviral, and antidepression. Progress in syntheses of pyrazole derivatives, including cyclocondensation of 1, 3-dielectrophilic compounds with hydrazines and 1, 3-dipolar cycloadditions methods are summarized.
2017, 80(2): 151-156
Abstract:
The application and development of molecular weight estimation for oils-soluble and water-soluble polymers by gel permeation chromatography (GPC) is summarized. The effects of pH, salt concentration and temperature on molecular weight estimation of water-soluble ones are presented. In addition, novel utilizations of GPC with dual detectors are introduced. Calibration methodologies in GPC, including various instrumental method and director calibration, as well as universal calibration are reviewed. With the combination of multi-detectors, the performance of one detector could be effectively checked against others and the estimated molecular weights of polymer tend to be reliable and precise.
The application and development of molecular weight estimation for oils-soluble and water-soluble polymers by gel permeation chromatography (GPC) is summarized. The effects of pH, salt concentration and temperature on molecular weight estimation of water-soluble ones are presented. In addition, novel utilizations of GPC with dual detectors are introduced. Calibration methodologies in GPC, including various instrumental method and director calibration, as well as universal calibration are reviewed. With the combination of multi-detectors, the performance of one detector could be effectively checked against others and the estimated molecular weights of polymer tend to be reliable and precise.
2017, 80(2): 157-163
Abstract:
With the progressing of halogen-free flame retardant (FR) materials globally, the nitrogen-containing FR, phosphorus-containing FR, silicone-containing FR, etc. and their derivatives have attracted much attention. Through employing in-situ polymerization and copolymerization methods in the preparation of FR nylon, the problems existed in blending method that FRs disperse unevenly in the matrix and resulting performance reduction can be effectively resolved. In-situ polymerization and copolymerization are usually distinguished by the way how retardant components disperse in the matrix. Commonly, the former is mainly physically dispersed in the matrix, while the latter is chemically bonded to the matrix. In this paper, under the premise of different preparation methods, FRs can be subdivided according to their categories, and the related researches on the preparation of non-halogen FR nylon by in-situ polymerization and copolymerization are reviewed. The current problems and the future direction in this field are also discussed.
With the progressing of halogen-free flame retardant (FR) materials globally, the nitrogen-containing FR, phosphorus-containing FR, silicone-containing FR, etc. and their derivatives have attracted much attention. Through employing in-situ polymerization and copolymerization methods in the preparation of FR nylon, the problems existed in blending method that FRs disperse unevenly in the matrix and resulting performance reduction can be effectively resolved. In-situ polymerization and copolymerization are usually distinguished by the way how retardant components disperse in the matrix. Commonly, the former is mainly physically dispersed in the matrix, while the latter is chemically bonded to the matrix. In this paper, under the premise of different preparation methods, FRs can be subdivided according to their categories, and the related researches on the preparation of non-halogen FR nylon by in-situ polymerization and copolymerization are reviewed. The current problems and the future direction in this field are also discussed.
2017, 80(2): 164-172, 163
Abstract:
Graphene was applied widely in environmental protection and detection due to its unique physicochemical properties, including larger specific surface area, high-speed electron mobility and excellent electrocatalytic activity. In the past few years, many efficient adsorbents and sensors based on graphene have been constructed for the treatment of heavy metal ions. In this article, recent research achievements are reviewed on the application of graphene-based materials for the removal and detection of heavy metal ions, the advantages and disadvantages of different methods are compared. Finally, a perspective on the future challenge and research focus is discussed.
Graphene was applied widely in environmental protection and detection due to its unique physicochemical properties, including larger specific surface area, high-speed electron mobility and excellent electrocatalytic activity. In the past few years, many efficient adsorbents and sensors based on graphene have been constructed for the treatment of heavy metal ions. In this article, recent research achievements are reviewed on the application of graphene-based materials for the removal and detection of heavy metal ions, the advantages and disadvantages of different methods are compared. Finally, a perspective on the future challenge and research focus is discussed.
2017, 80(2): 173-178
Abstract:
Anammox bacteria has a long generation time and is susceptible to the environmental conditions. Organic substrate concentration has significant impact on the anammox process and the denitrification effect. Therefore, how to reduce the effect of organic matter on the activity of anammox is a difficulty in its application. In this paper, effect of organic matter (type and concentration) on the process of anammox is introduced, and research progress in influencing factors of anaerobic ammonium oxidizing is summarized. It suggested that under the organic matter concentration of 100~200 mg/L, the activity of anammox bacteria is not inhibited. At the same time, regulating the ectopic utilization of different types and concentrations of organic compounds can help to achieve the purpose of removing carbon and nitrogen with the synchronization of the anammox, methaogenesis or denitrification. It concluded that further researches on metabolic mechanism of anammox bacteria, the competition and cooperation mechanism with other microorganisms, as well as the enrichment and purification of the bacteria under coupling effect should be carried out.
Anammox bacteria has a long generation time and is susceptible to the environmental conditions. Organic substrate concentration has significant impact on the anammox process and the denitrification effect. Therefore, how to reduce the effect of organic matter on the activity of anammox is a difficulty in its application. In this paper, effect of organic matter (type and concentration) on the process of anammox is introduced, and research progress in influencing factors of anaerobic ammonium oxidizing is summarized. It suggested that under the organic matter concentration of 100~200 mg/L, the activity of anammox bacteria is not inhibited. At the same time, regulating the ectopic utilization of different types and concentrations of organic compounds can help to achieve the purpose of removing carbon and nitrogen with the synchronization of the anammox, methaogenesis or denitrification. It concluded that further researches on metabolic mechanism of anammox bacteria, the competition and cooperation mechanism with other microorganisms, as well as the enrichment and purification of the bacteria under coupling effect should be carried out.
2017, 80(2): 179-184, 207
Abstract:
The Aryl hydrocarbon receptor (AhR), a ligand-actived nuclear transcription factor, regulates the expressions of a diverse group of genes when small molecules go into the pocket of its single ligand binding domain(LBD). In this study, we found Phe289, Tyr316 and Ile319 play "gatekeeper" roles via comparing genus-species specific and structure analysis. The four mutation models (WT, Phe289Ala, Tyr316Ala, Ile319Ala) were performed using the Amber99sb force field of GROMACS software package. The complex stability, protein conformational change, active site volume and binding free energy of the binary complex were analyzed by "gatekeeper" residues function. The results indicated that Phe289, Tyr316 and Ile319 play "gatekeeper" roles through hydrophobic interaction. The whole structure analyses demonstrate that mutagenesis comes from the pockets, which will destabilize cavity environment, causing obvious fluctuations and leading to low ligand-affinity and ligand escape. These simulation results interpret some experimental phenomena and provide further structural information that are useful in drug design based on aryl hydrocarbon receptor.
The Aryl hydrocarbon receptor (AhR), a ligand-actived nuclear transcription factor, regulates the expressions of a diverse group of genes when small molecules go into the pocket of its single ligand binding domain(LBD). In this study, we found Phe289, Tyr316 and Ile319 play "gatekeeper" roles via comparing genus-species specific and structure analysis. The four mutation models (WT, Phe289Ala, Tyr316Ala, Ile319Ala) were performed using the Amber99sb force field of GROMACS software package. The complex stability, protein conformational change, active site volume and binding free energy of the binary complex were analyzed by "gatekeeper" residues function. The results indicated that Phe289, Tyr316 and Ile319 play "gatekeeper" roles through hydrophobic interaction. The whole structure analyses demonstrate that mutagenesis comes from the pockets, which will destabilize cavity environment, causing obvious fluctuations and leading to low ligand-affinity and ligand escape. These simulation results interpret some experimental phenomena and provide further structural information that are useful in drug design based on aryl hydrocarbon receptor.
2017, 80(2): 185-190, 207
Abstract:
The binding of 4-hydroxyl-2, 2', 3, 4'-tetrabromodiphenyl ether (4-OH-BDE-42) with human serum albumin (HSA) was investigated by molecular modeling, fluorescence spectroscopy and UV-Vis absorption spectroscopy. The results of three-dimensional (3D) fluorescence showed that the fluorescence intensity of HSA decreases in the presence of 4-OH-BDE-42, and the microenvironment and conformation in HSA are also changed. In addition, the characterizations of fluorescence and UV-Vis spectroscopy showed that the intrinsic fluorescence of HSA with binding to 4-OH-BDE-42 is definitely quenched via static quenching and non-radiative energy transfer. Ka is higher than 106 L·mol-1, indicating there is a strong binding force between 4-OH-BDE-42 and HSA, and the binding distance r is obtained to be 3.66 nm. According to the analysis of thermodynamic parameters, the hydrophobic interaction was identified as the major driving force for the binding with ΔH>0, ΔS>0, which is consistent with the results of molecular docking and the analysis of binding free energy. The residues, LYS199, GLU292, ARG257, ARG218, ALA291, and HIS242, were identified as the key residues in binding site of HSA.
The binding of 4-hydroxyl-2, 2', 3, 4'-tetrabromodiphenyl ether (4-OH-BDE-42) with human serum albumin (HSA) was investigated by molecular modeling, fluorescence spectroscopy and UV-Vis absorption spectroscopy. The results of three-dimensional (3D) fluorescence showed that the fluorescence intensity of HSA decreases in the presence of 4-OH-BDE-42, and the microenvironment and conformation in HSA are also changed. In addition, the characterizations of fluorescence and UV-Vis spectroscopy showed that the intrinsic fluorescence of HSA with binding to 4-OH-BDE-42 is definitely quenched via static quenching and non-radiative energy transfer. Ka is higher than 106 L·mol-1, indicating there is a strong binding force between 4-OH-BDE-42 and HSA, and the binding distance r is obtained to be 3.66 nm. According to the analysis of thermodynamic parameters, the hydrophobic interaction was identified as the major driving force for the binding with ΔH>0, ΔS>0, which is consistent with the results of molecular docking and the analysis of binding free energy. The residues, LYS199, GLU292, ARG257, ARG218, ALA291, and HIS242, were identified as the key residues in binding site of HSA.
2017, 80(2): 191-195
Abstract:
The molecular electronegativity distance vector (mt) was used to describe the chemical structures of 20 kinds of N-acyl-thiochromenothiazol-2-amine derivatives. The optimal variable subset regression method was adopted to establish the three element model between inhibition activities of above molecules to acetylcholinesterase of electric eel and mt. The correlation coefficients (R2) and leave-one-out (LOO) cross validation Rcv2 of the optimal three-parameter QSAR models were 0.936 and 0.850 for pM model, respectively. The QSAR model has both favorable robustness and good prediction capability by R2, Radj2, F, Rcv2, VIF, AIC, FIT tests. The possible mechanism for the inhibition of acetylcholinesterase has been proposed according to the model. On the basis of the model analysis, hydrogen bond plays a primary and positive role, however, hydrophobicity plays the secondary and negative one.
The molecular electronegativity distance vector (mt) was used to describe the chemical structures of 20 kinds of N-acyl-thiochromenothiazol-2-amine derivatives. The optimal variable subset regression method was adopted to establish the three element model between inhibition activities of above molecules to acetylcholinesterase of electric eel and mt. The correlation coefficients (R2) and leave-one-out (LOO) cross validation Rcv2 of the optimal three-parameter QSAR models were 0.936 and 0.850 for pM model, respectively. The QSAR model has both favorable robustness and good prediction capability by R2, Radj2, F, Rcv2, VIF, AIC, FIT tests. The possible mechanism for the inhibition of acetylcholinesterase has been proposed according to the model. On the basis of the model analysis, hydrogen bond plays a primary and positive role, however, hydrophobicity plays the secondary and negative one.
2017, 80(2): 196-201
Abstract:
The novel dendritic salicylaldimine ligand was synthesized by Schiff's base reaction using 1.0 generation dendrimer as bridged group, and the cobalt catalyst with 1, 8-octanediamine as core based on dendritic salicylaldimine ligand was prepared by cobalt metallic coordination reaction. The structures of the dendritic ligand and the cobalt catalyst were characterized by FT-IR, UV, 1H NMR and MS, and proved to be consistent with the theoretical structures. The catalyst was evaluated as precursor for ethylene oligomerization with various co-catalysts, solvents, reaction conditions and metallic active centers. The results showed that the catalyst exhibit better catalytic performance after activation with Et2AlCl in toluene. Under the conditions of 25℃, Al/Co molar ratio 1500, 1.0 MPa and 0.5 h employed for the cobalt catalyst, the catalytic activity showed a maximum value of 6.84×105 g/(mol Co·h), and the selectivity for ≥C8 olefins was 52.77%.
The novel dendritic salicylaldimine ligand was synthesized by Schiff's base reaction using 1.0 generation dendrimer as bridged group, and the cobalt catalyst with 1, 8-octanediamine as core based on dendritic salicylaldimine ligand was prepared by cobalt metallic coordination reaction. The structures of the dendritic ligand and the cobalt catalyst were characterized by FT-IR, UV, 1H NMR and MS, and proved to be consistent with the theoretical structures. The catalyst was evaluated as precursor for ethylene oligomerization with various co-catalysts, solvents, reaction conditions and metallic active centers. The results showed that the catalyst exhibit better catalytic performance after activation with Et2AlCl in toluene. Under the conditions of 25℃, Al/Co molar ratio 1500, 1.0 MPa and 0.5 h employed for the cobalt catalyst, the catalytic activity showed a maximum value of 6.84×105 g/(mol Co·h), and the selectivity for ≥C8 olefins was 52.77%.
Preparation of Cysteamine Modified Polyacrylonitrile Fiber and Its Performance for Adsorption of Ag+
2017, 80(2): 202-207
Abstract:
A novel fiber material (cPAN) was prepared by the modification of polyacrylonitrile (PAN) fiber. Its structure was characterized by FT IR spectra, and its thiol content was determined to be 5.08 mmol/g. The Ag+ adsorption and regeneration performance of cPAN was examined at 25℃. The results showed that the optimum initial pH range for adsorption is 5~7, the maximum adsorption capacity is 500 mg/g. It can reach adsorption equilibrium within 30 min when the initial Ag+ concentration is 100 mg/L. More than 90% of the Ag+ could be eluted from cPAN fiber by the mixed solution of 5% thiourea and 1.0 mol/L hydrochloric acid, and the recycled fiber could be used repeatedly.
A novel fiber material (cPAN) was prepared by the modification of polyacrylonitrile (PAN) fiber. Its structure was characterized by FT IR spectra, and its thiol content was determined to be 5.08 mmol/g. The Ag+ adsorption and regeneration performance of cPAN was examined at 25℃. The results showed that the optimum initial pH range for adsorption is 5~7, the maximum adsorption capacity is 500 mg/g. It can reach adsorption equilibrium within 30 min when the initial Ag+ concentration is 100 mg/L. More than 90% of the Ag+ could be eluted from cPAN fiber by the mixed solution of 5% thiourea and 1.0 mol/L hydrochloric acid, and the recycled fiber could be used repeatedly.
2017, 80(2): 208-211, 215
Abstract:
γ-Al2O3 carriers were modified by hydrothermal treatment with two hydrothermal solvents and applied in catalytic isobutane dehydrogenation, the effect of hydrothermal treatment temperature on physicochemical properties of alumina carriers as well as the influence of hydrothermal modification on catalyst's dehydrogenation performance were studied. The modified γ-Al2O3 carriers were characterized by XRD, N2 adsorption-desorption and H2-TPR. The results showed that the crystallinity of γ-Al2O3 was increased after hydration and calcination process. And hydrothermal treatment enhanced the interaction between active component and carriers, and improved the performance of CrOx/Al2O3. Through hydrothermal treatment with salt solution, the CrOx/Al2O3 catalyst exhibited the optimal isobutane dehydrogenation performance when supports were treated at 140℃ for 4 h, average isobutane dehydrogenation conversion, average selectivity and deactivation ratio for reaction 10 h were 43.04%, 86.34% and 13.7%, respectively.
γ-Al2O3 carriers were modified by hydrothermal treatment with two hydrothermal solvents and applied in catalytic isobutane dehydrogenation, the effect of hydrothermal treatment temperature on physicochemical properties of alumina carriers as well as the influence of hydrothermal modification on catalyst's dehydrogenation performance were studied. The modified γ-Al2O3 carriers were characterized by XRD, N2 adsorption-desorption and H2-TPR. The results showed that the crystallinity of γ-Al2O3 was increased after hydration and calcination process. And hydrothermal treatment enhanced the interaction between active component and carriers, and improved the performance of CrOx/Al2O3. Through hydrothermal treatment with salt solution, the CrOx/Al2O3 catalyst exhibited the optimal isobutane dehydrogenation performance when supports were treated at 140℃ for 4 h, average isobutane dehydrogenation conversion, average selectivity and deactivation ratio for reaction 10 h were 43.04%, 86.34% and 13.7%, respectively.
2017, 80(2): 212-215
Abstract:
In this paper, the traditional chemical synthesis methods have been modified to get ranitidine with high yield and purity. Under the protection of nitrogen, N-methyl-1-alkylthio-2-nitroethenamines (referred to as "three side") and 2-[[[5-(dimethylamine)methyl-furan-2-yl]methyl]thio]ethylamine(referred to as "thiobisethylamine") as starting materials in the mole ratio of 1.156:1 was added to the water, keep the temperature at 36℃ for 4h. The reaction mixture was acidified to pH 3.5~4 and extracted with dichloromethane. The organic phase can be used to recycle three side with high recovery rate of 98.9%. Aqueous phase was basified to pH 9~10, then extracted with dichloromethane again, dried, filtered, evaporated, and recrystallized to get ranitidine with yield of 89.7%.
In this paper, the traditional chemical synthesis methods have been modified to get ranitidine with high yield and purity. Under the protection of nitrogen, N-methyl-1-alkylthio-2-nitroethenamines (referred to as "three side") and 2-[[[5-(dimethylamine)methyl-furan-2-yl]methyl]thio]ethylamine(referred to as "thiobisethylamine") as starting materials in the mole ratio of 1.156:1 was added to the water, keep the temperature at 36℃ for 4h. The reaction mixture was acidified to pH 3.5~4 and extracted with dichloromethane. The organic phase can be used to recycle three side with high recovery rate of 98.9%. Aqueous phase was basified to pH 9~10, then extracted with dichloromethane again, dried, filtered, evaporated, and recrystallized to get ranitidine with yield of 89.7%.
