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2016 Volume 79 Issue 8
2016, 79(8): 691-698
Abstract:
Carbon quantum dots (CQDs) possess excellent physical, chemical and biological properties, such as aqueous dispersibility, low cytotoxicity and high resistance to chemical and photo bleaching, and it has gained wide attention and application in chemistry, biomedicine, sensormetrics and optoelectronics. In this review, latest progress of CQDs synthesis was reported, the top-down (arc discharge, laser ablation and electrochemical oxidation) and bottom-up (chemical oxidation, thermal decomposition and microwave pyrolysis) methods for preparing CQDs were emphasized on especially. Advantages and disadvantages of these strategies were discussed through comprehensive analysis and specific comparison of their distinct characteristics, utilization factors of carbon precursor, reaction conditions, size distributions of CQDs, fluorescence properties and application situations. Meanwhile, based on the principle of microreactor, reversed micelle and mesoporous material were introduced in size-controlled synthesizing CQDs. Moreover, microfluidic chips show green safety, efficient and controllable superiority to macrosystem. Combined with recent progress of synthesizing CQDs with microfluidic system, it would be further successfully applied to the preparing of CQDs in the near future.
Carbon quantum dots (CQDs) possess excellent physical, chemical and biological properties, such as aqueous dispersibility, low cytotoxicity and high resistance to chemical and photo bleaching, and it has gained wide attention and application in chemistry, biomedicine, sensormetrics and optoelectronics. In this review, latest progress of CQDs synthesis was reported, the top-down (arc discharge, laser ablation and electrochemical oxidation) and bottom-up (chemical oxidation, thermal decomposition and microwave pyrolysis) methods for preparing CQDs were emphasized on especially. Advantages and disadvantages of these strategies were discussed through comprehensive analysis and specific comparison of their distinct characteristics, utilization factors of carbon precursor, reaction conditions, size distributions of CQDs, fluorescence properties and application situations. Meanwhile, based on the principle of microreactor, reversed micelle and mesoporous material were introduced in size-controlled synthesizing CQDs. Moreover, microfluidic chips show green safety, efficient and controllable superiority to macrosystem. Combined with recent progress of synthesizing CQDs with microfluidic system, it would be further successfully applied to the preparing of CQDs in the near future.
2016, 79(8): 699-706,713
Abstract:
Conjugated microporous polymers (CMPs) are a class of skeleton materials with extension of conjugated system and possess large surface area, excellent stability, accurately tunable micropore size and volume. CMPs have shown great application potential in many fields because of its unique structural characteristics. In this paper, the synthetic methods of CMP and CMP composite materials are summarized, and the application of CMPs in gas adsorption and storage, pollutant enrichment, heterogeneous catalysis, light emitters, chemosensors, light-harvesting and energy storage are reviewed.
Conjugated microporous polymers (CMPs) are a class of skeleton materials with extension of conjugated system and possess large surface area, excellent stability, accurately tunable micropore size and volume. CMPs have shown great application potential in many fields because of its unique structural characteristics. In this paper, the synthetic methods of CMP and CMP composite materials are summarized, and the application of CMPs in gas adsorption and storage, pollutant enrichment, heterogeneous catalysis, light emitters, chemosensors, light-harvesting and energy storage are reviewed.
2016, 79(8): 707-713
Abstract:
Composite material is a multi-phase material prepared by two or more kinds of materials with different properties, which shows better or more performances than the each component. As the most promising conductive polymer material, attention is widely paid to the research of polyaniline composites at home and abroad. In this paper, the preparation methods of polyaniline composites mainly including in situ chemical polymerization method, direct blend method, electrochemistry method, layer-by-layer assembly method and so on are reviewed. The application performances of polyaniline composites in the fields of electrode, conduction, anticorrosion, sensing, separation, catalysis etc are discussed. At last, the development trend of the studies and applications of polyaniline composites in the future was prospected.
Composite material is a multi-phase material prepared by two or more kinds of materials with different properties, which shows better or more performances than the each component. As the most promising conductive polymer material, attention is widely paid to the research of polyaniline composites at home and abroad. In this paper, the preparation methods of polyaniline composites mainly including in situ chemical polymerization method, direct blend method, electrochemistry method, layer-by-layer assembly method and so on are reviewed. The application performances of polyaniline composites in the fields of electrode, conduction, anticorrosion, sensing, separation, catalysis etc are discussed. At last, the development trend of the studies and applications of polyaniline composites in the future was prospected.
2016, 79(8): 714-718,722
Abstract:
Water-soluble polymers are widely used in petroleum development, water treatment, paper making, printing, medicine and so on, whose application at high temperature depends on their thermal stability. In this paper, the thermal performances of several typical water-soluble polymers are reviewed. Furthermore, the mechanisms of thermal degradation for different types of water-soluble polymers are revealed. In addition, the effect of molecular structure and external additives on thermal stability is discussed as well. Finally, the development prospects of water-soluble polymers utilized in high temperature environment are explored.
Water-soluble polymers are widely used in petroleum development, water treatment, paper making, printing, medicine and so on, whose application at high temperature depends on their thermal stability. In this paper, the thermal performances of several typical water-soluble polymers are reviewed. Furthermore, the mechanisms of thermal degradation for different types of water-soluble polymers are revealed. In addition, the effect of molecular structure and external additives on thermal stability is discussed as well. Finally, the development prospects of water-soluble polymers utilized in high temperature environment are explored.
2016, 79(8): 719-722
Abstract:
α-Helix mimetics are an important class of small molecule inhibitors of protein-protein interactions. Small molecular α-helix mimetics derived from aromatic oligoamides have many advantages and achieved rapid development in recent years. The latest progress of α-helix mimetics based on aromatic oligoamides was reviewed.
α-Helix mimetics are an important class of small molecule inhibitors of protein-protein interactions. Small molecular α-helix mimetics derived from aromatic oligoamides have many advantages and achieved rapid development in recent years. The latest progress of α-helix mimetics based on aromatic oligoamides was reviewed.
2016, 79(8): 723-730
Abstract:
Solid-phase microextraction (SPME) has been developed rapidly as a new sample pretreatment technique due to its simplicity, short duration, easy automation, and solvent-free properties. Coating is the core of SPME technique, which determines the selectivity and extraction capacity of analysis. Ionic liquids (ILs) and polymeric ionic liquids (PILs), which possess unique properties such as environment-friendliness, negligible vapor pressure, good thermal stability, design flexibility, high viscosity and so on, have been exploited as sorbent coatings in SPME for various analytes, exhibiting excellent extraction effect and unique selectivity. This paper comprehensively reviewed the progress of IL and PIL-based sorbent coatings in SPME in the following aspects, characteristics of preparation, coating morphology, selectivity, stability and coating lifetime and applications for the past few years. Then, the advantages and disadvantages of this technology were discussed. Finally, the improving direction of the preparation and applications of IL and PIL-based sorbent coatings in SPME were prospected.
Solid-phase microextraction (SPME) has been developed rapidly as a new sample pretreatment technique due to its simplicity, short duration, easy automation, and solvent-free properties. Coating is the core of SPME technique, which determines the selectivity and extraction capacity of analysis. Ionic liquids (ILs) and polymeric ionic liquids (PILs), which possess unique properties such as environment-friendliness, negligible vapor pressure, good thermal stability, design flexibility, high viscosity and so on, have been exploited as sorbent coatings in SPME for various analytes, exhibiting excellent extraction effect and unique selectivity. This paper comprehensively reviewed the progress of IL and PIL-based sorbent coatings in SPME in the following aspects, characteristics of preparation, coating morphology, selectivity, stability and coating lifetime and applications for the past few years. Then, the advantages and disadvantages of this technology were discussed. Finally, the improving direction of the preparation and applications of IL and PIL-based sorbent coatings in SPME were prospected.
2016, 79(8): 731-738
Abstract:
The progress in catalytic-oxidation degration of lignin in recent years are reviewed according to the different catalyzers, reaction condition and mechanism. Metal catalytic-oxidation including the reaction carried out with O2 and H2O2 as oxidants such as:organometal catalytic-oxidation, metal/bromide catalytic-oxidation, metal complexe catalytic-oxidation, multiple-metal oxidants and Perovskite-type oxide catalytic-oxidation, metal/zeolites catalytic-oxidation and catalytic-oxidation by the oxidants themselves, as well as metal-free catalytic-oxidation, microwave assisted oxidative, photocatalystic oxidization, electrochemical oxidation for upgrading lignin and lignin model compounds are introduced emphatically.
The progress in catalytic-oxidation degration of lignin in recent years are reviewed according to the different catalyzers, reaction condition and mechanism. Metal catalytic-oxidation including the reaction carried out with O2 and H2O2 as oxidants such as:organometal catalytic-oxidation, metal/bromide catalytic-oxidation, metal complexe catalytic-oxidation, multiple-metal oxidants and Perovskite-type oxide catalytic-oxidation, metal/zeolites catalytic-oxidation and catalytic-oxidation by the oxidants themselves, as well as metal-free catalytic-oxidation, microwave assisted oxidative, photocatalystic oxidization, electrochemical oxidation for upgrading lignin and lignin model compounds are introduced emphatically.
2016, 79(8): 739-743
Abstract:
A novel method for developing latent fingermarks (LFMs) on various conductive substrates (stainless steel plate, aluminum sheet, zinc sheet, copper sheet, 1 Yuan coin and 5 Jiao coin) through the electrochemical co-deposition of zinc oxide-copper oxide (ZnO-CuO) composite films has been developed here. The principle of visualizing LFMs is that the electrochemical co-deposition process selectively occurs on the valley regions and bare conductive surfaces owing to electrochemical inert property of the residues left at the ridges areas, so a color difference between the ridge and valley areas is generated resulting in a high visual contrast of the LFMs. The FE-SEM images and elemental analysis results confirmed that the ZnO-CuO composite films were electrochemically deposited on the valley regions of the LFMs rather than the ridge regions. Moreover, the visualization images of the LFMs originated from the deposition of ZnO-CuO composite films could provide the clear second level details and partial third level details of the LFMs. This method is simple, high efficient and widely applicable in the visualization of the LFMs and would be a promising tool in the practical application.
A novel method for developing latent fingermarks (LFMs) on various conductive substrates (stainless steel plate, aluminum sheet, zinc sheet, copper sheet, 1 Yuan coin and 5 Jiao coin) through the electrochemical co-deposition of zinc oxide-copper oxide (ZnO-CuO) composite films has been developed here. The principle of visualizing LFMs is that the electrochemical co-deposition process selectively occurs on the valley regions and bare conductive surfaces owing to electrochemical inert property of the residues left at the ridges areas, so a color difference between the ridge and valley areas is generated resulting in a high visual contrast of the LFMs. The FE-SEM images and elemental analysis results confirmed that the ZnO-CuO composite films were electrochemically deposited on the valley regions of the LFMs rather than the ridge regions. Moreover, the visualization images of the LFMs originated from the deposition of ZnO-CuO composite films could provide the clear second level details and partial third level details of the LFMs. This method is simple, high efficient and widely applicable in the visualization of the LFMs and would be a promising tool in the practical application.
2016, 79(8): 744-748
Abstract:
Acesulfame-K, aspartame and saccharin sodium are commonly used as food flavoring agents. All of them show strong absorptions in the UV spectral region which are seriously overlapped. This paper reports simultaneous determination of them using UV spectroscopic combined with chemometric methods. Firstly, partial least squares regression (PLSR) was used, the total relative deviation was 7.01%. Secondly, PLSR combined with the characteristic peaks were employed, the total relative deviation was 4.67%. Lastly, local partial least squares regression (LPLSR) combined with the characteristic peaks were employed for the design of a model. The characteristic peaks of UV spectra of calibrating samples were chose as the independent variable factor, and LPLSR was used in data processing. Compared with PLSR method, the total relative deviation of LPLSR method is smaller, which is only 3.05%. Finally, the model was used to the concentration prediction of beverage samples with satisfactory results. The linear range of acesulfame-K, aspartame and saccharin sodium is 1.0~30.0 mg/L, 1.0~10.0 mg/L and 1.0~10.0 mg/L respctively.
Acesulfame-K, aspartame and saccharin sodium are commonly used as food flavoring agents. All of them show strong absorptions in the UV spectral region which are seriously overlapped. This paper reports simultaneous determination of them using UV spectroscopic combined with chemometric methods. Firstly, partial least squares regression (PLSR) was used, the total relative deviation was 7.01%. Secondly, PLSR combined with the characteristic peaks were employed, the total relative deviation was 4.67%. Lastly, local partial least squares regression (LPLSR) combined with the characteristic peaks were employed for the design of a model. The characteristic peaks of UV spectra of calibrating samples were chose as the independent variable factor, and LPLSR was used in data processing. Compared with PLSR method, the total relative deviation of LPLSR method is smaller, which is only 3.05%. Finally, the model was used to the concentration prediction of beverage samples with satisfactory results. The linear range of acesulfame-K, aspartame and saccharin sodium is 1.0~30.0 mg/L, 1.0~10.0 mg/L and 1.0~10.0 mg/L respctively.
2016, 79(8): 749-753
Abstract:
Maleic anhydride-β-cyclodextrin chiral monolithic capillary electrochromatography column was prepared by one-step reaction with maleic anhydride-β-cyclodextrin(MAH-β-CD), glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EDMA) as functional monomers. Moreover, the preparation conditions of the monolithic column were also optimized. The structure and morphology of the monolithic column were characterized by IR and SEM. The column efficiency determined by using thiourea as the neutral marker was 99856 plates/m. The column was evaluated by arginine. The new monolithic column had good chiral recognition ability, better reproducibility and easy operation. In capillary electrochromatography mode, the Salbutamol enantiomers were separated by capillary electrochromatography-mass spectrometry (CEC-MS), and the resolution is 1.67.
Maleic anhydride-β-cyclodextrin chiral monolithic capillary electrochromatography column was prepared by one-step reaction with maleic anhydride-β-cyclodextrin(MAH-β-CD), glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EDMA) as functional monomers. Moreover, the preparation conditions of the monolithic column were also optimized. The structure and morphology of the monolithic column were characterized by IR and SEM. The column efficiency determined by using thiourea as the neutral marker was 99856 plates/m. The column was evaluated by arginine. The new monolithic column had good chiral recognition ability, better reproducibility and easy operation. In capillary electrochromatography mode, the Salbutamol enantiomers were separated by capillary electrochromatography-mass spectrometry (CEC-MS), and the resolution is 1.67.
2016, 79(8): 754-759
Abstract:
Density functional theory (DFT) and Raman spectroscopy have been employed in studying on copper chloride solution. The structures have been investigated using B3LYP, information of the clusters in solution is obtained in the kinetic and thermodynamic analysis. The theoretical Raman spectra in the 100~500 cm-1 is mainly Cu-O stretching vibration peak, the symmetric and asymmetric stretching vibration of O-H is located at 3400~4000 cm-1. Experimental spectra emerge newly peak in the 200~340 cm-1, stretching vibration peak of O-H is located in the 2500~4000 cm-1,with the increase of the solution concentration, stretching vibration peak intensity of O-H decreases gradually and peak shape was changed significantly. A comprehensive conclusion from the theoretical and experimental studies is that the newly peak caused by the vibration of the Cu-O, CuCl2 present in the aqueous solution can produce the solvation phenomenon, and solvation number decreases with the increase of the solution concentration.
Density functional theory (DFT) and Raman spectroscopy have been employed in studying on copper chloride solution. The structures have been investigated using B3LYP, information of the clusters in solution is obtained in the kinetic and thermodynamic analysis. The theoretical Raman spectra in the 100~500 cm-1 is mainly Cu-O stretching vibration peak, the symmetric and asymmetric stretching vibration of O-H is located at 3400~4000 cm-1. Experimental spectra emerge newly peak in the 200~340 cm-1, stretching vibration peak of O-H is located in the 2500~4000 cm-1,with the increase of the solution concentration, stretching vibration peak intensity of O-H decreases gradually and peak shape was changed significantly. A comprehensive conclusion from the theoretical and experimental studies is that the newly peak caused by the vibration of the Cu-O, CuCl2 present in the aqueous solution can produce the solvation phenomenon, and solvation number decreases with the increase of the solution concentration.
2016, 79(8): 760-767
Abstract:
A new class of sandwich complexes D4d[Ben(C4H4)2]2- and [Ben(C4H4)2] Li2 (n=2~8) containing-Be-Be-chain have been investigated by density functional theory (DFT). The equilibrium geometries, electronic structures, bonding characters, and thermodynamic stabilities of these complexes are studied by both B3LYP and BP86 methods at 6-311+G(d,p) level. These staggered (D4d) Ben2+ -chain sandwich complexes are all true minima on the potential energy surface. Natural bond orbital (NBO), atom in molecular (AIM) and molecular orbital (MO) analysis for the series of complexes reveal that the Be-Be bonds of the titled complexes are close to covalent σ single bonds, while the bonding between ligands and Ben2+ (n=2~8) nuclear is mainly ionic. Nucleus independent chemical shifts (NICS) values indicate that the aromatic character of C4H42- rings in D4d[Ben(C4H4)2]2- are well maintained. The lithium salts of stable sandwich complexes[Ben(C4H4)2] Li2 (n=2~8) may be prepared by C4H4Li2/C5H5- ligands exchange reaction in future experiments to expand the structural domain of multimental sandwich-type complexes.
A new class of sandwich complexes D4d[Ben(C4H4)2]2- and [Ben(C4H4)2] Li2 (n=2~8) containing-Be-Be-chain have been investigated by density functional theory (DFT). The equilibrium geometries, electronic structures, bonding characters, and thermodynamic stabilities of these complexes are studied by both B3LYP and BP86 methods at 6-311+G(d,p) level. These staggered (D4d) Ben2+ -chain sandwich complexes are all true minima on the potential energy surface. Natural bond orbital (NBO), atom in molecular (AIM) and molecular orbital (MO) analysis for the series of complexes reveal that the Be-Be bonds of the titled complexes are close to covalent σ single bonds, while the bonding between ligands and Ben2+ (n=2~8) nuclear is mainly ionic. Nucleus independent chemical shifts (NICS) values indicate that the aromatic character of C4H42- rings in D4d[Ben(C4H4)2]2- are well maintained. The lithium salts of stable sandwich complexes[Ben(C4H4)2] Li2 (n=2~8) may be prepared by C4H4Li2/C5H5- ligands exchange reaction in future experiments to expand the structural domain of multimental sandwich-type complexes.
2016, 79(8): 768-770
Abstract:
Tetrahydrothiophene derivatives were synthesized from the Michael-aldol reaction of 1,4-dithiane-2,5-diol and N-phenyl maleimide in water using alkaline protease as a promiscuous catalyst, the yield of 93% and the dr of 3:1 were obtained at 40℃. This method has the advantages of mild reaction conditions, short reaction time, simple post-processing, etc.
Tetrahydrothiophene derivatives were synthesized from the Michael-aldol reaction of 1,4-dithiane-2,5-diol and N-phenyl maleimide in water using alkaline protease as a promiscuous catalyst, the yield of 93% and the dr of 3:1 were obtained at 40℃. This method has the advantages of mild reaction conditions, short reaction time, simple post-processing, etc.
2016, 79(8): 771-774
Abstract:
Sodium polyaspartic acid (PASP) was used for the removal of cadmium from shellfish meat homogenate of mactra quadrangularis. The effects of PASP concentration, pH, removal time, and ratio of material to liquid on the cadmium removal rate were investigated, and the conditions of cadmium removal were optimized by orthogonal experiment method. The removal rate of cadmium was up to 89.77% when the concentration of PASP was 0.05mol/L, pH was 3.0, removal time was 3 h, and the ratio of material to liquid was 1:10. Therefore, PASP was suitable for the removal of cadmium from shellfish meat homogenate.
Sodium polyaspartic acid (PASP) was used for the removal of cadmium from shellfish meat homogenate of mactra quadrangularis. The effects of PASP concentration, pH, removal time, and ratio of material to liquid on the cadmium removal rate were investigated, and the conditions of cadmium removal were optimized by orthogonal experiment method. The removal rate of cadmium was up to 89.77% when the concentration of PASP was 0.05mol/L, pH was 3.0, removal time was 3 h, and the ratio of material to liquid was 1:10. Therefore, PASP was suitable for the removal of cadmium from shellfish meat homogenate.
2016, 79(8): 775-783,774
Abstract:
The space group deductions of crystals are the key link in the descriptions and expressions of crystal structures, and are the theoretical means as well for verifying the experimental structures. Because the descriptions involve mathematics methods, physics techniques, and graphics software usages, therefore, they are not only teaching emphases but also difficulties. Based on the parameters of crystal structure determinations of hexagonal vanadium sulfide, we can reproduce the crystal pattern in graphics software with self-compiling crystallographic code cryst 2015. In the point space and three-dimensional real vector space, the space group and the matrix representation group were obtained by expressing the translational and symmetrical operations with the linear mapping. The products of power of generators unambiguously derive the formation sequence of elements of space group and the crystallographic classification. This coherently deductive method with an example is advantageous for students to establish the crystallographic knowledge framework, especially is able to help abecedarians to comprehend the scientific ideological system of crystallography.
The space group deductions of crystals are the key link in the descriptions and expressions of crystal structures, and are the theoretical means as well for verifying the experimental structures. Because the descriptions involve mathematics methods, physics techniques, and graphics software usages, therefore, they are not only teaching emphases but also difficulties. Based on the parameters of crystal structure determinations of hexagonal vanadium sulfide, we can reproduce the crystal pattern in graphics software with self-compiling crystallographic code cryst 2015. In the point space and three-dimensional real vector space, the space group and the matrix representation group were obtained by expressing the translational and symmetrical operations with the linear mapping. The products of power of generators unambiguously derive the formation sequence of elements of space group and the crystallographic classification. This coherently deductive method with an example is advantageous for students to establish the crystallographic knowledge framework, especially is able to help abecedarians to comprehend the scientific ideological system of crystallography.
