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2015 Volume 32 Issue 12
2015, 32(12): 1343-1357
doi: 10.11944/j.issn.1000-0518.2015.12.150158
Abstract:
The use of ion exchange resins as catalysts in organic synthesis,such as esterification,alkylation,etherification,aldolization,isomerization and epoxidation was reviewed. Compared with inorganic catalysts,the ion exchange resin catalysts show excellent catalytic performance and readily recyclability. This article encompasses the progress made in current research and the application of ion exchange resins as catalyst is also summarized.
The use of ion exchange resins as catalysts in organic synthesis,such as esterification,alkylation,etherification,aldolization,isomerization and epoxidation was reviewed. Compared with inorganic catalysts,the ion exchange resin catalysts show excellent catalytic performance and readily recyclability. This article encompasses the progress made in current research and the application of ion exchange resins as catalyst is also summarized.
2015, 32(12): 1358-1363
doi: 10.11944/j.issn.1000-0518.2015.12.150228
Abstract:
Heparin sodium/polyvinyl alcohol(HS/PVA) composite hydrogel was prepared successfully by the cyclic freezing-thawing method. Effects of mass fraction of heparin sodium on visible light transmittance,moisture content,hydrophilcity,mechanical property and percentage of heparin sodium release of composite hydrogel were studied. The results show that the introduction of heparin sodium into the structure of PVA can enhance the moisture content and hydrophilic of HS/PVA composite hydrogel,simultaneously,reduce visible light transmittance and mechanical properties of HS/PVA composite hydrogel. The release of heparin sodium from HS/PVA composite hydrogel resists the cell adhesion. Therefore,the HS/PVA composite hydrogel has a potential application in the fields of optical central materials of artificial cornea.
Heparin sodium/polyvinyl alcohol(HS/PVA) composite hydrogel was prepared successfully by the cyclic freezing-thawing method. Effects of mass fraction of heparin sodium on visible light transmittance,moisture content,hydrophilcity,mechanical property and percentage of heparin sodium release of composite hydrogel were studied. The results show that the introduction of heparin sodium into the structure of PVA can enhance the moisture content and hydrophilic of HS/PVA composite hydrogel,simultaneously,reduce visible light transmittance and mechanical properties of HS/PVA composite hydrogel. The release of heparin sodium from HS/PVA composite hydrogel resists the cell adhesion. Therefore,the HS/PVA composite hydrogel has a potential application in the fields of optical central materials of artificial cornea.
2015, 32(12): 1364-1370
doi: 10.11944/j.issn.1000-0518.2015.12.150143
Abstract:
Glucoamylase(GA) was entrapped and immobilized in the poly(acrylic acid)(PAA)/polyvinyl alcohol(PVA) nanofibers membrane by the mixed liquid electrospinning entrapping method. The enzyme immobilization potential of PAA/PVA was investigated through appraised enzymatic characterization of immobilized GA. Its physicochemical properties and enzymatic characterizations were identified. Fourier transform infrared spectrum(FT-IR) and scanning electron microscope(SEM) photographs indicate that GA can be successfully entrapped in the interior of the electrospinning PAA/PVA composite nanofiber membrane.The optimum reaction temperature of immobilized GA is 68℃,9 degrees higher than that of free GA,and the applicable pH range of immobilized GA is wider than that of free GA significantly. In addition,immobilized GA also has good thermal stability,storage stability and reusability. PAA/PVA nanofiber membrane is a good carrier for enzyme immobilization with potential application. The protein molecules can be easily fixed into the inside of nanofiber membrane via mixed liquid electrospinning entrapping method.
Glucoamylase(GA) was entrapped and immobilized in the poly(acrylic acid)(PAA)/polyvinyl alcohol(PVA) nanofibers membrane by the mixed liquid electrospinning entrapping method. The enzyme immobilization potential of PAA/PVA was investigated through appraised enzymatic characterization of immobilized GA. Its physicochemical properties and enzymatic characterizations were identified. Fourier transform infrared spectrum(FT-IR) and scanning electron microscope(SEM) photographs indicate that GA can be successfully entrapped in the interior of the electrospinning PAA/PVA composite nanofiber membrane.The optimum reaction temperature of immobilized GA is 68℃,9 degrees higher than that of free GA,and the applicable pH range of immobilized GA is wider than that of free GA significantly. In addition,immobilized GA also has good thermal stability,storage stability and reusability. PAA/PVA nanofiber membrane is a good carrier for enzyme immobilization with potential application. The protein molecules can be easily fixed into the inside of nanofiber membrane via mixed liquid electrospinning entrapping method.
2015, 32(12): 1371-1378
doi: 10.11944/j.issn.1000-0518.2015.12.150165
Abstract:
A simple and efficient procedure for the preparation of 5-[(indol-3-yl)-arylmethyl]-2,2-dimethyl-1,3-dioxane-4,6-dione derivatives has been developed through the Yonemitsu condensation of indole with Meldrum's acid and aldehyde in the mixed solvent of ethanol and water at room temperature using KH2PO4 as an inexpensive,commercially available,and efficient catalyst. The crystal structure of compound 4o was confirmed by X-ray diffraction. This method has the advantages of mild reaction conditions,tolerance to diverse functional groups such as 4-methyl benzaldehyde and 4-methoxy benzaldehyde,and good to excellent yields(48%~98%). Furthermore,some of the products can be facilely obtained by vacuum filtration without further purification. This strategy provides an alternative approach for easy access to useful synthetic β-indole derivatives.
A simple and efficient procedure for the preparation of 5-[(indol-3-yl)-arylmethyl]-2,2-dimethyl-1,3-dioxane-4,6-dione derivatives has been developed through the Yonemitsu condensation of indole with Meldrum's acid and aldehyde in the mixed solvent of ethanol and water at room temperature using KH2PO4 as an inexpensive,commercially available,and efficient catalyst. The crystal structure of compound 4o was confirmed by X-ray diffraction. This method has the advantages of mild reaction conditions,tolerance to diverse functional groups such as 4-methyl benzaldehyde and 4-methoxy benzaldehyde,and good to excellent yields(48%~98%). Furthermore,some of the products can be facilely obtained by vacuum filtration without further purification. This strategy provides an alternative approach for easy access to useful synthetic β-indole derivatives.
2015, 32(12): 1379-1385
doi: 10.11944/j.issn.1000-0518.2015.12.150168
Abstract:
The ring-opening of pyridinium salt is an important multi-step tandem reaction,which have wide application in organic synthesis. However, principle of the ring-opening process partly remains some controversy. In this paper,based on the difference in molecular conjugate structure before and after ringopening reaction, the principle of ring-opening of pyridinium salt was studied by ultraviolet spectrum.Meanwhile,the factors influenced the formation of N-(5-anilino-2,4-pentadienylidene) aniline hydrochloride was evaluated in detail. Furthermore,ultrasonic radiation was introduced in the ring-opening reaction of pyridinnium salt and the efficiency of the ring-opening was improved for 94%.
The ring-opening of pyridinium salt is an important multi-step tandem reaction,which have wide application in organic synthesis. However, principle of the ring-opening process partly remains some controversy. In this paper,based on the difference in molecular conjugate structure before and after ringopening reaction, the principle of ring-opening of pyridinium salt was studied by ultraviolet spectrum.Meanwhile,the factors influenced the formation of N-(5-anilino-2,4-pentadienylidene) aniline hydrochloride was evaluated in detail. Furthermore,ultrasonic radiation was introduced in the ring-opening reaction of pyridinnium salt and the efficiency of the ring-opening was improved for 94%.
2015, 32(12): 1386-1391
doi: 10.11944/j.issn.1000-0518.2015.12.150176
Abstract:
A series of CeCl3·7H2O/NaI catalysts immobilized on various supports such as Y zeolite,activated carbon,and SiO2-CS was prepared. Their catalytic performances were evaluated in the deprotection reactions of tert-butyl phenyl ether. The supported catalyst exhibits good stability and catalytic activity. To further investigate the application of SiO2-CS-CeCl3·7H2O/NaI system in other deprotection reactions,t-butyl ether and 1,3-dithioacetals were explored. In neutral conditions, the catalyst can effectively promote the deprotection reaction,and the use of strong acid and strong base can be avoided.
A series of CeCl3·7H2O/NaI catalysts immobilized on various supports such as Y zeolite,activated carbon,and SiO2-CS was prepared. Their catalytic performances were evaluated in the deprotection reactions of tert-butyl phenyl ether. The supported catalyst exhibits good stability and catalytic activity. To further investigate the application of SiO2-CS-CeCl3·7H2O/NaI system in other deprotection reactions,t-butyl ether and 1,3-dithioacetals were explored. In neutral conditions, the catalyst can effectively promote the deprotection reaction,and the use of strong acid and strong base can be avoided.
2015, 32(12): 1392-1397
doi: 10.11944/j.issn.1000-0518.2015.12.150178
Abstract:
Aqueous catalytic Hantzsch reaction has been studied with aryl aldehyde,ethyl acetoacetate and ammonium salt. The influences of catalysts,substrate ratio and reaction temperature have been evaluated to optimize the reaction conditions. The optimum reaction conditions were:5 mmol benzaldehyde,0.5 mmol DL-proline,2.5 mmol(NH4)2CO3,10 mL water,reaction time 5 h and reaction temperature 70℃. The productivity was 90.1% under the determined optimum reaction conditions. Recycle of catalysts did not show compromise of catalytic activity. The reaction displayed wide scope of aryl aldehyde. All products were confirmed with IR and NMR spectra. Reaction has the advantages of environment friendly,mild conditions,simple operation and high yield. Results show that aqueous catalytic Hantzsch reaction has wide applicability.
Aqueous catalytic Hantzsch reaction has been studied with aryl aldehyde,ethyl acetoacetate and ammonium salt. The influences of catalysts,substrate ratio and reaction temperature have been evaluated to optimize the reaction conditions. The optimum reaction conditions were:5 mmol benzaldehyde,0.5 mmol DL-proline,2.5 mmol(NH4)2CO3,10 mL water,reaction time 5 h and reaction temperature 70℃. The productivity was 90.1% under the determined optimum reaction conditions. Recycle of catalysts did not show compromise of catalytic activity. The reaction displayed wide scope of aryl aldehyde. All products were confirmed with IR and NMR spectra. Reaction has the advantages of environment friendly,mild conditions,simple operation and high yield. Results show that aqueous catalytic Hantzsch reaction has wide applicability.
2015, 32(12): 1398-1401
doi: 10.11944/j.issn.1000-0518.2015.12.150232
Abstract:
New methods for the synthesis of 2,6-dichloropurineside and 2-chloroadenosine were developed.The key intermediate 2',3',5'-tri-O-acetyl-2,6-dichloropurineside was obtained from the condensation of 2,6-dichloropurine and β-D-ribofuranose 1,2,3,5-tetraacetate under the catalysis of 5% molar fraction of trifluoromethanesulfonic acid. 2,6-Dichloropurineside was obtained by sulfuric acid catalyzed hydrolysis of 2',3',5'-tri-O-acetyl-2,6-dichloropurineside in the yield of 89% and 2-chloroadenosine was obtained from the aminolysis of 2',3',5'-tri-O-acetyl-2,6-dichloropurineside in NH3/CH3OH with the yield of 92%. The starting substrates were all commercially available and affordable. The presented method avoided toxic metal catalysts and chromatography. Moreover,2-thioadenosine was obtained in reliable yield on a 100 g scale.
New methods for the synthesis of 2,6-dichloropurineside and 2-chloroadenosine were developed.The key intermediate 2',3',5'-tri-O-acetyl-2,6-dichloropurineside was obtained from the condensation of 2,6-dichloropurine and β-D-ribofuranose 1,2,3,5-tetraacetate under the catalysis of 5% molar fraction of trifluoromethanesulfonic acid. 2,6-Dichloropurineside was obtained by sulfuric acid catalyzed hydrolysis of 2',3',5'-tri-O-acetyl-2,6-dichloropurineside in the yield of 89% and 2-chloroadenosine was obtained from the aminolysis of 2',3',5'-tri-O-acetyl-2,6-dichloropurineside in NH3/CH3OH with the yield of 92%. The starting substrates were all commercially available and affordable. The presented method avoided toxic metal catalysts and chromatography. Moreover,2-thioadenosine was obtained in reliable yield on a 100 g scale.
2015, 32(12): 1402-1409
doi: 10.11944/j.issn.1000-0518.2015.12.150207
Abstract:
The adsorption of palladium from aqueous solution by pectin was studied. The effect of solution pH value,temperature, pectin dosage, contact time and initial concentration of palladium solution on the adsorption was investigated. The kinetics data were analyzed by the Pseudo-First-order,Pseudo-Second-order and Intraparticle Diffusion models. The equilibrium data were simulated using Langmuir,Freundlich,and Temkin isothermal equations. The results show that pectin has good adsorption ability and the adsorption ratio is as high as 96%. With the best pH of 6.5 and the best temperature of 50℃,the adsorption capacity decreases with the increase of the pectin dosage,while it increases as the initial concentration of palladium solution increases. The adsorption kinetics of palladium obeys the Pseudo-Second-order model to show that this is a chemical adsorption. The isotherm adsorption is fitted in the Freundlich equation. Gibbs free energy is negative,the enthalpy change is 3.23 kJ/mol and the entropy change is 13.32 J/(mol·K),showing that it is a spontaneous endothermic process. The adsorbed palladium was used as the catalyst for Suzuki reaction with a good catalytic activity.
The adsorption of palladium from aqueous solution by pectin was studied. The effect of solution pH value,temperature, pectin dosage, contact time and initial concentration of palladium solution on the adsorption was investigated. The kinetics data were analyzed by the Pseudo-First-order,Pseudo-Second-order and Intraparticle Diffusion models. The equilibrium data were simulated using Langmuir,Freundlich,and Temkin isothermal equations. The results show that pectin has good adsorption ability and the adsorption ratio is as high as 96%. With the best pH of 6.5 and the best temperature of 50℃,the adsorption capacity decreases with the increase of the pectin dosage,while it increases as the initial concentration of palladium solution increases. The adsorption kinetics of palladium obeys the Pseudo-Second-order model to show that this is a chemical adsorption. The isotherm adsorption is fitted in the Freundlich equation. Gibbs free energy is negative,the enthalpy change is 3.23 kJ/mol and the entropy change is 13.32 J/(mol·K),showing that it is a spontaneous endothermic process. The adsorbed palladium was used as the catalyst for Suzuki reaction with a good catalytic activity.
2015, 32(12): 1410-1415
doi: 10.11944/j.issn.1000-0518.2015.12.150250
Abstract:
Hydrolysis of bis(p-nitrophenyl) phosphate(BNPP) catalyzed by Ce(Ⅲ)-barbitone complex was explored. The results indicate that the Ce(Ⅲ)-barbitone complex exhibits excellent catalytic activity for BNPP hydrolysis. The complex can increase the rate of the BNPP hydrolysis by a factor of 1.52×108 times compared to that of the spontaneous hydrolysis. The effect of temperature and pH on the catalytic activity of Ce(Ⅲ)-barbitone complex for BNPP hydrolysis was also investigated. It is found that the optimal catalytic condition is at 25℃ and pH 8.50.
Hydrolysis of bis(p-nitrophenyl) phosphate(BNPP) catalyzed by Ce(Ⅲ)-barbitone complex was explored. The results indicate that the Ce(Ⅲ)-barbitone complex exhibits excellent catalytic activity for BNPP hydrolysis. The complex can increase the rate of the BNPP hydrolysis by a factor of 1.52×108 times compared to that of the spontaneous hydrolysis. The effect of temperature and pH on the catalytic activity of Ce(Ⅲ)-barbitone complex for BNPP hydrolysis was also investigated. It is found that the optimal catalytic condition is at 25℃ and pH 8.50.
2015, 32(12): 1416-1422
doi: 10.11944/j.issn.1000-0518.2015.12.150206
Abstract:
In order to deeply investigate the assembly and function of supramolecular topological structures based on the skeleton of carlixarenes,we launched the study on the synthesis and molecular structures of resorcinarene octasubstituted pyridymethylacetamides. A series of tetraalkyl resorcinarene octa[N-(2-pyridylmethyl) acetamides] was prepared by sequential alkylation of resorcinarene with methyl α-chloroacetate and ammonolysis of the corresponding resorcinarene octaacetates with 2-aminomethylpyridine. Single crystal structures of tetrapropyl resorcinarene acetate, tetrapropyl and tetrahexyl resorcinarene octa(N-2-pyridylmethylacetamides) obtained by X-ray diffraction method indicate that the resorcinarene core adopts rccc(all cis) conformation with two resorcinol rings almost perpendicular to the other two resorcinol rings,four alkyl groups stretching to the lower rim and octa[N-(2-pyridylmethyl) acetamides] groups stretching outside.
In order to deeply investigate the assembly and function of supramolecular topological structures based on the skeleton of carlixarenes,we launched the study on the synthesis and molecular structures of resorcinarene octasubstituted pyridymethylacetamides. A series of tetraalkyl resorcinarene octa[N-(2-pyridylmethyl) acetamides] was prepared by sequential alkylation of resorcinarene with methyl α-chloroacetate and ammonolysis of the corresponding resorcinarene octaacetates with 2-aminomethylpyridine. Single crystal structures of tetrapropyl resorcinarene acetate, tetrapropyl and tetrahexyl resorcinarene octa(N-2-pyridylmethylacetamides) obtained by X-ray diffraction method indicate that the resorcinarene core adopts rccc(all cis) conformation with two resorcinol rings almost perpendicular to the other two resorcinol rings,four alkyl groups stretching to the lower rim and octa[N-(2-pyridylmethyl) acetamides] groups stretching outside.
2015, 32(12): 1423-1430
doi: 10.11944/j.issn.1000-0518.2015.12.150171
Abstract:
The method of four factors and three levels was used to study the influence of the material ratio,reaction temperature, reaction time and stabilizer in order to obtain the optimal process condition of percarbamide. The results show that the yield of percarbamide is 99%,and the oxygen content is 17.5% under the optimmal synthetic condition. The thermal stability of percarbamide was investigated by thermal analysis. The results show that the content of oxygen and percarbamide decreases rapidly when the temperature exceeds 65℃. Finally,the crystal structure was determined by X-ray diffraction,and the software,Diamond,was used to describe the three-dimensional supramolecular structure of percarbamide and the connection mode of hydrogen bond.
The method of four factors and three levels was used to study the influence of the material ratio,reaction temperature, reaction time and stabilizer in order to obtain the optimal process condition of percarbamide. The results show that the yield of percarbamide is 99%,and the oxygen content is 17.5% under the optimmal synthetic condition. The thermal stability of percarbamide was investigated by thermal analysis. The results show that the content of oxygen and percarbamide decreases rapidly when the temperature exceeds 65℃. Finally,the crystal structure was determined by X-ray diffraction,and the software,Diamond,was used to describe the three-dimensional supramolecular structure of percarbamide and the connection mode of hydrogen bond.
2015, 32(12): 1431-1436
doi: 10.11944/j.issn.1000-0518.2015.12.150147
Abstract:
Photochromic bisthienylethene has advantages of thermal-stability and fatigue-resistance. This paper reported a new 3-stage synthesis of 1,2-bis(5-pyridyl-2-methylthien-3-yl) cyclopentene in 61% total yield via Suzuki coupling,Friedel-Crafts acylation and Mc Murry coupling by using 2-methylthiophene as the starting material. The intermediates and the target compound were confirmed by 1H NMR, 13C NMR,MS and IR. This synthetic method is concise,high yielding and easy for scaling up. Photochromic properties of the target compound and its interaction with Ni2+,Sn2+ were also investigated by UV-Vis spectroscopy and fluorescent emission spectroscopy. Symmetrical 1,2-bis(5-pyridyl-2-methylthien-3-yl) cyclopentene displayed different colors and UV-Vis spectra by coordinated with metal ions. The response to ions allowed the material to be used as a new kind of probe for metal ions.
Photochromic bisthienylethene has advantages of thermal-stability and fatigue-resistance. This paper reported a new 3-stage synthesis of 1,2-bis(5-pyridyl-2-methylthien-3-yl) cyclopentene in 61% total yield via Suzuki coupling,Friedel-Crafts acylation and Mc Murry coupling by using 2-methylthiophene as the starting material. The intermediates and the target compound were confirmed by 1H NMR, 13C NMR,MS and IR. This synthetic method is concise,high yielding and easy for scaling up. Photochromic properties of the target compound and its interaction with Ni2+,Sn2+ were also investigated by UV-Vis spectroscopy and fluorescent emission spectroscopy. Symmetrical 1,2-bis(5-pyridyl-2-methylthien-3-yl) cyclopentene displayed different colors and UV-Vis spectra by coordinated with metal ions. The response to ions allowed the material to be used as a new kind of probe for metal ions.
2015, 32(12): 1437-1447
doi: 10.11944/j.issn.1000-0518.2015.12.150170
Abstract:
The structures of dye 3,3'-bis(1-n-octyl-2-methylindol-3-yl) phthalide(ck-16) in coloring and decoloring states were analyzed by 13C NMR. The chromogenic properties of ck-16 interacted with different color developers in ethyl alcohol were studied by UV-visible spectroscopy. The composition ratio and instability constant of the complexes composed of ck-16 and the color developers were measured. Furthermore,the effect of external conditions on the absorbance at λmax of the system was investigated. 13C NMR results show that the delocalized bonds formed between electron donor(N) and acceptor(O) atoms lead to ring cleavage of the phthalide to a carboxylate as a colored form. The chromogenic properties of ck-16 vary with different color developers. When the molar ratio of ck-16 to four color developers(FeCl3,oxalic acid,CuCl2 and salicylic acid) are all 1:1,the combination between ck-16 with Fe3+ is the most stable,followed by oxalic acid and Cu2+. Among the four color developers,the combination between ck-16 with salicylic acid is the most instable. The time has little influence on the absorbance at λmax of ck-16/FeCl3 and ck-16/H2C2O4.However,different sensibility is observed when water is added. The ck-16/FeCl3 fades more rapidly with water than ck-16/H2C2O4,and exhibits potential application as water sensitive recording or copying materials.
The structures of dye 3,3'-bis(1-n-octyl-2-methylindol-3-yl) phthalide(ck-16) in coloring and decoloring states were analyzed by 13C NMR. The chromogenic properties of ck-16 interacted with different color developers in ethyl alcohol were studied by UV-visible spectroscopy. The composition ratio and instability constant of the complexes composed of ck-16 and the color developers were measured. Furthermore,the effect of external conditions on the absorbance at λmax of the system was investigated. 13C NMR results show that the delocalized bonds formed between electron donor(N) and acceptor(O) atoms lead to ring cleavage of the phthalide to a carboxylate as a colored form. The chromogenic properties of ck-16 vary with different color developers. When the molar ratio of ck-16 to four color developers(FeCl3,oxalic acid,CuCl2 and salicylic acid) are all 1:1,the combination between ck-16 with Fe3+ is the most stable,followed by oxalic acid and Cu2+. Among the four color developers,the combination between ck-16 with salicylic acid is the most instable. The time has little influence on the absorbance at λmax of ck-16/FeCl3 and ck-16/H2C2O4.However,different sensibility is observed when water is added. The ck-16/FeCl3 fades more rapidly with water than ck-16/H2C2O4,and exhibits potential application as water sensitive recording or copying materials.
2015, 32(12): 1448-1454
doi: 10.11944/j.issn.1000-0518.2015.12.150179
Abstract:
The discarded tobacco extracted by supercritical CO2 was separated by molecular distillation techniques and analyzed by GC-MS. Fifty-two kinds of compounds were identified in total. 15 kinds of compounds were identified by the 80℃ light fraction. Among them,heterocycles were dominant,accounting for 98.91% of the total,followed by esters(0.606%). Twenty-six kinds of compounds were identified by the 120℃ light fraction. The chemical classes were mainly made up of heterocycles(91.42%),with relatively small amounts of ketones(4.16%),alcohols(2.87%) and hydrocarbons(0.74%). There were 26 kinds of compounds identified by the 160℃ light fraction. Alcohols(67.97%) were the dominant chemicals,followed by heterocycles(11.57%),hydrocarbons(7.9%),ethers(4.09%),ketones(3.77%),esters(2.80%) and aldehydes(1.89%),respectively. There were obvious differences in the compound types and contents of different fractions,which reflected the selective enrichment feature of molecular distillation. The sensory evaluation of the mixture of the 80℃ and 120℃ light fraction with the mass ratio of 8:2 was better. The sample's aroma quantity and quality increased,the after taste got more comfortable. Meanwhile it presented sweet aroma and more pure smoke flavor.
The discarded tobacco extracted by supercritical CO2 was separated by molecular distillation techniques and analyzed by GC-MS. Fifty-two kinds of compounds were identified in total. 15 kinds of compounds were identified by the 80℃ light fraction. Among them,heterocycles were dominant,accounting for 98.91% of the total,followed by esters(0.606%). Twenty-six kinds of compounds were identified by the 120℃ light fraction. The chemical classes were mainly made up of heterocycles(91.42%),with relatively small amounts of ketones(4.16%),alcohols(2.87%) and hydrocarbons(0.74%). There were 26 kinds of compounds identified by the 160℃ light fraction. Alcohols(67.97%) were the dominant chemicals,followed by heterocycles(11.57%),hydrocarbons(7.9%),ethers(4.09%),ketones(3.77%),esters(2.80%) and aldehydes(1.89%),respectively. There were obvious differences in the compound types and contents of different fractions,which reflected the selective enrichment feature of molecular distillation. The sensory evaluation of the mixture of the 80℃ and 120℃ light fraction with the mass ratio of 8:2 was better. The sample's aroma quantity and quality increased,the after taste got more comfortable. Meanwhile it presented sweet aroma and more pure smoke flavor.
2015, 32(12): 1455-1461
doi: 10.11944/j.issn.1000-0518.2015.12.150181
Abstract:
Mesoporous α-NiS,Co3S4 and CoNi2S4 electrode materials were synthesized by a simple one-step hydrothermal method,and their electrochemical properties were investigated. X-ray diffraction and electron microscopy results show that as-obtained mesoporous sulfide electrode materials are assembled by single-phase sulfide nanoparticles and the CoNi2S4 electrode materials have the unique structure of ruffle-like microspheres consisting of 2D nanoplates. The binary CoNi2S4 electrode exhibits much higher specific capacitance of 1678.3 F/g than that of either Co3S4(1532.7 F/g) or α-NiS(787.4 F/g) in 6 mol/L KOH at a scan rate of 5 mV/s,and shows excellent capability retention of 45.8% from 5 mV/s to 100 mV/s,which is ~15% higher than that of α-NiS and Co3S4. The excellent cycling stability of binary CoNi2S4 electrode is achieved with 96.3% of the initial capacitance over 900 consecutive cycles at 15 A/g. Moreover,the columbic efficiency consistently remains above 94.3% within 900 cycles. The fine specific capacitance and good cycling stability demonstrate that the mesoporous CoNi2S4 electrode has potential applications in supercapacitors.
Mesoporous α-NiS,Co3S4 and CoNi2S4 electrode materials were synthesized by a simple one-step hydrothermal method,and their electrochemical properties were investigated. X-ray diffraction and electron microscopy results show that as-obtained mesoporous sulfide electrode materials are assembled by single-phase sulfide nanoparticles and the CoNi2S4 electrode materials have the unique structure of ruffle-like microspheres consisting of 2D nanoplates. The binary CoNi2S4 electrode exhibits much higher specific capacitance of 1678.3 F/g than that of either Co3S4(1532.7 F/g) or α-NiS(787.4 F/g) in 6 mol/L KOH at a scan rate of 5 mV/s,and shows excellent capability retention of 45.8% from 5 mV/s to 100 mV/s,which is ~15% higher than that of α-NiS and Co3S4. The excellent cycling stability of binary CoNi2S4 electrode is achieved with 96.3% of the initial capacitance over 900 consecutive cycles at 15 A/g. Moreover,the columbic efficiency consistently remains above 94.3% within 900 cycles. The fine specific capacitance and good cycling stability demonstrate that the mesoporous CoNi2S4 electrode has potential applications in supercapacitors.
2015, 32(12): 1462-1464
doi: 10.11944/j.issn.1000-0518.2015.12.150256
Abstract:
With carbon spheres(CS) as the template,vanadium pentoxide(V2O5) hollow microspheres were synthesized by the solvothermal reaction of vanadium oxytriisopropoxide(VOT). The structure,morphology and component of V2O5 hollow microspheres were characterized by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The results reveal that V2O5 hollow microspheres are perfectly generated with the diameter of ~1.5 μm and the wall thickness of ~100 nm. As a cathode material for rechargeable Mg batteries,the initial discharge capacity is up to 140 mA·h/g at the rate of 0.2 C and maintains 110 mA·h/g after 20 cycles.
With carbon spheres(CS) as the template,vanadium pentoxide(V2O5) hollow microspheres were synthesized by the solvothermal reaction of vanadium oxytriisopropoxide(VOT). The structure,morphology and component of V2O5 hollow microspheres were characterized by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The results reveal that V2O5 hollow microspheres are perfectly generated with the diameter of ~1.5 μm and the wall thickness of ~100 nm. As a cathode material for rechargeable Mg batteries,the initial discharge capacity is up to 140 mA·h/g at the rate of 0.2 C and maintains 110 mA·h/g after 20 cycles.
