The mechanical,thermal and ablation properties of carbon phenolic(C-Ph)composites(Type-I)reinforced with different weight percentages of organo-modified montmorillonite(o-MMT)nanoclay have been studied experimentally....The mechanical,thermal and ablation properties of carbon phenolic(C-Ph)composites(Type-I)reinforced with different weight percentages of organo-modified montmorillonite(o-MMT)nanoclay have been studied experimentally.Ball milling was used to disperse different weight(wt)percentages(0,1,2,4,6 wt.%)of nanoclay into phenolic resin.Viscosity changes to resin due to nanoclay was studied.On the other hand,nanoclay added phenolic matrix composites(Type-II)were prepared to study the dispersion of nanoclay in phenolic matrix by small angle X-ray scattering and thermal stability changes to the matrix by thermogravimetric analyser(TGA).This data was used to understand the mechanical,thermal and ablation properties of Type-I composites.Inter laminar shear strength(ILSS),flexural strength and flexural modulus of Type I composites increased by about 29%,12%and 7%respectively at2 wt.%addition of nanoclay beyond which these properties decreased.This was attributed to reduced fiber volume fraction(%Vf)of Type-I composites due to nanoclay addition at such high loadings.Mass ablation rate of Type-I composites was evaluated using oxy acetylene torch test at low heat flux(125 W/cm^(2))and high heat flux levels(500 W/cm^(2)).Mass ablation rates have increased at both flux levels marginally up to 2 wt.%addition of nanoclay beyond which it has increased significantly.This is in contrast to increased thermal stability observed for Type-I and Type-II composites up to 2 wt.%addition of nanoclay.Increased ablation rates due to nanoclay addition was attributed to higher insulation efficiency of nanolcay,which accumulates more heat energy in limited area behind the ablation front and self-propagating ablation mechanisms triggered by thermal decomposition of organic part of nanoclay.展开更多
Using novolac phenolic resin, aniline and formaldehyde as raw materials, benzoxazine-phenolic copolymers with different percentages of benzoxazine rings were prepared. FT-IR was adopted to characterize the molecular s...Using novolac phenolic resin, aniline and formaldehyde as raw materials, benzoxazine-phenolic copolymers with different percentages of benzoxazine rings were prepared. FT-IR was adopted to characterize the molecular structure of the novolac-type phenolic resin and the benzoxazine-phenolic copolymer BP31. In order to understand the curing process of the copolymers, the curing behavior and curing kinetic characteristics were studied by differential scanning calorimetry （DSC）, and the catalytical effect of phenolic hydroxyl on the curing behavior of copolymers was investigated. To investigate the thermal properties of this resin, the thermal degradation behaviors of the cured samples were studied by thermal gravimetric （TG） method, and glass-transition temperatures （Tg） of the cured copolymers were also evaluated by DSC. The dynamic Ozawa method was adopted to determine the kinetic parameters of the curing process as well. The activation energy is 78.8 kJ/mol and the reaction rate constant is in the range from 40.0 to 5.2 （K/min）＂ according to reaction temperatures. The Ozawa exponent decreases from 2.4 to 0.7 with the increase of reaction temperature, and curing mechanism is expounded briefly according to the results. TG result shows that the highest char yield of copolymers is 50.3%. The highest Tg of copolymers is 489 K, which is much higher than that of pure benzoxazine resin.展开更多
Lightweight and high-toughness carbon fiber/phenolic ablator(CFPA)is required as the Thermal Protection System(TPS)material of aerospace vehicles for next-generation space missions.To improve the ablative properties,s...Lightweight and high-toughness carbon fiber/phenolic ablator(CFPA)is required as the Thermal Protection System(TPS)material of aerospace vehicles for next-generation space missions.To improve the ablative properties,silica sol with good particle size distribution prepared using tetramethoxysilane(TMOS)was blended with natural rubber latex and deposited onto carbon fiber felt,which was then integrated with phenolic aerogel matrix,introducing nano-silica into the framework of CFPA.The modified CFPA with a low density of 0.28—0.31 g/cm3exhibits strain-in-fracture as high as 31.2%and thermal conductivity as low as 0.054 W/(m·K).Furthermore,a trace amount of nano-silica could effectively protect CFPA from erosion of oxidizing atmosphere in different high-temperature environments.The oxyacetylene ablation test of 3000°C for 20 s shows a mass ablation rate of 0.0225 g/s,a linear ablation rate of 0.209 mm/s for the modified CFPA,which are 9.64%and 24.82%lower than the unmodified one.Besides,the long-time butane ablation test of 1200°C for 200 s shows an insignificant recession with mass and linear ablation rate of 0.079 g/s and 0.039 mm/s,16.84%and 13.33%lower than the unmodified one.Meanwhile,the fixed thermocouple in the test also demonstrates a good thermal insulation performance with a low peak back-face temperature of 207.7°C,12.25%lower than the unmodified one.Therefore,the nano-silica modified CFPA with excellent overall performance presents promising prospects in high-temperature aerospace applications.展开更多
Due to editing errors,the ordinate and unit of Fig.5(a)in the article were incorrect.The correct ordinate of Fig.5(a)should be Flexural strength(MPa).In the published article<Effect of organo-modified montmorilloni...Due to editing errors,the ordinate and unit of Fig.5(a)in the article were incorrect.The correct ordinate of Fig.5(a)should be Flexural strength(MPa).In the published article<Effect of organo-modified montmorillonite nanoclay on mechanical,thermal and ablation behavior of carbon fiber/phenolic resin composites>.展开更多
OBJECTIVE To make full of resource,the bioactivity and active constituent analysis were firstly system⁃atically investigated on damask rose flower residue(DRFR).METHODS DPPH and ABTS experiments were applied to assess...OBJECTIVE To make full of resource,the bioactivity and active constituent analysis were firstly system⁃atically investigated on damask rose flower residue(DRFR).METHODS DPPH and ABTS experiments were applied to assess the antioxidant activity of DRFR.Then,column chromatography was used to purify compounds from DRFR-A,and the chemical structure was identified using nuclear magnetic resonance(NMR).The total phenolic acid content was measured by folin-ciocalteu colorimetric method and the content of gallic acid the indicator ingredient,was detected by high performance liquid chromatography(HPLC).RESULTS By DPPH and ABTS experiments,an antioxidation extract(DRFR-A)was found and displayed a high activity both on DPPH(IC50:2.760 mg·L^-1)and ABTS(IC50:2.258 mg·L^-1)compared to positive control VC.Ten compounds were isolated and identified from DRFR-A,and the most are phenolic acids.Among them,pyrogallic acid,2-phenylethyl-3,4,5-trihydroxybenzoate,p-hydroxybenzoic acid and p-hydroxy⁃phenethyl alcohol were obtained from the plant for the first time.The content of total phenolic acids and main ingredient,gallic acid,in DRFR-A was determined as 63.73%and 5.12%,respectively.CONCLUSION This study provides reliable science data and lays the foundation for the development and utilization of rose residue,and hence for the full utilization of rose resources.展开更多
The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extract...The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extracts had high ability of 1, 1-diphenyl-2-picrylhydrazyl（DPPH） radical scavenging, 2, 2＇-azinobis（3-ethylbenzthiazoline-6-sulphonic acid）（ABTS） radical scavenging and ferric reducing antioxidant power（FRAP）. The ethanol extract of Sichuan pepper showed the highest ability of DPPH radical scavenging. The extract with the highest ABTS radical scavenging effect was that of ethanol extract of cinnamon. Both ethanol and water extracts of cinnamon possessed the high ferric reducing antioxidant power（FRAP） with the values of 4 541.87 and 1 134.52 μmol of Fe（Ⅱ）/g. The extracts with high hydroxyl radical-mediated deoxyribose degradation were all the ethanol extracts as follows： cinnamon, bay leaf, Sichuan pepper, star anise and fennel. The extracts with high antioxidant activities also had the high contents of the phenols. The study indicated that these spices might be potentially be used as natural antioxidants in food.展开更多
Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin. Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structu...Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin. Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structures and characteristics of the carbon materials were determined by X-ray diffraction, Brunauer-Emmer-Teller surface area analysis and electrochemical measurements. With the increase of pyrolyzing temperature and soaking time, the resin carbon material has larger crystallite sizes of L_c and L_a, lower specific surface area, smaller irreversible capacity and higher initial coulombic efficiency. The pyrolyzing temperature and soaking time are optimized to be 1050℃ and 2h. The resin carbon anode obtained under the optimum conditions shows good electrochemical performances with reversible capacity of 387mA·h/g and initial coulombic efficiency of 69.1%.展开更多
In this paper,the samples were concentrated by solid phase extraction(SPE),then detected by GC-MS.The result showed that the detection limits of 12 phenols was range of 0.06-0.69 μg/L.The RSDs(n=7) were less than 8.2...In this paper,the samples were concentrated by solid phase extraction(SPE),then detected by GC-MS.The result showed that the detection limits of 12 phenols was range of 0.06-0.69 μg/L.The RSDs(n=7) were less than 8.2% and the recoveries were 84%-122%.This method is suitable for determination of phenols in surface water and drinking water.展开更多
In this paper the multi-position material of phenol installation were analyzed by gas chromatography-mass spectrometry and provides important information for colligation utilization of phenol material and all right mo...In this paper the multi-position material of phenol installation were analyzed by gas chromatography-mass spectrometry and provides important information for colligation utilization of phenol material and all right moved of phenol installation.展开更多
A novel heterogeneous catalytic ozonation process in water treatment was studied, with a copper-loaded activated carbon （Cu/AC） that was prepared by an incipient wetness impregnation method at low temperature and te...A novel heterogeneous catalytic ozonation process in water treatment was studied, with a copper-loaded activated carbon （Cu/AC） that was prepared by an incipient wetness impregnation method at low temperature and tested as a catalyst in the ozonation of phenol and oxalic acid. Cu/AC was characterized using XRD, BET and SEM techniques. Compared with ozonation alone, the presence of Cu/AC in the ozonation processes significantly improves the degradation of phenol or oxalic acid. With the introduction of the hydroxyl radical scavenger, i.e., turt-butanol alcohol （t-BuOH）, the degradation efficiency of both phenol and oxalic acid in the Cu/AC catalyzed ozonation process decreases by 22% at 30 min. This indicates that Cu/AC accelerates ozone decomposition into certain concentration of hydroxyl radicals. The amount of Cu（II ） produced during the reaction of Cu/AC-catalyzed ozonation of phenol or oxalic acid is very small, which shows that the two processes are both heterogeneous catalytic ozonation reactions.展开更多
Electrospun WO_(3) nanofibers were fabricated by coaxial electrospinning and directly annealing WCl_(6)/polyvinylpyrrolidone(PVP) nanofibers on activated carbon fibres(ACF), and characterized by scanning electron micr...Electrospun WO_(3) nanofibers were fabricated by coaxial electrospinning and directly annealing WCl_(6)/polyvinylpyrrolidone(PVP) nanofibers on activated carbon fibres(ACF), and characterized by scanning electron microscopy(SEM) and X-ray diffractometry(XRD). The most suitable condition for electrospinning is the mass ratio of WCl_(6) to PVP 0.6, appropriate amount DMF and ethanol, a voltage of 28 kV, the reception distance of 15 cm, the humidity range within 10% and 20% and the moving rate of the pump 0.001 mm/s. The photocatalytic activities of WO_(3) nanofibers were evaluated by the photo-degradation of phenol solution under the irradiation of 500 W xenon lamp. The results showed that, the sizes of the fibers are about 100 nm, and after being photodegraded for 210 min, the concentration of phenol decreased from 20.05 mg/L to 8.60 mg/L. Thus, the photo-degradation rate of WO_(3) nanofibers for phenol solution is 2.87 mg/(L·h).展开更多
Batch experiments were conducted to study the adsorption of phenol on clay-solidified grouting curtain (CSGC) and the effects of contact time,pH and adsorbent concentration on the adsorption were investigated.Under th...Batch experiments were conducted to study the adsorption of phenol on clay-solidified grouting curtain (CSGC) and the effects of contact time,pH and adsorbent concentration on the adsorption were investigated.Under the experimental conditions used,2 d was adequate to determine the equilibrium of phenol adsorption onto CSGC.The amount of phenol adsorbed by CSGC from an initial concentration of 100mg/L was found to be 8.4mg/g.The adsorption process includes particle diffusion and liquid film diffusion,and the latter is the predominating step of the adsorption process.The adsorption ability of CSGC decreased with pH but it increased non-linearly with the CSGC concentration.The optimized concentration for CSGC was found to be 20g/L for the adsorption of 100mg/L phenol.展开更多
The utilization of perovskite oxide materials as catalysts for the photodegradation of organic pollutants in water is a promising and rapidly advancing field.In this study,a series of La_(1−x)Ba_(x)CoO_(3)(x=0.2,0.3,0...The utilization of perovskite oxide materials as catalysts for the photodegradation of organic pollutants in water is a promising and rapidly advancing field.In this study,a series of La_(1−x)Ba_(x)CoO_(3)(x=0.2,0.3,0.4,0.5,0.6)catalysts with varying Ba doping ratios were synthesized using the citric acid complexation-hydrothermal synthesis combined method for the degradation of phenol under visible light irradiation.Among the synthesized catalysts,La_(0.5)Ba_(0.5)CoO_(3) exhibited the highest photocatalytic activity.In addition,the photocatalytic mechanism for La_(0.5)Ba_(0.5)CoO_(3) perovskite degradation of phenol was also discussed.The synthesized catalysts were characterized using XRD,SEM,FT-IR,XPS,MPMS and other characterization techniques.The results revealed that the diffraction peak intensity of La_(1−x)Ba_(x)CoO_(3) increased with higher Ba doping ratios,and the La_(0.4)Ba_(0.6)CoO_(3) exhibited the strongest diffraction peaks.The catalyst particle sizes ranged from 10 to 50 nm,and the specific surface area decreased with increasing Ba content.Additionally,the paramagnetic properties of La_(0.5)Ba_(0.5)CoO_(3) were similar to that of La_(0.4)Ba_(0.6)CoO_(3).The experimental results suggested that the incorporation of Ba could significantly improve the catalytic performance of La_(1−x)Ba_(x)CoO_(3) perovskites,promote electron transfer and favor to the generation of hydroxyl radicals(•OH),leading to the efficiently degradation of phenol.展开更多
TiO2/bauxite-tailings （TiO2/BTs） composites were prepared via a chemical liquid deposition method and characterized by X-ray diffractometry （XRD）, scanning electronic microscopy （SEM） and N2 adsorption analysis....TiO2/bauxite-tailings （TiO2/BTs） composites were prepared via a chemical liquid deposition method and characterized by X-ray diffractometry （XRD）, scanning electronic microscopy （SEM） and N2 adsorption analysis. The photocatalytic performance of TiO2/BTs composites was evaluated with UV-Vis spectrophotometer following the changes of phenol concentration under different illumination time. Effects of the calcination temperature, the pH and the cycles on the photocatalytic activity of TiO2/BTs composites were investigated. The composites calcined at 500 and 600 ℃ exhibit the best photocatalytic performance, and the phenol degradation ratios reacting for 40 and 160 rain reach 35% and 78% respectively under the same conditions, higher than those of 29% and 76% of the Degussa P25（TiO2）. The ability of TiO2/BTs500 （BTs500 represents bauxite-tailings calcined at 500 ℃） composites to degrade phenol increases with decreasing pH.展开更多
The Co@NC catalysts with different morphologies were prepared by two step process,solvent control growth and pyrolysis method.The polyhedral Co@NC-67P-450 catalyst has a relatively high CoNx content and exhibits excel...The Co@NC catalysts with different morphologies were prepared by two step process,solvent control growth and pyrolysis method.The polyhedral Co@NC-67P-450 catalyst has a relatively high CoNx content and exhibits excellent phenol hydrogenation activity(conversion 96.9%)at 160℃,3 MPa,which is higher than that of leaf shaped Co@NC-67L-450 catalyst(conversion 75.4%).We demonstrated Co_(3)O_(4)was reduced to the Co^(0)during the reaction.Moreover,CoNx species contribute to the superior hydrogenation activity of phenol.The Co-based catalysts can be easily recovered through the magnetic separation and performed the high stability.展开更多
文摘The mechanical,thermal and ablation properties of carbon phenolic(C-Ph)composites(Type-I)reinforced with different weight percentages of organo-modified montmorillonite(o-MMT)nanoclay have been studied experimentally.Ball milling was used to disperse different weight(wt)percentages(0,1,2,4,6 wt.%)of nanoclay into phenolic resin.Viscosity changes to resin due to nanoclay was studied.On the other hand,nanoclay added phenolic matrix composites(Type-II)were prepared to study the dispersion of nanoclay in phenolic matrix by small angle X-ray scattering and thermal stability changes to the matrix by thermogravimetric analyser(TGA).This data was used to understand the mechanical,thermal and ablation properties of Type-I composites.Inter laminar shear strength(ILSS),flexural strength and flexural modulus of Type I composites increased by about 29%,12%and 7%respectively at2 wt.%addition of nanoclay beyond which these properties decreased.This was attributed to reduced fiber volume fraction(%Vf)of Type-I composites due to nanoclay addition at such high loadings.Mass ablation rate of Type-I composites was evaluated using oxy acetylene torch test at low heat flux(125 W/cm^(2))and high heat flux levels(500 W/cm^(2)).Mass ablation rates have increased at both flux levels marginally up to 2 wt.%addition of nanoclay beyond which it has increased significantly.This is in contrast to increased thermal stability observed for Type-I and Type-II composites up to 2 wt.%addition of nanoclay.Increased ablation rates due to nanoclay addition was attributed to higher insulation efficiency of nanolcay,which accumulates more heat energy in limited area behind the ablation front and self-propagating ablation mechanisms triggered by thermal decomposition of organic part of nanoclay.
基金Project (20050106) supported by the Key Science and Technology Item of Guangdong Province,China
文摘Using novolac phenolic resin, aniline and formaldehyde as raw materials, benzoxazine-phenolic copolymers with different percentages of benzoxazine rings were prepared. FT-IR was adopted to characterize the molecular structure of the novolac-type phenolic resin and the benzoxazine-phenolic copolymer BP31. In order to understand the curing process of the copolymers, the curing behavior and curing kinetic characteristics were studied by differential scanning calorimetry （DSC）, and the catalytical effect of phenolic hydroxyl on the curing behavior of copolymers was investigated. To investigate the thermal properties of this resin, the thermal degradation behaviors of the cured samples were studied by thermal gravimetric （TG） method, and glass-transition temperatures （Tg） of the cured copolymers were also evaluated by DSC. The dynamic Ozawa method was adopted to determine the kinetic parameters of the curing process as well. The activation energy is 78.8 kJ/mol and the reaction rate constant is in the range from 40.0 to 5.2 （K/min）＂ according to reaction temperatures. The Ozawa exponent decreases from 2.4 to 0.7 with the increase of reaction temperature, and curing mechanism is expounded briefly according to the results. TG result shows that the highest char yield of copolymers is 50.3%. The highest Tg of copolymers is 489 K, which is much higher than that of pure benzoxazine resin.
基金partly supported by the National Natural Science Foundation of China(Grant Nos.22178107,U21A2060,22178116)Xinjiang Uygur Autonomous Region Key Research and Development Program(Grant No.2022B01030)Shanghai Pujiang Program(Grant No.21PJD019)。
文摘Lightweight and high-toughness carbon fiber/phenolic ablator(CFPA)is required as the Thermal Protection System(TPS)material of aerospace vehicles for next-generation space missions.To improve the ablative properties,silica sol with good particle size distribution prepared using tetramethoxysilane(TMOS)was blended with natural rubber latex and deposited onto carbon fiber felt,which was then integrated with phenolic aerogel matrix,introducing nano-silica into the framework of CFPA.The modified CFPA with a low density of 0.28—0.31 g/cm3exhibits strain-in-fracture as high as 31.2%and thermal conductivity as low as 0.054 W/(m·K).Furthermore,a trace amount of nano-silica could effectively protect CFPA from erosion of oxidizing atmosphere in different high-temperature environments.The oxyacetylene ablation test of 3000°C for 20 s shows a mass ablation rate of 0.0225 g/s,a linear ablation rate of 0.209 mm/s for the modified CFPA,which are 9.64%and 24.82%lower than the unmodified one.Besides,the long-time butane ablation test of 1200°C for 200 s shows an insignificant recession with mass and linear ablation rate of 0.079 g/s and 0.039 mm/s,16.84%and 13.33%lower than the unmodified one.Meanwhile,the fixed thermocouple in the test also demonstrates a good thermal insulation performance with a low peak back-face temperature of 207.7°C,12.25%lower than the unmodified one.Therefore,the nano-silica modified CFPA with excellent overall performance presents promising prospects in high-temperature aerospace applications.
文摘Due to editing errors,the ordinate and unit of Fig.5(a)in the article were incorrect.The correct ordinate of Fig.5(a)should be Flexural strength(MPa).In the published article<Effect of organo-modified montmorillonite nanoclay on mechanical,thermal and ablation behavior of carbon fiber/phenolic resin composites>.
基金National Natural Science Foundation of China(331/313400531021)
文摘OBJECTIVE To make full of resource,the bioactivity and active constituent analysis were firstly system⁃atically investigated on damask rose flower residue(DRFR).METHODS DPPH and ABTS experiments were applied to assess the antioxidant activity of DRFR.Then,column chromatography was used to purify compounds from DRFR-A,and the chemical structure was identified using nuclear magnetic resonance(NMR).The total phenolic acid content was measured by folin-ciocalteu colorimetric method and the content of gallic acid the indicator ingredient,was detected by high performance liquid chromatography(HPLC).RESULTS By DPPH and ABTS experiments,an antioxidation extract(DRFR-A)was found and displayed a high activity both on DPPH(IC50:2.760 mg·L^-1)and ABTS(IC50:2.258 mg·L^-1)compared to positive control VC.Ten compounds were isolated and identified from DRFR-A,and the most are phenolic acids.Among them,pyrogallic acid,2-phenylethyl-3,4,5-trihydroxybenzoate,p-hydroxybenzoic acid and p-hydroxy⁃phenethyl alcohol were obtained from the plant for the first time.The content of total phenolic acids and main ingredient,gallic acid,in DRFR-A was determined as 63.73%and 5.12%,respectively.CONCLUSION This study provides reliable science data and lays the foundation for the development and utilization of rose residue,and hence for the full utilization of rose resources.
基金Supported by the National Natural Science Foundation(31201356)Agricultural Science and Technology Innovation in Jiangsu Province(cx(13)3087)the Natural Science Foundation in Jiangsu Province(BK 20130701)
文摘The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extracts had high ability of 1, 1-diphenyl-2-picrylhydrazyl（DPPH） radical scavenging, 2, 2＇-azinobis（3-ethylbenzthiazoline-6-sulphonic acid）（ABTS） radical scavenging and ferric reducing antioxidant power（FRAP）. The ethanol extract of Sichuan pepper showed the highest ability of DPPH radical scavenging. The extract with the highest ABTS radical scavenging effect was that of ethanol extract of cinnamon. Both ethanol and water extracts of cinnamon possessed the high ferric reducing antioxidant power（FRAP） with the values of 4 541.87 and 1 134.52 μmol of Fe（Ⅱ）/g. The extracts with high hydroxyl radical-mediated deoxyribose degradation were all the ethanol extracts as follows： cinnamon, bay leaf, Sichuan pepper, star anise and fennel. The extracts with high antioxidant activities also had the high contents of the phenols. The study indicated that these spices might be potentially be used as natural antioxidants in food.
文摘Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin. Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structures and characteristics of the carbon materials were determined by X-ray diffraction, Brunauer-Emmer-Teller surface area analysis and electrochemical measurements. With the increase of pyrolyzing temperature and soaking time, the resin carbon material has larger crystallite sizes of L_c and L_a, lower specific surface area, smaller irreversible capacity and higher initial coulombic efficiency. The pyrolyzing temperature and soaking time are optimized to be 1050℃ and 2h. The resin carbon anode obtained under the optimum conditions shows good electrochemical performances with reversible capacity of 387mA·h/g and initial coulombic efficiency of 69.1%.
文摘In this paper,the samples were concentrated by solid phase extraction(SPE),then detected by GC-MS.The result showed that the detection limits of 12 phenols was range of 0.06-0.69 μg/L.The RSDs(n=7) were less than 8.2% and the recoveries were 84%-122%.This method is suitable for determination of phenols in surface water and drinking water.
文摘In this paper the multi-position material of phenol installation were analyzed by gas chromatography-mass spectrometry and provides important information for colligation utilization of phenol material and all right moved of phenol installation.
基金Project(40973074) supported by the National Natural Science Foundation of China
文摘A novel heterogeneous catalytic ozonation process in water treatment was studied, with a copper-loaded activated carbon （Cu/AC） that was prepared by an incipient wetness impregnation method at low temperature and tested as a catalyst in the ozonation of phenol and oxalic acid. Cu/AC was characterized using XRD, BET and SEM techniques. Compared with ozonation alone, the presence of Cu/AC in the ozonation processes significantly improves the degradation of phenol or oxalic acid. With the introduction of the hydroxyl radical scavenger, i.e., turt-butanol alcohol （t-BuOH）, the degradation efficiency of both phenol and oxalic acid in the Cu/AC catalyzed ozonation process decreases by 22% at 30 min. This indicates that Cu/AC accelerates ozone decomposition into certain concentration of hydroxyl radicals. The amount of Cu（II ） produced during the reaction of Cu/AC-catalyzed ozonation of phenol or oxalic acid is very small, which shows that the two processes are both heterogeneous catalytic ozonation reactions.
基金Project(15B003)supported by the Outlayed-up Youth Project of Hunan Provincial Department of Education,ChinaProject(KY201623)supported by the Housing and Urban Construction Department of Hunan Province,China+1 种基金Project(2016CL02)supported by the Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,ChinaProject(11405013)supported by the National Natural Science Foundation of China
文摘Electrospun WO_(3) nanofibers were fabricated by coaxial electrospinning and directly annealing WCl_(6)/polyvinylpyrrolidone(PVP) nanofibers on activated carbon fibres(ACF), and characterized by scanning electron microscopy(SEM) and X-ray diffractometry(XRD). The most suitable condition for electrospinning is the mass ratio of WCl_(6) to PVP 0.6, appropriate amount DMF and ethanol, a voltage of 28 kV, the reception distance of 15 cm, the humidity range within 10% and 20% and the moving rate of the pump 0.001 mm/s. The photocatalytic activities of WO_(3) nanofibers were evaluated by the photo-degradation of phenol solution under the irradiation of 500 W xenon lamp. The results showed that, the sizes of the fibers are about 100 nm, and after being photodegraded for 210 min, the concentration of phenol decreased from 20.05 mg/L to 8.60 mg/L. Thus, the photo-degradation rate of WO_(3) nanofibers for phenol solution is 2.87 mg/(L·h).
基金Project(40802064) supported by the National Natural Science Foundation of ChinaProject(Z110805) supported by the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences Project(200925) supported by the Progress and Innovation Fund for the Transportation Science and Technology of Hunan Province,China
文摘Batch experiments were conducted to study the adsorption of phenol on clay-solidified grouting curtain (CSGC) and the effects of contact time,pH and adsorbent concentration on the adsorption were investigated.Under the experimental conditions used,2 d was adequate to determine the equilibrium of phenol adsorption onto CSGC.The amount of phenol adsorbed by CSGC from an initial concentration of 100mg/L was found to be 8.4mg/g.The adsorption process includes particle diffusion and liquid film diffusion,and the latter is the predominating step of the adsorption process.The adsorption ability of CSGC decreased with pH but it increased non-linearly with the CSGC concentration.The optimized concentration for CSGC was found to be 20g/L for the adsorption of 100mg/L phenol.
基金The Fundamental Research Program for Young Scientists of Shanxi Province(Project No.202103021223294)The Fundamental Research Program of Shanxi Province(Project No.202203021211203)+1 种基金The Start-up Fund for Doctorate Scientific Research Project of Taiyuan University of Science and Technology(Project No.20232124)The Innovation and Entrepreneurship Training Program for Undergraduate,Taiyuan University of Science and Technology(Project No.DCX2024162).
文摘The utilization of perovskite oxide materials as catalysts for the photodegradation of organic pollutants in water is a promising and rapidly advancing field.In this study,a series of La_(1−x)Ba_(x)CoO_(3)(x=0.2,0.3,0.4,0.5,0.6)catalysts with varying Ba doping ratios were synthesized using the citric acid complexation-hydrothermal synthesis combined method for the degradation of phenol under visible light irradiation.Among the synthesized catalysts,La_(0.5)Ba_(0.5)CoO_(3) exhibited the highest photocatalytic activity.In addition,the photocatalytic mechanism for La_(0.5)Ba_(0.5)CoO_(3) perovskite degradation of phenol was also discussed.The synthesized catalysts were characterized using XRD,SEM,FT-IR,XPS,MPMS and other characterization techniques.The results revealed that the diffraction peak intensity of La_(1−x)Ba_(x)CoO_(3) increased with higher Ba doping ratios,and the La_(0.4)Ba_(0.6)CoO_(3) exhibited the strongest diffraction peaks.The catalyst particle sizes ranged from 10 to 50 nm,and the specific surface area decreased with increasing Ba content.Additionally,the paramagnetic properties of La_(0.5)Ba_(0.5)CoO_(3) were similar to that of La_(0.4)Ba_(0.6)CoO_(3).The experimental results suggested that the incorporation of Ba could significantly improve the catalytic performance of La_(1−x)Ba_(x)CoO_(3) perovskites,promote electron transfer and favor to the generation of hydroxyl radicals(•OH),leading to the efficiently degradation of phenol.
基金Project(2005CB623701) supported by the National Key Basic Research Program of China
文摘TiO2/bauxite-tailings （TiO2/BTs） composites were prepared via a chemical liquid deposition method and characterized by X-ray diffractometry （XRD）, scanning electronic microscopy （SEM） and N2 adsorption analysis. The photocatalytic performance of TiO2/BTs composites was evaluated with UV-Vis spectrophotometer following the changes of phenol concentration under different illumination time. Effects of the calcination temperature, the pH and the cycles on the photocatalytic activity of TiO2/BTs composites were investigated. The composites calcined at 500 and 600 ℃ exhibit the best photocatalytic performance, and the phenol degradation ratios reacting for 40 and 160 rain reach 35% and 78% respectively under the same conditions, higher than those of 29% and 76% of the Degussa P25（TiO2）. The ability of TiO2/BTs500 （BTs500 represents bauxite-tailings calcined at 500 ℃） composites to degrade phenol increases with decreasing pH.
基金The National Natural Science Foundation of China(22102194)The Science and Technology Plan of Gansu Province(20JR10RA044)The Youth Innovation Promotion Association of CAS(2022427).
文摘The Co@NC catalysts with different morphologies were prepared by two step process,solvent control growth and pyrolysis method.The polyhedral Co@NC-67P-450 catalyst has a relatively high CoNx content and exhibits excellent phenol hydrogenation activity(conversion 96.9%)at 160℃,3 MPa,which is higher than that of leaf shaped Co@NC-67L-450 catalyst(conversion 75.4%).We demonstrated Co_(3)O_(4)was reduced to the Co^(0)during the reaction.Moreover,CoNx species contribute to the superior hydrogenation activity of phenol.The Co-based catalysts can be easily recovered through the magnetic separation and performed the high stability.
