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2013 Volume 30 Issue 11
2013, 30(11): 1237-1249
doi: 10.3724/SP.J.1095.2013.30002
Abstract:
Ugi reaction is an important multicomponent reaction to yield polycondensation α-amido amide in which a molecule of aldehyde or ketone,an amine,an isocyanide and a carboxylic acid were involved.The reaction not only possesses the advantages of mild reaction condition,high yield and atom economy,but also can couple with some classical chemical reactions,for example,Suzuki,Heck and Smiles.Therefore it has attracted more and more research interest in the synthesis of natural products.The article generally summarizes the application of Ugi reaction in the synthesis of natural products in recent decades.
Ugi reaction is an important multicomponent reaction to yield polycondensation α-amido amide in which a molecule of aldehyde or ketone,an amine,an isocyanide and a carboxylic acid were involved.The reaction not only possesses the advantages of mild reaction condition,high yield and atom economy,but also can couple with some classical chemical reactions,for example,Suzuki,Heck and Smiles.Therefore it has attracted more and more research interest in the synthesis of natural products.The article generally summarizes the application of Ugi reaction in the synthesis of natural products in recent decades.
2013, 30(11): 1250-1256
doi: 10.3724/SP.J.1095.2013.20572
Abstract:
Since nanoscale iron particles and iron-containing nanomaterias are very effective for the transformation and detoxification of a wide variety of common environmental contaminants such as toxic metal ions,halogenated organic compounds and so on,they have been under active research in the field of environment remediation.Due to their large surface areas,high surface reactivity and application flexibility,they provide effective solutions to some of the most challenging environmental cleanup problems.In this paper,the progress of iron-containing nanomaterials and its various applications for recent years were summarized.Meanwhile,their potential microbial toxicity was also assessed,which can be a guide for further study in this research field.
Since nanoscale iron particles and iron-containing nanomaterias are very effective for the transformation and detoxification of a wide variety of common environmental contaminants such as toxic metal ions,halogenated organic compounds and so on,they have been under active research in the field of environment remediation.Due to their large surface areas,high surface reactivity and application flexibility,they provide effective solutions to some of the most challenging environmental cleanup problems.In this paper,the progress of iron-containing nanomaterials and its various applications for recent years were summarized.Meanwhile,their potential microbial toxicity was also assessed,which can be a guide for further study in this research field.
2013, 30(11): 1257-1264
doi: 10.3724/SP.J.1095.2013.30048
Abstract:
Metal-assisted chemical etching(MacEtch) is a recently developed anisotropic wet etching method that is capable of producing high aspect ratio semiconductor nanostructures from patterned metal film.The recent progress in the fabrication of silicon nanowires on the basis of MacEtch is reviewed.First,the basic process and mechanism of metal-assisted is briefly introduced.Then template-based metal-assisted chemical etching methods are presented in detail,which can achieve controlled preparation of highly ordered silicon nanowires with high aspect ratio.Next,the introduction to the potential application of silicon nanowires obtained by MacEtch is given,ranging from lithium ion battery,solar cell,to gas detection and biomimetic superhydrophobicity,demonstrating promising potentials of MacEtch.Finally,current problems and future research and development directions of MacEtch are discussed.
Metal-assisted chemical etching(MacEtch) is a recently developed anisotropic wet etching method that is capable of producing high aspect ratio semiconductor nanostructures from patterned metal film.The recent progress in the fabrication of silicon nanowires on the basis of MacEtch is reviewed.First,the basic process and mechanism of metal-assisted is briefly introduced.Then template-based metal-assisted chemical etching methods are presented in detail,which can achieve controlled preparation of highly ordered silicon nanowires with high aspect ratio.Next,the introduction to the potential application of silicon nanowires obtained by MacEtch is given,ranging from lithium ion battery,solar cell,to gas detection and biomimetic superhydrophobicity,demonstrating promising potentials of MacEtch.Finally,current problems and future research and development directions of MacEtch are discussed.
2013, 30(11): 1265-1269
doi: 10.3724/SP.J.1095.2013.20581
Abstract:
Three polyacrylate superabsorbent polymers:sodium-polyacrylate(PAA),poly(acrylic acid-co-acrylamide)(P(AA/AM)) and poly(acrylate acid-co-maleic acid)(P(AA/MA)) were synthesized by inverse suspension polymerization(ISP).Systematic tests and comparison were taken at water absorption,water retention,weather resistance and electrolyte resistance of the product.The results show that P(AA/MA) possesses the best water absorption performance with an absorbency for distilled water of 3578.4 g/g in 10 min.The three polymers all have good quality of water retention within a range of temperature and pressure,with P(AA/MA) showing the best in this performance.The three polymers all can keep their water absorption in different temperature storage,and P(AA/MA) has excellent quality toward electrolyte resistance,with an absorbency for normal saline of 107.2 g/g.Overall,the comparisons show that the comprehensive performance of P(AA/MA) is the best.
Three polyacrylate superabsorbent polymers:sodium-polyacrylate(PAA),poly(acrylic acid-co-acrylamide)(P(AA/AM)) and poly(acrylate acid-co-maleic acid)(P(AA/MA)) were synthesized by inverse suspension polymerization(ISP).Systematic tests and comparison were taken at water absorption,water retention,weather resistance and electrolyte resistance of the product.The results show that P(AA/MA) possesses the best water absorption performance with an absorbency for distilled water of 3578.4 g/g in 10 min.The three polymers all have good quality of water retention within a range of temperature and pressure,with P(AA/MA) showing the best in this performance.The three polymers all can keep their water absorption in different temperature storage,and P(AA/MA) has excellent quality toward electrolyte resistance,with an absorbency for normal saline of 107.2 g/g.Overall,the comparisons show that the comprehensive performance of P(AA/MA) is the best.
2013, 30(11): 1270-1275
doi: 10.3724/SP.J.1095.2013.20605
Abstract:
In this paper,we prepared a polymeric composite from a new self-prepared sulfobetaine amphoteric surfactant and a polyacrylamide with 25 million relative molecular mass,and investigated the effect of the asprepared polymeric composite on its surface performance and interfacial performance.Dropping volume method was used to determine the surface tension of the solution.The results show that the critical micelle concentration increases by adding polyacrylamide and the surface tension of the solution is greater than that of the single surfactant solution.Furthermore,the surface tension of the system increases significantly with the increase of salinity.The spinning drop interfacial tension was determined.It is shown that the water/crude oil interfacial tension increases with the increase of polymer concentration but increases indistinctively with the increase of salinity.When the polymer concentration is 1.5 g/L and the surfactant concentration is 0.3 g/L,water/crude oil interfacial tension of Gudao crude oil and Gudong crude oil from Shengli oil field achieves ultra low magnitude at 10-3 mN/m. Finally,we come to determine the emulsifying performance by diversion time method.The results show that the diversion time extends with the increase of polymer concentration.And we also investigated emulsifying property at 75℃,85℃,95℃,respectively.It is found that diversion time shortened with the increase of temperature.
In this paper,we prepared a polymeric composite from a new self-prepared sulfobetaine amphoteric surfactant and a polyacrylamide with 25 million relative molecular mass,and investigated the effect of the asprepared polymeric composite on its surface performance and interfacial performance.Dropping volume method was used to determine the surface tension of the solution.The results show that the critical micelle concentration increases by adding polyacrylamide and the surface tension of the solution is greater than that of the single surfactant solution.Furthermore,the surface tension of the system increases significantly with the increase of salinity.The spinning drop interfacial tension was determined.It is shown that the water/crude oil interfacial tension increases with the increase of polymer concentration but increases indistinctively with the increase of salinity.When the polymer concentration is 1.5 g/L and the surfactant concentration is 0.3 g/L,water/crude oil interfacial tension of Gudao crude oil and Gudong crude oil from Shengli oil field achieves ultra low magnitude at 10-3 mN/m. Finally,we come to determine the emulsifying performance by diversion time method.The results show that the diversion time extends with the increase of polymer concentration.And we also investigated emulsifying property at 75℃,85℃,95℃,respectively.It is found that diversion time shortened with the increase of temperature.
2013, 30(11): 1276-1280
doi: 10.3724/SP.J.1095.2013.30027
Abstract:
Non-ionic fluorocarbon surfactant N-(2-hydroxypropyl) perfluorooctane amide was synthesized via the fattyacid method using perfluorooctanoic acid and isopropyl amine as precursors.The structures of products were characterized by infrared adsorption spectra(IR) and nuclear magnetic resonance spectroscopy(NMR).The bubbling potential,foam stability,salt resistance and surface tension of the samples were evaluated and compared with sodium dodecylsulfate(SDS).The results show that foam comprehensive exponent of the product is 1.6 times that of SDS.The foaminess is not obviously influenced by the concentration of inorganic ions.The surface tensions of the samples can be increased up to 9.275 mN/m.At lower concentration,the capability of reducing surface tension is better than that of SDS.The property of the products is strongly influenced by the type and quantity of hydrogen bonds,and the content of amides in the chain of the products.
Non-ionic fluorocarbon surfactant N-(2-hydroxypropyl) perfluorooctane amide was synthesized via the fattyacid method using perfluorooctanoic acid and isopropyl amine as precursors.The structures of products were characterized by infrared adsorption spectra(IR) and nuclear magnetic resonance spectroscopy(NMR).The bubbling potential,foam stability,salt resistance and surface tension of the samples were evaluated and compared with sodium dodecylsulfate(SDS).The results show that foam comprehensive exponent of the product is 1.6 times that of SDS.The foaminess is not obviously influenced by the concentration of inorganic ions.The surface tensions of the samples can be increased up to 9.275 mN/m.At lower concentration,the capability of reducing surface tension is better than that of SDS.The property of the products is strongly influenced by the type and quantity of hydrogen bonds,and the content of amides in the chain of the products.
2013, 30(11): 1281-1284
doi: 10.3724/SP.J.1095.2013.20570
Abstract:
FT3C hapten was synthesized via a fast,mild "Click Chemistry",which contained a "spacer arm" of triazole ring conjugated to carboxyl site of free triiodothyronine(FT3).Immunogen and coating antigen of FT3C were respectively prepared by the coupling reaction between hapten and bovine serum albumin(BSA) or keyhole limpet hemocyanin(KLH),using the N-hydroxysuccinimide active ester method. UV spectrum of the artificial antigen(FT3C-BSA) differed significantly from those of hapten(FT3C) and BSA,the results also showed that FT3C was conjugated to BSA successfully,the coupling ratio of hapten to BSA was 7:1;the antibody with high titer(6.24 × 104) and IC50value of 0.37 mg/L was produced through immunization of Balb/c mice.This study provided a new way to prepare FT3 artificial antigen.
FT3C hapten was synthesized via a fast,mild "Click Chemistry",which contained a "spacer arm" of triazole ring conjugated to carboxyl site of free triiodothyronine(FT3).Immunogen and coating antigen of FT3C were respectively prepared by the coupling reaction between hapten and bovine serum albumin(BSA) or keyhole limpet hemocyanin(KLH),using the N-hydroxysuccinimide active ester method. UV spectrum of the artificial antigen(FT3C-BSA) differed significantly from those of hapten(FT3C) and BSA,the results also showed that FT3C was conjugated to BSA successfully,the coupling ratio of hapten to BSA was 7:1;the antibody with high titer(6.24 × 104) and IC50value of 0.37 mg/L was produced through immunization of Balb/c mice.This study provided a new way to prepare FT3 artificial antigen.
2013, 30(11): 1285-1288
doi: 10.3724/SP.J.1095.2013.20601
Abstract:
Emedastine difumarate(1) was prepared via improved synthetic processes.After adding phase transfer catalyst,the synthesis of the two key intermediates such as 2-chloro-1-(2-ethoxyethyl) benzimidazole(4) and emedastine(5) for the reactions could be optimized.No water was needed for the reactions and the yields were significantly enhanced.Typically,the yields of compounds 4 and 5 are up to 67.9% and 74.9%,respectively.The structure of the prepared product was confirmed by IR,1H NMR,13C NMR,MS,elemental analysis,differential thermal analysis,and X-ray powder diffraction.
Emedastine difumarate(1) was prepared via improved synthetic processes.After adding phase transfer catalyst,the synthesis of the two key intermediates such as 2-chloro-1-(2-ethoxyethyl) benzimidazole(4) and emedastine(5) for the reactions could be optimized.No water was needed for the reactions and the yields were significantly enhanced.Typically,the yields of compounds 4 and 5 are up to 67.9% and 74.9%,respectively.The structure of the prepared product was confirmed by IR,1H NMR,13C NMR,MS,elemental analysis,differential thermal analysis,and X-ray powder diffraction.
2013, 30(11): 1289-1292
doi: 10.3724/SP.J.1095.2013.30071
Abstract:
A new method to prepare N-(3-aminopropyl) methacrylamide hydrochloride(Ⅴ) was introduced. N-(3-Chloropropyl) methacrylamide(Ⅱ),obtained by acylation reaction between 3-chloropropylamine hydrochloride(Ⅰ) and methacrylic anhydride,was transformed via Gabriel method to N-[N'-(methacryl)-3-aminopropyl] phthalimide(Ⅲ) and hydrazinolysis product N-(3-aminopropyl) methacrylamide(Ⅳ) and then hydrochloric acidification to compound Ⅴ. The overall yield of the reaction is about 61.1%. This process does not need to use any expensive amino protection reagent,which can dramatically reduces the cost of raw materials.
A new method to prepare N-(3-aminopropyl) methacrylamide hydrochloride(Ⅴ) was introduced. N-(3-Chloropropyl) methacrylamide(Ⅱ),obtained by acylation reaction between 3-chloropropylamine hydrochloride(Ⅰ) and methacrylic anhydride,was transformed via Gabriel method to N-[N'-(methacryl)-3-aminopropyl] phthalimide(Ⅲ) and hydrazinolysis product N-(3-aminopropyl) methacrylamide(Ⅳ) and then hydrochloric acidification to compound Ⅴ. The overall yield of the reaction is about 61.1%. This process does not need to use any expensive amino protection reagent,which can dramatically reduces the cost of raw materials.
2013, 30(11): 1293-1298
doi: 10.3724/SP.J.1095.2013.30198
Abstract:
Ethylene polymerizations were explored by monochloro half-zirconocene complexes containing phosphine oxide-(thio) phenolate chelating ligands of the type,ClCp'Zr[X-2-R1-4-R2-6-(PH2P=O)C6H2]2(Cp'=C5H5,a:X=O,R1=Ph,R2=H;b:X=O,R1=F,R2=H;c:X=O,R1=tBu,R2=H;d:X=O,R1=R2=tBu;e:X=O,R1=SiMe3,R2=H;f:X=S,R1=SiMe3,R2=H;Cp'=C5Me5;g:X=O,R1=SiMe3,R2=H) in the presence of Ph3CB(C6F5)4/iBu3Al as co-catalyst at high temperature(50~125℃). As reveled by the polymerization results,under optimized reaction temperature of 75℃,complexes a~d were efficient ethylene polymerization catalysts under high temperature(50~100℃). Catalytic activity was improved by increasing the steric bulk of R1 substituent or the introduction of electron withdrawing groups at the same position. The occurrence of trimethylsilyl rendered a greatly improved temperature resistance for catalyst e than those of catalysts a~d,exhibiting an ethylene polymerization activity of 5628 kg/(mol Zr·h) under 100℃ optimized reaction temperature. The variation of coordinated atom or the substituents at the Cp moiety had certain influences upon the catalytic activity and the PDI of the resulting polymer material.
Ethylene polymerizations were explored by monochloro half-zirconocene complexes containing phosphine oxide-(thio) phenolate chelating ligands of the type,ClCp'Zr[X-2-R1-4-R2-6-(PH2P=O)C6H2]2(Cp'=C5H5,a:X=O,R1=Ph,R2=H;b:X=O,R1=F,R2=H;c:X=O,R1=tBu,R2=H;d:X=O,R1=R2=tBu;e:X=O,R1=SiMe3,R2=H;f:X=S,R1=SiMe3,R2=H;Cp'=C5Me5;g:X=O,R1=SiMe3,R2=H) in the presence of Ph3CB(C6F5)4/iBu3Al as co-catalyst at high temperature(50~125℃). As reveled by the polymerization results,under optimized reaction temperature of 75℃,complexes a~d were efficient ethylene polymerization catalysts under high temperature(50~100℃). Catalytic activity was improved by increasing the steric bulk of R1 substituent or the introduction of electron withdrawing groups at the same position. The occurrence of trimethylsilyl rendered a greatly improved temperature resistance for catalyst e than those of catalysts a~d,exhibiting an ethylene polymerization activity of 5628 kg/(mol Zr·h) under 100℃ optimized reaction temperature. The variation of coordinated atom or the substituents at the Cp moiety had certain influences upon the catalytic activity and the PDI of the resulting polymer material.
2013, 30(11): 1299-1303
doi: 10.3724/SP.J.1095.2013.30095
Abstract:
A catalyst for the oxybromination of spiro[fluorene-9,9'-xanthene],12-tungstophosphoric acid (TPA) supported on zirconia,was prepared. Effects of TPA loading and activation temperature on the structure of the catalyst and the catalytic performance for oxybromination of spiro[fluorine-9,9'-xanthene] (SFX) have been investigated. The results of XRD and FTIR analysis show that the monoclinic zirconia transformed to tetragonal phase with the increase of TPA loading and calcinations temperature. A preliminary study on catalysts with 15% (mass fraction) TPA indicated that calcination at 300℃ could greatly enhance the stability of catalyst. The bromination position of the products was confirmed in the position of 2 of SFX from1H NMR.
A catalyst for the oxybromination of spiro[fluorene-9,9'-xanthene],12-tungstophosphoric acid (TPA) supported on zirconia,was prepared. Effects of TPA loading and activation temperature on the structure of the catalyst and the catalytic performance for oxybromination of spiro[fluorine-9,9'-xanthene] (SFX) have been investigated. The results of XRD and FTIR analysis show that the monoclinic zirconia transformed to tetragonal phase with the increase of TPA loading and calcinations temperature. A preliminary study on catalysts with 15% (mass fraction) TPA indicated that calcination at 300℃ could greatly enhance the stability of catalyst. The bromination position of the products was confirmed in the position of 2 of SFX from1H NMR.
2013, 30(11): 1304-1309
doi: 10.3724/SP.J.1095.2013.30059
Abstract:
Cr2O3/γ-Al2O3 catalysts were prepared through the wetness impregnation method and characterized by XRD,UV-Vis DRS and TG-DTA. The effects of Cr loadings,catalyst calcination temperature,oxidation reaction temperature and the catalyst quantity on the catalytic oxidation of tetralin to α-tetralone were investigated. The results demonstrate that the dominant active specie of the catalysts is Cr2O3 with a small amount of CrO3 highly dispersed on the surface of γ-Al2O3. A conversion of 50.1% of tetralin and a selectivity of 79.7% of α-tetralone are obtained over the 7.5% Cr2O3/γ-Al2O3 catalyst at 120℃ after 8 h oxidation. The as-obtained catalysts exhibit a good stability.
Cr2O3/γ-Al2O3 catalysts were prepared through the wetness impregnation method and characterized by XRD,UV-Vis DRS and TG-DTA. The effects of Cr loadings,catalyst calcination temperature,oxidation reaction temperature and the catalyst quantity on the catalytic oxidation of tetralin to α-tetralone were investigated. The results demonstrate that the dominant active specie of the catalysts is Cr2O3 with a small amount of CrO3 highly dispersed on the surface of γ-Al2O3. A conversion of 50.1% of tetralin and a selectivity of 79.7% of α-tetralone are obtained over the 7.5% Cr2O3/γ-Al2O3 catalyst at 120℃ after 8 h oxidation. The as-obtained catalysts exhibit a good stability.
2013, 30(11): 1310-1318
doi: 10.3724/SP.J.1095.2013.30061
Abstract:
Mesoporous molecular sieves MCM-41 supported Schiff base was prepared from MCM-41,3-chloropropyltriethoxysilane,dis-thiocarbohydrazone and salicylide.Both as-prepared supported catalyst and K2CO3 were used to catalyze the epoxidation of α,β-unsaturated ketones in the presence of H2O2. All products from these oxidations were characterized by 1H NMR and IR. The effects of reaction conditions such as metal salts,solvents,reaction temperature,the loading of catalyst,and reaction time on the oxidation reaction were investigated.It was found that the epoxidation products of α,β-unsaturated ketones were easily obtained with excellent yields (up to 93%) at room temperature in a short time. Especially,the heterogeneous catalyst can be reused four times without significant loss of its catalytic activity.
Mesoporous molecular sieves MCM-41 supported Schiff base was prepared from MCM-41,3-chloropropyltriethoxysilane,dis-thiocarbohydrazone and salicylide.Both as-prepared supported catalyst and K2CO3 were used to catalyze the epoxidation of α,β-unsaturated ketones in the presence of H2O2. All products from these oxidations were characterized by 1H NMR and IR. The effects of reaction conditions such as metal salts,solvents,reaction temperature,the loading of catalyst,and reaction time on the oxidation reaction were investigated.It was found that the epoxidation products of α,β-unsaturated ketones were easily obtained with excellent yields (up to 93%) at room temperature in a short time. Especially,the heterogeneous catalyst can be reused four times without significant loss of its catalytic activity.
2013, 30(11): 1319-1325
doi: 10.3724/SP.J.1095.2013.30001
Abstract:
KF/Zn-Al solid base catalyst was prepared by coprecipitation and calcination by doping KF on calcined Zn-Al hydrotalcite-like compounds.Effects of different preparation conditions on the catalytic activity of the KF/Zn-Al solid base were investigated through orthogonal experiments. The optimal condition was obtained at aging temperature of 353 K,aging time of 16 h,calcination temperature of 823 K,calcination time of 6 h and KF/Zn-Al mass ratio of 1. When the reaction was carried out at 338 K for 0.5 h with alcohol/oil molar ratio of 9,catalyst/oil mass ratio of 0.04,rapeseed oil conversion could reach 97.75% in the presence of the KF/Zn-Al catalyst prepared at optimal conditions. The catalyst and its precursor were characterized using TG-DTG,BET,XRD,SEM and Hammett indicator method.Relationship between the structure and the surface properties of the catalyst and its activity was discussed.
KF/Zn-Al solid base catalyst was prepared by coprecipitation and calcination by doping KF on calcined Zn-Al hydrotalcite-like compounds.Effects of different preparation conditions on the catalytic activity of the KF/Zn-Al solid base were investigated through orthogonal experiments. The optimal condition was obtained at aging temperature of 353 K,aging time of 16 h,calcination temperature of 823 K,calcination time of 6 h and KF/Zn-Al mass ratio of 1. When the reaction was carried out at 338 K for 0.5 h with alcohol/oil molar ratio of 9,catalyst/oil mass ratio of 0.04,rapeseed oil conversion could reach 97.75% in the presence of the KF/Zn-Al catalyst prepared at optimal conditions. The catalyst and its precursor were characterized using TG-DTG,BET,XRD,SEM and Hammett indicator method.Relationship between the structure and the surface properties of the catalyst and its activity was discussed.
2013, 30(11): 1326-1332
doi: 10.3724/SP.J.1095.2013.30019
Abstract:
The CeO2-TiO2 sol-gel was prepared by the sol-gel method using polyvinylpyrrolidone(PVP) sol/titaniumn-butyloxide (Ti(OC4H9)4) as the precursor and Ce(NO3)3·6H2O as the doping agent,and the CeO2 doped TiO2 nanofiber was prepared by the electrospinning technique. Finally,a layer of carbon membrane was deposited on the surface of the CeO2-TiO2 composite nanofibers using chemical vapor deposition(CVD). The structure and properties of the carbon-coated nanofibers were studied using SEM,FTIR,TEM,XRD,and its photocatalytic activity toward the degradation of ciprofloxacin hydrochloride was investigated under UV-light irradiation. The experimental results show that carbon-coated TiO2 composite nanofibers exhibit higher photocatalytic performance. When the irradiation time is 40 min,the degradation rate of ciprofloxacin hydrochloride is up to 85.8%.
The CeO2-TiO2 sol-gel was prepared by the sol-gel method using polyvinylpyrrolidone(PVP) sol/titaniumn-butyloxide (Ti(OC4H9)4) as the precursor and Ce(NO3)3·6H2O as the doping agent,and the CeO2 doped TiO2 nanofiber was prepared by the electrospinning technique. Finally,a layer of carbon membrane was deposited on the surface of the CeO2-TiO2 composite nanofibers using chemical vapor deposition(CVD). The structure and properties of the carbon-coated nanofibers were studied using SEM,FTIR,TEM,XRD,and its photocatalytic activity toward the degradation of ciprofloxacin hydrochloride was investigated under UV-light irradiation. The experimental results show that carbon-coated TiO2 composite nanofibers exhibit higher photocatalytic performance. When the irradiation time is 40 min,the degradation rate of ciprofloxacin hydrochloride is up to 85.8%.
2013, 30(11): 1333-1337
doi: 10.3724/SP.J.1095.2013.30026
Abstract:
A chlorination combined oxidation process was proposed to recover and remove phenolic compounds from simulated wastewater containing 30 g/L phenol.First,enough chloride and hydrogen ions were introduced into the phenolic solution by adding hydrochloric acid under indication with a pH meter;sodium chlorate was then added to react with above ions to produce chlorine qualitatively. Under controlled experimental conditions,the chlorine combined with phenol and selectivity converted to the insoluble trichlorophenol,which was confirmed by GC-MS and its content was measured to be 97.76% through area normalization method.The chemical oxygen demand (COD) of filtrate obtained after the above process declined to 1125 mg/L,and the recovery of phenols was up to 98.7% by calculations.Later,Fenton oxidation technology was used to further remove the phenolic compounds in filtrate. The results show that under optimized conditions (pH=3,c(Fe2+)=1 mmol/L),the residual chlorophenols can be degraded effectively with H2O2 consumption of 15 mL/L,and the degraded solution is colorless and transparent when adjusting its pH to 10 to precipitate the ferrous and ferric irons. After combined treatments,the COD reduces to 52 mg/L,which the value can meet the national sewage effluent discharge standards.
A chlorination combined oxidation process was proposed to recover and remove phenolic compounds from simulated wastewater containing 30 g/L phenol.First,enough chloride and hydrogen ions were introduced into the phenolic solution by adding hydrochloric acid under indication with a pH meter;sodium chlorate was then added to react with above ions to produce chlorine qualitatively. Under controlled experimental conditions,the chlorine combined with phenol and selectivity converted to the insoluble trichlorophenol,which was confirmed by GC-MS and its content was measured to be 97.76% through area normalization method.The chemical oxygen demand (COD) of filtrate obtained after the above process declined to 1125 mg/L,and the recovery of phenols was up to 98.7% by calculations.Later,Fenton oxidation technology was used to further remove the phenolic compounds in filtrate. The results show that under optimized conditions (pH=3,c(Fe2+)=1 mmol/L),the residual chlorophenols can be degraded effectively with H2O2 consumption of 15 mL/L,and the degraded solution is colorless and transparent when adjusting its pH to 10 to precipitate the ferrous and ferric irons. After combined treatments,the COD reduces to 52 mg/L,which the value can meet the national sewage effluent discharge standards.
2013, 30(11): 1338-1342
doi: 10.3724/SP.J.1095.2013.20515
Abstract:
With the sodium tungstate as tungsten source,the mixture of water and alcohol solution as solvent,and triblock copolymer of ethylene oxide with propylene oxide (P123) as structure directing agent and porogen,mesoporous WO3 of special morphology was synthesized by precursor route and solvothermal method,and meanwhile the influence of different reaction time and temperature were also discussed. These samples were characterized and analyzed by the X-ray diffraction (XRD),scanning electron microscope (SEM),transmission electric microscope (TEM),N2 adsorption-desorption,UV-visible spectroscopy,and the thermo gravimetric (TG). The results show that the as-prepared WO3 materials possess mesoporous structure and large specific surface area,moreover,the increasing of the solvothermal time and reaction temperature are beneficial to the size enlargement and also the morphology variance of the WO3 particles. Absorption test of the synthesized mesoporous WO3 materials for rhodamine B dye in aqueous solution was also performed,and a good adsorption performance with a removal efficiency of 93.13% was achieved.
With the sodium tungstate as tungsten source,the mixture of water and alcohol solution as solvent,and triblock copolymer of ethylene oxide with propylene oxide (P123) as structure directing agent and porogen,mesoporous WO3 of special morphology was synthesized by precursor route and solvothermal method,and meanwhile the influence of different reaction time and temperature were also discussed. These samples were characterized and analyzed by the X-ray diffraction (XRD),scanning electron microscope (SEM),transmission electric microscope (TEM),N2 adsorption-desorption,UV-visible spectroscopy,and the thermo gravimetric (TG). The results show that the as-prepared WO3 materials possess mesoporous structure and large specific surface area,moreover,the increasing of the solvothermal time and reaction temperature are beneficial to the size enlargement and also the morphology variance of the WO3 particles. Absorption test of the synthesized mesoporous WO3 materials for rhodamine B dye in aqueous solution was also performed,and a good adsorption performance with a removal efficiency of 93.13% was achieved.
2013, 30(11): 1343-1347
doi: 10.3724/SP.J.1095.2013.20604
Abstract:
Cathode materials for Li-ion batteries such as pure LiV3O8 and LiV3O8/V2O5 composite have been prepared by a hydrothermal reaction method.XRD,SEM and BET were employed to characterize the samples. The results show that the chemical formula of the as-prepared composite is LiV3O8·0.2 V2O5.The interlayer distance of LiV3O8 in the composite is enhanced due to the existence of V2O5. SEM results show that pure LiV3O8 product consists of small laminar nanocrystallites that stacked together. While numerous cavities have been formed between the stacked laminar nanocrystallites in the composite. The porous structures in the composites can increase the penetration of electrolyte and therefore benefit the lithium intercalation/deintercalation reaction. Charge-discharge cycling tests show that LiV3O8/V2O5 composite has a higher initial discharge capacity and better cycling performance compared with LiV3O8.
Cathode materials for Li-ion batteries such as pure LiV3O8 and LiV3O8/V2O5 composite have been prepared by a hydrothermal reaction method.XRD,SEM and BET were employed to characterize the samples. The results show that the chemical formula of the as-prepared composite is LiV3O8·0.2 V2O5.The interlayer distance of LiV3O8 in the composite is enhanced due to the existence of V2O5. SEM results show that pure LiV3O8 product consists of small laminar nanocrystallites that stacked together. While numerous cavities have been formed between the stacked laminar nanocrystallites in the composite. The porous structures in the composites can increase the penetration of electrolyte and therefore benefit the lithium intercalation/deintercalation reaction. Charge-discharge cycling tests show that LiV3O8/V2O5 composite has a higher initial discharge capacity and better cycling performance compared with LiV3O8.
2013, 30(11): 1348-1353
doi: 10.3724/SP.J.1095.2013.30033
Abstract:
The effect of the anode backing layer consisting of carbon papers with different polytetrafluoroethylene(PTFE) contents on the methanol mass transfer and cell performance of a passive direct methanol fuel cell (DMFC) was investigated by methanol permeability measurement.The membrane electrode assemblies(MEAs) were fabricated with the same anode catalyst layer,membrane and cathode.The experimental results showed that the methanol permeability decreased with the increase of PTFE contents in anode backing layer.It was found that PTFE-treated backing layer results in a lower limiting current density,which could be attributed primarily to the increased mass transfer resistance. When the PTFE content in the anode backing layer is up to 40%,the maximum power density of passive DMFC feeding with 9 mol/L methanol solution can achieve 32 × 10-3 W/cm2. Moreover,the use of a PTFE-treated backing layer also can decrease water transfer from the anode to the cathode,thus mitigating water flooding problem in the cathode.
The effect of the anode backing layer consisting of carbon papers with different polytetrafluoroethylene(PTFE) contents on the methanol mass transfer and cell performance of a passive direct methanol fuel cell (DMFC) was investigated by methanol permeability measurement.The membrane electrode assemblies(MEAs) were fabricated with the same anode catalyst layer,membrane and cathode.The experimental results showed that the methanol permeability decreased with the increase of PTFE contents in anode backing layer.It was found that PTFE-treated backing layer results in a lower limiting current density,which could be attributed primarily to the increased mass transfer resistance. When the PTFE content in the anode backing layer is up to 40%,the maximum power density of passive DMFC feeding with 9 mol/L methanol solution can achieve 32 × 10-3 W/cm2. Moreover,the use of a PTFE-treated backing layer also can decrease water transfer from the anode to the cathode,thus mitigating water flooding problem in the cathode.
2013, 30(11): 1354-1360
doi: 10.3724/SP.J.1095.2013.30023
Abstract:
In this work,the surface of GO was functionalized by different method and used to load noble metal Pd.It is found that the surface modification of GO can effectively enhance the loading amount of Pd and reduce the Pd agglomeration on the support surface,and thereby improve the catalytic activity of Pd-based catalyst for oxidation of formic acid.The activity of Pd-based electrocatalyst toward the oxygen reductionreaction (ORR) was examined using cyclic voltammetry through roating-disk electrode measurements in 0.5 mol/L H2SO4 electrolyte. Under the same experimental conditions,the loading amount and the catalytic performance of Pd on graphene oxide (GO),reduced graphene oxide (RGO) and sulfonated graphene (SGO) were studied.The results show that SGO is easier to load Pd and the obtained composite catalyst for CO tolerance is also improved significantly,which may be due to the synergetic effect from the π-π bonding of graphene and the van der Waals interactions of the -SO3H functionality,enhancing the loading and dispersion of Pd on the supporting materials effectively.
In this work,the surface of GO was functionalized by different method and used to load noble metal Pd.It is found that the surface modification of GO can effectively enhance the loading amount of Pd and reduce the Pd agglomeration on the support surface,and thereby improve the catalytic activity of Pd-based catalyst for oxidation of formic acid.The activity of Pd-based electrocatalyst toward the oxygen reductionreaction (ORR) was examined using cyclic voltammetry through roating-disk electrode measurements in 0.5 mol/L H2SO4 electrolyte. Under the same experimental conditions,the loading amount and the catalytic performance of Pd on graphene oxide (GO),reduced graphene oxide (RGO) and sulfonated graphene (SGO) were studied.The results show that SGO is easier to load Pd and the obtained composite catalyst for CO tolerance is also improved significantly,which may be due to the synergetic effect from the π-π bonding of graphene and the van der Waals interactions of the -SO3H functionality,enhancing the loading and dispersion of Pd on the supporting materials effectively.
2013, 30(11): 1361-1365
doi: 10.3724/SP.J.1095.2013.30030
Abstract:
A sensitive chlorpromazine sensor based on molecularly imprinted membrane(MIP) was fabricated with chlorpromazine as template molecule and o-aminophenol as functional monomers. The performance of MIP and the electrochemical behavior of molecular imprinted sensor were obtained by cyclic voltammetry(CV) and differential pulse voltammetry(DPV). The sensor exhibits good selectivity and sensitivity for measuring chlorpromazine compared with the structurally-related compounds of promethazine and perphenazine. The linear relationship between the peak current and chlorpromazine concentration is found at the range of 6.0 × 10-7~9.0 × 10-5 mol/L,the liner equation is I(μA)=61.25lg c(μmol/L) + 23.47(r=0.9975),the limit of detection is 2.0 × 10-7 mol/L. This sensor has many advantages such as high sensitivity,good reproducibility and repeatability.
A sensitive chlorpromazine sensor based on molecularly imprinted membrane(MIP) was fabricated with chlorpromazine as template molecule and o-aminophenol as functional monomers. The performance of MIP and the electrochemical behavior of molecular imprinted sensor were obtained by cyclic voltammetry(CV) and differential pulse voltammetry(DPV). The sensor exhibits good selectivity and sensitivity for measuring chlorpromazine compared with the structurally-related compounds of promethazine and perphenazine. The linear relationship between the peak current and chlorpromazine concentration is found at the range of 6.0 × 10-7~9.0 × 10-5 mol/L,the liner equation is I(μA)=61.25lg c(μmol/L) + 23.47(r=0.9975),the limit of detection is 2.0 × 10-7 mol/L. This sensor has many advantages such as high sensitivity,good reproducibility and repeatability.
2013, 30(11): 1366-1368
doi: 10.3724/SP.J.1095.2013.30056
Abstract:
Two synthetic methods have been developed for the synthesis of 3,5-dichloro-2,4,6-trinitrobenzenamine.In the first process,3,5-dichlorobenzenamine was selected as precursor,followed by N-protection,nitration,and hydrolysis. In another process,1,3,5-trichloro-2,4,6-tri-nitrobenzene(TCTNB) reacted with 2-amino-2-methylpropane and then trifluoroacetic acid to deprotect.The condensation between 3,5-dichloro-2,4,6-trinitrobenzenamine and methylamine gave 3,5-dimethylamino-2,4,6-trinitrobenzenamine in 85% yield which can be converted to the nitrate of 3,5-dimethylnitramino-2,4,6-trinitrobenzenamine in 70% yield. The structure of the product was confirmed by 1H NMR,MS,IR and elemental analysis. The results of selective of TCTNB under different conditions were discussed.The optimized conditions are:n(TCTNB):n(t-butylamine)=1:2,CuO as catalyst,KHCO3 as base.
Two synthetic methods have been developed for the synthesis of 3,5-dichloro-2,4,6-trinitrobenzenamine.In the first process,3,5-dichlorobenzenamine was selected as precursor,followed by N-protection,nitration,and hydrolysis. In another process,1,3,5-trichloro-2,4,6-tri-nitrobenzene(TCTNB) reacted with 2-amino-2-methylpropane and then trifluoroacetic acid to deprotect.The condensation between 3,5-dichloro-2,4,6-trinitrobenzenamine and methylamine gave 3,5-dimethylamino-2,4,6-trinitrobenzenamine in 85% yield which can be converted to the nitrate of 3,5-dimethylnitramino-2,4,6-trinitrobenzenamine in 70% yield. The structure of the product was confirmed by 1H NMR,MS,IR and elemental analysis. The results of selective of TCTNB under different conditions were discussed.The optimized conditions are:n(TCTNB):n(t-butylamine)=1:2,CuO as catalyst,KHCO3 as base.
2013, 30(11): 1369-1371
doi: 10.3724/SP.J.1095.2013.30005
Abstract:
(R)-1-(4-Benzyloxy-3-nitrophenyl)-2-bromoethanol,a key intermediate for the preparation of (R,R)-formoterol,was prepared from 4-benzyloxy-3-nitrophenyl-α-bromoacetophenone using BH3 complex with polymer-bonded (R)-diphenylpyrrolidinemethanol as the catalyst and NaBH4/Me3SiCl as reductant via an enantioselective reduction. The yield and ee value for the reaction are 95% and 95.4% respectively. The resulted chiral compounds can be easily separated and recycled,which reduce the production cost. Using NaBH4/Me3SiCl as the reductant could minimize the toxicity of the reaction and help to improve the safety issue.
(R)-1-(4-Benzyloxy-3-nitrophenyl)-2-bromoethanol,a key intermediate for the preparation of (R,R)-formoterol,was prepared from 4-benzyloxy-3-nitrophenyl-α-bromoacetophenone using BH3 complex with polymer-bonded (R)-diphenylpyrrolidinemethanol as the catalyst and NaBH4/Me3SiCl as reductant via an enantioselective reduction. The yield and ee value for the reaction are 95% and 95.4% respectively. The resulted chiral compounds can be easily separated and recycled,which reduce the production cost. Using NaBH4/Me3SiCl as the reductant could minimize the toxicity of the reaction and help to improve the safety issue.
2013, 30(11): 1372-1374
doi: 10.3724/SP.J.1095.2013.20597
Abstract:
In a planetary or a shaking ball milling machine,when H2O (50 μL) or DMF (50 μL) or methanol (150 μL) were added as assisting liquids in ball milling processes,the mechanochemical reactions between nicotinic acid and zinc oxide or basic zinc carbonate have been studied.The results show that ball milling the starting materials in the presence of H2O or DMF in the planetary (at 45 Hz) or shaking (at 20 Hz) ball milling machine,a zero-dimensional coordination compound,[Zn(NA)2(H2O)4] could be obtained after 30 min reactions. With the absence of DMF and methanol,the target compound could not be synthesized in a planetary ball milling process at lower frequency of 15 Hz. However,the similar reaction could be initiated once prolonging the reaction time to 60 min under similar conditions.
In a planetary or a shaking ball milling machine,when H2O (50 μL) or DMF (50 μL) or methanol (150 μL) were added as assisting liquids in ball milling processes,the mechanochemical reactions between nicotinic acid and zinc oxide or basic zinc carbonate have been studied.The results show that ball milling the starting materials in the presence of H2O or DMF in the planetary (at 45 Hz) or shaking (at 20 Hz) ball milling machine,a zero-dimensional coordination compound,[Zn(NA)2(H2O)4] could be obtained after 30 min reactions. With the absence of DMF and methanol,the target compound could not be synthesized in a planetary ball milling process at lower frequency of 15 Hz. However,the similar reaction could be initiated once prolonging the reaction time to 60 min under similar conditions.
