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2009 Volume 26 Issue 9
2009, 26(9): 1005-1010
Abstract:
A novel ionic liquid,1-allyl-3-ethyl imidazolium chloride([AEIM]Cl),was synthesized and its chemical structure was confirmed by FT-IR and 1H NMR.The solution of microcrystalline cellulose(MCC) in [AEIM]Cl was prepared by microwave heating.Influences of three treatment methods,such as NaOH,microwave and high pressure,on the crystallinity,degree of polymerization(DP) and dissolution rate of MCC were studied.Chemical structure,change of crystal form,thermostability and appearance of the regenerated cellulose after dissolution were analyzed by FT-IR,XRD,TGA,and SEM,respectively.It showed that the ionic liquid was a direct solvent for MCC.Compared to original MCC,crystallinity of MCC treated decreased from 92.0% to 49.2%,DP decreased from 306 to 153,and dissolution rate increased from 5.2% to 28.8% when the MCC was treated with 15%(mass fraction) NaOH in a high pressure pot at 140 ℃.Chemical reaction did not occur during the dissolution of MCC.Crystal form of the regenerated cellulose changed from original cellulose Ⅰto cellulose Ⅱ,crystallite dimension of the regenerated cellulose was decreased from 4.92 nm to 1.76 nm,and thermal decomposition temperature decreased from 246.6 ℃ to 183.0 ℃.
A novel ionic liquid,1-allyl-3-ethyl imidazolium chloride([AEIM]Cl),was synthesized and its chemical structure was confirmed by FT-IR and 1H NMR.The solution of microcrystalline cellulose(MCC) in [AEIM]Cl was prepared by microwave heating.Influences of three treatment methods,such as NaOH,microwave and high pressure,on the crystallinity,degree of polymerization(DP) and dissolution rate of MCC were studied.Chemical structure,change of crystal form,thermostability and appearance of the regenerated cellulose after dissolution were analyzed by FT-IR,XRD,TGA,and SEM,respectively.It showed that the ionic liquid was a direct solvent for MCC.Compared to original MCC,crystallinity of MCC treated decreased from 92.0% to 49.2%,DP decreased from 306 to 153,and dissolution rate increased from 5.2% to 28.8% when the MCC was treated with 15%(mass fraction) NaOH in a high pressure pot at 140 ℃.Chemical reaction did not occur during the dissolution of MCC.Crystal form of the regenerated cellulose changed from original cellulose Ⅰto cellulose Ⅱ,crystallite dimension of the regenerated cellulose was decreased from 4.92 nm to 1.76 nm,and thermal decomposition temperature decreased from 246.6 ℃ to 183.0 ℃.
2009, 26(9): 1011-1014
Abstract:
In the presence of each of 3 hexadecane toluene sulfonates synthesized in the laboratory,the effects of internal factors such as branched degree of the fatty chain and the concentration of the sulfonates and the external factors like the different kinds of aliphatic alcohols and the concentration of inorganic salt on either the minimum alkane carbon number or the interfacial tension were investigated.The results show that as the branch-degree increased,the minimum number of alkane carbon nmin increased,while the minimum value of interfacial tension decreased.As the concentration increased,the value of interfacial tension first decreased and then increased.The minimum alkane carbon number became big as the carbon chain length of the aliphatic alcohol increased.When the salt concentration increased,the interfacial tension rose after the first drop,and ultra-low interfacial tension appeared at a suitable salt concentration.
In the presence of each of 3 hexadecane toluene sulfonates synthesized in the laboratory,the effects of internal factors such as branched degree of the fatty chain and the concentration of the sulfonates and the external factors like the different kinds of aliphatic alcohols and the concentration of inorganic salt on either the minimum alkane carbon number or the interfacial tension were investigated.The results show that as the branch-degree increased,the minimum number of alkane carbon nmin increased,while the minimum value of interfacial tension decreased.As the concentration increased,the value of interfacial tension first decreased and then increased.The minimum alkane carbon number became big as the carbon chain length of the aliphatic alcohol increased.When the salt concentration increased,the interfacial tension rose after the first drop,and ultra-low interfacial tension appeared at a suitable salt concentration.
2009, 26(9): 1015-1018
Abstract:
Inorganic proton conductor SnP2O7 was synthesized.Its conductivity was measured from ambient temperature to 250 ℃ without humidification.At 170 ℃,the highest conductivity of 0.053 S/cm was reached for SnP2O7.Hybrid membranes of SnP2O7 with polyvinylidenefluoride(PVDF) or sulfonated poly(ether ether) ketone(SPEEK) were prepared by solution casting.For the hybrid membranes containing 60% SnP2O7,the conductivity at 210 ℃ was 9.2×10-5 S/cm for SnP2O7/PVDF,and 9.3×10-5 S/cm for SnP2O7/SPEEK with a sulfonation degree of 51%,respectively.The proton conduction mechanism of SnP2O7 as well as its hybrid membranes was discussed.The mechanical strength of the hybrid membranes was measured.The tensile strength of SnP2O7/PVDF membranes at break was much higher than that of SnP2O7/SPEEK membranes at 130 ℃.
Inorganic proton conductor SnP2O7 was synthesized.Its conductivity was measured from ambient temperature to 250 ℃ without humidification.At 170 ℃,the highest conductivity of 0.053 S/cm was reached for SnP2O7.Hybrid membranes of SnP2O7 with polyvinylidenefluoride(PVDF) or sulfonated poly(ether ether) ketone(SPEEK) were prepared by solution casting.For the hybrid membranes containing 60% SnP2O7,the conductivity at 210 ℃ was 9.2×10-5 S/cm for SnP2O7/PVDF,and 9.3×10-5 S/cm for SnP2O7/SPEEK with a sulfonation degree of 51%,respectively.The proton conduction mechanism of SnP2O7 as well as its hybrid membranes was discussed.The mechanical strength of the hybrid membranes was measured.The tensile strength of SnP2O7/PVDF membranes at break was much higher than that of SnP2O7/SPEEK membranes at 130 ℃.
2009, 26(9): 1019-1022
Abstract:
High-density polyethylene(HDPE),a photoinitiator(benzil dimethyl ketal,BDK),and a cross-linker(triallyl isocyanurate,TAIC) were mixed at elevated temperature,and then a series of samples with different degrees of crosslinking were prepared by UV photocrosslinking under a high pressure mercury lamp.The effects of ultraviolet(UV) photocrosslinking on the crystal structure and non-isothermal crystallization kinetics were studied by means of X-ray diffraction(XRD) and differential scanning calorimetry(DSC).The results show that UV phtocrosslinking did not change the crystal type of the HDPE.However,the degree of crystallinity and the size of the crystals decreased with increasing UV irradiation time.With the cooling rate increasing,the crystalline peaks of both neat HDPE and photocrosslinked HDPE(XLPE) became wider,and the crystallization temperatures(Tp) moved toward lower temperature,the crystallization rate increased,and the degrees of crystallinity(Xc) were reduced.In comparison with un-photocrosslinked HDPE,XLPE possesses lower Tp,bigger F(T),smaller Xc and higher effective activation energy(ΔE),indicating that UV photocrosslinking suppresses the crystallization process of HDPE.
High-density polyethylene(HDPE),a photoinitiator(benzil dimethyl ketal,BDK),and a cross-linker(triallyl isocyanurate,TAIC) were mixed at elevated temperature,and then a series of samples with different degrees of crosslinking were prepared by UV photocrosslinking under a high pressure mercury lamp.The effects of ultraviolet(UV) photocrosslinking on the crystal structure and non-isothermal crystallization kinetics were studied by means of X-ray diffraction(XRD) and differential scanning calorimetry(DSC).The results show that UV phtocrosslinking did not change the crystal type of the HDPE.However,the degree of crystallinity and the size of the crystals decreased with increasing UV irradiation time.With the cooling rate increasing,the crystalline peaks of both neat HDPE and photocrosslinked HDPE(XLPE) became wider,and the crystallization temperatures(Tp) moved toward lower temperature,the crystallization rate increased,and the degrees of crystallinity(Xc) were reduced.In comparison with un-photocrosslinked HDPE,XLPE possesses lower Tp,bigger F(T),smaller Xc and higher effective activation energy(ΔE),indicating that UV photocrosslinking suppresses the crystallization process of HDPE.
2009, 26(9): 1023-1026
Abstract:
The surface properties of synthesized pentadecyl m-xylene sodium sulfonates in pure water and 0.039 3 mol/L isopropanol solution were measured.The measurements indicate that with the moving of the aryl from the terminal to the center of the long alkyl chain,the critical micelle concentration(cmc),the saturated adsorption area Amin and the negative logarithms of surfactant concentrations needed to reduce surface tension efficiency 20 mN/m(pc20) increased.The standard free energy of adsorption(ΔG0) became more negative,the surface tension at the cmc(γcmc) and the maximum surface excess at the cmc(Γmax) decreased.With the addition of isopropanol,the cmc decreased.The effects of molecular branched structures on surface properties were explained from the view of molecular structure.
The surface properties of synthesized pentadecyl m-xylene sodium sulfonates in pure water and 0.039 3 mol/L isopropanol solution were measured.The measurements indicate that with the moving of the aryl from the terminal to the center of the long alkyl chain,the critical micelle concentration(cmc),the saturated adsorption area Amin and the negative logarithms of surfactant concentrations needed to reduce surface tension efficiency 20 mN/m(pc20) increased.The standard free energy of adsorption(ΔG0) became more negative,the surface tension at the cmc(γcmc) and the maximum surface excess at the cmc(Γmax) decreased.With the addition of isopropanol,the cmc decreased.The effects of molecular branched structures on surface properties were explained from the view of molecular structure.
2009, 26(9): 1027-1030
Abstract:
Eleven novel compounds were designed and synthesized from 3-substituted-4-amino-5-mercapto-1,2,4-triazoles with heterocyclic carboxylic acid via cyclization in the presence of phosphoryl chloride on the basis of the princple of combination of active structural moieties.All the compounds were characterized by melting point,IR,1H NMR and elemental analysis.The results of bioassay experiments with 10 commonly used fungi show that all the compounds had satisfactory fungicidal activity against Botrytis cinerea,with the growth inhibition rate of compounds 5ae,5ag,5bd against Botrytis cinerea being up to 70% and that of 5ad,5cd,5ce against Botrytis cinerea more than 60%;compound 5bd exhibited fungicidal activity against Pellicularia sasakii with growth inhibition of up to 60%,and the growth inhibition rate of compound 5cg against Colletotrichum lagenarium was 69%.
Eleven novel compounds were designed and synthesized from 3-substituted-4-amino-5-mercapto-1,2,4-triazoles with heterocyclic carboxylic acid via cyclization in the presence of phosphoryl chloride on the basis of the princple of combination of active structural moieties.All the compounds were characterized by melting point,IR,1H NMR and elemental analysis.The results of bioassay experiments with 10 commonly used fungi show that all the compounds had satisfactory fungicidal activity against Botrytis cinerea,with the growth inhibition rate of compounds 5ae,5ag,5bd against Botrytis cinerea being up to 70% and that of 5ad,5cd,5ce against Botrytis cinerea more than 60%;compound 5bd exhibited fungicidal activity against Pellicularia sasakii with growth inhibition of up to 60%,and the growth inhibition rate of compound 5cg against Colletotrichum lagenarium was 69%.
2009, 26(9): 1031-1035
Abstract:
Hyperbranched aqueous polyurethane(HBAPU) was synthesized via A2+bB2 approach with 2,4-toluylene diisocyanate(TDI),polycarbonatediol(PCDL),dimethylol propionic acid(DMPA) and diethanol amine(DEOA) as materials.The structures of products were characterized by FT-IR and 13C NMR.The results show that the degree of the branching(DB) of HBAPU increased with increasing the molar ratio of n(NCO)/n(OH).The properties of the products were measured by photon correlation spectroscopy(PCS),TG,and tensile tests.The water-resistant ability of the cast films were also investigated.The distribution of the particle sizes of HBAPU varied from 15 nm to 65 nm.The partical size of HBAPU was only 20.6 nm when the content of DMPA was 0.4 mmol/g,while it was 130.9 nm for linear aqueous polyurethane at the sance conditions.Meanwhile,the HBAPU exhibited a good heat resistance,the degradation temperature of the product was up to 200 ℃,the lap shear strength increased with increasing the molar ratio of n(NCO)/n(OH),but it decreased when it reached to 33 MPa.The films showed a good water-resistance ability,the maximum water-swell(%) value was 4.3% even if the films were emerged in water for 24 h.
Hyperbranched aqueous polyurethane(HBAPU) was synthesized via A2+bB2 approach with 2,4-toluylene diisocyanate(TDI),polycarbonatediol(PCDL),dimethylol propionic acid(DMPA) and diethanol amine(DEOA) as materials.The structures of products were characterized by FT-IR and 13C NMR.The results show that the degree of the branching(DB) of HBAPU increased with increasing the molar ratio of n(NCO)/n(OH).The properties of the products were measured by photon correlation spectroscopy(PCS),TG,and tensile tests.The water-resistant ability of the cast films were also investigated.The distribution of the particle sizes of HBAPU varied from 15 nm to 65 nm.The partical size of HBAPU was only 20.6 nm when the content of DMPA was 0.4 mmol/g,while it was 130.9 nm for linear aqueous polyurethane at the sance conditions.Meanwhile,the HBAPU exhibited a good heat resistance,the degradation temperature of the product was up to 200 ℃,the lap shear strength increased with increasing the molar ratio of n(NCO)/n(OH),but it decreased when it reached to 33 MPa.The films showed a good water-resistance ability,the maximum water-swell(%) value was 4.3% even if the films were emerged in water for 24 h.
2009, 26(9): 1036-1039
Abstract:
Sodium 2-(N-methyl-4-perfluorous nonenyloxyphenylsulfonamido) ethyl sulfate(Ⅰ) was synthesized from 4-perfluorononenyloxy benzenesulfonyl chloride,2-(methylamino) ethanol and chlorsulfonic acid via amidation and esterification,and the intermedium and product were characterized by IR,19F NMR and 1H NMR respectively.The reaction conditions were optimized by means of orthogonal experiments.For the amidation,the optimal reaction conditions were n(4-perfluorononenyloxy benzenesulfonyl chloride) :n(2-methylamino ethanol) =1.0:2.0,with triethylamide as acid acceptor,in THF at 30 ℃ for 3.0 h,and N-hydroxyethyl-N-methyl-4-perfluorous nonenyloxybenzenesulfonated amide(Ⅱ) was obtained in a yield of 93.4%.The optimal reaction conditions of esterification were n(Ⅱ) :n(chlorsulfonic acid) =1.0:2.0 in THF at room temperature for 0.5 h,with a yield of 97.1% for compound Ⅰ.The critical micelle concentration(CMC) of compound Ⅰ was 8.0×10-4 mol/L,and its surface tension(γcmc) was 23.1 mN/m(25 ℃).
Sodium 2-(N-methyl-4-perfluorous nonenyloxyphenylsulfonamido) ethyl sulfate(Ⅰ) was synthesized from 4-perfluorononenyloxy benzenesulfonyl chloride,2-(methylamino) ethanol and chlorsulfonic acid via amidation and esterification,and the intermedium and product were characterized by IR,19F NMR and 1H NMR respectively.The reaction conditions were optimized by means of orthogonal experiments.For the amidation,the optimal reaction conditions were n(4-perfluorononenyloxy benzenesulfonyl chloride) :n(2-methylamino ethanol) =1.0:2.0,with triethylamide as acid acceptor,in THF at 30 ℃ for 3.0 h,and N-hydroxyethyl-N-methyl-4-perfluorous nonenyloxybenzenesulfonated amide(Ⅱ) was obtained in a yield of 93.4%.The optimal reaction conditions of esterification were n(Ⅱ) :n(chlorsulfonic acid) =1.0:2.0 in THF at room temperature for 0.5 h,with a yield of 97.1% for compound Ⅰ.The critical micelle concentration(CMC) of compound Ⅰ was 8.0×10-4 mol/L,and its surface tension(γcmc) was 23.1 mN/m(25 ℃).
2009, 26(9): 1040-1044
Abstract:
The synthesis of methyl 4-(5-nitro-6-hydroxybenzoxazol-2-yl) benzoate(MNB),an AB-type monomer precursor for a new AB-type poly(p-phenylene benzobizoxazole) (PBO) was studied,and the synthesis of MNB from 4-amino-6-nitroresorcinol hydrochloride(ANR·HCl) and mono-methyl terephthalate(MTA) was developed by means of acyl chlorination,condensation and cyclization separately or in situ synthesis.The optimum conditions were methyl isobutyl ketone as solvent,feed ratio(mol ratio) of ANR·HCl/MTA of 1.00:1.03,and condensation reaction at 115 ℃ for 2.5 h.Cyclization reaction at 120 ℃ for 8.5 h after adding PPA as dehydrating agent at a feed ratio(mass ratio) of ANR·HCl/PPA of 1.00:3.25,the product was obtained with a yield of 75.68% and the purity of MNB without further purification was 96.32% by HPLC method.Structures of the products were characterized by 1H NMR and IR.
The synthesis of methyl 4-(5-nitro-6-hydroxybenzoxazol-2-yl) benzoate(MNB),an AB-type monomer precursor for a new AB-type poly(p-phenylene benzobizoxazole) (PBO) was studied,and the synthesis of MNB from 4-amino-6-nitroresorcinol hydrochloride(ANR·HCl) and mono-methyl terephthalate(MTA) was developed by means of acyl chlorination,condensation and cyclization separately or in situ synthesis.The optimum conditions were methyl isobutyl ketone as solvent,feed ratio(mol ratio) of ANR·HCl/MTA of 1.00:1.03,and condensation reaction at 115 ℃ for 2.5 h.Cyclization reaction at 120 ℃ for 8.5 h after adding PPA as dehydrating agent at a feed ratio(mass ratio) of ANR·HCl/PPA of 1.00:3.25,the product was obtained with a yield of 75.68% and the purity of MNB without further purification was 96.32% by HPLC method.Structures of the products were characterized by 1H NMR and IR.
2009, 26(9): 1045-1049
Abstract:
The interaction between breviscapine and DNA was studied by electrochemical tests.The results show that the oxidation peak current of breviscapine decreased and the peak potential shifted positively in the presence of DNA.The absorption spectrum measurement shows that with the addition of DNA,the intensity of absorption peak of breviscapine at 335 nm decreased,showing hypochromic effect,at the same time,two isoelectric absorption point appeared.The results indicate that breviscapine interacts with DNA mainly through intercalation.Calculation indicats that the binding ratio between breviscapine and dsDNA was 1:3,with a binding constant of 3.63×1013.
The interaction between breviscapine and DNA was studied by electrochemical tests.The results show that the oxidation peak current of breviscapine decreased and the peak potential shifted positively in the presence of DNA.The absorption spectrum measurement shows that with the addition of DNA,the intensity of absorption peak of breviscapine at 335 nm decreased,showing hypochromic effect,at the same time,two isoelectric absorption point appeared.The results indicate that breviscapine interacts with DNA mainly through intercalation.Calculation indicats that the binding ratio between breviscapine and dsDNA was 1:3,with a binding constant of 3.63×1013.
2009, 26(9): 1050-1053
Abstract:
Garlic juice used as a corrosion inhibitor was added into high temperature acidized solution and oilfield water with or without saturated CO2 or H2S.The effects of garlic juice on the corrosion behavior of carbon steel were studied using mass-loss method,and the corrosion inhibition mechanism was proposed based on SEM and electrochemical analysis results.The results show that garlic juice can obviously slow down the corrosion of carbon steel in high temperature acidized solution,and the inhibition efficiency reached 95.4% in 15% HCl solution at 80 ℃.The inhibition efficiency decreased with the increase of the hydrochloric acid concentration.Garlic juice can also slow down the corrosion of steel in three kinds of oilfield water,and the inhibition efficiency was from 42% to 62%.Electrochemical studies reveal that garlic juice can obviously change the anodic polarizability of steel in acidized solutions,and one kind of passivetion film can form on the steel surface.
Garlic juice used as a corrosion inhibitor was added into high temperature acidized solution and oilfield water with or without saturated CO2 or H2S.The effects of garlic juice on the corrosion behavior of carbon steel were studied using mass-loss method,and the corrosion inhibition mechanism was proposed based on SEM and electrochemical analysis results.The results show that garlic juice can obviously slow down the corrosion of carbon steel in high temperature acidized solution,and the inhibition efficiency reached 95.4% in 15% HCl solution at 80 ℃.The inhibition efficiency decreased with the increase of the hydrochloric acid concentration.Garlic juice can also slow down the corrosion of steel in three kinds of oilfield water,and the inhibition efficiency was from 42% to 62%.Electrochemical studies reveal that garlic juice can obviously change the anodic polarizability of steel in acidized solutions,and one kind of passivetion film can form on the steel surface.
2009, 26(9): 1054-1059
Abstract:
PAn-co-PPy/Fe3O4 network nanofiber composites were synthesized in Fe3O4 magnetic fluid by in situ chemical oxidative co-polymerization of aniline(An) and pyrrole(Py) monomers in the presence of cetyltrimethylammoniun bromide(CTAB).It was found that the morphology structures and electromagnetic properties of the nanocomposites can be tuned by varying the concentration of CTAB,the molar ratio of An/Py and the amount of Fe3O4 used.The resulting products were characterized by SEM,TEM,XRD,FT-IR,TG and the measurements of their electrical conductivities and hysteresis loops.The complex permittivity and permeability of samples were measured on a vector network analyzer in a range of 2~18 GHz,from which the reflection loss(R) curves of microwave vs frequency were calculated.The results show that the PAn-co-PPy/Fe3O4 nanocomposites take on a regular network nanofiber structure when the concentration of CTAB is 42 mmol/L,and the saturated magnetization is 14.8 emu/g when the content of Fe3O4 in the composite is 22.1%.XRD patterns confirmed the nanocomposite was composed of the Fe3O4 nanoparticles and PAn-PPy co-polymers.FT-IR spectra demonstrate the main characteristic absorption peaks corresponding to both PAn and PPy have red-shifted for the PAn-co-PPy/Fe3O4 nanocomposites.The PAn-co-PPy/Fe3O4 nanocomposites exhibit better microwave-absorbing properties than PAn,PPy,PAn-co-PPy,PAn/Fe3O4 or PPy/Fe3O4 composites,and it had a maximum reflection loss of-36.5 dB at 9.0 GHz with about 4.7 GHz bandwidth above-10 dB when the content of Fe3O4 in the composite was 12.4%.
PAn-co-PPy/Fe3O4 network nanofiber composites were synthesized in Fe3O4 magnetic fluid by in situ chemical oxidative co-polymerization of aniline(An) and pyrrole(Py) monomers in the presence of cetyltrimethylammoniun bromide(CTAB).It was found that the morphology structures and electromagnetic properties of the nanocomposites can be tuned by varying the concentration of CTAB,the molar ratio of An/Py and the amount of Fe3O4 used.The resulting products were characterized by SEM,TEM,XRD,FT-IR,TG and the measurements of their electrical conductivities and hysteresis loops.The complex permittivity and permeability of samples were measured on a vector network analyzer in a range of 2~18 GHz,from which the reflection loss(R) curves of microwave vs frequency were calculated.The results show that the PAn-co-PPy/Fe3O4 nanocomposites take on a regular network nanofiber structure when the concentration of CTAB is 42 mmol/L,and the saturated magnetization is 14.8 emu/g when the content of Fe3O4 in the composite is 22.1%.XRD patterns confirmed the nanocomposite was composed of the Fe3O4 nanoparticles and PAn-PPy co-polymers.FT-IR spectra demonstrate the main characteristic absorption peaks corresponding to both PAn and PPy have red-shifted for the PAn-co-PPy/Fe3O4 nanocomposites.The PAn-co-PPy/Fe3O4 nanocomposites exhibit better microwave-absorbing properties than PAn,PPy,PAn-co-PPy,PAn/Fe3O4 or PPy/Fe3O4 composites,and it had a maximum reflection loss of-36.5 dB at 9.0 GHz with about 4.7 GHz bandwidth above-10 dB when the content of Fe3O4 in the composite was 12.4%.
2009, 26(9): 1060-1064
Abstract:
Co-Mn alloys were electro-plated from an acidic sulfate plating solution containing sodium citrate as a complexing agent and boric acid as a buffer agent.The cyclic voltammetric experiments show that the initial co-deposition potential of the alloy was about-1.282 V(vs.Hg-Hg2SO4,sat.K2SO4).The effects of the plating conditions on the structure and the magnetic performance of the Co-Mn coatings were studied by means of scanning electron microscopy(SEM),energy dispersive X-ray(EDS),X-ray diffraction(XRD) and vibrating sample magnetometer(VSM),respectively.It was found that the influence of the plating conditions on the coating composition was relatively remarkable.With the increase of the cathodic current density from 10×10-3 to 40×10-3 A/cm2 at pH=4.0,the manganese molar content in the coating increased from 0.3% to 6.6%,and the coating structure changed from hcp Co-Mn solid solution to fcc Co-Mn solid solution.With the increase of the manganese molar content in the film,the saturation magnetization increased and then decreased.The maximal saturation magnetization reached 1 926.0 kA/m.The value of the film coercive force ranged from 31.6 kA/m to 33.9 kA/m.
Co-Mn alloys were electro-plated from an acidic sulfate plating solution containing sodium citrate as a complexing agent and boric acid as a buffer agent.The cyclic voltammetric experiments show that the initial co-deposition potential of the alloy was about-1.282 V(vs.Hg-Hg2SO4,sat.K2SO4).The effects of the plating conditions on the structure and the magnetic performance of the Co-Mn coatings were studied by means of scanning electron microscopy(SEM),energy dispersive X-ray(EDS),X-ray diffraction(XRD) and vibrating sample magnetometer(VSM),respectively.It was found that the influence of the plating conditions on the coating composition was relatively remarkable.With the increase of the cathodic current density from 10×10-3 to 40×10-3 A/cm2 at pH=4.0,the manganese molar content in the coating increased from 0.3% to 6.6%,and the coating structure changed from hcp Co-Mn solid solution to fcc Co-Mn solid solution.With the increase of the manganese molar content in the film,the saturation magnetization increased and then decreased.The maximal saturation magnetization reached 1 926.0 kA/m.The value of the film coercive force ranged from 31.6 kA/m to 33.9 kA/m.
2009, 26(9): 1065-1069
Abstract:
The electrochemical behavior of Sudan I was examined by means of linear sweep voltammetry(LSV),cyclic voltammetry(CV) and chronocoulometry.At the carbon paste electrode(CPE),a non-sensitive oxidation peak was observed for Sudan Ⅰ.However,the oxidation peak current of Sudan Ⅰ remarkably increased after sodium dodecyl benzene sulfonate(SDBS) was added at a low concentration,suggesting that SDBS exhibtis an efficient enhancement effect towards Sudan Ⅰ.The results obtained from chronocoulometry indicate that SDBS significantly improves the adsorption of Sudan Ⅰ at the CPE surface.The experimental parameters such as pH value,concentration of SDBS,accumulation potential and time were optimized,and a new electrochemical method was then developed for the determination of Sudan Ⅰ.The linear range was from 2.0×10-7 to 1.5×10-5 mol/L,and the limit of detection was 6.0×10-8 mol/L after 180 s accumulation.Finally,this method was successfully used to detect Sudan Ⅰ in hot pepper and ketchup food.
The electrochemical behavior of Sudan I was examined by means of linear sweep voltammetry(LSV),cyclic voltammetry(CV) and chronocoulometry.At the carbon paste electrode(CPE),a non-sensitive oxidation peak was observed for Sudan Ⅰ.However,the oxidation peak current of Sudan Ⅰ remarkably increased after sodium dodecyl benzene sulfonate(SDBS) was added at a low concentration,suggesting that SDBS exhibtis an efficient enhancement effect towards Sudan Ⅰ.The results obtained from chronocoulometry indicate that SDBS significantly improves the adsorption of Sudan Ⅰ at the CPE surface.The experimental parameters such as pH value,concentration of SDBS,accumulation potential and time were optimized,and a new electrochemical method was then developed for the determination of Sudan Ⅰ.The linear range was from 2.0×10-7 to 1.5×10-5 mol/L,and the limit of detection was 6.0×10-8 mol/L after 180 s accumulation.Finally,this method was successfully used to detect Sudan Ⅰ in hot pepper and ketchup food.
2009, 26(9): 1070-1074
Abstract:
A method of rapid identification of Kadsura and Schisandra was established based on their fluore-scence spectra.Fluorescence properties of the five active components(schisandrol A,schisantedrin A,deoxyschizandrin,γ-schisandrin and anwulignan) and the ethanol extracts of Schisandra chinensis and Hugan tablets were investigated by fluorospectrophotometry.The contents of the five components were determined by HPLC.The results show that the fluorescence properties of anwulignan and γ-schisandrin were much stronger than that of deoxyschizandrin and schisandrol A.The emission and excitation spectra of γ-schisandrin and anwulignan showed obvious difference.No fluorescence was produced by schisantherin A under the same condition.The main substance of fluorescence in Kadsura and Schisandra was anwulignan and γ-schisandrin,respectively.Fluorescence spectra of the ethanol extract could be used for the rapid identification of Kadsura and Schisandra.
A method of rapid identification of Kadsura and Schisandra was established based on their fluore-scence spectra.Fluorescence properties of the five active components(schisandrol A,schisantedrin A,deoxyschizandrin,γ-schisandrin and anwulignan) and the ethanol extracts of Schisandra chinensis and Hugan tablets were investigated by fluorospectrophotometry.The contents of the five components were determined by HPLC.The results show that the fluorescence properties of anwulignan and γ-schisandrin were much stronger than that of deoxyschizandrin and schisandrol A.The emission and excitation spectra of γ-schisandrin and anwulignan showed obvious difference.No fluorescence was produced by schisantherin A under the same condition.The main substance of fluorescence in Kadsura and Schisandra was anwulignan and γ-schisandrin,respectively.Fluorescence spectra of the ethanol extract could be used for the rapid identification of Kadsura and Schisandra.
2009, 26(9): 1075-1079
Abstract:
The inhibition effect of red tetrazolium on the corrosion of cold rolled steel(CRS) in 1.0~5.0 mol/L HCl was studied by mass loss and potentiodynamic polarization methods.Atomic force microscopy(AFM) was used to observe the CRS surface.The results show that neutral red tetrazolium was a good inhibitor for CRS,and the adsorption of red tetrazolium on the CRS surface follows Langmuir adsorption isotherm equation.Polarization curves show that red tetrazolium was a mixed-type inhibitor in hydrochloric acid.Based on the adsorption thermodynamic and kinetic parameters,the inhibitive mechanism is discussed.AFM results show that the introduction of red tetrazolium into HCl solution resulted in the formation of a compact and dense inhibitive film on the CRS surface.
The inhibition effect of red tetrazolium on the corrosion of cold rolled steel(CRS) in 1.0~5.0 mol/L HCl was studied by mass loss and potentiodynamic polarization methods.Atomic force microscopy(AFM) was used to observe the CRS surface.The results show that neutral red tetrazolium was a good inhibitor for CRS,and the adsorption of red tetrazolium on the CRS surface follows Langmuir adsorption isotherm equation.Polarization curves show that red tetrazolium was a mixed-type inhibitor in hydrochloric acid.Based on the adsorption thermodynamic and kinetic parameters,the inhibitive mechanism is discussed.AFM results show that the introduction of red tetrazolium into HCl solution resulted in the formation of a compact and dense inhibitive film on the CRS surface.
2009, 26(9): 1080-1083
Abstract:
BiO(OH)/C catalysts were prepared by the impregnation of activated carbon in a bismuth nitrate solution.XRD patterns of the catalysts show that BiO(OH) was well-dispersed in activated carbon when the mass percent of BiO(OH) in catalyst is no more than 10%.At 75 ℃,the catalytic activity was maintained after 7 runs.In 5 mL of ethanol,1 mmol of aromatic nitro compounds reacted with 2 mmol of hydrazine hydrate in the presence of 0.05 g of 10%BiO(OH)/C,at 75 ℃ and for a certain period of time,a yield of 88%~99% is obtained for producing anilines.
BiO(OH)/C catalysts were prepared by the impregnation of activated carbon in a bismuth nitrate solution.XRD patterns of the catalysts show that BiO(OH) was well-dispersed in activated carbon when the mass percent of BiO(OH) in catalyst is no more than 10%.At 75 ℃,the catalytic activity was maintained after 7 runs.In 5 mL of ethanol,1 mmol of aromatic nitro compounds reacted with 2 mmol of hydrazine hydrate in the presence of 0.05 g of 10%BiO(OH)/C,at 75 ℃ and for a certain period of time,a yield of 88%~99% is obtained for producing anilines.
2009, 26(9): 1084-1087
Abstract:
A novel and simple method for the preparation of 4-methoxy-7H-furo[3,2-g][1]benzopyran-7-one was proposed.The target compound was synthesized from phloroglucinol as the starting material by etherification,iodination,Pechmann condensation,coupling reaction,hydrolysis and decarboxylation.The intermediates and the target compound were characterized by IR,MS and 1H NMR.The proper technological parameters were ascertained by experiments,and the feasibility of the route to linear furanocoumarins by regiosele-ctive iodination,Pechmann condensation and coupling reaction was studied.All the reactions were performed under normal pressure and mild conditions in the presence of an inexpensive catalyst followed by relatively simple post treatment.It is a new method with a total yield of 12% for the preparation of furanocoumarins.
A novel and simple method for the preparation of 4-methoxy-7H-furo[3,2-g][1]benzopyran-7-one was proposed.The target compound was synthesized from phloroglucinol as the starting material by etherification,iodination,Pechmann condensation,coupling reaction,hydrolysis and decarboxylation.The intermediates and the target compound were characterized by IR,MS and 1H NMR.The proper technological parameters were ascertained by experiments,and the feasibility of the route to linear furanocoumarins by regiosele-ctive iodination,Pechmann condensation and coupling reaction was studied.All the reactions were performed under normal pressure and mild conditions in the presence of an inexpensive catalyst followed by relatively simple post treatment.It is a new method with a total yield of 12% for the preparation of furanocoumarins.
2009, 26(9): 1088-1089
Abstract:
The extraction of glutathione(GSH) from distillate of bread yeast with reversed micelle made up of phosphoric acid dioctyl ester(P204) and n-octanol was researched.The factors affecting the extraction ratio of GSH were examined.The optimum conditions were confirmed by means of orthogonal tests,that is,extraction time was 15 min;pH value in aqueous phase was 2.0;concentration of P204 was 0.16 mol/L and concentration of K+ was 0.1 mol/L.The extraction ratio of GSH was 33.1% and the twi-extraction ratio was 49.7% under the optimum conditions.
The extraction of glutathione(GSH) from distillate of bread yeast with reversed micelle made up of phosphoric acid dioctyl ester(P204) and n-octanol was researched.The factors affecting the extraction ratio of GSH were examined.The optimum conditions were confirmed by means of orthogonal tests,that is,extraction time was 15 min;pH value in aqueous phase was 2.0;concentration of P204 was 0.16 mol/L and concentration of K+ was 0.1 mol/L.The extraction ratio of GSH was 33.1% and the twi-extraction ratio was 49.7% under the optimum conditions.
2009, 26(9): 1090-1099
Abstract:
A series of 2-amino phenyl hexafluoroisopropanols were prepared from HFA·3H2O and anilines.The effects of the mole ratio of HFA·3H2O and aniline,catalyst,solvent,reaction time and substituent on the reaction were investigated.The optimum reaction conditions were selected as follows:90 mmol of HFA·3H2O,30 mmol of aromatic amine,a mole fraction of TsOH of 6% based on aniline,reflux for 5～35 h.Under these conditions,the conversion and yield were respectively 40%～100% and 39%～99%.The reaction mechanism of aniline and HFA·3H2O was discussed.
A series of 2-amino phenyl hexafluoroisopropanols were prepared from HFA·3H2O and anilines.The effects of the mole ratio of HFA·3H2O and aniline,catalyst,solvent,reaction time and substituent on the reaction were investigated.The optimum reaction conditions were selected as follows:90 mmol of HFA·3H2O,30 mmol of aromatic amine,a mole fraction of TsOH of 6% based on aniline,reflux for 5～35 h.Under these conditions,the conversion and yield were respectively 40%～100% and 39%～99%.The reaction mechanism of aniline and HFA·3H2O was discussed.
2009, 26(9): 1100-1103
Abstract:
A novel 2,6-bis(imino) pyridine iron(Ⅱ) complex(2,6-bis[1-(4-hydroxy-2,6-dimethylphen-ylimino) ethyl]pyridine iron chloride,1a) was synthesized and investigated as a catalyst for ethylene polymerization in the presence of modified methylaluminoxane as a cocatlyst.The new iron complex displays higher catalytic activity and increases higher molecular mass polyethylene than 2,6-bis[1-(2,6-dimethylphenyli-mino) ethyl]pyridine iron chloride 1b under the identical conditions.The novel complex 1a shows a very high activit(polyethylene mass catalyized by one molar catalyst in one hour) :6.78×106 g/(mol·h).
A novel 2,6-bis(imino) pyridine iron(Ⅱ) complex(2,6-bis[1-(4-hydroxy-2,6-dimethylphen-ylimino) ethyl]pyridine iron chloride,1a) was synthesized and investigated as a catalyst for ethylene polymerization in the presence of modified methylaluminoxane as a cocatlyst.The new iron complex displays higher catalytic activity and increases higher molecular mass polyethylene than 2,6-bis[1-(2,6-dimethylphenyli-mino) ethyl]pyridine iron chloride 1b under the identical conditions.The novel complex 1a shows a very high activit(polyethylene mass catalyized by one molar catalyst in one hour) :6.78×106 g/(mol·h).
2009, 26(9): 1104-1107
Abstract:
N,N-Dimethyl-N'-(2-trifluorometyl-1-pentafluoroethyl) perfluoro-propenyl propane diamine(Ⅰ) was prepared via the reaction of hexafluoropropene dimer and N,N-dimethyl propylene diamine with the molar ratio of 1:1 at about 35 ℃ for 8 h,and the structure of compound Ⅰ was identified by IR and NMR.Then compound Ⅰ was respectively reacted with bromoethane,bromopropane,bromobutane,bromohexane,bromooctane and bromolaurane to get a series of quaternary ammonium cationic fluoro-surfactants.The results indicate that the novel fluoro-containing quaternary ammonium cationic surfactants had rather low surface tensions(17.8~28.1 mN/m),low critical micelle concentrations(2.03~1.58 mmol/L),and their Krafft points were below 0 ℃,showing execllent solubility in water.
N,N-Dimethyl-N'-(2-trifluorometyl-1-pentafluoroethyl) perfluoro-propenyl propane diamine(Ⅰ) was prepared via the reaction of hexafluoropropene dimer and N,N-dimethyl propylene diamine with the molar ratio of 1:1 at about 35 ℃ for 8 h,and the structure of compound Ⅰ was identified by IR and NMR.Then compound Ⅰ was respectively reacted with bromoethane,bromopropane,bromobutane,bromohexane,bromooctane and bromolaurane to get a series of quaternary ammonium cationic fluoro-surfactants.The results indicate that the novel fluoro-containing quaternary ammonium cationic surfactants had rather low surface tensions(17.8~28.1 mN/m),low critical micelle concentrations(2.03~1.58 mmol/L),and their Krafft points were below 0 ℃,showing execllent solubility in water.
2009, 26(9): 1108-1110
Abstract:
With fluoropolymer containing carboxyl group electrospun fiber mats as the carrier,zinc sulfide(ZnS) particles of diameter of about 50 nm were uniformly immobilized on the surface of fluoropolymer electrospun fiber through solution precipitation at room temperature.The degradation of methylene blue in solution was performed by ZnS-fluoropolymer composites under UV irradiation.The results show residual mass fraction of methylene blue is 0.03% by ZnS-fluoropolymer composites at 220 min,and is lower than that of ZnS nanoparticles under the same condition.The ZnS-fluoropolymer composites have good photocatalytic activity and stability after 5 repeated tests.
With fluoropolymer containing carboxyl group electrospun fiber mats as the carrier,zinc sulfide(ZnS) particles of diameter of about 50 nm were uniformly immobilized on the surface of fluoropolymer electrospun fiber through solution precipitation at room temperature.The degradation of methylene blue in solution was performed by ZnS-fluoropolymer composites under UV irradiation.The results show residual mass fraction of methylene blue is 0.03% by ZnS-fluoropolymer composites at 220 min,and is lower than that of ZnS nanoparticles under the same condition.The ZnS-fluoropolymer composites have good photocatalytic activity and stability after 5 repeated tests.
2009, 26(9): 1111-1113
Abstract:
Cellulose was pretreated with an IL,1-n-butyl-methylimidazolium chloride([C4mim]Cl).The experimental results show that the degree of polymerization(DP) of cellulose decreased after treated with [C4mim]Cl.With the increase of pretreatment temperature,the saccharification rate increased first and then decreased,reaching a maximal value of 11.77 g/(L·h) at 90 ℃.Extending pretreatment time or using ethanol as anti-solvent enhanced the saccharification kinetics.The saccharification rate increased by 70% as compared to that of untreated cellulose.SEM studies show that the cellulose depolymerized into fragments by [C4mim]Cl.
Cellulose was pretreated with an IL,1-n-butyl-methylimidazolium chloride([C4mim]Cl).The experimental results show that the degree of polymerization(DP) of cellulose decreased after treated with [C4mim]Cl.With the increase of pretreatment temperature,the saccharification rate increased first and then decreased,reaching a maximal value of 11.77 g/(L·h) at 90 ℃.Extending pretreatment time or using ethanol as anti-solvent enhanced the saccharification kinetics.The saccharification rate increased by 70% as compared to that of untreated cellulose.SEM studies show that the cellulose depolymerized into fragments by [C4mim]Cl.
2009, 26(9): 1114-1116
Abstract:
Phosphatotungstic acids(H3PW12O40,PW12) supported on alumina were employed to catalyze the synthesis of ethyl p-hydroxybenzoate.By means of the yield of ethyl p-hydroxybenzoate and the dissolution of HPAs,we researched the function and strength of the catalyst.When the roasting temperature of alumina was 400 ℃ and PW12 was 180 ℃,the yield of ethyl p-hydroxybenzoate was up to 83.8%,and the rate of dissolution of PW12 was 2.8%.Even after the catalyst was recycled for six times,the rate of dissolution of phosohotungstic acid was 12.5%.
Phosphatotungstic acids(H3PW12O40,PW12) supported on alumina were employed to catalyze the synthesis of ethyl p-hydroxybenzoate.By means of the yield of ethyl p-hydroxybenzoate and the dissolution of HPAs,we researched the function and strength of the catalyst.When the roasting temperature of alumina was 400 ℃ and PW12 was 180 ℃,the yield of ethyl p-hydroxybenzoate was up to 83.8%,and the rate of dissolution of PW12 was 2.8%.Even after the catalyst was recycled for six times,the rate of dissolution of phosohotungstic acid was 12.5%.
2009, 26(9): 1117-1119
Abstract:
Poly(para-hydroxybenzoic acid) (poly-PHB) modified glassy carbon electrode(GCE) was prepared by cyclic voltammetry.The modified GCE showed good electrocatalytic activity for AA and current response.The peak potential was shifted negatively from 0.238 3 V to 0.033 6 V.A linear relationship existed between the anodic current and the AA concentration in the range of 2.6×10-5 to 3.68 ×10-4 mol/L with a correlation coefficient of 0.998 4(n=11).The detection limit(S/N=3) was 5×10-6 mol/L.The poly-PHB/GCE exhibited an effective and fast catalytic response to the oxidation of AA with good reprodu-cibility and stability.
Poly(para-hydroxybenzoic acid) (poly-PHB) modified glassy carbon electrode(GCE) was prepared by cyclic voltammetry.The modified GCE showed good electrocatalytic activity for AA and current response.The peak potential was shifted negatively from 0.238 3 V to 0.033 6 V.A linear relationship existed between the anodic current and the AA concentration in the range of 2.6×10-5 to 3.68 ×10-4 mol/L with a correlation coefficient of 0.998 4(n=11).The detection limit(S/N=3) was 5×10-6 mol/L.The poly-PHB/GCE exhibited an effective and fast catalytic response to the oxidation of AA with good reprodu-cibility and stability.
2009, 26(9): 1120-1122
Abstract:
One-pot simultaneous debrominative decarboxylation and sulfamation of anti-3-(4-chlorosulfonyl-benzyl)-2,3-dibromopropanoic acid and aqueous ammonia(2.2 mmol) in DMF under microwave irradiation for 25 s stereoselectively afforded intermediate(Z)-4-(2-brompvinyl) benzenesulfonamides.The intermediates,without isolation and purification,were treated with 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU,2 mmol) under microwave irradiation for 1 min to give desired 4-ethynylbenzenesulfonamide in a yield of 70%.The structure of the product was identified by 1H NMR,13C NMR and IR.
One-pot simultaneous debrominative decarboxylation and sulfamation of anti-3-(4-chlorosulfonyl-benzyl)-2,3-dibromopropanoic acid and aqueous ammonia(2.2 mmol) in DMF under microwave irradiation for 25 s stereoselectively afforded intermediate(Z)-4-(2-brompvinyl) benzenesulfonamides.The intermediates,without isolation and purification,were treated with 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU,2 mmol) under microwave irradiation for 1 min to give desired 4-ethynylbenzenesulfonamide in a yield of 70%.The structure of the product was identified by 1H NMR,13C NMR and IR.
2009, 26(9): 1123-1125
Abstract:
A novel functionalized ionic liquid N,N,N',N'-tetramethyl-N,N'-disulfopropylammonium hydrogen sulfate(TSIL) was prepared from tetramethylethylenediamine and 1,3-propanesultone.This ionic liquid has both Brønsted acidic functional group and quaternary ammonium salt group that is generally used as phase-transfer catalyst,which can be used as a novel catalyst for the condensation reaction of aromatic aldehydes with 5,5-dimethyl-1,3-cyclohexandione in water.The TSIL shows a good catalytic activity and the reaction could be carried out at 100 ℃ for 2 to 3 hours in water to produce 1,8-dioxo-octahydroxanthenes in a yield of 80%～93%.The product was immiscible with catalyst/water and could be separated simply by filtration after the reaction.This method is manipulatively simple,environment-friendly and the catalyst is reusable.
A novel functionalized ionic liquid N,N,N',N'-tetramethyl-N,N'-disulfopropylammonium hydrogen sulfate(TSIL) was prepared from tetramethylethylenediamine and 1,3-propanesultone.This ionic liquid has both Brønsted acidic functional group and quaternary ammonium salt group that is generally used as phase-transfer catalyst,which can be used as a novel catalyst for the condensation reaction of aromatic aldehydes with 5,5-dimethyl-1,3-cyclohexandione in water.The TSIL shows a good catalytic activity and the reaction could be carried out at 100 ℃ for 2 to 3 hours in water to produce 1,8-dioxo-octahydroxanthenes in a yield of 80%～93%.The product was immiscible with catalyst/water and could be separated simply by filtration after the reaction.This method is manipulatively simple,environment-friendly and the catalyst is reusable.
2009, 26(9): 1126-1128
Abstract:
Sevoflurane was synthesized from 1,1,13,3,3-hexafluoro-2-(chloromethoxy)-propane by halogen-exchange in the presence of an ionic liquid as the solvent and a fluorinating agent.Mechanism of the phase transfer catalysis was discussed.The effects of [bpy]BF4,[bmim]BF4,[bepy]BF4 and [bmim]PF6 on the yield were investigated.The ionic liquid-water system and high surface area could not only induce KF to enter into the ionic liquid to produce high active F-but also reduce the formation of byproducts.The yield was 94.6%.The ionic liquid could be reused for three times without noticeable loss of activity.
Sevoflurane was synthesized from 1,1,13,3,3-hexafluoro-2-(chloromethoxy)-propane by halogen-exchange in the presence of an ionic liquid as the solvent and a fluorinating agent.Mechanism of the phase transfer catalysis was discussed.The effects of [bpy]BF4,[bmim]BF4,[bepy]BF4 and [bmim]PF6 on the yield were investigated.The ionic liquid-water system and high surface area could not only induce KF to enter into the ionic liquid to produce high active F-but also reduce the formation of byproducts.The yield was 94.6%.The ionic liquid could be reused for three times without noticeable loss of activity.
