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2002 Volume 19 Issue 1
2002, 19(1): 1-3
Abstract:
Four crystal compounds were isolated from the ethanol extract of the marine sponge Sigmadocia cymiformis Esper. On the basis of spectroscopic analysis and chemical methods, the structures of these compounds were determined as ergoster-5,24(28)-dien-3U-ol(1), 4S,7S-aurantiamide acetate(2), N-triacontanoyl-haxadecaspingosin(3), and thymine(4). Among them 3 is a new compound, named cymiforamide. Aurantiamide acetate (2) is a modified dipetide first found from the marine sponge.
Four crystal compounds were isolated from the ethanol extract of the marine sponge Sigmadocia cymiformis Esper. On the basis of spectroscopic analysis and chemical methods, the structures of these compounds were determined as ergoster-5,24(28)-dien-3U-ol(1), 4S,7S-aurantiamide acetate(2), N-triacontanoyl-haxadecaspingosin(3), and thymine(4). Among them 3 is a new compound, named cymiforamide. Aurantiamide acetate (2) is a modified dipetide first found from the marine sponge.
2002, 19(1): 4-9
Abstract:
The process of adsorption of lysozyme onto bare and thioglycolic acid or n-dodecanethiol modified Au electrodes in a phosphate buffer (pH=7.3) solution has been investigated in situ using an electrochemical quartz crystal impedance system(EQCIS). Equivalent circuit parameters and resonance frequencies in piezoelectric quartz crystal(PQC) resonance as well as the electrical double layer capacitances were obtained and analyzed. A scheme of two consecutive reactions occurring at the interface was used to analyze the adsorption kinetics, suggesting that the double layer capacitance is more sensitive to the rearrangement of the adsorbed protein molecules compared with the resonance frequency. The effect of potential and hydrophilicity of electrode surface on the lysozyme adsorption was investigated. It is found that a more negative potential resulted in a larger responses of PQC resonance and the amount of adsorbed lysozyme on a hydrophobic surface was larger than that on a hydrophilic one. The standard heterogeneous rate constants of ferricyanide/ferrocyanide and charge transfer resistance before and after the lysozyme adsorption were determined. Decrease in standard heterogeneous rate constants of ferricyanide/ferrocyanide and increase in charge transfer resonance were observed after the lysozyme adsorption, showing that the reversibility of ferricyanide/ferrocyanide redox reaction was decreased.
The process of adsorption of lysozyme onto bare and thioglycolic acid or n-dodecanethiol modified Au electrodes in a phosphate buffer (pH=7.3) solution has been investigated in situ using an electrochemical quartz crystal impedance system(EQCIS). Equivalent circuit parameters and resonance frequencies in piezoelectric quartz crystal(PQC) resonance as well as the electrical double layer capacitances were obtained and analyzed. A scheme of two consecutive reactions occurring at the interface was used to analyze the adsorption kinetics, suggesting that the double layer capacitance is more sensitive to the rearrangement of the adsorbed protein molecules compared with the resonance frequency. The effect of potential and hydrophilicity of electrode surface on the lysozyme adsorption was investigated. It is found that a more negative potential resulted in a larger responses of PQC resonance and the amount of adsorbed lysozyme on a hydrophobic surface was larger than that on a hydrophilic one. The standard heterogeneous rate constants of ferricyanide/ferrocyanide and charge transfer resistance before and after the lysozyme adsorption were determined. Decrease in standard heterogeneous rate constants of ferricyanide/ferrocyanide and increase in charge transfer resonance were observed after the lysozyme adsorption, showing that the reversibility of ferricyanide/ferrocyanide redox reaction was decreased.
2002, 19(1): 10-14
Abstract:
Two chain extenders DTH and DTHM (prepared from diethanol amine, toluene diisocyanate and 2-hydroxyethyl acrylate/2-hydroxyethyl methacrylate, respectively) containing acryloyl and methacryloyl group were synthesized. The pre-polymer prepared by reaction of DTH or DTHM with polyether-polyurethane was photopolymerized to give a flexible material. The linear relation was found between the Shore hardness and the methacryloyl group content in the above photo-crosslinked polymer products. The contribution of polymer compositions to the hardness, flexibility and resolution power of the photosensitive materials has been investigated. The results provided for the further preparation of developing solvents. The optimum exposure time for the different photosensitive prepolymer systems has been determined.
Two chain extenders DTH and DTHM (prepared from diethanol amine, toluene diisocyanate and 2-hydroxyethyl acrylate/2-hydroxyethyl methacrylate, respectively) containing acryloyl and methacryloyl group were synthesized. The pre-polymer prepared by reaction of DTH or DTHM with polyether-polyurethane was photopolymerized to give a flexible material. The linear relation was found between the Shore hardness and the methacryloyl group content in the above photo-crosslinked polymer products. The contribution of polymer compositions to the hardness, flexibility and resolution power of the photosensitive materials has been investigated. The results provided for the further preparation of developing solvents. The optimum exposure time for the different photosensitive prepolymer systems has been determined.
2002, 19(1): 15-17
Abstract:
Solid FePO4 was prepared by precipitation method. A TEA-CO2 laser generator was adopted as light source to carry out laser stimulated surface reaction(LSSR) of ethylene. The vibration structure and adsorption state of C2H4ad-FePO4 system were discussed based on the infrared and temperature programmed desorption results. It is showed that C2H4 is adsorbed in a molecular state by H atom bonding with terminal O of P=O in FePO4 surface. 1 079 cm-1 laser was selected to activate solid surfacial bond P=O, which absorbs the photon energy efficiently. At atmospheric pressure and <100℃, after 100 laser pulses C2H4 conversed to butadiene with 100% selectivity. Increasing laser pulse can improve conversion of C2H4 without change of selectivity. After 200 pulses, C2H4 in the system was consumed in a high level and the product occupied most active sites on the surface, impeding further conversion of C2H4. A mechanism of LSSR has been proposed for the conversion of ethylene to butadiene.
Solid FePO4 was prepared by precipitation method. A TEA-CO2 laser generator was adopted as light source to carry out laser stimulated surface reaction(LSSR) of ethylene. The vibration structure and adsorption state of C2H4ad-FePO4 system were discussed based on the infrared and temperature programmed desorption results. It is showed that C2H4 is adsorbed in a molecular state by H atom bonding with terminal O of P=O in FePO4 surface. 1 079 cm-1 laser was selected to activate solid surfacial bond P=O, which absorbs the photon energy efficiently. At atmospheric pressure and <100℃, after 100 laser pulses C2H4 conversed to butadiene with 100% selectivity. Increasing laser pulse can improve conversion of C2H4 without change of selectivity. After 200 pulses, C2H4 in the system was consumed in a high level and the product occupied most active sites on the surface, impeding further conversion of C2H4. A mechanism of LSSR has been proposed for the conversion of ethylene to butadiene.
2002, 19(1): 18-21
Abstract:
Reaction of dibasic acid half-ester with epoxy compound has been investigated as function of factors affecting the reaction between carboxyl groups and epoxy using half-esters of a series of acid:maleic acid(MAM), succinic acid(SAM), phthalic acid(PAM), cis-1,2,3,6-tetrahydrophthalic acid(H4PAM) and cis-hexahydrophthalic acid(H6PAM), and phenyl glycidyl ether(PGE) as model compounds. It was found that higher reactivity would be achieved for the dibasic acid half-esters with smaller molecular size or stronger acidity. In the case of reaction between maleic acid monomethyl eater(MAM) and PGE, the catalytic activity of the catalysts decreased in the order of chromium acetylacetonate (CrAA) > tetramethyl ammonium bromide(TMAB) > 1-methylimidazole(MI) > N,N-dimethyl benzylamine(DMBA). The effects of solvent polarity and temperature on the reaction has also been examined.
Reaction of dibasic acid half-ester with epoxy compound has been investigated as function of factors affecting the reaction between carboxyl groups and epoxy using half-esters of a series of acid:maleic acid(MAM), succinic acid(SAM), phthalic acid(PAM), cis-1,2,3,6-tetrahydrophthalic acid(H4PAM) and cis-hexahydrophthalic acid(H6PAM), and phenyl glycidyl ether(PGE) as model compounds. It was found that higher reactivity would be achieved for the dibasic acid half-esters with smaller molecular size or stronger acidity. In the case of reaction between maleic acid monomethyl eater(MAM) and PGE, the catalytic activity of the catalysts decreased in the order of chromium acetylacetonate (CrAA) > tetramethyl ammonium bromide(TMAB) > 1-methylimidazole(MI) > N,N-dimethyl benzylamine(DMBA). The effects of solvent polarity and temperature on the reaction has also been examined.
2002, 19(1): 22-25
Abstract:
It was found that for chinese ink carbon nanoparticle there were four resonance scattering peaks at 400 nm, 470 nm, 510 nm and 940 nm when its concentration was less than 360 mg/L . When c(C) was more than 0.9 g/L, no resonance scattering peak was observed. A linear dependence between intensity I470 nm and the concentration of carbon particles ranged in 0.45~45 mg/L was found. The effects of lamp source and the scanning rate on the RSS of carbon nanoparticle were investigated. The results showed that the difference in distribution emission intensity of lamp source appeared one of important factor to produce resonance scattering peaks. It is explained in terms of interface resonance absorption and resonance emission of white and black carbon nanoparticle in ink.
It was found that for chinese ink carbon nanoparticle there were four resonance scattering peaks at 400 nm, 470 nm, 510 nm and 940 nm when its concentration was less than 360 mg/L . When c(C) was more than 0.9 g/L, no resonance scattering peak was observed. A linear dependence between intensity I470 nm and the concentration of carbon particles ranged in 0.45~45 mg/L was found. The effects of lamp source and the scanning rate on the RSS of carbon nanoparticle were investigated. The results showed that the difference in distribution emission intensity of lamp source appeared one of important factor to produce resonance scattering peaks. It is explained in terms of interface resonance absorption and resonance emission of white and black carbon nanoparticle in ink.
2002, 19(1): 26-29
Abstract:
The adsorption behavior of water-soluble hydrophobic association copolymer prepared from acrylamide(AM), sodium acrylate(NaAA) and octadecyl dimethylallyl ammonium chloride(C18DMAAC) at water/kaolin interface and the influences of sodium dodecyl benzene sulfonate(SDBS), sodium chloride(NaCl) and calcium chloride(CaCl2) on the adsorption behavior have been studied. The adsorbtion capacity of the copolymer was found firstly increased with the increase in equilibrium concentration of the copolymer, then became to a nearly constant value being characteristic of a multilayer adsorption. The amount of the adsorbed copolymer increased with the increase of NaCl and CaCl2 concentration firstly, then kept constant at higher salt concentration. The amount of the adsorbed copolymer decreased monotonously with the increase of SDBS concentration in the solution.
The adsorption behavior of water-soluble hydrophobic association copolymer prepared from acrylamide(AM), sodium acrylate(NaAA) and octadecyl dimethylallyl ammonium chloride(C18DMAAC) at water/kaolin interface and the influences of sodium dodecyl benzene sulfonate(SDBS), sodium chloride(NaCl) and calcium chloride(CaCl2) on the adsorption behavior have been studied. The adsorbtion capacity of the copolymer was found firstly increased with the increase in equilibrium concentration of the copolymer, then became to a nearly constant value being characteristic of a multilayer adsorption. The amount of the adsorbed copolymer increased with the increase of NaCl and CaCl2 concentration firstly, then kept constant at higher salt concentration. The amount of the adsorbed copolymer decreased monotonously with the increase of SDBS concentration in the solution.
2002, 19(1): 30-33
Abstract:
The electrochemical behavior of the lithium ion battery using poly(p-phenylene) resin carbon materials as electrodes have been studied. The results indicated that the irreversibility of the charge-discharge capacity decreased with increase in the carbonization temperature. Compared with those for sample treated at 620℃, the irreversibilities of the samples treated at 1 000℃ and 1 300℃ dropped to about 84% and 80%, respectively. And the irreversibilities of samples treated at over 1 000℃ dropped to 50%. At temperature ranged in 550℃ to 1 300℃, the charge-discharge capacity of resin carbon electrodes was firstly increased and then dropped with increase in carbonization temperature. The results still indicated that the specific surface of the resin carbon was an important factor affecting the charge-discharge capacities of battery. The larger the specific surface of the carbon, the higher the capacity of the battery. And the charge-discharge capacity of carbon electrodes varied inversely with charge-discharge velocity. The stable charge-discharge capacity of carbon electrodes derived from poly(p-phenylene) resin could reach 580 mA·h/g when the charge-discharge current density was 1.0A/m2.
The electrochemical behavior of the lithium ion battery using poly(p-phenylene) resin carbon materials as electrodes have been studied. The results indicated that the irreversibility of the charge-discharge capacity decreased with increase in the carbonization temperature. Compared with those for sample treated at 620℃, the irreversibilities of the samples treated at 1 000℃ and 1 300℃ dropped to about 84% and 80%, respectively. And the irreversibilities of samples treated at over 1 000℃ dropped to 50%. At temperature ranged in 550℃ to 1 300℃, the charge-discharge capacity of resin carbon electrodes was firstly increased and then dropped with increase in carbonization temperature. The results still indicated that the specific surface of the resin carbon was an important factor affecting the charge-discharge capacities of battery. The larger the specific surface of the carbon, the higher the capacity of the battery. And the charge-discharge capacity of carbon electrodes varied inversely with charge-discharge velocity. The stable charge-discharge capacity of carbon electrodes derived from poly(p-phenylene) resin could reach 580 mA·h/g when the charge-discharge current density was 1.0A/m2.
2002, 19(1): 34-37
Abstract:
A non-toxic ammonium borate containing mixture(named BPN) was found to decrease the yields of hydrogen and coke by 35% and 10%, respectively, and increase the yield of gasoline by 1.2%. The passivating mechanism of BPN has been investigated by MAT, TPR, TPD and XRD techniques with simultaneous quantum chemistry calculation. The results showed that Ni2B2O5 was formed in addition of BPN to Ni-deposited zeolite under the condition of FCC regeneration. Ni2B2O5 is more difficult to be reduced than NiO under the condition of FCC reaction due to the much higher LUMO energy than that in NiO. The dehydrogenation activity of Ni0 is thus to be inhibited.
A non-toxic ammonium borate containing mixture(named BPN) was found to decrease the yields of hydrogen and coke by 35% and 10%, respectively, and increase the yield of gasoline by 1.2%. The passivating mechanism of BPN has been investigated by MAT, TPR, TPD and XRD techniques with simultaneous quantum chemistry calculation. The results showed that Ni2B2O5 was formed in addition of BPN to Ni-deposited zeolite under the condition of FCC regeneration. Ni2B2O5 is more difficult to be reduced than NiO under the condition of FCC reaction due to the much higher LUMO energy than that in NiO. The dehydrogenation activity of Ni0 is thus to be inhibited.
2002, 19(1): 38-42
Abstract:
The CdS nanoparticles were formed in the holes of a TiO2 nanoporous film, named as TiO2/CdS composite semiconductor nanoporous film. The films were then sensitized by Ru(bpy)2(NCS)2. The conversion efficiency of light to electricity for the TiO2/CdS/Ru(bpy)2(NCS)2 composite semiconductor nanoporous films was investigated as function of the deposition time of CdS on TiO2 and it was proved that the efficiency was dependent on the depositing time. When CdS was deposited on TiO2 for five minutes. The resulting cell had an energy conversion efficiency of 0.77%, with open circuit voltage of 0.716 V and short circuit current density of 5.23 A/m2.
The CdS nanoparticles were formed in the holes of a TiO2 nanoporous film, named as TiO2/CdS composite semiconductor nanoporous film. The films were then sensitized by Ru(bpy)2(NCS)2. The conversion efficiency of light to electricity for the TiO2/CdS/Ru(bpy)2(NCS)2 composite semiconductor nanoporous films was investigated as function of the deposition time of CdS on TiO2 and it was proved that the efficiency was dependent on the depositing time. When CdS was deposited on TiO2 for five minutes. The resulting cell had an energy conversion efficiency of 0.77%, with open circuit voltage of 0.716 V and short circuit current density of 5.23 A/m2.
2002, 19(1): 43-47
Abstract:
Four novel heterobinuclear complexes have been synthesized,[Cu(oxca)M(phen)2]ClO4·2H2O where oxca=N-(2-carboxy phenyl)-N'-(3-aminopropyl) oxamide; phen=1,10-phenanthroline; M=Mn2+, Co2+, Ni2+, Zn2+. The results obtained from IR、elemental analysis、thermogravimetric analysis conductivity, electronic spectrum and room temperature magnetic moment measurements showed these complexes appeared to have extended oxamido-bridged structures. The electrochemical properties of the heterobinuclear complexes have been measured by cyclic votammetry in DMSO. The temperature dependence of the magnetic susceptibility of Cu(Ⅱ)-Mn(Ⅱ) and Cu(Ⅱ)-Ni(Ⅱ) over the range 4~300 K gave the exchange integral of J=-10.56 cm-1 and J=-17.08 cm-1.
Four novel heterobinuclear complexes have been synthesized,[Cu(oxca)M(phen)2]ClO4·2H2O where oxca=N-(2-carboxy phenyl)-N'-(3-aminopropyl) oxamide; phen=1,10-phenanthroline; M=Mn2+, Co2+, Ni2+, Zn2+. The results obtained from IR、elemental analysis、thermogravimetric analysis conductivity, electronic spectrum and room temperature magnetic moment measurements showed these complexes appeared to have extended oxamido-bridged structures. The electrochemical properties of the heterobinuclear complexes have been measured by cyclic votammetry in DMSO. The temperature dependence of the magnetic susceptibility of Cu(Ⅱ)-Mn(Ⅱ) and Cu(Ⅱ)-Ni(Ⅱ) over the range 4~300 K gave the exchange integral of J=-10.56 cm-1 and J=-17.08 cm-1.
2002, 19(1): 48-52
Abstract:
TiO2 and Pt/TiO2 antibacterial thin films were prepared by sol-gel process and dip-coating method on the substrate of ordinary glazed ceramic plate. The relationship between film thickness, exposure time and antibacterial effect of the thin films on Colibacillus and Staphylococcus aureus under the irradiation of ultraviolet and sunlight was studied. TiO2 films of about 80 nm and 55 nm thicknesses and Pt/TiO2 films of about 50 nm thicknesses showed antibacterial efficiencies of 90% or more on Colibacillus after 30 min ultraviolet irradiation. The experimental results has also shown that the ultraviolet irradiation effect is better than Sun does in the same concentration of the film. TiO2 film of about 55 nm thicknesses presented the best efficiency on the Staphylococcus aureus.
TiO2 and Pt/TiO2 antibacterial thin films were prepared by sol-gel process and dip-coating method on the substrate of ordinary glazed ceramic plate. The relationship between film thickness, exposure time and antibacterial effect of the thin films on Colibacillus and Staphylococcus aureus under the irradiation of ultraviolet and sunlight was studied. TiO2 films of about 80 nm and 55 nm thicknesses and Pt/TiO2 films of about 50 nm thicknesses showed antibacterial efficiencies of 90% or more on Colibacillus after 30 min ultraviolet irradiation. The experimental results has also shown that the ultraviolet irradiation effect is better than Sun does in the same concentration of the film. TiO2 film of about 55 nm thicknesses presented the best efficiency on the Staphylococcus aureus.
2002, 19(1): 53-57
Abstract:
Poly(N,N-dimethylacrylamide)(PDMAA) and poly(N,N-diethylacrlyamide)(PDEAA) were obtained from the monomers of N,N-dimethylacrylamide(DMAA) and N,N-diethylacrlyamide(DEAA) in aqueous by plasma-initiated polymerization at low temperature. The results showed that the conversion of two monomers increased with post-polymerization time and discharge duration, the conversion of DEAA increased with discharge power, but the power had little influence on the conversion of DMAA, and the optimum mass fraction of the two monomers were 50%. The effect of post-polymerization time, discharge power, discharge duration and mass fraction of monomer on water-absorbing power of polymers were also investigated and found that the optimum post-polymerization time was about 4 h (for PDMAA) and 8 d (for PDEAA) respectively, the absorbencies of both PDMAA and PDEAA decreased with the increasing of discharge duration, and the absorbency of PDEAA decreased with the increasing of discharge power, but it had little influence on the absorbency of PDMAA. The thermal sensitivities of the polymers were studied and found that PDMAA showed a higher critical solution temperature(HCST) within the scope of 20~30℃, while PDEAA showed a lower critical solution temperature(LCST) at 31℃. The highest water-absorbing power of the polymers reached more than 100 g/g, which was 4~10 times that of the polymer synthesized by conventional method.
Poly(N,N-dimethylacrylamide)(PDMAA) and poly(N,N-diethylacrlyamide)(PDEAA) were obtained from the monomers of N,N-dimethylacrylamide(DMAA) and N,N-diethylacrlyamide(DEAA) in aqueous by plasma-initiated polymerization at low temperature. The results showed that the conversion of two monomers increased with post-polymerization time and discharge duration, the conversion of DEAA increased with discharge power, but the power had little influence on the conversion of DMAA, and the optimum mass fraction of the two monomers were 50%. The effect of post-polymerization time, discharge power, discharge duration and mass fraction of monomer on water-absorbing power of polymers were also investigated and found that the optimum post-polymerization time was about 4 h (for PDMAA) and 8 d (for PDEAA) respectively, the absorbencies of both PDMAA and PDEAA decreased with the increasing of discharge duration, and the absorbency of PDEAA decreased with the increasing of discharge power, but it had little influence on the absorbency of PDMAA. The thermal sensitivities of the polymers were studied and found that PDMAA showed a higher critical solution temperature(HCST) within the scope of 20~30℃, while PDEAA showed a lower critical solution temperature(LCST) at 31℃. The highest water-absorbing power of the polymers reached more than 100 g/g, which was 4~10 times that of the polymer synthesized by conventional method.
2002, 19(1): 58-60
Abstract:
Isocyanate-capped reactive hot melt adhesive(RHMA) based on poly(hexanediol adipate)(PHA)/poly(diethylene glycol adipate) (PDEA) and methylene di-p-phenyl diisocyanate(MDI) have been prepared. The relationship between melting enthalpy of RHMA and their green strengths has been investigated using DSC. It suggests that the green strength of RHMA decreased with increase in PDEA content in the adhesives. Storage modulus (E') and loss tangent (tanW) of RHMA have been determined by DMTA. It is concluded that the DSC and DMTA results have good corelationship with green strength of RHMA.
Isocyanate-capped reactive hot melt adhesive(RHMA) based on poly(hexanediol adipate)(PHA)/poly(diethylene glycol adipate) (PDEA) and methylene di-p-phenyl diisocyanate(MDI) have been prepared. The relationship between melting enthalpy of RHMA and their green strengths has been investigated using DSC. It suggests that the green strength of RHMA decreased with increase in PDEA content in the adhesives. Storage modulus (E') and loss tangent (tanW) of RHMA have been determined by DMTA. It is concluded that the DSC and DMTA results have good corelationship with green strength of RHMA.
2002, 19(1): 61-65
Abstract:
Polyvinyl alcohol(PVA) preirradiated by 60CoV ray was graft copolymerized and crosslinked with N,N'-methylenebisacrylamide(MBAA) in buffered aqueous solution in the presence of ferrous ions. The effects of monomer concentration, mass ratio of MBAA to PVA, ferrous ion concentration, pH value, temperature and time on the grafting degree were investigated. The results showed that the softing point of PVA could be increased 15%~20% under the following grafting conditions:c(Fe2+)>0.001 mol/L, c(MBAA)=2.5 g/dL, m(N,N'-MBAA)/m(PVA)>0.4, pH=3.4, at 80℃ for 15~30 min.
Polyvinyl alcohol(PVA) preirradiated by 60CoV ray was graft copolymerized and crosslinked with N,N'-methylenebisacrylamide(MBAA) in buffered aqueous solution in the presence of ferrous ions. The effects of monomer concentration, mass ratio of MBAA to PVA, ferrous ion concentration, pH value, temperature and time on the grafting degree were investigated. The results showed that the softing point of PVA could be increased 15%~20% under the following grafting conditions:c(Fe2+)>0.001 mol/L, c(MBAA)=2.5 g/dL, m(N,N'-MBAA)/m(PVA)>0.4, pH=3.4, at 80℃ for 15~30 min.
2002, 19(1): 66-70
Abstract:
A new bonded stationary phase, N-methylaniline bonded silica for reversed-phase HPLC was synthesized by reacting N-methylanilinetriethoxylsiliane with silica directly. The packing material was characterized by diffuse reflectance infrared Fourier transform spectrometry and elemental analysis. The chromatographic behavior of hydrophobicity, charge-transfer ability, dipole-dipole and hydrogen bonding interaction have been studied on the bonded stationary phase using methanol-water as binary mobile phase. Compared with octadecyl stationary phase(ODS), the new bonded phase was superior in selectivity and separation rate for PAH and it's derivatives, and exhibited the best separation selectivity for acidic aromatic derivatives.
A new bonded stationary phase, N-methylaniline bonded silica for reversed-phase HPLC was synthesized by reacting N-methylanilinetriethoxylsiliane with silica directly. The packing material was characterized by diffuse reflectance infrared Fourier transform spectrometry and elemental analysis. The chromatographic behavior of hydrophobicity, charge-transfer ability, dipole-dipole and hydrogen bonding interaction have been studied on the bonded stationary phase using methanol-water as binary mobile phase. Compared with octadecyl stationary phase(ODS), the new bonded phase was superior in selectivity and separation rate for PAH and it's derivatives, and exhibited the best separation selectivity for acidic aromatic derivatives.
2002, 19(1): 71-75
Abstract:
The structure of nano-scale layered double hydroxides MgAl-CO3-LDH and its flame retarding properties for PVC have been studied. LDH has been characterized by X-ray powder diffraction, scanning electronic micrograph observations and thermal analysis. The particle size of LDH was 50~100 nm. LDH-PVC composite has been characterized by electronic micrograph and the modified-LDH was found fairly distributed in PVC. The LDH showed flame retarding effect for PVC and appeared a favorable smoke suppressant. The smoke generation rate and the maximum density of smoke of LDH-PVC composite decreased by 40% with 20~40 phr LDH in comparison with unique PVC.
The structure of nano-scale layered double hydroxides MgAl-CO3-LDH and its flame retarding properties for PVC have been studied. LDH has been characterized by X-ray powder diffraction, scanning electronic micrograph observations and thermal analysis. The particle size of LDH was 50~100 nm. LDH-PVC composite has been characterized by electronic micrograph and the modified-LDH was found fairly distributed in PVC. The LDH showed flame retarding effect for PVC and appeared a favorable smoke suppressant. The smoke generation rate and the maximum density of smoke of LDH-PVC composite decreased by 40% with 20~40 phr LDH in comparison with unique PVC.
2002, 19(1): 76-79
Abstract:
Thermocuring and heat resistance of the complexes of sodium borate with phenol-formaldehyde resol resin were studied by thermal analysis and infrared spectroscopy. The results showed that the curing process is an exothermal reaction. On heating, condensation reaction of the hydroxymethyl groups in the complexes takes place and forms methylenes or carbonyl groups. With increase of sodium borate in the complexes the heat resistance of the complexes increases significantly.
Thermocuring and heat resistance of the complexes of sodium borate with phenol-formaldehyde resol resin were studied by thermal analysis and infrared spectroscopy. The results showed that the curing process is an exothermal reaction. On heating, condensation reaction of the hydroxymethyl groups in the complexes takes place and forms methylenes or carbonyl groups. With increase of sodium borate in the complexes the heat resistance of the complexes increases significantly.
2002, 19(1): 80-81
Abstract:
Quartz crystal microbalance(QCM) was used to study the autocatalytic polymerization of aniline. The deposition of polyaniline film via autocatalytic polymerization onto a Pt quartz crystal causes the decrease in oscillation frequency of the crystal in QCM, thereby the mass of the film is determined. The experimental results show that the catalytic activity of Pt substrate is much stronger than that of the polyaniline film on the autocatalytic polymerization. The rate of the autocatalytic polymerization falls down gradually with the time and reaches a steady value finally. The film can reach about 0.17 μm after 24 hours'deposition.
Quartz crystal microbalance(QCM) was used to study the autocatalytic polymerization of aniline. The deposition of polyaniline film via autocatalytic polymerization onto a Pt quartz crystal causes the decrease in oscillation frequency of the crystal in QCM, thereby the mass of the film is determined. The experimental results show that the catalytic activity of Pt substrate is much stronger than that of the polyaniline film on the autocatalytic polymerization. The rate of the autocatalytic polymerization falls down gradually with the time and reaches a steady value finally. The film can reach about 0.17 μm after 24 hours'deposition.
2002, 19(1): 82-84
Abstract:
The flotation process for calcite, diaspore and pyrite using 1,2,3-benzenetrioxylacetic acid(BTAA) as a depressant has been studied. The results showed that, when sodium oleate, dodecylamine and butyl xanthate are used as the collectors, BTAA exhibits a good depressing ability to the three minerals in the order:calcite > diaspore > pyrite. The depressing ability of BTAA was improved by increasing pH value of the medium and BTAA concentration. When the collector concentration was 0.1 mmol/L and the concentration of BTAA was up to 0.7 mmol/L, the recovery of calcite, diaspore and pyrite was 3%, 12% and 21%, respectively. The results were discussed in ferms of the electronegativity of BTAA, specific exponent of flotation agent and HLB value of BTAA molecule.
The flotation process for calcite, diaspore and pyrite using 1,2,3-benzenetrioxylacetic acid(BTAA) as a depressant has been studied. The results showed that, when sodium oleate, dodecylamine and butyl xanthate are used as the collectors, BTAA exhibits a good depressing ability to the three minerals in the order:calcite > diaspore > pyrite. The depressing ability of BTAA was improved by increasing pH value of the medium and BTAA concentration. When the collector concentration was 0.1 mmol/L and the concentration of BTAA was up to 0.7 mmol/L, the recovery of calcite, diaspore and pyrite was 3%, 12% and 21%, respectively. The results were discussed in ferms of the electronegativity of BTAA, specific exponent of flotation agent and HLB value of BTAA molecule.
2002, 19(1): 85-87
Abstract:
(S)-2-Acetoxyltridecane, which is the aggregation pheromone of Drosophila Mulleric and the sex pheromone component of the pea midge (Contarinia pisi), was synthesized from ethyl acetoacetate by enzymatic reduction with baker's yeast in the presence of ethyl chloroacetate as a key step. The optical purity of the target product is about 98%e.e.
(S)-2-Acetoxyltridecane, which is the aggregation pheromone of Drosophila Mulleric and the sex pheromone component of the pea midge (Contarinia pisi), was synthesized from ethyl acetoacetate by enzymatic reduction with baker's yeast in the presence of ethyl chloroacetate as a key step. The optical purity of the target product is about 98%e.e.
2002, 19(1): 88-90
Abstract:
Electrodeposition of Sm-Co alloy in DMF solution was studied by cyclic voltammetry and potentiostatic deposition at room temperature. The results show that small amount of water in a solution of Sm(NO3)3+CoCl2+DMF blocked the electrodeposition of Sm-Co due to the formation of nonconductive Sm(OH)3 film on the cathode surface. Citric acid could buffer the pH change and inhibit the precipitation of Sm(OH)3 on the cathode surface which makes the co-deposition of Sm and Co easy. Potentiostatic deposition was carried out on copper electrode in Sm(NO3)3+CoCl2+Citric acid+DMF solution and Sm-Co alloy films were obtained where the content of Sm could be as high as 57 56%.
Electrodeposition of Sm-Co alloy in DMF solution was studied by cyclic voltammetry and potentiostatic deposition at room temperature. The results show that small amount of water in a solution of Sm(NO3)3+CoCl2+DMF blocked the electrodeposition of Sm-Co due to the formation of nonconductive Sm(OH)3 film on the cathode surface. Citric acid could buffer the pH change and inhibit the precipitation of Sm(OH)3 on the cathode surface which makes the co-deposition of Sm and Co easy. Potentiostatic deposition was carried out on copper electrode in Sm(NO3)3+CoCl2+Citric acid+DMF solution and Sm-Co alloy films were obtained where the content of Sm could be as high as 57 56%.
2002, 19(1): 91-93
Abstract:
The photocurrent created by the TiO2 nanoporous film electrode modified by octadecanethiol(18SH) self-assembled monolayer(SAM) was found to be 1 95 times greater than that without modification as shown by cyclic voltammetry(CV). Meanwhile the maximum adsorbed peak has extended to the infrared range for about 20 nm. The formation of SAM was also assured with CV and small amplitude isosceles triangle potential methods, where the sensitization of SAM on the oxidation of CH3OH on the TiO2 nanoporous film electrode could be observed clearly. The results elucidated that the increased photocurrent by modification of octadecanethiol could not be simply attributed to the oxidation of octadecanethiol or ethanol. The results also implied that the application of SAM would be practicable in the sensitization of TiO2 nanoporous film electrode in solar cell area.
The photocurrent created by the TiO2 nanoporous film electrode modified by octadecanethiol(18SH) self-assembled monolayer(SAM) was found to be 1 95 times greater than that without modification as shown by cyclic voltammetry(CV). Meanwhile the maximum adsorbed peak has extended to the infrared range for about 20 nm. The formation of SAM was also assured with CV and small amplitude isosceles triangle potential methods, where the sensitization of SAM on the oxidation of CH3OH on the TiO2 nanoporous film electrode could be observed clearly. The results elucidated that the increased photocurrent by modification of octadecanethiol could not be simply attributed to the oxidation of octadecanethiol or ethanol. The results also implied that the application of SAM would be practicable in the sensitization of TiO2 nanoporous film electrode in solar cell area.
2002, 19(1): 94-96
Abstract:
A kind of polythioether cellulose compound(PTEC) was synthesized by etherification of rice husk cellulose with chloromethylthiirane(CMT) in alkaline media. The preparation conditions have been investigated. The PTEC with 4.31% sulfur content was obtained by reacting 12 g rice husk cellulose with 36 mL chloromethylthiirane in 3 mol/L NaOH solution. The product has an adsorption capacity for Ag(Ⅰ) and Hg(Ⅱ) of 24.92 mg/g and 66.80 mg/g, respectively at pH=7 and for Pb(Ⅱ) it is 0.15 mg/g at pH=3. The fiber could be used as a adsorbent for metal ions.
A kind of polythioether cellulose compound(PTEC) was synthesized by etherification of rice husk cellulose with chloromethylthiirane(CMT) in alkaline media. The preparation conditions have been investigated. The PTEC with 4.31% sulfur content was obtained by reacting 12 g rice husk cellulose with 36 mL chloromethylthiirane in 3 mol/L NaOH solution. The product has an adsorption capacity for Ag(Ⅰ) and Hg(Ⅱ) of 24.92 mg/g and 66.80 mg/g, respectively at pH=7 and for Pb(Ⅱ) it is 0.15 mg/g at pH=3. The fiber could be used as a adsorbent for metal ions.
2002, 19(1): 97-99
Abstract:
A novel method for synthesis of p-phenylphenol from phenol and cyclohexanone by acidic catalytic condensation at 60~70℃ and dehydrogenation in phenol under N2 in the presence of catalyst(5% Pd/C/MgO) is reported. The product was obtained in the yield of over 90% based on cyclohexanone.
A novel method for synthesis of p-phenylphenol from phenol and cyclohexanone by acidic catalytic condensation at 60~70℃ and dehydrogenation in phenol under N2 in the presence of catalyst(5% Pd/C/MgO) is reported. The product was obtained in the yield of over 90% based on cyclohexanone.
2002, 19(1): 100-102
Abstract:
The flotation separation behaviour of cadmium by sodium nitrate-potassium iodide-malachite green-water system and the conditions for the separation of cadmium with other metal ions were studied. The results showed that Cd(Ⅱ) can be separated completely from Zn(Ⅱ)、Cu(Ⅱ)、Ni(Ⅱ)、Mn(Ⅱ)、Fe(Ⅱ)、Co(Ⅱ)、Al(Ⅲ) by flotation at the optimum conditions.
The flotation separation behaviour of cadmium by sodium nitrate-potassium iodide-malachite green-water system and the conditions for the separation of cadmium with other metal ions were studied. The results showed that Cd(Ⅱ) can be separated completely from Zn(Ⅱ)、Cu(Ⅱ)、Ni(Ⅱ)、Mn(Ⅱ)、Fe(Ⅱ)、Co(Ⅱ)、Al(Ⅲ) by flotation at the optimum conditions.
