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2002 Volume 19 Issue 8
2002, 19(8): 715-718
Abstract:
Light controllable films were prepared by photopolymerization and crosslinking reaction of 4,4'-diphenol dicinnamic ester. The effects of exposure time of polarized UV light on the IR dichroism of film and that of illumination light angle on the pretilt angle of liquid crystal obtained have been investigated. The texture alignment of the liquid crystal has been observed by a polarized microscope. The results showed that the film exhibited a maximum IR dichroism ratio and best uniform liquid crystal alignment under UV light illumination for 15 min.
Light controllable films were prepared by photopolymerization and crosslinking reaction of 4,4'-diphenol dicinnamic ester. The effects of exposure time of polarized UV light on the IR dichroism of film and that of illumination light angle on the pretilt angle of liquid crystal obtained have been investigated. The texture alignment of the liquid crystal has been observed by a polarized microscope. The results showed that the film exhibited a maximum IR dichroism ratio and best uniform liquid crystal alignment under UV light illumination for 15 min.
2002, 19(8): 719-722
Abstract:
The effects of polyurethane(PU) branches on the crystallization behavior of polypropylene grafted with polyurethane(PP-g-PU) have been studied by DSC and WAXD techniques. The results showed that the presence of PU branches could lower the melting temperature and increase the crystallization temperature of the copolymers. The apparent crystallization rate of PP-g-PU increased with increase of the PU content in the samples. The growth direction of the crystallites was found to be varied with the content of PU in the copolymers.
The effects of polyurethane(PU) branches on the crystallization behavior of polypropylene grafted with polyurethane(PP-g-PU) have been studied by DSC and WAXD techniques. The results showed that the presence of PU branches could lower the melting temperature and increase the crystallization temperature of the copolymers. The apparent crystallization rate of PP-g-PU increased with increase of the PU content in the samples. The growth direction of the crystallites was found to be varied with the content of PU in the copolymers.
2002, 19(8): 723-726
Abstract:
A series of surfactants with double end hydrophilic groups and different chain spacers were synthesized by reacting compounds containing two end epoxy groups and different long carbon chains with poly(ethylene oxide)(PEO, Mw=400) or SPAN80. The surfactants were characterized by FTIR and 1H NMR. It was shown that the activity of the surfactant with two end hydrophilic groups and a lipophilic spacer is better than that of which has only one hydrophilic group, and the activity was increased with the length of the lipophilic spacer.
A series of surfactants with double end hydrophilic groups and different chain spacers were synthesized by reacting compounds containing two end epoxy groups and different long carbon chains with poly(ethylene oxide)(PEO, Mw=400) or SPAN80. The surfactants were characterized by FTIR and 1H NMR. It was shown that the activity of the surfactant with two end hydrophilic groups and a lipophilic spacer is better than that of which has only one hydrophilic group, and the activity was increased with the length of the lipophilic spacer.
2002, 19(8): 727-729
Abstract:
A new Schiff base crown ether 2,5,14,17-tetraoxa-11,20-diazatricyclo[20,2,2,26,9]-octacosa-1(24),6,8,10,21,23,25,27-octene was prepared by condensation of ethylenedioxybis (4-formylbenzene) with 2,2'-(ethylenedioxy)bis(ethylamine) in anhydrous acetonitrile. It's rare earth(Nd,Gd,Y) nitrate complexes were prepared and characterized by elemental analysis, TG-DTA, electric conductivity measurements and IR spectroscopy. The three complexes have the same molecular structure, and the nitrogen atoms in Schiff base do not take part in coordination.
A new Schiff base crown ether 2,5,14,17-tetraoxa-11,20-diazatricyclo[20,2,2,26,9]-octacosa-1(24),6,8,10,21,23,25,27-octene was prepared by condensation of ethylenedioxybis (4-formylbenzene) with 2,2'-(ethylenedioxy)bis(ethylamine) in anhydrous acetonitrile. It's rare earth(Nd,Gd,Y) nitrate complexes were prepared and characterized by elemental analysis, TG-DTA, electric conductivity measurements and IR spectroscopy. The three complexes have the same molecular structure, and the nitrogen atoms in Schiff base do not take part in coordination.
2002, 19(8): 730-733
Abstract:
The monopatassium salt of 4-sulfophthalic acid and monopotassium salt of 4-sulfophthalonitrile were synthesized and condensed to give tetrapotassium salt of zinc tetra sulfophthalocyanine by the solid fusion method or reaction in an inert solvent in the presence of (NH4)2MoO4, urea, ZnCl2 and NH4Cl. The results showed that the first method gave a better yield (46%). The structures of precursors and the end product were characterized by elemental analysis, IR, 1H NMR and 13C NMR.
The monopatassium salt of 4-sulfophthalic acid and monopotassium salt of 4-sulfophthalonitrile were synthesized and condensed to give tetrapotassium salt of zinc tetra sulfophthalocyanine by the solid fusion method or reaction in an inert solvent in the presence of (NH4)2MoO4, urea, ZnCl2 and NH4Cl. The results showed that the first method gave a better yield (46%). The structures of precursors and the end product were characterized by elemental analysis, IR, 1H NMR and 13C NMR.
2002, 19(8): 734-737
Abstract:
The magnetic compounds were prepared from Mg-Al hydrotalcites by the method of co-precipitation, and the magnetic Mg-Al hydrotalcite particles sized in 20~50 nm were synthesized to give assembled layered magnetic materials. The influences of Mg/Fe(Ⅱ) molar ratio on the structure of hydrotalcites and its magnetic property were investigated by XRD, TEM, vibrating-sample magnetometer(VSM), TG-DTA and FT-IR. The results showed that the addition of magnetic substrates didn't change the typical characters of layered-structure and mass loss on heating. And the specific saturation magnetization of products increased linearly with the content of magnetic particles.
The magnetic compounds were prepared from Mg-Al hydrotalcites by the method of co-precipitation, and the magnetic Mg-Al hydrotalcite particles sized in 20~50 nm were synthesized to give assembled layered magnetic materials. The influences of Mg/Fe(Ⅱ) molar ratio on the structure of hydrotalcites and its magnetic property were investigated by XRD, TEM, vibrating-sample magnetometer(VSM), TG-DTA and FT-IR. The results showed that the addition of magnetic substrates didn't change the typical characters of layered-structure and mass loss on heating. And the specific saturation magnetization of products increased linearly with the content of magnetic particles.
2002, 19(8): 738-741
Abstract:
Cobalt-8-quinolinolate/U-zeolite composites (Co(8-Q)2/U) were prepared by in-situ complexation using the flexible ligand method and characterized by XRD、UV-Vis、FT-IR and DTA. The results indicated that the cobalt-8-quinolinol encapsulated within the beta zeolite possessed high heat and chemical resistance. It has much higher activity than that without U-zeolite in oxidation of cyclohexane. The turnover number(TON) by Co(8-Q)2/U is 1.24 times higher than that by free cobalt-8-quinolinol.
Cobalt-8-quinolinolate/U-zeolite composites (Co(8-Q)2/U) were prepared by in-situ complexation using the flexible ligand method and characterized by XRD、UV-Vis、FT-IR and DTA. The results indicated that the cobalt-8-quinolinol encapsulated within the beta zeolite possessed high heat and chemical resistance. It has much higher activity than that without U-zeolite in oxidation of cyclohexane. The turnover number(TON) by Co(8-Q)2/U is 1.24 times higher than that by free cobalt-8-quinolinol.
2002, 19(8): 742-745
Abstract:
Semi-interpenetrating network(semi-IPN) hydrogels, poly[NVP-IPN]/PEG were prepared from N-vinyl-2-pyrrolidone(NVP), acrylic acid(AA) and polyethylene glycol(PEG) through free radical polymerization, in which AIBN was used as a free radical initiator and N,N'-methylene bis(acryl-amide)(BIS) as crosslinking agent. In polymer systems as characterized by DSC poly[NVP-AA] and PEG are partially compatible. The hydrogel thereof was pH sensitive due to the carboxyl group in the polymer structure. 5-Fuorouracil(5-FU), an anti cancer drug was choiced for entrapment test of the polymer capsule. The in-vitro release studies were carried out in synthetic gastric and intestinal fluids(SGF and SIF buffer solution) at 37℃. The results showed that with the increase of PEG content in the hydrogel, the corresponding release profile became flatter, release period longer, and the final equilibrium release percentage decreased. Moreover, the drug releasing behavior are affected by the cross-linking degree of the polymer and the medium it contacts with. The drug release profiles for hydrogels with different BIS content were similar in SIF buffer solution, while in SGF buffer solution, the higher degree of cross linking of poly[NVP-AA], the longer the releasing time.
Semi-interpenetrating network(semi-IPN) hydrogels, poly[NVP-IPN]/PEG were prepared from N-vinyl-2-pyrrolidone(NVP), acrylic acid(AA) and polyethylene glycol(PEG) through free radical polymerization, in which AIBN was used as a free radical initiator and N,N'-methylene bis(acryl-amide)(BIS) as crosslinking agent. In polymer systems as characterized by DSC poly[NVP-AA] and PEG are partially compatible. The hydrogel thereof was pH sensitive due to the carboxyl group in the polymer structure. 5-Fuorouracil(5-FU), an anti cancer drug was choiced for entrapment test of the polymer capsule. The in-vitro release studies were carried out in synthetic gastric and intestinal fluids(SGF and SIF buffer solution) at 37℃. The results showed that with the increase of PEG content in the hydrogel, the corresponding release profile became flatter, release period longer, and the final equilibrium release percentage decreased. Moreover, the drug releasing behavior are affected by the cross-linking degree of the polymer and the medium it contacts with. The drug release profiles for hydrogels with different BIS content were similar in SIF buffer solution, while in SGF buffer solution, the higher degree of cross linking of poly[NVP-AA], the longer the releasing time.
2002, 19(8): 746-749
Abstract:
Fourteen alkoxyl-4-methylthiophenoxy phosphoramidates were synthesized by one-pot reaction process in toluene with yields of 45.9%~95.9%. Their structures were characterized by elemental analysis, IR and NMR spectroscopy. Their insecticidal activities were tested. They showed remarkable activities, mortality for aphid in nearly 100% at concentration of 0.012 5%(mass fraction). The cropland trial of compound 4e showed not only better mortality but also smaller dose than the methamidophos on aphid and spider mite.
Fourteen alkoxyl-4-methylthiophenoxy phosphoramidates were synthesized by one-pot reaction process in toluene with yields of 45.9%~95.9%. Their structures were characterized by elemental analysis, IR and NMR spectroscopy. Their insecticidal activities were tested. They showed remarkable activities, mortality for aphid in nearly 100% at concentration of 0.012 5%(mass fraction). The cropland trial of compound 4e showed not only better mortality but also smaller dose than the methamidophos on aphid and spider mite.
2002, 19(8): 750-753
Abstract:
Nanometer SnO2 particles have been prepared from SnCl4·5H2O by precipitation and followed by calcination. The structure and morphology of the product were characterized by IR, XRD, SEM, TEM and BET techniques. The results indicated the products were rutile SnO2 with average particle size of 8 nm, specific surface of 54.186 m2/g. At the preparation conditions:c(SnCl4)=5.7×10-2mol/L, pH=5.0, hydrolysis temperature 3℃, and calcination temperature 680℃, the sample with best photocatalytic degradation activity was obtained. The degradation degree of dimethyldichlorovinyl phosphate(DDVP) reached 18.32% after 30 min illumination in the presence of nanometer SnO2.
Nanometer SnO2 particles have been prepared from SnCl4·5H2O by precipitation and followed by calcination. The structure and morphology of the product were characterized by IR, XRD, SEM, TEM and BET techniques. The results indicated the products were rutile SnO2 with average particle size of 8 nm, specific surface of 54.186 m2/g. At the preparation conditions:c(SnCl4)=5.7×10-2mol/L, pH=5.0, hydrolysis temperature 3℃, and calcination temperature 680℃, the sample with best photocatalytic degradation activity was obtained. The degradation degree of dimethyldichlorovinyl phosphate(DDVP) reached 18.32% after 30 min illumination in the presence of nanometer SnO2.
2002, 19(8): 754-758
Abstract:
The nonisothermal crystallization processes of polypropylene(PP) and polypropylene/poly(propylene-g-maleic anhydride)(PP-g-MAH)/organo montmorillonite(Org-MMT) have been investigated by DSC. The Avrami and Ozawa equations were used to describe the nonisothermal crystallization processes of the above systems. The parameter values of t1/2、Zc、F(T)、Tp indicated that at the same cooling rate the crystallization rate of PP/PP-g-MAH/Org-MMT composite was greater than that of PP and that the crystallization temperature of the former was higher than that of the latter. The activation energies of PP and composites calculated by Kissinger method revealed that the addition of Org-MMT in PP increased the activation energy of PP, however, the addition of PP-g-MAH in PP/Org-MMT composite decreased its activation energy, even close to that of pure PP.
The nonisothermal crystallization processes of polypropylene(PP) and polypropylene/poly(propylene-g-maleic anhydride)(PP-g-MAH)/organo montmorillonite(Org-MMT) have been investigated by DSC. The Avrami and Ozawa equations were used to describe the nonisothermal crystallization processes of the above systems. The parameter values of t1/2、Zc、F(T)、Tp indicated that at the same cooling rate the crystallization rate of PP/PP-g-MAH/Org-MMT composite was greater than that of PP and that the crystallization temperature of the former was higher than that of the latter. The activation energies of PP and composites calculated by Kissinger method revealed that the addition of Org-MMT in PP increased the activation energy of PP, however, the addition of PP-g-MAH in PP/Org-MMT composite decreased its activation energy, even close to that of pure PP.
2002, 19(8): 759-763
Abstract:
The air electrodes with different mass ratio of active carbon to carbon nanotube as catalyst layer material have been prepared. The electrocatalytic performances for oxygen reduction were evaluated by means of polarization curve and electrochemical impedance spectroscopy(EIS). The results disclosed that carbon nanotube content in the catalyst layer obviously affected the electrocatalytic activity. The air electrode with the mass ratio of active carbon to carbon nanotube of 50:50 showed the highest electrocatalytic activity, i.e., the output current density reached 300~500 mA/cm2 when the overpotential was 400~600 mV. The EIS of the as-prepared air electrode consisted of two semi-circles, in which the high frequency zone was ascribed to the ohmic process and the low frequency zone to the electrochemical kinetic process. The addition of carbon nanotube in the catalyst layer decreased greatly ohmic and kinetic impedance and thereby produced greater enhancement in performances. The mass transport process in the electrode was dominated by the thin film diffusion. The low catalytic activity of the air electrode prepared by the pure carbon nanotube appeared to be a consequence of the penetration of electrolyte into the porous structure. The equivalent circuit of the air electrode was proposed and the simulated kinetics data was analyzed.
The air electrodes with different mass ratio of active carbon to carbon nanotube as catalyst layer material have been prepared. The electrocatalytic performances for oxygen reduction were evaluated by means of polarization curve and electrochemical impedance spectroscopy(EIS). The results disclosed that carbon nanotube content in the catalyst layer obviously affected the electrocatalytic activity. The air electrode with the mass ratio of active carbon to carbon nanotube of 50:50 showed the highest electrocatalytic activity, i.e., the output current density reached 300~500 mA/cm2 when the overpotential was 400~600 mV. The EIS of the as-prepared air electrode consisted of two semi-circles, in which the high frequency zone was ascribed to the ohmic process and the low frequency zone to the electrochemical kinetic process. The addition of carbon nanotube in the catalyst layer decreased greatly ohmic and kinetic impedance and thereby produced greater enhancement in performances. The mass transport process in the electrode was dominated by the thin film diffusion. The low catalytic activity of the air electrode prepared by the pure carbon nanotube appeared to be a consequence of the penetration of electrolyte into the porous structure. The equivalent circuit of the air electrode was proposed and the simulated kinetics data was analyzed.
Water-Swelling Rubber-like Plastics Based on Blends of Chlorinated Polyethylene with Sodium Acrylate
2002, 19(8): 764-767
Abstract:
The water-swelling rubber-like plastic material(WSM) was prepared by blending chlorinated polyethylene(CPE) with sodium acrylate(AANa). The shear force occurred in the process of mixing caused the formation of CPE chain free radicals which reacted with sodium acrylate to give graft polymer. WSM obtained was stable in water with a little loss of hydrophilic polymer moiety even for 30 days. But the simple physical mixture of AANa and CPE lost almost all of its mass after immersion in water for the same time.
The water-swelling rubber-like plastic material(WSM) was prepared by blending chlorinated polyethylene(CPE) with sodium acrylate(AANa). The shear force occurred in the process of mixing caused the formation of CPE chain free radicals which reacted with sodium acrylate to give graft polymer. WSM obtained was stable in water with a little loss of hydrophilic polymer moiety even for 30 days. But the simple physical mixture of AANa and CPE lost almost all of its mass after immersion in water for the same time.
2002, 19(8): 768-771
Abstract:
A maximum resonance scattering(RS) peak at 470 nm for the system of protein-phosphomolybdic acid(PMA) was observed. The enhanced resonance scattering signal appeared to be the formation of protein-PMA composite nanoparticles with diameter about 80 nm. A resonance scattering spectroscopic method has been developed for the quantitative determination of human serum albumin (HSA) and casein. In the condition selected, the value of I470 nm was found linear to the concentration of protein in the range of 6.0×10-8~5.0×10-5g/mL, with detection limit about 2.0×10-8~1.0×10-7g/mL. The method has advantages of easy operation, high sensitivity, high accuracy and wide determinination range. Proteins in synthetic samples and human serum samples have been determined by this RS method with satisfactory results.
A maximum resonance scattering(RS) peak at 470 nm for the system of protein-phosphomolybdic acid(PMA) was observed. The enhanced resonance scattering signal appeared to be the formation of protein-PMA composite nanoparticles with diameter about 80 nm. A resonance scattering spectroscopic method has been developed for the quantitative determination of human serum albumin (HSA) and casein. In the condition selected, the value of I470 nm was found linear to the concentration of protein in the range of 6.0×10-8~5.0×10-5g/mL, with detection limit about 2.0×10-8~1.0×10-7g/mL. The method has advantages of easy operation, high sensitivity, high accuracy and wide determinination range. Proteins in synthetic samples and human serum samples have been determined by this RS method with satisfactory results.
2002, 19(8): 772-775
Abstract:
Polyvinyl chloride(PVC) was chemically modified with polyhydromethylsiloxane(PHMS) via reactive processing in a Haake Rheomix 600P mixing mill. Two kinds of PHMS with different contents of Si-H (202#PHMS and 206#PHMS) were used to reduce the maximum torque(TQmax) of PVC. On increasing the 206#PHMS amount, the equilibrium torque(TQeq) of PVC increased slightly and passed through a maximum at 0.2 phr of 206#PHMS. In contrast, the TQeq of PVC modified with 202# PHMS increased continuously with increase in 202# PHMS content. Furthermore, the gelating-melting time for PVC modified with 202# PHMS was shorter than that for PVC with 206# PHMS. With addition of PHMS the equilibrium temperature(Teq) of PVC increased firstly and then decreased. PHMS was able to decrease not only the total energy(TTQeq) consumed in the reactive processing but also the consumption rate of energy in the initial period of the reactive processing.
Polyvinyl chloride(PVC) was chemically modified with polyhydromethylsiloxane(PHMS) via reactive processing in a Haake Rheomix 600P mixing mill. Two kinds of PHMS with different contents of Si-H (202#PHMS and 206#PHMS) were used to reduce the maximum torque(TQmax) of PVC. On increasing the 206#PHMS amount, the equilibrium torque(TQeq) of PVC increased slightly and passed through a maximum at 0.2 phr of 206#PHMS. In contrast, the TQeq of PVC modified with 202# PHMS increased continuously with increase in 202# PHMS content. Furthermore, the gelating-melting time for PVC modified with 202# PHMS was shorter than that for PVC with 206# PHMS. With addition of PHMS the equilibrium temperature(Teq) of PVC increased firstly and then decreased. PHMS was able to decrease not only the total energy(TTQeq) consumed in the reactive processing but also the consumption rate of energy in the initial period of the reactive processing.
2002, 19(8): 776-779
Abstract:
The flotation separation behaviour of zinc(Ⅱ) by sodium chloride-ammonium thiocyanate-cetylpyridinium chloride(CPC)-water system and the separation conditions for zinc(Ⅱ) with other metal ions have been studied. The results showed that in the presence of 1.0 g solid NaCl, 2.0 mL NH4SCN(0.1 mol/L) and CPC(0.01 mol/L), Zn(Ⅱ) could be separated completely in a mixture solution (pH=4.0) containing Cd(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Mn(Ⅱ)、Fe(Ⅱ)and Al(Ⅲ) by flotation process. The method was used in separation of Zn(Ⅱ) in synthetic multiple ion mixture solution with satisfactory result.
The flotation separation behaviour of zinc(Ⅱ) by sodium chloride-ammonium thiocyanate-cetylpyridinium chloride(CPC)-water system and the separation conditions for zinc(Ⅱ) with other metal ions have been studied. The results showed that in the presence of 1.0 g solid NaCl, 2.0 mL NH4SCN(0.1 mol/L) and CPC(0.01 mol/L), Zn(Ⅱ) could be separated completely in a mixture solution (pH=4.0) containing Cd(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Mn(Ⅱ)、Fe(Ⅱ)and Al(Ⅲ) by flotation process. The method was used in separation of Zn(Ⅱ) in synthetic multiple ion mixture solution with satisfactory result.
2002, 19(8): 780-782
Abstract:
A series of abscisic amide analogs containing T-amino phosphonic esters were synthesized by the condensation reaction of O,O-diphenyl T-amino benzylphosphonates with 5-aryl-2E,4E-pentadienoic acids. Their structures were confirmed by 1H NMR, 31P NMR, IR, elemental analyses and MS. The results of bioassays showed that some of the new compounds have considerable plant growth inhibiting activities.
A series of abscisic amide analogs containing T-amino phosphonic esters were synthesized by the condensation reaction of O,O-diphenyl T-amino benzylphosphonates with 5-aryl-2E,4E-pentadienoic acids. Their structures were confirmed by 1H NMR, 31P NMR, IR, elemental analyses and MS. The results of bioassays showed that some of the new compounds have considerable plant growth inhibiting activities.
2002, 19(8): 783-785
Abstract:
The cationic starch was prepared via reaction of starch with N-(2,3-glycidyl)trimethyl ammonium chloride(GTA) using fatty alcohol polyoxyethylene ether(FAPE) as a catalyst in dry process. The effects of the catalyst, reaction time, reaction temperature, amounts of FAPE and sodium hydroxide on the reaction efficiency were discussed. With 0.6 g catalyst the reaction efficiency achieved 92.1% in 50 minutes.
The cationic starch was prepared via reaction of starch with N-(2,3-glycidyl)trimethyl ammonium chloride(GTA) using fatty alcohol polyoxyethylene ether(FAPE) as a catalyst in dry process. The effects of the catalyst, reaction time, reaction temperature, amounts of FAPE and sodium hydroxide on the reaction efficiency were discussed. With 0.6 g catalyst the reaction efficiency achieved 92.1% in 50 minutes.
2002, 19(8): 786-788
Abstract:
The thermal conductivity of glycerine aqueous solution was measured at 20℃ by means of a transient method with error in parallel analysis <1%. The equation correlating the concentration with thermal conductivity was presented. The time of measurement was 1s. The method avoids the heat convection of liquid sample due to its rapidity and is promising for on-line analysis in production control.
The thermal conductivity of glycerine aqueous solution was measured at 20℃ by means of a transient method with error in parallel analysis <1%. The equation correlating the concentration with thermal conductivity was presented. The time of measurement was 1s. The method avoids the heat convection of liquid sample due to its rapidity and is promising for on-line analysis in production control.
2002, 19(8): 789-791
Abstract:
An improved sol-gel method was proposed for glucose oxidase immobilization. Gelatin film was introduced onto the surface of the substrate electrode before the formation of the sol-gel membrane. The condition parameters affecting the sol-gel membrane preparation have been investi-gated and optimized. The covered gel membrane with entrapped enzyme was aged in a vessel at 4℃ for 48 h in order to prevent the membrane cracking and peeling off from the surface of substrate electrode. The fabricated glucose sensors exhibited sensitivity of 50 nA/(mmol·L-1) with linear range in range of 0.05~12 mmol/L, response time 1.5 min and satisfactory lifetime.
An improved sol-gel method was proposed for glucose oxidase immobilization. Gelatin film was introduced onto the surface of the substrate electrode before the formation of the sol-gel membrane. The condition parameters affecting the sol-gel membrane preparation have been investi-gated and optimized. The covered gel membrane with entrapped enzyme was aged in a vessel at 4℃ for 48 h in order to prevent the membrane cracking and peeling off from the surface of substrate electrode. The fabricated glucose sensors exhibited sensitivity of 50 nA/(mmol·L-1) with linear range in range of 0.05~12 mmol/L, response time 1.5 min and satisfactory lifetime.
2002, 19(8): 792-794
Abstract:
The washed and dried porous silica gel was soaked in water glass of moderate viscosity, then mixed with nanometer TiO2, stired until TiO2 has been uniformly distributed on the porous silica gel. After dried naturally, it was calcined at 300℃ for 1h to give the immobilized nanometer TiO2 which was mechanically and chemically stable, and can be reused. Under the illumination of high-pressure Hg lamp, the X-3B dye could be degraded almost quantitatively(98%) in a solution containing the photocatalyst, Fe3+ and H2O2 with bubbling of air.
The washed and dried porous silica gel was soaked in water glass of moderate viscosity, then mixed with nanometer TiO2, stired until TiO2 has been uniformly distributed on the porous silica gel. After dried naturally, it was calcined at 300℃ for 1h to give the immobilized nanometer TiO2 which was mechanically and chemically stable, and can be reused. Under the illumination of high-pressure Hg lamp, the X-3B dye could be degraded almost quantitatively(98%) in a solution containing the photocatalyst, Fe3+ and H2O2 with bubbling of air.
2002, 19(8): 795-797
Abstract:
By combining 2-chloropyridine, 1,3,4-thiadiazole and acylamide, three toxophoric moieties seven 2-[N-(1-methoxycarbonyl)ethyl-N-acyl]amino-5-[(2-chloropyrid)-4-yl]-1,3,4-thiadiazoles(8) were synthesized in seven steps. The preliminary biological activity tests show that the title compounds reveal a certain plant growth regulating effect as well as fungicidal activity.
By combining 2-chloropyridine, 1,3,4-thiadiazole and acylamide, three toxophoric moieties seven 2-[N-(1-methoxycarbonyl)ethyl-N-acyl]amino-5-[(2-chloropyrid)-4-yl]-1,3,4-thiadiazoles(8) were synthesized in seven steps. The preliminary biological activity tests show that the title compounds reveal a certain plant growth regulating effect as well as fungicidal activity.
2002, 19(8): 798-800
Abstract:
The visible absorption spectra of some pyridone-based disperse azo-dyes have been studied as function of pH values and solvents. The relationship between the hydrazone azo-anion equilibrium and the pH value of dye solution is discussed. The pyridone-based disperse dyes readily undergo acid dissociation to give the anion form at higher pH values or in ethanol, DMF and DMSO.
The visible absorption spectra of some pyridone-based disperse azo-dyes have been studied as function of pH values and solvents. The relationship between the hydrazone azo-anion equilibrium and the pH value of dye solution is discussed. The pyridone-based disperse dyes readily undergo acid dissociation to give the anion form at higher pH values or in ethanol, DMF and DMSO.
2002, 19(8): 801-803
Abstract:
The electrochemical property of natural graphite was improved by heat-treatment. The treated natural graphite(average particle size of 20 μm) showed reversible specific capacitance of 335 mA·h/g and charge-discharge efficiency of 84.3% in the first cycle. The cause of the improvement has been explained in terms of formation of more stable solid electrolyte interface.
The electrochemical property of natural graphite was improved by heat-treatment. The treated natural graphite(average particle size of 20 μm) showed reversible specific capacitance of 335 mA·h/g and charge-discharge efficiency of 84.3% in the first cycle. The cause of the improvement has been explained in terms of formation of more stable solid electrolyte interface.
2002, 19(8): 804-806
Abstract:
La4-x(P2O5)3:Eux were synthesized from a mixed solution of La(NO3)3 and Eu(NO3)3 in nitric acid solution(pH=4.5) followed by precipitation on addition of Na4P2O7 solution and calcination at 900℃. The products showed a highest excitation peak at 349 nm and highest emission peak at 596 nm.
La4-x(P2O5)3:Eux were synthesized from a mixed solution of La(NO3)3 and Eu(NO3)3 in nitric acid solution(pH=4.5) followed by precipitation on addition of Na4P2O7 solution and calcination at 900℃. The products showed a highest excitation peak at 349 nm and highest emission peak at 596 nm.
2002, 19(8): 807-809
Abstract:
The preparation of peroxodisulfated zirconia titania(PSZT) solid super acid has been investigated as function of molar ratio of Ti to Zr, impregnation time, calcination time and temperature in esterification of maleic anhydride with n-octanol. The highest yield of dioctyl maleate was 98.2% at the optimum reaction conditions.
The preparation of peroxodisulfated zirconia titania(PSZT) solid super acid has been investigated as function of molar ratio of Ti to Zr, impregnation time, calcination time and temperature in esterification of maleic anhydride with n-octanol. The highest yield of dioctyl maleate was 98.2% at the optimum reaction conditions.
2002, 19(8): 810-811
Abstract:
1,3-Dimethylbenzimidazolium iodide as an available convenient agent has been reacted with a Grignard reagent CH3(CH2)5MgBr to give heptanal. The method need not neccessarily to isolate benzimidazolidine. The reaction mechanism is discussed.
1,3-Dimethylbenzimidazolium iodide as an available convenient agent has been reacted with a Grignard reagent CH3(CH2)5MgBr to give heptanal. The method need not neccessarily to isolate benzimidazolidine. The reaction mechanism is discussed.
2002, 19(8): 812-813
Abstract:
The thermal power-time relation of starch hydrolysis reaction catalyzed by hydrolytic enzyme has been evaluated using a microcalorimeter. The maximum velocity(Vmax) was calculated according to the equation Vmax=[-2.975 79×10-4+2.401 91×10-4 pH-6.940 00×10-5 pH2+ 9 040 00×10-6 pH3-4 450 00×10-7pH4] g/(dm3·s).The optimum acidity was found to be pH=5.78.
The thermal power-time relation of starch hydrolysis reaction catalyzed by hydrolytic enzyme has been evaluated using a microcalorimeter. The maximum velocity(Vmax) was calculated according to the equation Vmax=[-2.975 79×10-4+2.401 91×10-4 pH-6.940 00×10-5 pH2+ 9 040 00×10-6 pH3-4 450 00×10-7pH4] g/(dm3·s).The optimum acidity was found to be pH=5.78.
2002, 19(8): 814-816
Abstract:
Three poly(2,5-dialkoxyl-phenelene vinylene) derivatives were synthesized from 1,4-dialkoxyl benzene and 1,2-dibromoethane by Friedel-Crafts reaction followed by dehydrogenation. Their molecular weights are determined by gel permeation chromotography and structures characterized by IR, 1H NMR and UV-Vis spectroscopy. All of the polymers obtained are constructed through a great number of c conjugated bonds.
Three poly(2,5-dialkoxyl-phenelene vinylene) derivatives were synthesized from 1,4-dialkoxyl benzene and 1,2-dibromoethane by Friedel-Crafts reaction followed by dehydrogenation. Their molecular weights are determined by gel permeation chromotography and structures characterized by IR, 1H NMR and UV-Vis spectroscopy. All of the polymers obtained are constructed through a great number of c conjugated bonds.
