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2012 Volume 29 Issue 12
2012, 29(12): 1343-1355
doi: 10.3724/SP.J.1095.2012.20428
Abstract:
The N-,O-,and S-containing heteroarenes such as pyrrole,furan,and thiophene-based derivatives are fundamental structural motifs in numerous natural products,bioactive compounds,and functional materials.Therefore,methods for effective and straight forward functionalization of this class of molecules would be of great interest.Allylic substitution represents one of the most appealing reactions.In this paper,the developments of allylation and benzylation of heteroarenes are reviewed.
The N-,O-,and S-containing heteroarenes such as pyrrole,furan,and thiophene-based derivatives are fundamental structural motifs in numerous natural products,bioactive compounds,and functional materials.Therefore,methods for effective and straight forward functionalization of this class of molecules would be of great interest.Allylic substitution represents one of the most appealing reactions.In this paper,the developments of allylation and benzylation of heteroarenes are reviewed.
2012, 29(12): 1356-1363
doi: 10.3724/SP.J.1095.2012.20210
Abstract:
Atomic force microscopy(AFM) is widely used in biological research,AFM based single molecule force spectroscopy can be applied to study the intramolecular and intermolecular interactions of biomolecules at the single-molecule and single-cell levels.In this paper,we present the latest progress of AFM based single molecule force spectroscopy in biomolecular interaction,protein unfolding,cell surface biomolecules,cell mechanical properties and single molecule force spectroscopy imaging.
Atomic force microscopy(AFM) is widely used in biological research,AFM based single molecule force spectroscopy can be applied to study the intramolecular and intermolecular interactions of biomolecules at the single-molecule and single-cell levels.In this paper,we present the latest progress of AFM based single molecule force spectroscopy in biomolecular interaction,protein unfolding,cell surface biomolecules,cell mechanical properties and single molecule force spectroscopy imaging.
2012, 29(12): 1364-1370
doi: 10.3724/SP.J.1095.2012.20443
Abstract:
Among a large number of available methods,glucose biosensor has attracted wide interests for its high sensitivity,good selectivity,fast response and stability.Herein,we reviewed detection methods of glucose specifically:enzymatic measurements and non-enzymatic measurements.Besides main methods,research progress and advancements in these two kinds of biosensors were introduced in detail,respectively.Moreover,some future research trends and the need of glucose detection have been proposed in the article of interest.
Among a large number of available methods,glucose biosensor has attracted wide interests for its high sensitivity,good selectivity,fast response and stability.Herein,we reviewed detection methods of glucose specifically:enzymatic measurements and non-enzymatic measurements.Besides main methods,research progress and advancements in these two kinds of biosensors were introduced in detail,respectively.Moreover,some future research trends and the need of glucose detection have been proposed in the article of interest.
2012, 29(12): 1371-1380
doi: 10.3724/SP.J.1095.2012.20329
Abstract:
A macrocyclic compound containing three spiropyran subunits(macrocyclic spiropyrans) has been synthesized.Click chemistry has been conducted in a dilute solution to construct the cyclic structure of the target product.The yield of macrocylic compound is 64%.The structure of the macrocyclic compounds is characterized by FT-IR,1H NMR,13C NMR and ESI-MS.Cyclization of the macrocyclic spiropyrans is confirmed via MS analysis.The pH-responsive chromic properties of macrocyclic spiropyrans and linear compounds have been studied by using UV-Vis absorption spectroscopy in solutions at pH near 4.The maximum UV-Vis absorption(464 nm) of the macrocylic compound exhibits a blue shift comparing with that of linear compounds(476 nm).It is found that the molar extinction coefficient of the maximum UV-Vis absorption of macrocyclic spiropyrans is greater than those of its linear precursors.Furthermore,macrocyclic spiropyrans shows more sensitive pH-responsivity than its linear precursors.
A macrocyclic compound containing three spiropyran subunits(macrocyclic spiropyrans) has been synthesized.Click chemistry has been conducted in a dilute solution to construct the cyclic structure of the target product.The yield of macrocylic compound is 64%.The structure of the macrocyclic compounds is characterized by FT-IR,1H NMR,13C NMR and ESI-MS.Cyclization of the macrocyclic spiropyrans is confirmed via MS analysis.The pH-responsive chromic properties of macrocyclic spiropyrans and linear compounds have been studied by using UV-Vis absorption spectroscopy in solutions at pH near 4.The maximum UV-Vis absorption(464 nm) of the macrocylic compound exhibits a blue shift comparing with that of linear compounds(476 nm).It is found that the molar extinction coefficient of the maximum UV-Vis absorption of macrocyclic spiropyrans is greater than those of its linear precursors.Furthermore,macrocyclic spiropyrans shows more sensitive pH-responsivity than its linear precursors.
2012, 29(12): 1381-1388
doi: 10.3724/SP.J.1095.2012.20490
Abstract:
A series of phosphinophenolate neutral nickel catalysts bearing pyridine as spectator ligands(2-P(R1)(R2)-C6H3(R)O)Ni(Me)(Py)(3a,R=H,R1=R2=Ph;3b,R=t-Bu,R1=R2=Ph;3c,R=R1=R2=Ph;3d,R=anthr,R1=R2=Ph;3e,R=R1=t-Bu,R2=Ph) have been synthesized and characterized by 1H,13C and 31P NMR.As a kind of single component catalysts,other than 3a they all showed a higher catalitic activty to ethylene polymerization reaction,and a high catalytic activity up to 4460 kg PE/(mol(Ni)·h) was achieved by introducing proper steric effection groups at ortho position of its phenoxy group(3c~3d).Molecular mass of the polymer can be adjusted by varying the substituents as the ortho-position of phenoxy group,and using catalysts 3c~3d with aryl substituents in ethylene polymerization reaction could produced higher molecular mass polymer.Catalyst 3e with a tert-butyl group at its phosphorous atom showed similar activity as that of catalyst 3b and was more readily initiated,producing polymers of lower molecular msses under the same conditions.Moreover,these catalysts were tolerant towards polar groups and able to catalyze copolymerization of ethylene with norbornene or its polar derivative 5-norbornene-2-yl acetate.
A series of phosphinophenolate neutral nickel catalysts bearing pyridine as spectator ligands(2-P(R1)(R2)-C6H3(R)O)Ni(Me)(Py)(3a,R=H,R1=R2=Ph;3b,R=t-Bu,R1=R2=Ph;3c,R=R1=R2=Ph;3d,R=anthr,R1=R2=Ph;3e,R=R1=t-Bu,R2=Ph) have been synthesized and characterized by 1H,13C and 31P NMR.As a kind of single component catalysts,other than 3a they all showed a higher catalitic activty to ethylene polymerization reaction,and a high catalytic activity up to 4460 kg PE/(mol(Ni)·h) was achieved by introducing proper steric effection groups at ortho position of its phenoxy group(3c~3d).Molecular mass of the polymer can be adjusted by varying the substituents as the ortho-position of phenoxy group,and using catalysts 3c~3d with aryl substituents in ethylene polymerization reaction could produced higher molecular mass polymer.Catalyst 3e with a tert-butyl group at its phosphorous atom showed similar activity as that of catalyst 3b and was more readily initiated,producing polymers of lower molecular msses under the same conditions.Moreover,these catalysts were tolerant towards polar groups and able to catalyze copolymerization of ethylene with norbornene or its polar derivative 5-norbornene-2-yl acetate.
2012, 29(12): 1389-1393
doi: 10.3724/SP.J.1095.2012.20424
Abstract:
Novel constrained-geometry-configuration(CGC) rare-earth metal complexes(IndCH2-Py)2Sc(CH2SiMe3)(1) and(FluCH2-Py)Sc(CH2SiMe3)2(2)(Py=Pyridyl,Ind=Indenyl,Flu=Fluorenyl) have been synthesized by treating rare-earth metal trisalkyls with CpCH2-Py(Cp=Ind,Flu) compound,and fully characterized by NMR and X-ray diffraction analyses.Upon activation with AliBu3 and[B(C6F5)4],the two compounds showed different catalytic behavior towards copolymerization.A catalytic system containing complex 2 could initiate the copolymerization between styrene and ethylene while complex 1 was inert for the same purpose.Both gel permeation chromatography(GPC) curves and solvent extraction experiments corroborated that the products were mainly consisted of copolymers with negligible by product.The catalytic system based on complex 2,not only exhibited excellent activity(up to 1.21×103 kg/(mol(Sc)·h) and selectivity for syndiospecific styrene polymerization and styrene-ethylene copolymerization,but also afforded syndiotactic styrene-styrene sequences with controllable styrene contents in the styrene-ethylene copolymers.These copolymers were further confirmed by the observation of an endothermic peak(Tm) at 237~253℃ in the differential scanning calorimetry(DSC) curves.These copolymers have moderate relative molecular mass(Mn=3.2×104~10.7×104) and relative molecular mass distributions(Mw/Mn=2.05~2.34).
Novel constrained-geometry-configuration(CGC) rare-earth metal complexes(IndCH2-Py)2Sc(CH2SiMe3)(1) and(FluCH2-Py)Sc(CH2SiMe3)2(2)(Py=Pyridyl,Ind=Indenyl,Flu=Fluorenyl) have been synthesized by treating rare-earth metal trisalkyls with CpCH2-Py(Cp=Ind,Flu) compound,and fully characterized by NMR and X-ray diffraction analyses.Upon activation with AliBu3 and[B(C6F5)4],the two compounds showed different catalytic behavior towards copolymerization.A catalytic system containing complex 2 could initiate the copolymerization between styrene and ethylene while complex 1 was inert for the same purpose.Both gel permeation chromatography(GPC) curves and solvent extraction experiments corroborated that the products were mainly consisted of copolymers with negligible by product.The catalytic system based on complex 2,not only exhibited excellent activity(up to 1.21×103 kg/(mol(Sc)·h) and selectivity for syndiospecific styrene polymerization and styrene-ethylene copolymerization,but also afforded syndiotactic styrene-styrene sequences with controllable styrene contents in the styrene-ethylene copolymers.These copolymers were further confirmed by the observation of an endothermic peak(Tm) at 237~253℃ in the differential scanning calorimetry(DSC) curves.These copolymers have moderate relative molecular mass(Mn=3.2×104~10.7×104) and relative molecular mass distributions(Mw/Mn=2.05~2.34).
2012, 29(12): 1394-1398
doi: 10.3724/SP.J.1095.2012.20431
Abstract:
Treatment of scandium tris(alkyl)s,Sc(CH2SiMe3)3(THF)2,with 2-Me-C6H4NHPPh2=NC6H2-2,4,6-Me3(NPNArH) via deprotonation affords the bis(alkyl) derivative [NPNAr]Sc(CH2SiMe3)2(THF).The complex structure was characterized by means of 1H NMR,13C NMR,elemental analysis and X-ray diffraction analysis.Complex activated with [Ph3C][B(C6F5)4] and AliBu3 exhibited highly catalytic activity to the polymerization of butadiene.The 1,2-selectivity of polybutadiene noticeably increased with decrease of temperature.The molecular mass is 2.95×104 and the molecular mass distribution(Mw/Mn) is 1.65 at-75℃.
Treatment of scandium tris(alkyl)s,Sc(CH2SiMe3)3(THF)2,with 2-Me-C6H4NHPPh2=NC6H2-2,4,6-Me3(NPNArH) via deprotonation affords the bis(alkyl) derivative [NPNAr]Sc(CH2SiMe3)2(THF).The complex structure was characterized by means of 1H NMR,13C NMR,elemental analysis and X-ray diffraction analysis.Complex activated with [Ph3C][B(C6F5)4] and AliBu3 exhibited highly catalytic activity to the polymerization of butadiene.The 1,2-selectivity of polybutadiene noticeably increased with decrease of temperature.The molecular mass is 2.95×104 and the molecular mass distribution(Mw/Mn) is 1.65 at-75℃.
2012, 29(12): 1399-1405
doi: 10.3724/SP.J.1095.2012.20482
Abstract:
[6,6]-Thienyl-C61-butyric acid ester derivatives with different alkyl chains at the 5-position of thiophene ring(TCBM-Cn,n represents the number of carbon atom in the alkyl chain) are introduced as compatibilizers in poly(3-hexyl thiophene)/[6,6]-phenyl-C61-butyric acid methyl ester(P3HT/PCBM) blend films.The effect of different crystalline ability of TCBM-Cn on the thermal stability and the crystallization of P3HT in blend films is discussed.Although it is difficult to completely prevent the aggregation of fullerene,a small amount of good crystalline compatibilizer can enhance the crystallization of P3HT.To the contrary,poor crystalline compatibilizer can completely prevent the aggregation of fullerene,but more compatibilizers are required to improve the crystallization of P3HT.
[6,6]-Thienyl-C61-butyric acid ester derivatives with different alkyl chains at the 5-position of thiophene ring(TCBM-Cn,n represents the number of carbon atom in the alkyl chain) are introduced as compatibilizers in poly(3-hexyl thiophene)/[6,6]-phenyl-C61-butyric acid methyl ester(P3HT/PCBM) blend films.The effect of different crystalline ability of TCBM-Cn on the thermal stability and the crystallization of P3HT in blend films is discussed.Although it is difficult to completely prevent the aggregation of fullerene,a small amount of good crystalline compatibilizer can enhance the crystallization of P3HT.To the contrary,poor crystalline compatibilizer can completely prevent the aggregation of fullerene,but more compatibilizers are required to improve the crystallization of P3HT.
2012, 29(12): 1406-1411
doi: 10.3724/SP.J.1095.2012.20449
Abstract:
Crystallization and orientation behaviors of syndiotactic polystyrene(sPS) were investigated by polarized micro-FTIR.Surface of anodized aluminum oxide(AAO) templates was modified via a vapor phase reaction using n-hexyltrimethoxylsilane to yield an n-alkane template surface,and effect of template surface property on crystal orientation of sPS in the nanopores of various diameters was studied.After isothermally crystallized at 255℃,sPS chains in the crystals adopted a perpendicular orientation with respect to the pore direction of nanopores.The degree of orientation was found to decrease with the pore diameter,and was lower in the modified nanopores than in the pristine ones of the same pore diameter.This could be attributed to the surface induced nucleation,the orientation of which affected by interactions between sPS chains and the pore surface of different properties.
Crystallization and orientation behaviors of syndiotactic polystyrene(sPS) were investigated by polarized micro-FTIR.Surface of anodized aluminum oxide(AAO) templates was modified via a vapor phase reaction using n-hexyltrimethoxylsilane to yield an n-alkane template surface,and effect of template surface property on crystal orientation of sPS in the nanopores of various diameters was studied.After isothermally crystallized at 255℃,sPS chains in the crystals adopted a perpendicular orientation with respect to the pore direction of nanopores.The degree of orientation was found to decrease with the pore diameter,and was lower in the modified nanopores than in the pristine ones of the same pore diameter.This could be attributed to the surface induced nucleation,the orientation of which affected by interactions between sPS chains and the pore surface of different properties.
2012, 29(12): 1412-1416
doi: 10.3724/SP.J.1095.2012.20445
Abstract:
Efficient blue phosphorescent inverted bottom-emission organic light-emitting diode(IBOLED) based on indium tin oxide(ITO) cathode has been successfully fabricated by thermal evaporation using Al(2 nm)/Li2CO3(2 nm) as the electron-injection layer.The structure of this device is ITO/Al/Li2CO3/SPPO13/SPPO13:FIrpic/TCTA/MoO3/Al(SPPO13:2,7-bis(diphenylphosphoryl)-9,9'-spirobi[fluorene];FIrpic:bis(4,6-difluorophenylpyridinato-N,C2)picolinatoiridium;TCTA:4,4',4"-tri(9-carbazoyl)triphenylamine).It is found that the electron injection barrier between ITO and the organic layer can be significantly reduced with the presence of Al/Li2CO3,leading to the reduction of the turn-on voltage from 11 V to 4.2 V and the significant enhancement of efficiencies.The inverted device exhibits a maximum current efficiency of 28.2 cd/A and a maximum power efficiency of 19.6 lm/W,which are comparable with the conventional device.This suggests that Al/Li2CO3 has the potential to be used as the electron injection layer for inverted OLEDs.
Efficient blue phosphorescent inverted bottom-emission organic light-emitting diode(IBOLED) based on indium tin oxide(ITO) cathode has been successfully fabricated by thermal evaporation using Al(2 nm)/Li2CO3(2 nm) as the electron-injection layer.The structure of this device is ITO/Al/Li2CO3/SPPO13/SPPO13:FIrpic/TCTA/MoO3/Al(SPPO13:2,7-bis(diphenylphosphoryl)-9,9'-spirobi[fluorene];FIrpic:bis(4,6-difluorophenylpyridinato-N,C2)picolinatoiridium;TCTA:4,4',4"-tri(9-carbazoyl)triphenylamine).It is found that the electron injection barrier between ITO and the organic layer can be significantly reduced with the presence of Al/Li2CO3,leading to the reduction of the turn-on voltage from 11 V to 4.2 V and the significant enhancement of efficiencies.The inverted device exhibits a maximum current efficiency of 28.2 cd/A and a maximum power efficiency of 19.6 lm/W,which are comparable with the conventional device.This suggests that Al/Li2CO3 has the potential to be used as the electron injection layer for inverted OLEDs.
2012, 29(12): 1417-1422
doi: 10.3724/SP.J.1095.2012.20440
Abstract:
The effects of the substrate temperature on the performance of active layers and characteristics of the polymer solar cells fabricated with doctor-blading were studied.As the substrate temperature increases,the drying time of wet film could be shortened while the large scale aggregation of[6,6]-phenyl C61-butyric acid methyl ester(PCBM) phase could be restrained.Along with the increase of substrate temperature,both the crystallinity of poly(3-hexylthiophene)(P3HT) at the(100) direction and the producing efficiency of the film were increased while the ordering of the π-π stacking was lowered.After annealing,an interpenetrate network was formed in the active layer of the polymer photovoltaic cell and the power conversion efficiency could reach up to 3.93%.
The effects of the substrate temperature on the performance of active layers and characteristics of the polymer solar cells fabricated with doctor-blading were studied.As the substrate temperature increases,the drying time of wet film could be shortened while the large scale aggregation of[6,6]-phenyl C61-butyric acid methyl ester(PCBM) phase could be restrained.Along with the increase of substrate temperature,both the crystallinity of poly(3-hexylthiophene)(P3HT) at the(100) direction and the producing efficiency of the film were increased while the ordering of the π-π stacking was lowered.After annealing,an interpenetrate network was formed in the active layer of the polymer photovoltaic cell and the power conversion efficiency could reach up to 3.93%.
2012, 29(12): 1423-1427
doi: 10.3724/SP.J.1095.2012.20433
Abstract:
Large-area inverted polymer solar cells with a device structure of ITO/ZnO/P3HT:PCBM/V2O5/Ag(P3HT:poly(3-hexylthiophene);PCBM:[6,6]-phenyl C61-butyric acid methyl ester) were prepared with an active area of 1.0×1.1 cm2 by spray coating technique.UV-Vis absorption spectrum of the P3HT:PCBM film indicated that the absorbance was dramatically strengthened,and the absorption peaks were red-shifted to some extent.ZnO and V2O5 were used to replace LiF and PEDOT:PSS(4-ethylenedioxythiophene:polystyrene sulfonate) as the interfacial modified layers,in order to avoid corrosion of PEDOT:PSS to ITO layer and deliquescence of LiF.In addition,Ag instead of Al was evaporated as the back electrode to avoid the oxidization of Al electrode.The efficiency of the device increased from 1.1% to 1.65% after thermal annealing.The stability of the inverted devices was markedly improved compared with traditional devices,with the efficiencies decreased by only 10% after storage for 8 weeks.
Large-area inverted polymer solar cells with a device structure of ITO/ZnO/P3HT:PCBM/V2O5/Ag(P3HT:poly(3-hexylthiophene);PCBM:[6,6]-phenyl C61-butyric acid methyl ester) were prepared with an active area of 1.0×1.1 cm2 by spray coating technique.UV-Vis absorption spectrum of the P3HT:PCBM film indicated that the absorbance was dramatically strengthened,and the absorption peaks were red-shifted to some extent.ZnO and V2O5 were used to replace LiF and PEDOT:PSS(4-ethylenedioxythiophene:polystyrene sulfonate) as the interfacial modified layers,in order to avoid corrosion of PEDOT:PSS to ITO layer and deliquescence of LiF.In addition,Ag instead of Al was evaporated as the back electrode to avoid the oxidization of Al electrode.The efficiency of the device increased from 1.1% to 1.65% after thermal annealing.The stability of the inverted devices was markedly improved compared with traditional devices,with the efficiencies decreased by only 10% after storage for 8 weeks.
2012, 29(12): 1428-1432
doi: 10.3724/SP.J.1095.2012.20171
Abstract:
Excessive water swelling has been an important problem for proton exchange membranes materials,especially for sulfonated poly aryl ether ketone.In this article,a sulfonated polymer containing ester group was hydrolyzed to yield carboxylic side group on its side chain,then the polymer was blended with polyvinyl alcohol and heat-treated to obtain crosslinked blend membranes.The results showed that Tg of the crosslinked membrane was increased significantly suggesting the presence of crosslinking reaction in the polymers.At 100℃,the proton conductivity,water uptake and swelling ratio of the crosslinked membranes are in the ranges of 0.072~0.065 S/cm,51%~89%,and 19%~30%,respectively.Both the water uptake and swelling rate of the membrane decreased in a certain degree.This method is promising for the preparation of sulfonated poly arylene ether based proton exchange membrane with improved overall performance.
Excessive water swelling has been an important problem for proton exchange membranes materials,especially for sulfonated poly aryl ether ketone.In this article,a sulfonated polymer containing ester group was hydrolyzed to yield carboxylic side group on its side chain,then the polymer was blended with polyvinyl alcohol and heat-treated to obtain crosslinked blend membranes.The results showed that Tg of the crosslinked membrane was increased significantly suggesting the presence of crosslinking reaction in the polymers.At 100℃,the proton conductivity,water uptake and swelling ratio of the crosslinked membranes are in the ranges of 0.072~0.065 S/cm,51%~89%,and 19%~30%,respectively.Both the water uptake and swelling rate of the membrane decreased in a certain degree.This method is promising for the preparation of sulfonated poly arylene ether based proton exchange membrane with improved overall performance.
2012, 29(12): 1433-1437
doi: 10.3724/SP.J.1095.2012.20426
Abstract:
Polyelectrolyte multilayers were assembled via the layer-by-layer technique from poly(diallyldimethylammonium chloride)(PDDA) and poly(styrene sulfonate)(PSS).AuCl4- and PtCl62-,precursor ions for Au and Pt,respectively,were exchanged into the multilayers and then reduced in situ via a sequential anion exchange/reduction process to produce Au@Pt bimetallic nanoparticles in the multilayer films.The core-shell structure of the bimetallic nanoparticles produced was confirmed using ultraviolet-visible absorption spectroscopy(UV-Vis),transmission electron microscopy(TEM) and energy dispersive X-ray spectroscopy(EDX).These core-shell nanoparticles may find application in the fields of electrocatalysis and fuel cells.
Polyelectrolyte multilayers were assembled via the layer-by-layer technique from poly(diallyldimethylammonium chloride)(PDDA) and poly(styrene sulfonate)(PSS).AuCl4- and PtCl62-,precursor ions for Au and Pt,respectively,were exchanged into the multilayers and then reduced in situ via a sequential anion exchange/reduction process to produce Au@Pt bimetallic nanoparticles in the multilayer films.The core-shell structure of the bimetallic nanoparticles produced was confirmed using ultraviolet-visible absorption spectroscopy(UV-Vis),transmission electron microscopy(TEM) and energy dispersive X-ray spectroscopy(EDX).These core-shell nanoparticles may find application in the fields of electrocatalysis and fuel cells.
2012, 29(12): 1438-1446
doi: 10.3724/SP.J.1095.2012.20429
Abstract:
One-dimensional CaTiO3:Er3+ microbelts have been prepared by electrospinning method.X-ray diffraction,Fourier transform infrared spectroscopy,Raman spectroscopy,scanning electron microscopy(SEM),transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),up-converted luminescence were used to characterize the resulting samples.SEM and TEM analysis indicate that the obtained precursor belts have a uniform size,and the as-formed microbelts consist of nanoparticles.Under 980 nm laser beam excitation,the CaTiO3:Er3+ samples exhibit a green emission band with a maximum at 546 nm originating from the 4S3/2→4I15/2 transitions of Er3+ ions.When the Er3+ concentration increases,the red emission of CaTiO3:Er3+ increases relative to the green emission,which is due to the energy transfer between Er3+ ions.
One-dimensional CaTiO3:Er3+ microbelts have been prepared by electrospinning method.X-ray diffraction,Fourier transform infrared spectroscopy,Raman spectroscopy,scanning electron microscopy(SEM),transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),up-converted luminescence were used to characterize the resulting samples.SEM and TEM analysis indicate that the obtained precursor belts have a uniform size,and the as-formed microbelts consist of nanoparticles.Under 980 nm laser beam excitation,the CaTiO3:Er3+ samples exhibit a green emission band with a maximum at 546 nm originating from the 4S3/2→4I15/2 transitions of Er3+ ions.When the Er3+ concentration increases,the red emission of CaTiO3:Er3+ increases relative to the green emission,which is due to the energy transfer between Er3+ ions.
2012, 29(12): 1447-1451
doi: 10.3724/SP.J.1095.2012.20418
Abstract:
A four-spin complex {[Mn(hfac)2]2(4P4NIT)2}·CHCl3(4P4NIT=2-(4'-(4"-pyridyl)phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide,hfac=1,1,1,5,5,5-hexafluoro-acetylaceonate anion) was synthesized using a pyridyl substituted nitroxide radical.The single crystal X-ray analysis reveals that two 4P4NIT radicals act as bridging ligand linking two Mn(hfac)2 units together.The magnetic study shows that there exists strong magnetic interaction between Mn(Ⅱ) ions and directly bonded radicals.
A four-spin complex {[Mn(hfac)2]2(4P4NIT)2}·CHCl3(4P4NIT=2-(4'-(4"-pyridyl)phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide,hfac=1,1,1,5,5,5-hexafluoro-acetylaceonate anion) was synthesized using a pyridyl substituted nitroxide radical.The single crystal X-ray analysis reveals that two 4P4NIT radicals act as bridging ligand linking two Mn(hfac)2 units together.The magnetic study shows that there exists strong magnetic interaction between Mn(Ⅱ) ions and directly bonded radicals.
2012, 29(12): 1452-1456
doi: 10.3724/SP.J.1095.2012.20436
Abstract:
Mg-1.5Y-1.2Zn-0.44Zr alloys by adding small amounts(mass fraction) of yttrium(1.5%),zinc(1.2%) and zirconium(0.35%) into pure magnesium were developed as degradable metallic biomaterials.Also,solution treatment and hot extrusion were used as the methods for fabrication.An investigation of microstructure and in vitro degradation responses were made.The alloys are mainly composed of the matrix α-Mg phases and the Mg12ZnY secondary phases.The grains of the as-cast alloys were significantly refined by hot extrusion.The biodegradation resistance of the as-cast alloys is obviously improved by hot extrusion via microstructure refinement.The results of in vitro degradation responses in the simulated body fluid(SBF) indicate that the product of degradation precipitated on the alloy's surface is the phosphate which contains Ca and Mg elements.
Mg-1.5Y-1.2Zn-0.44Zr alloys by adding small amounts(mass fraction) of yttrium(1.5%),zinc(1.2%) and zirconium(0.35%) into pure magnesium were developed as degradable metallic biomaterials.Also,solution treatment and hot extrusion were used as the methods for fabrication.An investigation of microstructure and in vitro degradation responses were made.The alloys are mainly composed of the matrix α-Mg phases and the Mg12ZnY secondary phases.The grains of the as-cast alloys were significantly refined by hot extrusion.The biodegradation resistance of the as-cast alloys is obviously improved by hot extrusion via microstructure refinement.The results of in vitro degradation responses in the simulated body fluid(SBF) indicate that the product of degradation precipitated on the alloy's surface is the phosphate which contains Ca and Mg elements.
2012, 29(12): 1457-1462
doi: 10.3724/SP.J.1095.2012.20434
Abstract:
Ethanol methylimidazole bromide and ethoxy ehanol methylimidazole chloride were synthetized by the reaction of 1-methylimidazole with 2-(2-chloro-ethoxy)-ethanol and 2-bromoethanol,respectively.The structures were characterized using 1H HMR and FT-IR.The thermal performances of the products were examined by TG and DSC,and the electrochemical properties were also studied.The results show that the hydroxyl imidazole ionic liquid has an eminent thermal stability.The short-chain ionic liquid containing an ether bond and a hydroxyl is beneficial to improving the conductivity,and the conductive mechanism can be rationalized by the Vogel-Tmman-Fulcher(VTF) function.the ethanol methylimidazole bromide and ethoxy ethanol methylimidazole chloride have conductivities of 1.2×10-4 S/cm and 1.7×10-4 S/cm,respectively,at room temperature.For the system containing propylene carbonate,ethoxy ethanol methylimidazole chloride and potassium,the maxium conductivity can reach 3.82×10-3 S/cm.The electrochemical window of the ethoxy ethanol methylimidazole chloride is 3.4 V.
Ethanol methylimidazole bromide and ethoxy ehanol methylimidazole chloride were synthetized by the reaction of 1-methylimidazole with 2-(2-chloro-ethoxy)-ethanol and 2-bromoethanol,respectively.The structures were characterized using 1H HMR and FT-IR.The thermal performances of the products were examined by TG and DSC,and the electrochemical properties were also studied.The results show that the hydroxyl imidazole ionic liquid has an eminent thermal stability.The short-chain ionic liquid containing an ether bond and a hydroxyl is beneficial to improving the conductivity,and the conductive mechanism can be rationalized by the Vogel-Tmman-Fulcher(VTF) function.the ethanol methylimidazole bromide and ethoxy ethanol methylimidazole chloride have conductivities of 1.2×10-4 S/cm and 1.7×10-4 S/cm,respectively,at room temperature.For the system containing propylene carbonate,ethoxy ethanol methylimidazole chloride and potassium,the maxium conductivity can reach 3.82×10-3 S/cm.The electrochemical window of the ethoxy ethanol methylimidazole chloride is 3.4 V.
2012, 29(12): 1463-1467
doi: 10.3724/SP.J.1095.2012.20415
Abstract:
This work investigated the elecrocatalytic performance of tungsten carbide(WC) and Vulcan XC-72 carbon(XC) supported Pd(Pd/WC-XC) catalysts for formic acid oxidation.It is found that the electrocatalytic performance of the Pd/WC-XC catalysts for formic acid oxidation is better than that of the Pd/XC catalyst.Furthermore,the electrocatalytic performance of the Pd/WC-XC catalyst is related to the mass ratio of WC and XC.When the mass ratio of WC and XC is 3:1,the electrocatalytic activity of the catalyst is best.When the mass ratio of WC and XC is 2:1,the electrocatalytic stability of the catalyst is best.
This work investigated the elecrocatalytic performance of tungsten carbide(WC) and Vulcan XC-72 carbon(XC) supported Pd(Pd/WC-XC) catalysts for formic acid oxidation.It is found that the electrocatalytic performance of the Pd/WC-XC catalysts for formic acid oxidation is better than that of the Pd/XC catalyst.Furthermore,the electrocatalytic performance of the Pd/WC-XC catalyst is related to the mass ratio of WC and XC.When the mass ratio of WC and XC is 3:1,the electrocatalytic activity of the catalyst is best.When the mass ratio of WC and XC is 2:1,the electrocatalytic stability of the catalyst is best.
2012, 29(12): 1468-1470
doi: 10.3724/SP.J.1095.2012.20014
Abstract:
1-Azabicyclo[2.2.2]octane(quinuclidine) was obtained via the direct intramolecular dehydration reaction of 4-(2-hydroxyethyl) piperidine vapor in presence of CNM-3,a solid acidic catalyst.The yield of quinuclidine can reach 76.8% at 425℃ for 4 h with the highest yield up to 84.3%.Due to the easy accessible of the precursors,the established method is believed to be promising for the scale-up of quinuclidine.
1-Azabicyclo[2.2.2]octane(quinuclidine) was obtained via the direct intramolecular dehydration reaction of 4-(2-hydroxyethyl) piperidine vapor in presence of CNM-3,a solid acidic catalyst.The yield of quinuclidine can reach 76.8% at 425℃ for 4 h with the highest yield up to 84.3%.Due to the easy accessible of the precursors,the established method is believed to be promising for the scale-up of quinuclidine.
