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2018 Volume 35 Issue 7
2018, 35(7): 735-744
doi: 10.11944/j.issn.1000-0518.2018.07.180031
Abstract:
Gene therapy is a method for curing diseases caused by genetic defects and anomalies through introducing normal foreign genes into targeted cells. Efficient and sustained expression of foreign genes in cells is the decisive factor in gene therapy, which is significantly relied on the vectors used in the treatment. With the development of science and technology, the research of liposome/nanocomposites as gene carriers has widely attracted people's attention, due to the following advantages:versatile functions, easy surface modification, good biocompatibility, high transfection efficiency. Herein, the structure of liposome bilayer was introduced and the complexes of magnetic nanoparticles, gold nanoparticles, quantum dots, chitosan, upconversion nanoparticles with liposomes as gene carriers have been reviewed and prospected.
Gene therapy is a method for curing diseases caused by genetic defects and anomalies through introducing normal foreign genes into targeted cells. Efficient and sustained expression of foreign genes in cells is the decisive factor in gene therapy, which is significantly relied on the vectors used in the treatment. With the development of science and technology, the research of liposome/nanocomposites as gene carriers has widely attracted people's attention, due to the following advantages:versatile functions, easy surface modification, good biocompatibility, high transfection efficiency. Herein, the structure of liposome bilayer was introduced and the complexes of magnetic nanoparticles, gold nanoparticles, quantum dots, chitosan, upconversion nanoparticles with liposomes as gene carriers have been reviewed and prospected.
2018, 35(7): 745-755
doi: 10.11944/j.issn.1000-0518.2018.07.170387
Abstract:
As the typical anode material for lithium batteries, antimony-based materials have attracted much attention due to their high theoretical specific capacity and high safety performance. Nevertheless, antimony-based materials suffer significant capacity fading due to their large volume expansion in the charge-discharge process and poor electrical conductivity, which severely hinders their commercial applications in lithium batteries. The research progress of antimony-based anode materials in recent years is presented in this paper. Reaction mechanism, synthetic method and electrochemical performance are introduced and the research trend of antimony-based anode materials is prospected in the end.
As the typical anode material for lithium batteries, antimony-based materials have attracted much attention due to their high theoretical specific capacity and high safety performance. Nevertheless, antimony-based materials suffer significant capacity fading due to their large volume expansion in the charge-discharge process and poor electrical conductivity, which severely hinders their commercial applications in lithium batteries. The research progress of antimony-based anode materials in recent years is presented in this paper. Reaction mechanism, synthetic method and electrochemical performance are introduced and the research trend of antimony-based anode materials is prospected in the end.
2018, 35(7): 756-766
doi: 10.11944/j.issn.1000-0518.2018.07.170293
Abstract:
Hydrazine hydrate reduction of metal is mainly applied in the preparation of metal nanoparticles, recovery of metal ions in spent liquid and nuclear fuel. This article reviews the research progress in recent years on the preparation of nano metal materials, the recovery and reuse of metal ions and the used nuclear fuel by hydrazine hydrate as reducing agent or complexing agent in liquid phase reduction process. In liquid phase reduction, the differences and the related mechanisms, characteristics and influencing factors between acidic and alkaline conditions are analyzed and summarized in the process of hydrazine hydrate reduction of metals. This article gives a reference for future research on this field.
Hydrazine hydrate reduction of metal is mainly applied in the preparation of metal nanoparticles, recovery of metal ions in spent liquid and nuclear fuel. This article reviews the research progress in recent years on the preparation of nano metal materials, the recovery and reuse of metal ions and the used nuclear fuel by hydrazine hydrate as reducing agent or complexing agent in liquid phase reduction process. In liquid phase reduction, the differences and the related mechanisms, characteristics and influencing factors between acidic and alkaline conditions are analyzed and summarized in the process of hydrazine hydrate reduction of metals. This article gives a reference for future research on this field.
2018, 35(7): 767-775
doi: 10.11944/j.issn.1000-0518.2018.07.170273
Abstract:
The influence of graphene oxide(GO) on the linear and nonlinear rheological properties of poly(vinyl alcohol)(PVA)/borate hydrogel was explored in this work. Results of scanning electron microscopy, 11B nuclear magnetic resonance and rheology reveal that elastically active points formed between dispersed GO sheets and PVA chains have enhanced plateau modulus(G0), relaxation time(τ) and zero shear viscosity(η0) of samples when the mass concentration of GO(ρ(GO)) is in the dilute concentration regime. As ρ(GO) is further increased to the semi-dilute concentration regime, part of cross-linkers is occupied by GO aggregation and exists as non-elastically active GO-borate-GO bond, then G0, τ and η0 of samples are decreased with ρ(GO). Under steady shear, the enhancement of viscosity in shear thickening regime always increases with ρ(GO) in different concentration regimes, which is related with the participation of oriented GO sheets to reorganization of the network.
The influence of graphene oxide(GO) on the linear and nonlinear rheological properties of poly(vinyl alcohol)(PVA)/borate hydrogel was explored in this work. Results of scanning electron microscopy, 11B nuclear magnetic resonance and rheology reveal that elastically active points formed between dispersed GO sheets and PVA chains have enhanced plateau modulus(G0), relaxation time(τ) and zero shear viscosity(η0) of samples when the mass concentration of GO(ρ(GO)) is in the dilute concentration regime. As ρ(GO) is further increased to the semi-dilute concentration regime, part of cross-linkers is occupied by GO aggregation and exists as non-elastically active GO-borate-GO bond, then G0, τ and η0 of samples are decreased with ρ(GO). Under steady shear, the enhancement of viscosity in shear thickening regime always increases with ρ(GO) in different concentration regimes, which is related with the participation of oriented GO sheets to reorganization of the network.
Preparation of Macromolecular Ultra-violet Absorber and Its Application in Poly(vinylidene fluoride)
2018, 35(7): 776-780
doi: 10.11944/j.issn.1000-0518.2018.07.170331
Abstract:
The macromolecular ultraviolet(UV) absorber P(MMA-co-BPMA) was synthesized by copolymerization of 2-hydroxy-4-(3-methacryloxy-2-hydroxylpropoxy) benzophenone(BPMA) and methylmethacrylate(MMA) through atom transfer radical polymerization(ATRP). The UV-absorbing poly(vinylidene fluoride)(PVDF) composite membranes were made by blend coating. The structure and property of BPMA and P(MMA-co-BPMA) were characterized by nuclear magnetic resonance spectroscopy(NMR), gel permeation chromatography(GPC) and differential scanning calorimeter(DSC). UV absorbing property of the obtained composite membranes was investigated by UV-Vis spectroscopy. The results demonstrate that the relative molecular mass polydispersity index(PDI) of P(MMA-co-BPMA) is 1.11. When the mass fraction of BPMA is 0.68%, the UV transmittance of P(MMA-co-BPMA)/PVDF composite membrane decreases to less than 0.4% in the range of 200~345 nm. In addition, copolymerization of the UV absorber effectively prevents the out-migration as demonstrated in the extraction experiment.
The macromolecular ultraviolet(UV) absorber P(MMA-co-BPMA) was synthesized by copolymerization of 2-hydroxy-4-(3-methacryloxy-2-hydroxylpropoxy) benzophenone(BPMA) and methylmethacrylate(MMA) through atom transfer radical polymerization(ATRP). The UV-absorbing poly(vinylidene fluoride)(PVDF) composite membranes were made by blend coating. The structure and property of BPMA and P(MMA-co-BPMA) were characterized by nuclear magnetic resonance spectroscopy(NMR), gel permeation chromatography(GPC) and differential scanning calorimeter(DSC). UV absorbing property of the obtained composite membranes was investigated by UV-Vis spectroscopy. The results demonstrate that the relative molecular mass polydispersity index(PDI) of P(MMA-co-BPMA) is 1.11. When the mass fraction of BPMA is 0.68%, the UV transmittance of P(MMA-co-BPMA)/PVDF composite membrane decreases to less than 0.4% in the range of 200~345 nm. In addition, copolymerization of the UV absorber effectively prevents the out-migration as demonstrated in the extraction experiment.
2018, 35(7): 781-787
doi: 10.11944/j.issn.1000-0518.2018.07.170291
Abstract:
To provide experimental basis for the design of new ibuprofen(IBU) sustained release system, the layered double hydroxide-ibuprofen intercalation compound(LDH-IBU), the starch gel-ibuprofen(starch gel-IBU) compound and layered double hydroxide/starch gel-ibuprofen(LDH/starch gel-IBU) intercalation compound were prepared by co-precipitation, roasting reduction and freeze-thaw methods based on magnesium chloride hexahydrate, aluminum chloride hexahydrate, IBU and starch as raw materials. The structures of three kinds of above composites were characterized by Fourier transform infrared spectrometer(FT-IR) and X-ray diffractometer(XRD). Their controlled release properties under the condition of simulated human body environment were studied. The results show that IBU in three kinds of complexes in different release media has certain controlled release effect. The release rates decrease in the order of LDH/starch gel-IBU, LDH-IBU and starch gel-IBU. The release rates in 3 buffer media decrease in the order of pH=6.6, pH=7.4 and 0.9% normal saline. The release kinetics can be fitted to the pseudo-first order kinetic model.
To provide experimental basis for the design of new ibuprofen(IBU) sustained release system, the layered double hydroxide-ibuprofen intercalation compound(LDH-IBU), the starch gel-ibuprofen(starch gel-IBU) compound and layered double hydroxide/starch gel-ibuprofen(LDH/starch gel-IBU) intercalation compound were prepared by co-precipitation, roasting reduction and freeze-thaw methods based on magnesium chloride hexahydrate, aluminum chloride hexahydrate, IBU and starch as raw materials. The structures of three kinds of above composites were characterized by Fourier transform infrared spectrometer(FT-IR) and X-ray diffractometer(XRD). Their controlled release properties under the condition of simulated human body environment were studied. The results show that IBU in three kinds of complexes in different release media has certain controlled release effect. The release rates decrease in the order of LDH/starch gel-IBU, LDH-IBU and starch gel-IBU. The release rates in 3 buffer media decrease in the order of pH=6.6, pH=7.4 and 0.9% normal saline. The release kinetics can be fitted to the pseudo-first order kinetic model.
2018, 35(7): 788-794
doi: 10.11944/j.issn.1000-0518.2018.07.170332
Abstract:
The use of variant inhibitors to regulate the bioactivities of tyrosinase, which is the key enzyme in charge of the production of melanin and pigments, is a long-standing approach to design cosmetic and pharmaceutical products. The quantitative description of the structure-activity relationship of tyrosinase inhibitors is still unclear. In this study, we constructed descriptive models by integrating ligand-and structure-based approaches for such purpose. They provide correlation coefficients of 0.961 for implicit models and 0.775 for explicit model, respectively, to descript the activities of three tea polyphenols with the tyrosinase inhibitory activity order of (-)-Epicatechin gallate(ECG) > (-)-Epigallocatechin gallate(EGCG) > Gallic acid(G). As revealing from the descriptive models, entropy loss is more important than other features for determining inhibitory activity and thus the tyrosinase-ECG complex with the fewer conformational entropy loss has the strongest inhibitory activity in vitro among the four tea polyphenols. Moreover, residues including His57, His201, Asn202, His205 Glu192 and Val215 are the core of active sites in tyrosinase, and stabilize the tyrosinase-inhibitor complex by van der Waals and hydrogen bonding interactions.
The use of variant inhibitors to regulate the bioactivities of tyrosinase, which is the key enzyme in charge of the production of melanin and pigments, is a long-standing approach to design cosmetic and pharmaceutical products. The quantitative description of the structure-activity relationship of tyrosinase inhibitors is still unclear. In this study, we constructed descriptive models by integrating ligand-and structure-based approaches for such purpose. They provide correlation coefficients of 0.961 for implicit models and 0.775 for explicit model, respectively, to descript the activities of three tea polyphenols with the tyrosinase inhibitory activity order of (-)-Epicatechin gallate(ECG) > (-)-Epigallocatechin gallate(EGCG) > Gallic acid(G). As revealing from the descriptive models, entropy loss is more important than other features for determining inhibitory activity and thus the tyrosinase-ECG complex with the fewer conformational entropy loss has the strongest inhibitory activity in vitro among the four tea polyphenols. Moreover, residues including His57, His201, Asn202, His205 Glu192 and Val215 are the core of active sites in tyrosinase, and stabilize the tyrosinase-inhibitor complex by van der Waals and hydrogen bonding interactions.
2018, 35(7): 795-801
doi: 10.11944/j.issn.1000-0518.2018.07.170326
Abstract:
Four n-butyltin complexes, (n-BuSn)2Cl3(OH2)[(2-OH, R)PhCH=NNH]2CX[R:4-NEt2, X:O(A1); R:4-NEt2, X:S(A2); R:3, 5-(t-Bu)2, X:O(A3); R:3, 5-(t-Bu)2, X:S(A4)], were obtained by microwave-assisted solvothermal reaction of n-butyltintrichloride(n-BuSnCl3) with bis(4-diethylamino or 3, 5-di-t-butyl salicylaldehyde)carbohydrazide and thiocarbohydrazide in methanol environments, which were characterized by elemental analysis, IR, 1H NMR, and 13C NMR spectra.The crystal structure of complex A2 shows a binuclear hexacoordinated distorted octahedral configuration.The ligands and their butyltin complexes inhibit the growth of plants, such as Portulaca oleracea, Amaranthus spinosus, Brassica campestris ssp.chinensis var.Utilis, Amaranthus tricolor and Cassia tora.Complexes A1, A2 have a broad range of growth inhibition activity, while complexes A3 and A4 have selective inhibitory activity.They can be used as candidate herbicides for weed growth inhibition.
Four n-butyltin complexes, (n-BuSn)2Cl3(OH2)[(2-OH, R)PhCH=NNH]2CX[R:4-NEt2, X:O(A1); R:4-NEt2, X:S(A2); R:3, 5-(t-Bu)2, X:O(A3); R:3, 5-(t-Bu)2, X:S(A4)], were obtained by microwave-assisted solvothermal reaction of n-butyltintrichloride(n-BuSnCl3) with bis(4-diethylamino or 3, 5-di-t-butyl salicylaldehyde)carbohydrazide and thiocarbohydrazide in methanol environments, which were characterized by elemental analysis, IR, 1H NMR, and 13C NMR spectra.The crystal structure of complex A2 shows a binuclear hexacoordinated distorted octahedral configuration.The ligands and their butyltin complexes inhibit the growth of plants, such as Portulaca oleracea, Amaranthus spinosus, Brassica campestris ssp.chinensis var.Utilis, Amaranthus tricolor and Cassia tora.Complexes A1, A2 have a broad range of growth inhibition activity, while complexes A3 and A4 have selective inhibitory activity.They can be used as candidate herbicides for weed growth inhibition.
2018, 35(7): 802-811
doi: 10.11944/j.issn.1000-0518.2018.07.170321
Abstract:
The adsorption process of anion exchange resin to organphosphorus extractant in water was explored in this work. By comparing the removal of P507(2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester) in water with different anion exchange resins, it is found that D201-OH(macroporous strong basic anion exchange resin) has the strongest ability to remove P507 from water, and the removal rate can reach to 99.24%. Secondly, at pH=1.0, the adsorption of P507 on D201-OH is mainly molecular adsorption and its adsorption isotherm is better fit to the Langmuir model; at pH=5.0, the anion exchange reaction is dominant and its adsorption isotherm is more suitable for the Freundlich model. Furthermore, the adsorption capacity of D201-OH to P507 reaches 99.8% of which in the adsorption equilibrium in 20 min. Kinetic study shows that the pseudo-first-order model(R2 > 0.99) exhibits a better fit to describe the experimental data and the adsorption rate may be controlled mainly by the film diffusion. Moreover, the adsorption capacity of D201-OH remains above 93% after eight cycles of adsorption-desorption. In summary, D201-OH is an excellent adsorbent for organphosphorus extractants with high stability in the repeated cycle. Therefore, it can be used to recover organphosphorus extractant in the practical production process.
The adsorption process of anion exchange resin to organphosphorus extractant in water was explored in this work. By comparing the removal of P507(2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester) in water with different anion exchange resins, it is found that D201-OH(macroporous strong basic anion exchange resin) has the strongest ability to remove P507 from water, and the removal rate can reach to 99.24%. Secondly, at pH=1.0, the adsorption of P507 on D201-OH is mainly molecular adsorption and its adsorption isotherm is better fit to the Langmuir model; at pH=5.0, the anion exchange reaction is dominant and its adsorption isotherm is more suitable for the Freundlich model. Furthermore, the adsorption capacity of D201-OH to P507 reaches 99.8% of which in the adsorption equilibrium in 20 min. Kinetic study shows that the pseudo-first-order model(R2 > 0.99) exhibits a better fit to describe the experimental data and the adsorption rate may be controlled mainly by the film diffusion. Moreover, the adsorption capacity of D201-OH remains above 93% after eight cycles of adsorption-desorption. In summary, D201-OH is an excellent adsorbent for organphosphorus extractants with high stability in the repeated cycle. Therefore, it can be used to recover organphosphorus extractant in the practical production process.
2018, 35(7): 818-824
doi: 10.11944/j.issn.1000-0518.2018.07.170290
Abstract:
A new D-π-A type two-photon absorption ligand(L) based on imidazo[4, 5-f] [1 , 10 ] phenanthroline and its Ru(Ⅱ) complex(1) have been synthesized and characterized. The third-order nonlinear optical(NLO) properties of all compounds are studied by open/close aperture Z-scan techniques. The results reveal that complex 1 possesses larger third-order nonlinear susceptibility and two-photon absorption cross section than its free ligand L in the near infrared range. A reverse nonlinear optical refraction character takes place from self-defocusing to self-focusing response after complexation. Calf-thymus DNA binding properties combined with complex 1 are studied by UV-Vis absorption, DNA competitive binding with ethidium bromide, viscosity measurements, and circular dichrosim spectra. The results indicate that complex 1 binds to DNA via an intercalative mode. Therefore, the complex 1 with nonlinear optical properties can be used for bioimaging applications.
A new D-π-A type two-photon absorption ligand(L) based on imidazo[4, 5-f] [
2018, 35(7): 825-833
doi: 10.11944/j.issn.1000-0518.2018.07.180158
Abstract:
Flexible free-standing tin oxide(SnO2) nanoparticles with different particle size/graphene sandwich paper electrodes were fabricated via a simple filtration method.The influence of SnO2 particle size on electrochemical performances was investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electronic microscopy(TEM), Brunauer, atomic force microscope(AFM), Emmett and Teller analysis(BET) and electrochemical measurements.The results show that the best electrochemical performance can be obtained when the particle size of nanoparticle is at 6 nm.When applied as an anode for lithium ion battery, an excellent cycling stability with a reversible capacity of 555 mA·h/g after 100 cycles at 100 mA/g is delivered, which is far superior to those of pristine SnO2 and the corresponding composites composed of larger or smaller particles than optimum.
Flexible free-standing tin oxide(SnO2) nanoparticles with different particle size/graphene sandwich paper electrodes were fabricated via a simple filtration method.The influence of SnO2 particle size on electrochemical performances was investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electronic microscopy(TEM), Brunauer, atomic force microscope(AFM), Emmett and Teller analysis(BET) and electrochemical measurements.The results show that the best electrochemical performance can be obtained when the particle size of nanoparticle is at 6 nm.When applied as an anode for lithium ion battery, an excellent cycling stability with a reversible capacity of 555 mA·h/g after 100 cycles at 100 mA/g is delivered, which is far superior to those of pristine SnO2 and the corresponding composites composed of larger or smaller particles than optimum.
2018, 35(7): 834-841
doi: 10.11944/j.issn.1000-0518.2018.07.180005
Abstract:
Iodine oxygen bismuth/titanium dioxide nanorod arrays(BiOI/TiO2 NRAs) composite was synthesized in situ on fluorine-doped tin oxide-coated glass(FTO) substrate by simple two-step hydrothermal method.The composite was characterized by scanning electron microscope and X-ray diffraction.The photoelectrochemical(PEC) behaviors were studied using current-time curve.The combination of BiOI with TiO2 NRAs extends effectively the adsorption of TiO2 to visible region, and the formed p-n heterojunction could contribute to the spatial charge separation as well as the enhanced photocatalytic activity.The PEC sensing platform fabricated by using this composite was applied for detection of bisphenol A(BPA) via the oxidation of BPA by the consumption of photogenerated holes during PEC reaction.Under 420 nm irradiation, current-time curve was used for sensitive detection of BPA at applied potential of 0.0 V, a wide linear work range from 0.0047 to 14.7 μmol/L was obtained with a low detection limit of 0.93 nmol/L(S/N=3).The developed PEC sensor exhibits high sensitivity, good stability and reproducibility.This sensor was also used to evaluate the level of BPA in real samples with good recovery from 98.0% to 107.1%.
Iodine oxygen bismuth/titanium dioxide nanorod arrays(BiOI/TiO2 NRAs) composite was synthesized in situ on fluorine-doped tin oxide-coated glass(FTO) substrate by simple two-step hydrothermal method.The composite was characterized by scanning electron microscope and X-ray diffraction.The photoelectrochemical(PEC) behaviors were studied using current-time curve.The combination of BiOI with TiO2 NRAs extends effectively the adsorption of TiO2 to visible region, and the formed p-n heterojunction could contribute to the spatial charge separation as well as the enhanced photocatalytic activity.The PEC sensing platform fabricated by using this composite was applied for detection of bisphenol A(BPA) via the oxidation of BPA by the consumption of photogenerated holes during PEC reaction.Under 420 nm irradiation, current-time curve was used for sensitive detection of BPA at applied potential of 0.0 V, a wide linear work range from 0.0047 to 14.7 μmol/L was obtained with a low detection limit of 0.93 nmol/L(S/N=3).The developed PEC sensor exhibits high sensitivity, good stability and reproducibility.This sensor was also used to evaluate the level of BPA in real samples with good recovery from 98.0% to 107.1%.
2018, 35(7): 842-848
doi: 10.11944/j.issn.1000-0518.2018.07.170312
Abstract:
A novel method for the extraction, isolation, identification and determination of the active component of Chinese medicine and its inhibitory activity on glucoamylase in a simple and efficient way was developed.The active ingredient baicalin was extracted from Scutellaria baicalensis using green nontoxic water-extracting and acid-depositing method.It was identified qualitatively by thin layer chromatography and the content was determined by ultraviolet spectrophotometry.An effective electrochemical glucose sensor was fabricated and a new method of characterizing hypoglycemic activity was developed based on electrochemical amperometric detection.Acarbose(clinical antidiabetic drug) was further used to demonstrate the reliability and stability of determining the inhibitory activity of glucoamylase by electrochemical amperometry.The results show that the baicalin has a good inhibitory activity on glucoamylase with a half maximal inhibitory concentration(IC50) at 0.056 g/L.This study provides a novel method for the extraction and isolation of hypoglycemic components from natural medicines.
A novel method for the extraction, isolation, identification and determination of the active component of Chinese medicine and its inhibitory activity on glucoamylase in a simple and efficient way was developed.The active ingredient baicalin was extracted from Scutellaria baicalensis using green nontoxic water-extracting and acid-depositing method.It was identified qualitatively by thin layer chromatography and the content was determined by ultraviolet spectrophotometry.An effective electrochemical glucose sensor was fabricated and a new method of characterizing hypoglycemic activity was developed based on electrochemical amperometric detection.Acarbose(clinical antidiabetic drug) was further used to demonstrate the reliability and stability of determining the inhibitory activity of glucoamylase by electrochemical amperometry.The results show that the baicalin has a good inhibitory activity on glucoamylase with a half maximal inhibitory concentration(IC50) at 0.056 g/L.This study provides a novel method for the extraction and isolation of hypoglycemic components from natural medicines.
2018, 35(7): 849-856
doi: 10.11944/j.issn.1000-0518.2018.07.170239
Abstract:
Octylferrocene is often used as a burning rate catalyst for solid rocket propellants because of its excellent catalytic performance and good compatibility. However, so far, there is no its reference material, which makes it difficult to trace and unify the magnitude of the weapons and equipment quality monitoring process, and the quality of related products can not be guaranteed. The reference material of n-octylferrocence in relative purity greater than 99.5% was prepared from industrial product as primary substance by re-crystalization from mixed solvent at low temperature, and its uniformity and stability was investigated by gas chromatography. The purity of n-octylferrocence reference material was certified by the method of mass balance. Other homologues were controlled by self-contrast method. The result shows that the certified result is 99.6% and the expanded uncertainty is 0.2%(k=2).
Octylferrocene is often used as a burning rate catalyst for solid rocket propellants because of its excellent catalytic performance and good compatibility. However, so far, there is no its reference material, which makes it difficult to trace and unify the magnitude of the weapons and equipment quality monitoring process, and the quality of related products can not be guaranteed. The reference material of n-octylferrocence in relative purity greater than 99.5% was prepared from industrial product as primary substance by re-crystalization from mixed solvent at low temperature, and its uniformity and stability was investigated by gas chromatography. The purity of n-octylferrocence reference material was certified by the method of mass balance. Other homologues were controlled by self-contrast method. The result shows that the certified result is 99.6% and the expanded uncertainty is 0.2%(k=2).
2018, 35(7): 812-817
doi: 10.11944/j.issn.1000-0518.2018.07.170295
Abstract:
Uniform BaF2:Tb3+ nanoparticles have been prepared by hydrothermal synthesis, and sodium salicylate(SS) sensitized BaF2:Tb3+(SS-BaF2:Tb3+) nanoparticles have been prepared by the ion exchange technique. Their structures, morphologies and photoluminescence properties were studied. A broad excitation band from 200 to 385 nm by monitoring 5D4→7F5 transition of Tb3+ at 547 nm in SS-BaF2:Tb3+ nanoparticles was detected. Under excitation of the π-π* electron transition absorption of salicylate, enhanced green emission of Tb3+ ions in SS-BaF2:Tb3+ nanoparticles was observed due to the energy transfer from SS to Tb3+ ions by "antenna effect". The photoluminescence lifetimes of Tb3+ ions in SS sensitized nanoparticles were found to be longer than those in un-sensitized nanoparticles.
Uniform BaF2:Tb3+ nanoparticles have been prepared by hydrothermal synthesis, and sodium salicylate(SS) sensitized BaF2:Tb3+(SS-BaF2:Tb3+) nanoparticles have been prepared by the ion exchange technique. Their structures, morphologies and photoluminescence properties were studied. A broad excitation band from 200 to 385 nm by monitoring 5D4→7F5 transition of Tb3+ at 547 nm in SS-BaF2:Tb3+ nanoparticles was detected. Under excitation of the π-π* electron transition absorption of salicylate, enhanced green emission of Tb3+ ions in SS-BaF2:Tb3+ nanoparticles was observed due to the energy transfer from SS to Tb3+ ions by "antenna effect". The photoluminescence lifetimes of Tb3+ ions in SS sensitized nanoparticles were found to be longer than those in un-sensitized nanoparticles.
