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2016 Volume 33 Issue 9
2016, 33(9): 977-993
doi: 10.11944/j.issn.1000-0518.2016.09.160212
Abstract:
Inorganic halide perovskite CsPbX3(X=Cl,Br,I) nanocrystals(NCs) have been received much concern because it owns many excellent optical properties, such as high quantum yield(~90%), the emission wavelength covering the entire visible light region(400~700 nm), and the narrow full width at half maximum(12~42 nm). These advantages make it becomes one of the luminescence materials which have the most potential applications. Therefore, in recent years, reports involving inorganic halide perovskite materials become more and more. In this review, the development history, the synthetic routes, structures, growth mechanisms, and applications of inorganic halide perovskite NCs that make them excellent optoelectronic materials for various strategies are mainly discussed and highlighted. The existing problems of inorganic halide perovskite luminescence materials under the current research backgrounds are summarized. Finally, perspectives on future exploration of inorganic halide perovskite NCs for photoelectric devices are also given.
Inorganic halide perovskite CsPbX3(X=Cl,Br,I) nanocrystals(NCs) have been received much concern because it owns many excellent optical properties, such as high quantum yield(~90%), the emission wavelength covering the entire visible light region(400~700 nm), and the narrow full width at half maximum(12~42 nm). These advantages make it becomes one of the luminescence materials which have the most potential applications. Therefore, in recent years, reports involving inorganic halide perovskite materials become more and more. In this review, the development history, the synthetic routes, structures, growth mechanisms, and applications of inorganic halide perovskite NCs that make them excellent optoelectronic materials for various strategies are mainly discussed and highlighted. The existing problems of inorganic halide perovskite luminescence materials under the current research backgrounds are summarized. Finally, perspectives on future exploration of inorganic halide perovskite NCs for photoelectric devices are also given.
2016, 33(9): 994-1001
doi: 10.11944/j.issn.1000-0518.2016.09.160231
Abstract:
The Er3+-doped crystals can produce 2.7~3.0 μm mid-infrared(MIR) lasers, which have attracted much attention for their numerous applications in laser medical surgery, optical communication, enviromental detector and electro-optical countermeasure, etc. Based on the past few years' work on the study of Er3+ activated crystals by our team, we review the effect of co-dopant rare-earth ions on the spectroscopic properties of Er3+ activated MIR laser crystals, including the sensitizing ions Cr3+, Yb3+, etc. which can enhance the intensity of characteristic absorption peaks of Er3+; the deactivating ions Ho3+, Pr3+, etc. which can inhibit the self-termination bottleneck effects, furthermore, the co-dopant Nd3+ ion can play a dual role at the same time. In the end, the expectations on the study of MIR lasers are presented.
The Er3+-doped crystals can produce 2.7~3.0 μm mid-infrared(MIR) lasers, which have attracted much attention for their numerous applications in laser medical surgery, optical communication, enviromental detector and electro-optical countermeasure, etc. Based on the past few years' work on the study of Er3+ activated crystals by our team, we review the effect of co-dopant rare-earth ions on the spectroscopic properties of Er3+ activated MIR laser crystals, including the sensitizing ions Cr3+, Yb3+, etc. which can enhance the intensity of characteristic absorption peaks of Er3+; the deactivating ions Ho3+, Pr3+, etc. which can inhibit the self-termination bottleneck effects, furthermore, the co-dopant Nd3+ ion can play a dual role at the same time. In the end, the expectations on the study of MIR lasers are presented.
2016, 33(9): 1002-1008
doi: 10.11944/j.issn.1000-0518.2016.09.150461
Abstract:
Organic light-emitting devices that are widely used in solid-state lighting and flat panel display have attracted the attention of researchers because of their advantages such as low voltage, high brightness and high efficiency. Among three primary colors devices, the performances of green and blue organic light-emitting devices are generally higher than those of red devices and basically satisfy the requirements of practical application. Due to the narrow energy gap, it is difficult to realize the matched energy levels between red light-emitting materials and host materials, thus causing the low efficiency and color purity of red devices. In addition, red light-emitting materials are necessary for the realization of white organic light-emitting devices. Therefore, how to realize high performance red light-emitting materials is very important for the development of organic light-emitting devices. Herein we reviewed the recent progress of red iridium complexes phosphorescent materials and devices, especially the strategies of enhancing efficiency and color purity.
Organic light-emitting devices that are widely used in solid-state lighting and flat panel display have attracted the attention of researchers because of their advantages such as low voltage, high brightness and high efficiency. Among three primary colors devices, the performances of green and blue organic light-emitting devices are generally higher than those of red devices and basically satisfy the requirements of practical application. Due to the narrow energy gap, it is difficult to realize the matched energy levels between red light-emitting materials and host materials, thus causing the low efficiency and color purity of red devices. In addition, red light-emitting materials are necessary for the realization of white organic light-emitting devices. Therefore, how to realize high performance red light-emitting materials is very important for the development of organic light-emitting devices. Herein we reviewed the recent progress of red iridium complexes phosphorescent materials and devices, especially the strategies of enhancing efficiency and color purity.
2016, 33(9): 1009-1016
doi: 10.11944/j.issn.1000-0518.2016.09.160075
Abstract:
Gold nanoparticles(AuNPs) are one of ideal nanomaterials for constructing diagnostic and therapeutic nanosystems. Therefore, it is important to understand interactions of AuNPs and cells. In this review, we present a detailed analysis of data on the cytotoxicity of most popular AuNPs including gold nanoclusters(AuNCs), spherical AuNPs(AuNPss), gold nanoshells(AuNSs) and gold nanorods(AuNRs). We discuss the effects of the cell models, physicochemical properties(size, shape, chemical functionality, and surface charge) of AuNPs on the cytotoxicity of AuNPs. Some general conclusions, current challenges and future prospects/solutions on the issue have been provided.
Gold nanoparticles(AuNPs) are one of ideal nanomaterials for constructing diagnostic and therapeutic nanosystems. Therefore, it is important to understand interactions of AuNPs and cells. In this review, we present a detailed analysis of data on the cytotoxicity of most popular AuNPs including gold nanoclusters(AuNCs), spherical AuNPs(AuNPss), gold nanoshells(AuNSs) and gold nanorods(AuNRs). We discuss the effects of the cell models, physicochemical properties(size, shape, chemical functionality, and surface charge) of AuNPs on the cytotoxicity of AuNPs. Some general conclusions, current challenges and future prospects/solutions on the issue have been provided.
2016, 33(9): 1017-1025
doi: 10.11944/j.issn.1000-0518.2016.09.150452
Abstract:
2,2,6,6-Tetramethylpiperidine-1-oxyl(TEMPO) was immobilized on crosslinked polystyrene(CPS) microspheres to give a heterogeneous microspheres TEMPO/CPS catalyst. A combined catalysts of TEMPO/CPS microspheres and metal salts were used in the oxidation of cinnamyl alcohol with molecular oxygen as the oxidant. The catalytic properties and catalytic mechanisms of these combinational catalysts were investigated. Some combined catalysts can effectively catalyze the oxidation reaction of cinnamyl alcohol to cinnamyl aldehyde as sole product. For nitrate co-catalysts, if the corresponding metal ion has weaker oxidizing ability than NO3- ion, for example, Fe(NO3)3 and Cu(NO3)2, the cations and anions will work together in the catalytic process. If the oxidizability of metal ion is stronger than NO3- ion, for example, Co(NO3)2 and Mn(NO3)2, the metal ion will alone play a role in the oxidation. Among several transition metal salts, Fe(NO3)3 is the best co-catalyst, and leads to the oxidation of cinnamyl alcohol to cinnamyl aldehyde in 92% conversion under mild conditions (at 55℃ and with O2 at ordinary pressure).
2,2,6,6-Tetramethylpiperidine-1-oxyl(TEMPO) was immobilized on crosslinked polystyrene(CPS) microspheres to give a heterogeneous microspheres TEMPO/CPS catalyst. A combined catalysts of TEMPO/CPS microspheres and metal salts were used in the oxidation of cinnamyl alcohol with molecular oxygen as the oxidant. The catalytic properties and catalytic mechanisms of these combinational catalysts were investigated. Some combined catalysts can effectively catalyze the oxidation reaction of cinnamyl alcohol to cinnamyl aldehyde as sole product. For nitrate co-catalysts, if the corresponding metal ion has weaker oxidizing ability than NO3- ion, for example, Fe(NO3)3 and Cu(NO3)2, the cations and anions will work together in the catalytic process. If the oxidizability of metal ion is stronger than NO3- ion, for example, Co(NO3)2 and Mn(NO3)2, the metal ion will alone play a role in the oxidation. Among several transition metal salts, Fe(NO3)3 is the best co-catalyst, and leads to the oxidation of cinnamyl alcohol to cinnamyl aldehyde in 92% conversion under mild conditions (at 55℃ and with O2 at ordinary pressure).
2016, 33(9): 1026-1032
doi: 10.11944/j.issn.1000-0518.2016.09.150429
Abstract:
Three copolymers P(CL-co-LA) made from ε-caprolactone(ε-CL) and L-lactide(L-LA) have been synthesized via the ring-opening polymerization(ROP). Copolymers and PCL were added to PLA by melt blending, and then the PLA/PCL/P(CL-co-LA) blends were obtained. The compatibility, thermal and mechanical properties of the blends were studied. The results show that the interface compatibilizer of PLA/PCL blends, P(CL-co-LA) reduces the size of the PCL dispersed phase, moreover, the compatibility and toughness of PLA/PCL blends are enhanced. When the mass ratio of PLA/PCL/P(CL-co-LA) is 80/20/10, P(CL49/LA51), is which the numbers reprent the molar fraction(%), is the most suitable interface compatibilizer, and the elongation at break of the blends reaches as high as (210±30)%.
Three copolymers P(CL-co-LA) made from ε-caprolactone(ε-CL) and L-lactide(L-LA) have been synthesized via the ring-opening polymerization(ROP). Copolymers and PCL were added to PLA by melt blending, and then the PLA/PCL/P(CL-co-LA) blends were obtained. The compatibility, thermal and mechanical properties of the blends were studied. The results show that the interface compatibilizer of PLA/PCL blends, P(CL-co-LA) reduces the size of the PCL dispersed phase, moreover, the compatibility and toughness of PLA/PCL blends are enhanced. When the mass ratio of PLA/PCL/P(CL-co-LA) is 80/20/10, P(CL49/LA51), is which the numbers reprent the molar fraction(%), is the most suitable interface compatibilizer, and the elongation at break of the blends reaches as high as (210±30)%.
2016, 33(9): 1033-1039
doi: 10.11944/j.issn.1000-0518.2016.09.150456
Abstract:
The stereocomplex powder was prepared by mixing the same amount of poly(L-lactide)(PLLA) and poly(D-lactide)(PDLA) resins at a relative low temperature and then was mixed with the nucleation agent and glass fiber. The mixture was molded in the injection machine, followed by annealing at different temperatures to form the blends with high heat resistance. The vicat softening temperature reached to 165℃ and the DSC results revealed that the blends were rich in stereocomplex and the enthalpy was as high as 27.6 J/g. Moreover, the tensile strength was increased greatly to 129 MPa.
The stereocomplex powder was prepared by mixing the same amount of poly(L-lactide)(PLLA) and poly(D-lactide)(PDLA) resins at a relative low temperature and then was mixed with the nucleation agent and glass fiber. The mixture was molded in the injection machine, followed by annealing at different temperatures to form the blends with high heat resistance. The vicat softening temperature reached to 165℃ and the DSC results revealed that the blends were rich in stereocomplex and the enthalpy was as high as 27.6 J/g. Moreover, the tensile strength was increased greatly to 129 MPa.
2016, 33(9): 1040-1046
doi: 10.11944/j.issn.1000-0518.2016.09.160211
Abstract:
Adsorption of phenols such as o-nitrophenol, phenol, and catechol on metal-organic framework aluminum terephthalate[MIL-53(Al), MIL:Materials of Institut Lavoisier] was investigated in detail in terms of adsorption isotherms, thermodynamics, and kinetics. The adsorption of the phenols on MIL-53(Al) follows a pseudo-second order kinetic model. Intraparticle diffusion model analysis reveals that the adsorption of the phenols on MIL-53(Al) proceeds by two phases, surface sorption and intraparticle/pore diffusion. The adsorption of phenols fits well with the Freundlich model. In addition, the results indicate that the adsorption of the phenols on MIL-53(Al) is a thermodynamically spontaneous process with positive enthalpy change and positive entropy change. The adsorption capacities for o-nitrophenol, phenol, and catechol at 40℃ are 78.6, 30.5, and 16.5 mg/g, respectively.
Adsorption of phenols such as o-nitrophenol, phenol, and catechol on metal-organic framework aluminum terephthalate[MIL-53(Al), MIL:Materials of Institut Lavoisier] was investigated in detail in terms of adsorption isotherms, thermodynamics, and kinetics. The adsorption of the phenols on MIL-53(Al) follows a pseudo-second order kinetic model. Intraparticle diffusion model analysis reveals that the adsorption of the phenols on MIL-53(Al) proceeds by two phases, surface sorption and intraparticle/pore diffusion. The adsorption of phenols fits well with the Freundlich model. In addition, the results indicate that the adsorption of the phenols on MIL-53(Al) is a thermodynamically spontaneous process with positive enthalpy change and positive entropy change. The adsorption capacities for o-nitrophenol, phenol, and catechol at 40℃ are 78.6, 30.5, and 16.5 mg/g, respectively.
2016, 33(9): 1047-1055
doi: 10.11944/j.issn.1000-0518.2016.09.160058
Abstract:
The novel absorbent H6P2Mo15W3O62/MOF-5 was prepared by the hydrothermal synthesis method. The active component H6P2Mo15W3O62 was introduced during the synthesis of metal organic framework MOF-5. The adsorption property of the composites on methylene blue from water solution was investigated, and the effects of the experimental parameters including the temperature, the initial pH value and initial concentration of methylene blue solution were discussed. The results demonstrate that the lower temperature and lower initial pH value are more favorable for the adsorption methylene blue onto H6P2Mo15W3O62/MOF-5. The experiment data can be well described in the Langmuir equation and a pseudo-second-order kinetic model, and the maximum adsorption capacity of methylene blue is 401.6 mg/g. Thermodynamic parameters ΔG<0, ΔH<0 and ΔS>0 reveal that the adsorption process is spontaneous and exothermic. Furthermore, we also explored the adsorption properties of H6P2 Mo15W3O62/MOF-5 to methyl violet, malachite green, rhodamine B, methyl orange and other dyes. The results indicate that this new absorbent shows better adsorption performance towards cationic dyes.
The novel absorbent H6P2Mo15W3O62/MOF-5 was prepared by the hydrothermal synthesis method. The active component H6P2Mo15W3O62 was introduced during the synthesis of metal organic framework MOF-5. The adsorption property of the composites on methylene blue from water solution was investigated, and the effects of the experimental parameters including the temperature, the initial pH value and initial concentration of methylene blue solution were discussed. The results demonstrate that the lower temperature and lower initial pH value are more favorable for the adsorption methylene blue onto H6P2Mo15W3O62/MOF-5. The experiment data can be well described in the Langmuir equation and a pseudo-second-order kinetic model, and the maximum adsorption capacity of methylene blue is 401.6 mg/g. Thermodynamic parameters ΔG<0, ΔH<0 and ΔS>0 reveal that the adsorption process is spontaneous and exothermic. Furthermore, we also explored the adsorption properties of H6P2 Mo15W3O62/MOF-5 to methyl violet, malachite green, rhodamine B, methyl orange and other dyes. The results indicate that this new absorbent shows better adsorption performance towards cationic dyes.
2016, 33(9): 1056-1060
doi: 10.11944/j.issn.1000-0518.2016.09.150302
Abstract:
5,6-Dimethyl-2,3-pyrazinedimethylformamide-Cu was prepared from Cu(CH3COO)2 and 5,6-dimethyl-2,3-pyrazinedimethylformamide which was synthesized via hydrolysis of 5,6-dimethyl-2,3-pyrazinecarbonitrile in the dilute basic solution using H2O2 as the oxidant. The antibacterial activity of 5,6-dimethyl-2,3- pyrazinedimethylformamide and the complex were compared by the Oxford cup method and tube double dilution method. The complex was characterized by UV and IR spectroscopies and TGA. The 5,6-dimethyl-2,3-pyrazinedimethylformamide-Cu shows good bacteriostatic and bactericidal effects. Both the minimum antimicrobial and the germicidal dosages against E.coli and Staphylococcus aureus are 50 mg/L and 25 mg/L, respectively, while 5,6-dimethyl-2,3-pyrazinedimethylformamide does not show obvious inhibitory effect, providing a reference for the clinical treatment of diseases and the development of food additives.
5,6-Dimethyl-2,3-pyrazinedimethylformamide-Cu was prepared from Cu(CH3COO)2 and 5,6-dimethyl-2,3-pyrazinedimethylformamide which was synthesized via hydrolysis of 5,6-dimethyl-2,3-pyrazinecarbonitrile in the dilute basic solution using H2O2 as the oxidant. The antibacterial activity of 5,6-dimethyl-2,3- pyrazinedimethylformamide and the complex were compared by the Oxford cup method and tube double dilution method. The complex was characterized by UV and IR spectroscopies and TGA. The 5,6-dimethyl-2,3-pyrazinedimethylformamide-Cu shows good bacteriostatic and bactericidal effects. Both the minimum antimicrobial and the germicidal dosages against E.coli and Staphylococcus aureus are 50 mg/L and 25 mg/L, respectively, while 5,6-dimethyl-2,3-pyrazinedimethylformamide does not show obvious inhibitory effect, providing a reference for the clinical treatment of diseases and the development of food additives.
2016, 33(9): 1061-1066
doi: 10.11944/j.issn.1000-0518.2016.09.150434
Abstract:
Oxfendazole, a benzimidazolecarbamate(BZC) compound, is a broad-spectrum antihelmintic and antimicrobial agent. The insufficient sources of its impurities affected the quality control of the product. Herein, a simple and efficient method for synthesis of four impurities, fenbendazole, methyl (5-(phenylsulfonyl)-1H-benzo[d]imidazol-2-yl)carbamate, 5-(phenylsulfinyl)-1H-benzo[d]imidazol-2-amine and 1,3-bis(5-(phenylsulfinyl)-1H-benzo[d]imidazol-2-yl)urea, is revealed. Especially, the key imidazole ring was constructed efficiently via two different strategies. Furthermore, oxidative products of sulfur ether, sulphone and sulfoxide were obtained by controlling oxidative conditions. This method not only increases the source of the standard substances for quality control of oxfendazole, but also provides an efficient synthetic strategy to prepare the novel antihelmintic, antimicrobial and antitumor agents based on oxfendazol.
Oxfendazole, a benzimidazolecarbamate(BZC) compound, is a broad-spectrum antihelmintic and antimicrobial agent. The insufficient sources of its impurities affected the quality control of the product. Herein, a simple and efficient method for synthesis of four impurities, fenbendazole, methyl (5-(phenylsulfonyl)-1H-benzo[d]imidazol-2-yl)carbamate, 5-(phenylsulfinyl)-1H-benzo[d]imidazol-2-amine and 1,3-bis(5-(phenylsulfinyl)-1H-benzo[d]imidazol-2-yl)urea, is revealed. Especially, the key imidazole ring was constructed efficiently via two different strategies. Furthermore, oxidative products of sulfur ether, sulphone and sulfoxide were obtained by controlling oxidative conditions. This method not only increases the source of the standard substances for quality control of oxfendazole, but also provides an efficient synthetic strategy to prepare the novel antihelmintic, antimicrobial and antitumor agents based on oxfendazol.
2016, 33(9): 1067-1072
doi: 10.11944/j.issn.1000-0518.2016.09.150420
Abstract:
Twelve unreported 4H-1,2,4-benzothiadiazine 1,1-dioxide derivatives were synthesized from 2-nitrobenzene sulfonyl chloride with good water-solubility in high yields. These compounds were characterized by 1H NMR, 13C NMR, MS-ESI and elemental analysis. Their inhibiting effects on HepG-2 cell were evaluated with MTT protocol. The results show that 7-(aminomethyl)-3-cyclopropyl-1,1-dioxide-4H-benzo[e] [1,2,4]thiadiazine(7c) exhibits the highest inhibition rate of 79.3% among the synthesized compounds.
Twelve unreported 4H-1,2,4-benzothiadiazine 1,1-dioxide derivatives were synthesized from 2-nitrobenzene sulfonyl chloride with good water-solubility in high yields. These compounds were characterized by 1H NMR, 13C NMR, MS-ESI and elemental analysis. Their inhibiting effects on HepG-2 cell were evaluated with MTT protocol. The results show that 7-(aminomethyl)-3-cyclopropyl-1,1-dioxide-4H-benzo[e] [1,2,4]thiadiazine(7c) exhibits the highest inhibition rate of 79.3% among the synthesized compounds.
2016, 33(9): 1073-1078
doi: 10.11944/j.issn.1000-0518.2016.09.150444
Abstract:
Danshensu is one of water-soluble components in Chinese medicine Danshen(Salvia miltiorrhiza bunge) and has some potential pharmaceutical activities. Danshensu was prepared through chemoenzymatic synthesis starting from the Erlenmeyer condensation of 3,4-dihydroxybenzaldehyde and acetyl glycine and followed by ring opening reaction to give α-acetamino-β-(3,4-diacetoxylphenyl)acrylic acid. Hydrolysis of the substituted acrylic acid with hydrochloric acid gave β-(3,4-dihydroxyphenyl) pyruvate. Finally, Danshensu was obtained by enzymatic reduction of β-(3,4-dihydroxyphenyl) pyruvate with resting cells of pediococcus acidilactici. The overall yield is 69.4% and the optical purity of Danshensu is 97.5% ee.
Danshensu is one of water-soluble components in Chinese medicine Danshen(Salvia miltiorrhiza bunge) and has some potential pharmaceutical activities. Danshensu was prepared through chemoenzymatic synthesis starting from the Erlenmeyer condensation of 3,4-dihydroxybenzaldehyde and acetyl glycine and followed by ring opening reaction to give α-acetamino-β-(3,4-diacetoxylphenyl)acrylic acid. Hydrolysis of the substituted acrylic acid with hydrochloric acid gave β-(3,4-dihydroxyphenyl) pyruvate. Finally, Danshensu was obtained by enzymatic reduction of β-(3,4-dihydroxyphenyl) pyruvate with resting cells of pediococcus acidilactici. The overall yield is 69.4% and the optical purity of Danshensu is 97.5% ee.
2016, 33(9): 1079-1084
doi: 10.11944/j.issn.1000-0518.2016.09.160021
Abstract:
A series of KxMoP/Al2O3(x is K/Mo molar ratio, 0≤x≤3) catalysts with different K/Mo molar ratios was prepared through co-impregnation and characterized using X-ray diffraction(XRD), temperature-programmed reduction(TPR) and laser Raman spectroscopy(LRS). The effects of different potassium content of the catalysts for the synthesis of methyl mercaptan from high H2S-containing syngas were investigated. The results indicate that MoP/Al2O3 catalysts are formed by hydrogen reduction at 850℃ from phosphorus molybdenum oxide precursor. With a small amount of potassium, the catalysts show higher methane selectivity. Further increase of potassium content promotes the generation of activity molybdenum sulfur phase, showing good methyl mercaptan selectivity. Excessive potassium hinders the generation of methyl mercaptan. When K/Mo molar ratio is between 2 and 2.5, MoP-based catalysts shows good catalytic activity and selectivity.
A series of KxMoP/Al2O3(x is K/Mo molar ratio, 0≤x≤3) catalysts with different K/Mo molar ratios was prepared through co-impregnation and characterized using X-ray diffraction(XRD), temperature-programmed reduction(TPR) and laser Raman spectroscopy(LRS). The effects of different potassium content of the catalysts for the synthesis of methyl mercaptan from high H2S-containing syngas were investigated. The results indicate that MoP/Al2O3 catalysts are formed by hydrogen reduction at 850℃ from phosphorus molybdenum oxide precursor. With a small amount of potassium, the catalysts show higher methane selectivity. Further increase of potassium content promotes the generation of activity molybdenum sulfur phase, showing good methyl mercaptan selectivity. Excessive potassium hinders the generation of methyl mercaptan. When K/Mo molar ratio is between 2 and 2.5, MoP-based catalysts shows good catalytic activity and selectivity.
2016, 33(9): 1085-1092
doi: 10.11944/j.issn.1000-0518.2016.09.150410
Abstract:
A new kind of small molecule Schiff base liquid crystal unit, p-phenylene(p-styrene acrylic oxo alcohol)imine was synthesized using hydroxybenzaldehyde, 3-chloropropanol, p-phenylenediamine as raw meterials. Schiff base type silicone polyurethane liquid crystal polymer was synthesized by the liquid crystal unit, 1,4-phenylene diisocyanate and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. The construction of liquid crystal unit and the silicone liquid crystalline polymer were characterized by Fourier transform infrared spectrometry. The crystal structures of the liquid crystal unit and the Schiff base type silicone polyurethane liquid crystal polymer liquid crystal were identified by X-ray diffraction. The liquid crystal phase and phase transition temperature of the Schiff base type silicone polyurethane liquid crystal polymer were investigated by differential scanning calorimetry. The phase change process and optical properties of the liquid crystal material were observed by polarizing optical microscope. The chromatography column was made using Schiff base type silicone polyurethane liquid crystal polymer as stationary phase. The relative polarity of stationary liquid and the chromatographic separation performance for substituted benzene isomers were determined. Liquid crystal temperature ranges of the liquid crystal polymer are 103~146℃. It belongs to strongly polar stationary liquid(Px=79), the separation degree of the chromatographic peaks are 0.96~3.33.
A new kind of small molecule Schiff base liquid crystal unit, p-phenylene(p-styrene acrylic oxo alcohol)imine was synthesized using hydroxybenzaldehyde, 3-chloropropanol, p-phenylenediamine as raw meterials. Schiff base type silicone polyurethane liquid crystal polymer was synthesized by the liquid crystal unit, 1,4-phenylene diisocyanate and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. The construction of liquid crystal unit and the silicone liquid crystalline polymer were characterized by Fourier transform infrared spectrometry. The crystal structures of the liquid crystal unit and the Schiff base type silicone polyurethane liquid crystal polymer liquid crystal were identified by X-ray diffraction. The liquid crystal phase and phase transition temperature of the Schiff base type silicone polyurethane liquid crystal polymer were investigated by differential scanning calorimetry. The phase change process and optical properties of the liquid crystal material were observed by polarizing optical microscope. The chromatography column was made using Schiff base type silicone polyurethane liquid crystal polymer as stationary phase. The relative polarity of stationary liquid and the chromatographic separation performance for substituted benzene isomers were determined. Liquid crystal temperature ranges of the liquid crystal polymer are 103~146℃. It belongs to strongly polar stationary liquid(Px=79), the separation degree of the chromatographic peaks are 0.96~3.33.
2016, 33(9): 1093-1098
doi: 10.11944/j.issn.1000-0518.2016.09.150408
Abstract:
The electrochemical behavior of 0.25 mol/L tantalum pentachloride is investigated in 1-butyl-3-methylimidazolium hexafluorophosphate([Bmim]PF6) by cyclic voltammetry. The results show that the electrodeposition process of tantalum is a two-step irreversible electrode reaction by diffusion control. Tantalum(Ⅴ) is first reduced to tantalum(Ⅲ), and tantalum(Ⅲ) is further reduced to tantalum metal and tantalum subchloride. The cathodic transfer coefficients of Ta(Ⅴ)/Ta(Ⅲ) and Ta(Ⅲ)/Ta are 0.155 and 0.406, respectively. The diffusion coefficient of Ta(Ⅴ) is 1.629×10-9 cm2/s. The electrodeposition of tantalum on platinum substrate from TaCl5-[Bmim]PF6 is performed using the potentiostatic method at 100℃ and -1.25 V.SEM and EDS analysis results indicate that the electrodeposits are mixtures of tantalum metal and tantalum subchiloride.
The electrochemical behavior of 0.25 mol/L tantalum pentachloride is investigated in 1-butyl-3-methylimidazolium hexafluorophosphate([Bmim]PF6) by cyclic voltammetry. The results show that the electrodeposition process of tantalum is a two-step irreversible electrode reaction by diffusion control. Tantalum(Ⅴ) is first reduced to tantalum(Ⅲ), and tantalum(Ⅲ) is further reduced to tantalum metal and tantalum subchloride. The cathodic transfer coefficients of Ta(Ⅴ)/Ta(Ⅲ) and Ta(Ⅲ)/Ta are 0.155 and 0.406, respectively. The diffusion coefficient of Ta(Ⅴ) is 1.629×10-9 cm2/s. The electrodeposition of tantalum on platinum substrate from TaCl5-[Bmim]PF6 is performed using the potentiostatic method at 100℃ and -1.25 V.SEM and EDS analysis results indicate that the electrodeposits are mixtures of tantalum metal and tantalum subchiloride.
