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2019 Volume 36 Issue 2
2019, 36(2): 123-136
doi: 10.11944/j.issn.1000-0518.2019.02.180116
Abstract:
Due to simple operation, high resolution and real-time imaging, fluorescence technology has been widely used in detection and bioimaging. The second near-infrared window dyes(NIR-Ⅱ, 1000~1700 nm) have longer emission wavelength, less interference with light scattering and tissue autofluorescence, resulting in higher temporal and spatial resolution and deeper imaging depth in tissue imaging. In this review, we mainly introduce the designed mechanism and research progress in bioimaging based on NIR-Ⅱ dyes, and further give an outlook in the following studies.
Due to simple operation, high resolution and real-time imaging, fluorescence technology has been widely used in detection and bioimaging. The second near-infrared window dyes(NIR-Ⅱ, 1000~1700 nm) have longer emission wavelength, less interference with light scattering and tissue autofluorescence, resulting in higher temporal and spatial resolution and deeper imaging depth in tissue imaging. In this review, we mainly introduce the designed mechanism and research progress in bioimaging based on NIR-Ⅱ dyes, and further give an outlook in the following studies.
2019, 36(2): 137-145
doi: 10.11944/j.issn.1000-0518.2019.02.180121
Abstract:
The concept of water-jet printing has made a great contribution to the reduction of environmental pollution and resource consumption. However, there are few hydrochromic dyes and they are difficult to develop. Therefore, in order to realize the adjustment of acidochromic dyes to hydrochromic dyes, we adjust the dynamic balance of the switch-ring in molecules by changing the switch units of fluoranes. Fluoranes are synthesized directly from commercial raw materials in two steps and have a high molar absorption coefficient up to 1×105. The reflectivity changes 50% before and after writing with water, which makes it possible to apply widely in water-jet printing.
The concept of water-jet printing has made a great contribution to the reduction of environmental pollution and resource consumption. However, there are few hydrochromic dyes and they are difficult to develop. Therefore, in order to realize the adjustment of acidochromic dyes to hydrochromic dyes, we adjust the dynamic balance of the switch-ring in molecules by changing the switch units of fluoranes. Fluoranes are synthesized directly from commercial raw materials in two steps and have a high molar absorption coefficient up to 1×105. The reflectivity changes 50% before and after writing with water, which makes it possible to apply widely in water-jet printing.
2019, 36(2): 146-154
doi: 10.11944/j.issn.1000-0518.2019.02.180106
Abstract:
Phenylboronic acid and derivatives that conjugate with diol units to form a reversible ester bond can be used to prepare self-healing and stimuli-responsive materials. Stimuli-responsive hydrogels based on phenylboronic acid have been reported to have excellent self-healing properties. However, in these examples, employed polymers are not fully degradable nor have low biocompatibility. Therefore, this study aims to prepare a bio-based hydrogel for potential biomedical applications. Poly(γ-glutamic acid-g-3-aminophenylboronic acid)(γ-PGA-g-APBA) was synthesized by grafting 3-aminophenylboronic acid(APBA) in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide(EDC) and N-hydroxysuccinimide(NHS) as catalysts, and guar gum was modified by cationic etherification agent, 2, 3-epoxypropyltrimethylammonium chloride(CHGTA). These two modified bio-polymers were characterized by Fourier transform infrared(FT-IR) spectroscopy, nuclear magnetic resonance(1H NMR), and ultraviolet-visible(UV-Vis) spectrophotometer, and were mixed to form hydrogels. Mechanical properties of the prepared hydrogels were characterized by the rheometer. The results show that(γ-PGA-g-APBA/CGG) hydrogels have self-healing and pH-responsive properties. The structure of the gels is damaged with large strain and reconstructed completely with small strain, indicating that the hydrogel have the self-healing property and the repeatability. With the increase of pH value from 7 to 9, the hydrogels are formed and their strengths increase with pH, due to the conversion of the trigonal boronic-ester bond to tetrahedral boronic-ester bond. In the presence of 4 g/L glucose, the formed gel dissociates and changes to sol, because of the competing reaction between glucose and guar gum with PBA group. Moreover, rheology test indicates the shear-thinning and injectable properties of the hydrogels. Thus, the bio-based(γ-PGA-g-APBA/CGG) hydrogels have the potential applications in sensors, medicine and tissue engineering.
Phenylboronic acid and derivatives that conjugate with diol units to form a reversible ester bond can be used to prepare self-healing and stimuli-responsive materials. Stimuli-responsive hydrogels based on phenylboronic acid have been reported to have excellent self-healing properties. However, in these examples, employed polymers are not fully degradable nor have low biocompatibility. Therefore, this study aims to prepare a bio-based hydrogel for potential biomedical applications. Poly(γ-glutamic acid-g-3-aminophenylboronic acid)(γ-PGA-g-APBA) was synthesized by grafting 3-aminophenylboronic acid(APBA) in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide(EDC) and N-hydroxysuccinimide(NHS) as catalysts, and guar gum was modified by cationic etherification agent, 2, 3-epoxypropyltrimethylammonium chloride(CHGTA). These two modified bio-polymers were characterized by Fourier transform infrared(FT-IR) spectroscopy, nuclear magnetic resonance(1H NMR), and ultraviolet-visible(UV-Vis) spectrophotometer, and were mixed to form hydrogels. Mechanical properties of the prepared hydrogels were characterized by the rheometer. The results show that(γ-PGA-g-APBA/CGG) hydrogels have self-healing and pH-responsive properties. The structure of the gels is damaged with large strain and reconstructed completely with small strain, indicating that the hydrogel have the self-healing property and the repeatability. With the increase of pH value from 7 to 9, the hydrogels are formed and their strengths increase with pH, due to the conversion of the trigonal boronic-ester bond to tetrahedral boronic-ester bond. In the presence of 4 g/L glucose, the formed gel dissociates and changes to sol, because of the competing reaction between glucose and guar gum with PBA group. Moreover, rheology test indicates the shear-thinning and injectable properties of the hydrogels. Thus, the bio-based(γ-PGA-g-APBA/CGG) hydrogels have the potential applications in sensors, medicine and tissue engineering.
2019, 36(2): 155-160
doi: 10.11944/j.issn.1000-0518.2019.02.180150
Abstract:
In order to obtain dispersive and stable polydopamine nanoparticles, an aqueous dispersion of polydopamine nanoparticles was efficiently prepared using the "precipitation-redispersion" method. First, polydopamine nanoparticles dispersed in water/ethanol were prepared by a solution oxidation method, and then acetone was added to the dispersion to flocculate the polydopamine nanoparticles. The precipitate was collected, rinsed with acetone and dried, and then redispersed in water to obtain a purified aqueous dispersion of polydopamine nanoparticles. The polydopamine nanoparticles obtained by the acetone precipitation method are regular in shape with good dispersibility. The particle size distribution is about 250 nm, and has good storage stability and photothermal properties in water. Compared with conventional ultracentrifugation purification method, the yield increases by 57.4%. This method is essential for further applications in drug delivery and photothermal therapy/>
In order to obtain dispersive and stable polydopamine nanoparticles, an aqueous dispersion of polydopamine nanoparticles was efficiently prepared using the "precipitation-redispersion" method. First, polydopamine nanoparticles dispersed in water/ethanol were prepared by a solution oxidation method, and then acetone was added to the dispersion to flocculate the polydopamine nanoparticles. The precipitate was collected, rinsed with acetone and dried, and then redispersed in water to obtain a purified aqueous dispersion of polydopamine nanoparticles. The polydopamine nanoparticles obtained by the acetone precipitation method are regular in shape with good dispersibility. The particle size distribution is about 250 nm, and has good storage stability and photothermal properties in water. Compared with conventional ultracentrifugation purification method, the yield increases by 57.4%. This method is essential for further applications in drug delivery and photothermal therapy/>
2019, 36(2): 161-169
doi: 10.11944/j.issn.1000-0518.2019.02.180204
Abstract:
Linear maltodextrin polymer modified magnetic nanoparticles(LM-SP-MNPs) were prepared by chemical co-precipitation. The structure and morphology of LM-SP-MNPs were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and thermogravimetric analysis. The loading and release behaviors of LM-SP-MNPs as drug carrier were evaluated by fluorescence spectroscopy using doxorubicin(DOX) as a model drug. The pH effects on LM-SP-MNPs for drug releasing were investigated. Under the optimal pH conditions, the maximum loading of DOX into LM-SP-MNPs is 357.1 mg/g, and the loading behavior follows Freundlich adsorption balance equations with multilayer adsorption. Furthermore, the release ability of DOX@LM-SP-MNPs is more efficient under acid solution than that under natural solution at 37℃ in vitro. Accumulated release efficiency of DOX in 7 h is 26.9% at pH=5.3. In addition, the MTT assays show that LM-SP-MNPs have an excellent biocompatibility, and the DOX@LM-SP-MNPs decrease the relative cellular viability of HepG2 cells evidently.
Linear maltodextrin polymer modified magnetic nanoparticles(LM-SP-MNPs) were prepared by chemical co-precipitation. The structure and morphology of LM-SP-MNPs were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and thermogravimetric analysis. The loading and release behaviors of LM-SP-MNPs as drug carrier were evaluated by fluorescence spectroscopy using doxorubicin(DOX) as a model drug. The pH effects on LM-SP-MNPs for drug releasing were investigated. Under the optimal pH conditions, the maximum loading of DOX into LM-SP-MNPs is 357.1 mg/g, and the loading behavior follows Freundlich adsorption balance equations with multilayer adsorption. Furthermore, the release ability of DOX@LM-SP-MNPs is more efficient under acid solution than that under natural solution at 37℃ in vitro. Accumulated release efficiency of DOX in 7 h is 26.9% at pH=5.3. In addition, the MTT assays show that LM-SP-MNPs have an excellent biocompatibility, and the DOX@LM-SP-MNPs decrease the relative cellular viability of HepG2 cells evidently.
2019, 36(2): 170-175
doi: 10.11944/j.issn.1000-0518.2019.02.180380
Abstract:
In this work, poly(ethylene terephthalate)(PET) homopolymer and copolymers were synthesized from biomass-derived ethylene glycol containing 0, 2.0%, 2.7%, and 5.6% mole fraction of 1, 2-butanediol(1, 2-BDO) in order to explore the effects of the comonomer on the crystallization behavior and the mechanical properties of the PET. The polymers were investigated by Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry(DSC), and mechanical testing. It is found that the melting temperature, crystallization rate and crystallinity of the PET decrease as mole fraction of 1, 2-BDO comonomer increases, indicating that the incorporation of the 1, 2-BDO units can disrupt the ordered structure of the PET chains and therefore hinder the crystallization. In addition, the tensile strength of PET materials decreases while the flexural modulus and strength increase slightly at higher 1, 2-BDO mole fraction.
In this work, poly(ethylene terephthalate)(PET) homopolymer and copolymers were synthesized from biomass-derived ethylene glycol containing 0, 2.0%, 2.7%, and 5.6% mole fraction of 1, 2-butanediol(1, 2-BDO) in order to explore the effects of the comonomer on the crystallization behavior and the mechanical properties of the PET. The polymers were investigated by Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry(DSC), and mechanical testing. It is found that the melting temperature, crystallization rate and crystallinity of the PET decrease as mole fraction of 1, 2-BDO comonomer increases, indicating that the incorporation of the 1, 2-BDO units can disrupt the ordered structure of the PET chains and therefore hinder the crystallization. In addition, the tensile strength of PET materials decreases while the flexural modulus and strength increase slightly at higher 1, 2-BDO mole fraction.
2019, 36(2): 176-181
doi: 10.11944/j.issn.1000-0518.2019.02.180157
Abstract:
The novel MgO/SBA-15 catalysts were prepared via impregnation of magnesium oxide onto the SBA-15 zeolite support. The effect of MgO content on the structure, physic-chemical properties and catalytic performances of catalysts was studied by Brunauer-Emmett-Teller(BET) measurement, X-ray diffraction(XRD), transmission electron microscopy(TEM), 29Si NMR(nuclear magnetic resonance) spectroscopy, NH3-TPD(temperature programmed desorption) and CO2-TPD. It is found that the catalyst with 20% mass fraction of MgO can form well-dispersed MgO in the inner pores of SBA-15 zeolite and the Mg-O-Si structure between MgO and SBA-15, which is beneficial to the production of 1, 3-butadiene. Under the optimal reaction conditions of 350℃ and feed weight hourly space velocity of 2.64 h-1, the best catalytic performance is obtained with the ethanol conversion of 55.8% and the 1, 3-butadiene selectivity of 80.2%. The MgO/SBA-15 catalyst has potential applications in the production of butadiene from ethanol.
The novel MgO/SBA-15 catalysts were prepared via impregnation of magnesium oxide onto the SBA-15 zeolite support. The effect of MgO content on the structure, physic-chemical properties and catalytic performances of catalysts was studied by Brunauer-Emmett-Teller(BET) measurement, X-ray diffraction(XRD), transmission electron microscopy(TEM), 29Si NMR(nuclear magnetic resonance) spectroscopy, NH3-TPD(temperature programmed desorption) and CO2-TPD. It is found that the catalyst with 20% mass fraction of MgO can form well-dispersed MgO in the inner pores of SBA-15 zeolite and the Mg-O-Si structure between MgO and SBA-15, which is beneficial to the production of 1, 3-butadiene. Under the optimal reaction conditions of 350℃ and feed weight hourly space velocity of 2.64 h-1, the best catalytic performance is obtained with the ethanol conversion of 55.8% and the 1, 3-butadiene selectivity of 80.2%. The MgO/SBA-15 catalyst has potential applications in the production of butadiene from ethanol.
2019, 36(2): 182-187
doi: 10.11944/j.issn.1000-0518.2019.02.180094
Abstract:
Microwave-assisted one-pot synthesis of a variety of N, N-dimethyl-2-benzoxazolamine derivatives were achieved by the cascade reaction of substituted 2-iodoanilines with dimethylcarbamothioic chloride in pyridine in the presence of CuI at 100℃ with moderate to good yields(up to 90%).
Microwave-assisted one-pot synthesis of a variety of N, N-dimethyl-2-benzoxazolamine derivatives were achieved by the cascade reaction of substituted 2-iodoanilines with dimethylcarbamothioic chloride in pyridine in the presence of CuI at 100℃ with moderate to good yields(up to 90%).
2019, 36(2): 188-194
doi: 10.11944/j.issn.1000-0518.2019.02.180089
Abstract:
Fe3O4 magnetic nano particles(MNPs) with sulfonic acid groups on the surface were readily prepared via coupling reaction between 4-amino phenylsulfonic acid diazonium tetrafluoroborate and Fe3O4 nano particles. Transmission electron microscopy(TEM) images reveal that the average size of these acidic particles is about 20 nm. These acidic particles show good solubility in water, but they are insoluble in most of common organic solvents, allowing easy isolation and recycling of the particles by their magnetic property in catalytic reactions. In terms of application, when the acidic magnetic particles were used to catalyze esterification reactions between carboxylic acids and alcohols, moderate to high isolated yields(71%~86%) of ester products were obtained. The optimized catalyst loading is 1.5%(mass fraction). Furthermore, 5-hydroxymethyl furfural(HMF) was also synthesized in a 32% yield from fructose utilizing the acidic magnetic particles as a catalyst.
Fe3O4 magnetic nano particles(MNPs) with sulfonic acid groups on the surface were readily prepared via coupling reaction between 4-amino phenylsulfonic acid diazonium tetrafluoroborate and Fe3O4 nano particles. Transmission electron microscopy(TEM) images reveal that the average size of these acidic particles is about 20 nm. These acidic particles show good solubility in water, but they are insoluble in most of common organic solvents, allowing easy isolation and recycling of the particles by their magnetic property in catalytic reactions. In terms of application, when the acidic magnetic particles were used to catalyze esterification reactions between carboxylic acids and alcohols, moderate to high isolated yields(71%~86%) of ester products were obtained. The optimized catalyst loading is 1.5%(mass fraction). Furthermore, 5-hydroxymethyl furfural(HMF) was also synthesized in a 32% yield from fructose utilizing the acidic magnetic particles as a catalyst.
2019, 36(2): 195-202
doi: 10.11944/j.issn.1000-0518.2019.02.180109
Abstract:
Noble metal catalyst exhibits excellent effects on the catalytic oxidation of NOx, but the cost is high. The supported catalysts and non-noble metal catalysts have been widely explored. In this work, SmMn2O5(SMO) and SmMn2O5/γ-Al2O3 catalysts were prepared by hydrothermal method and impregnation method, respectively, and the effect of the content of SmMn2O5 on the catalytic oxidation of NO was investigated. Scanning electron microscopy(SEM), specific surface area(BET) and pore size distribution analysis, temperature programmed reduction(TPR) and temperature programmed desorption(TPD) were conducted towards different SmMn2O5 loadings(5%~100% mass fraction). The catalytic oxidation performance of NO was subsequently carried out. The results indicate that the 25%(mass fraction) SmMn2O5/γ-Al2O3 catalyst shows the lowest light off temperature(260℃) among the load mass fraction of 35%, 25%, 15% and 5%. Continuing increasing SMO loadings mass fraction up to 50% and 75%, it is found that the light off temperature of the two samples only drops off 10℃ relative to 25% SmMn2O5/γ-Al2O3 catalyst and increases 40℃ in regards to the pure phase of mullite SMO. This exploration will provide some guidance for the effective utilization of SmMn2O5 catalyst in the future, and introduce certain method for the design of supported non-noble metal catalysts.
Noble metal catalyst exhibits excellent effects on the catalytic oxidation of NOx, but the cost is high. The supported catalysts and non-noble metal catalysts have been widely explored. In this work, SmMn2O5(SMO) and SmMn2O5/γ-Al2O3 catalysts were prepared by hydrothermal method and impregnation method, respectively, and the effect of the content of SmMn2O5 on the catalytic oxidation of NO was investigated. Scanning electron microscopy(SEM), specific surface area(BET) and pore size distribution analysis, temperature programmed reduction(TPR) and temperature programmed desorption(TPD) were conducted towards different SmMn2O5 loadings(5%~100% mass fraction). The catalytic oxidation performance of NO was subsequently carried out. The results indicate that the 25%(mass fraction) SmMn2O5/γ-Al2O3 catalyst shows the lowest light off temperature(260℃) among the load mass fraction of 35%, 25%, 15% and 5%. Continuing increasing SMO loadings mass fraction up to 50% and 75%, it is found that the light off temperature of the two samples only drops off 10℃ relative to 25% SmMn2O5/γ-Al2O3 catalyst and increases 40℃ in regards to the pure phase of mullite SMO. This exploration will provide some guidance for the effective utilization of SmMn2O5 catalyst in the future, and introduce certain method for the design of supported non-noble metal catalysts.
2019, 36(2): 203-211
doi: 10.11944/j.issn.1000-0518.2019.02.180110
Abstract:
By ion-imprinting technology, 3-chloropropyltriethoxysilane as anchor, functional monomer linear polyethyleneimine(PEI) was grafted on the surface of MCM-41 molecular sieve. With Yb ions as template ions, and epichlorohydrin as cross-linking agent, a Yb(Ⅲ) ion-imprinted polymer(IIP), Yb(Ⅲ)-IIP-PEI/MCM-41, was prepared on MCM-41 surface. A non-ion-imprinted polymer(NIP-PEI/MCM-41) was prepared via similar process. Yb3+ imprinted polymer was characterized by infrared spectroscopy and scanning electron microscopy. The optimal adsorption conditions and selective adsorption performance of Yb(Ⅲ)-IIP-PEI/MCM-41 for Yb3+ were determined by static adsorption method. The maximum adsorption capacities of Yb(Ⅲ)-IIP-PEI/MCM-41 and NIP-PEI/MCM-41 are 229.93 mg/g and 99.27 mg/g, respectively. The adsorption of Yb3+ by the imprinted material is conformed to the Langmuir model; The equilibrium can basically be reached in 40 min, and the adsorption process can be described using the pseudo-second-order kinetic model. Yb(Ⅲ)-IIP-PEI/MCM-41 has strong selectivity toward Yb3+ and also has good recyclability. This adsorbent with high adsorption capacity and high selectivity for rare earth Yb ions combining the advantages of MCM-41 and ion-imprinted polymer thus-prepared lays the foundation for further application in the separation and recovery of low-concentration earth elements from wastewater.
By ion-imprinting technology, 3-chloropropyltriethoxysilane as anchor, functional monomer linear polyethyleneimine(PEI) was grafted on the surface of MCM-41 molecular sieve. With Yb ions as template ions, and epichlorohydrin as cross-linking agent, a Yb(Ⅲ) ion-imprinted polymer(IIP), Yb(Ⅲ)-IIP-PEI/MCM-41, was prepared on MCM-41 surface. A non-ion-imprinted polymer(NIP-PEI/MCM-41) was prepared via similar process. Yb3+ imprinted polymer was characterized by infrared spectroscopy and scanning electron microscopy. The optimal adsorption conditions and selective adsorption performance of Yb(Ⅲ)-IIP-PEI/MCM-41 for Yb3+ were determined by static adsorption method. The maximum adsorption capacities of Yb(Ⅲ)-IIP-PEI/MCM-41 and NIP-PEI/MCM-41 are 229.93 mg/g and 99.27 mg/g, respectively. The adsorption of Yb3+ by the imprinted material is conformed to the Langmuir model; The equilibrium can basically be reached in 40 min, and the adsorption process can be described using the pseudo-second-order kinetic model. Yb(Ⅲ)-IIP-PEI/MCM-41 has strong selectivity toward Yb3+ and also has good recyclability. This adsorbent with high adsorption capacity and high selectivity for rare earth Yb ions combining the advantages of MCM-41 and ion-imprinted polymer thus-prepared lays the foundation for further application in the separation and recovery of low-concentration earth elements from wastewater.
2019, 36(2): 212-222
doi: 10.11944/j.issn.1000-0518.2019.02.180161
Abstract:
Four 1, 2, 4-triazine-phenanthroling derivatives(ARTP1~ARTP4) were designed and synthesized successfully. ARTP1~ARTP4 were selected to coordinate with Co3+ to afford four novel complexes(Co-ARTP1~Co-ARTP4). The structures and properties of ARTP1~ARTP4 and Co-ARTP1~Co-ARTP4 were studied by means of Fourier transform infrared spectrometer(FT-IR), nuclear magnetic resonance(NMR), high resolution mass spectrometry(HRMS) and ultraviolet-visible spectroscopy(UV-Vis). As a result, the excitation peaks of the complexes are weakened and show red shift. The complexes interact with calf thymus DNA(CT-DNA) through the insert mode and the binding constants are Kb=4.78×105, 6.52×105, 5.97×105 and 6.01×105 L/mol, respectively, which indicates that the complexes are expected to be the DNA fluorescence probes. It provides the important theory references for further study on the interaction between small organic molecules with DNA.
Four 1, 2, 4-triazine-phenanthroling derivatives(ARTP1~ARTP4) were designed and synthesized successfully. ARTP1~ARTP4 were selected to coordinate with Co3+ to afford four novel complexes(Co-ARTP1~Co-ARTP4). The structures and properties of ARTP1~ARTP4 and Co-ARTP1~Co-ARTP4 were studied by means of Fourier transform infrared spectrometer(FT-IR), nuclear magnetic resonance(NMR), high resolution mass spectrometry(HRMS) and ultraviolet-visible spectroscopy(UV-Vis). As a result, the excitation peaks of the complexes are weakened and show red shift. The complexes interact with calf thymus DNA(CT-DNA) through the insert mode and the binding constants are Kb=4.78×105, 6.52×105, 5.97×105 and 6.01×105 L/mol, respectively, which indicates that the complexes are expected to be the DNA fluorescence probes. It provides the important theory references for further study on the interaction between small organic molecules with DNA.
2019, 36(2): 223-229
doi: 10.11944/j.issn.1000-0518.2019.02.180190
Abstract:
Hydrothermal reaction of 5, 5'-dicyano-3, 3'-bipyridyl ligands and sodium azide in the presence of the Lewis acid CuSO4 in water and ethanol provided a novel metal organic tetrazole complex. X-ray single crystal diffraction analysis shows that this complex belongs to a tetragonal system with P4/ncc space group. This complex displays an interesting infinite two-dimensional(2D) network structure bridge linked by the pyridyl N atoms. The highly disordered sulfate around the central metals are likely to become ordered at low temperatures, leading to structural phase changes. The packing diagram of the crystal structure shows a butterfly hairpin shape. The highly nitrogenated structure allows this complex to be a potential high-energy material.
Hydrothermal reaction of 5, 5'-dicyano-3, 3'-bipyridyl ligands and sodium azide in the presence of the Lewis acid CuSO4 in water and ethanol provided a novel metal organic tetrazole complex. X-ray single crystal diffraction analysis shows that this complex belongs to a tetragonal system with P4/ncc space group. This complex displays an interesting infinite two-dimensional(2D) network structure bridge linked by the pyridyl N atoms. The highly disordered sulfate around the central metals are likely to become ordered at low temperatures, leading to structural phase changes. The packing diagram of the crystal structure shows a butterfly hairpin shape. The highly nitrogenated structure allows this complex to be a potential high-energy material.
2019, 36(2): 230-235
doi: 10.11944/j.issn.1000-0518.2019.02.180163
Abstract:
The organic salt hydrate of berberine with genistein, [C20H18NO4]+·[C15H9O5]-·2.5H2O·0.5(C2H5OH), was prepared and its crystal structure was determined. The result showed that the organic salt hydrate crystallized in monoclinic crystal system and P21/c space group. The 7-substituted hydroxyl of genistein lost its proton and turned to be anion. The resulting hydroxyl anion was involved in O—H····O- hydrogen bonding with 4'-substituted hydroxyl, which gave rise to an one-dimensional hydrogen-bonded chain-like structure. Two water molecules formed a chain-like structure through hydrogen-bonding interactions and further connected the 1D chain of genistein into a 2D hydrogen-bonded network. The hydrate turned to be amorphous form after losing water molecules by heating. The amorphous form could transform into crystalline organic salt hydrate after suspending in ethanol-water for 24 h. After forming berberine-genistein salt hydrate, the solubility of genistein in water increased slightly.
The organic salt hydrate of berberine with genistein, [C20H18NO4]+·[C15H9O5]-·2.5H2O·0.5(C2H5OH), was prepared and its crystal structure was determined. The result showed that the organic salt hydrate crystallized in monoclinic crystal system and P21/c space group. The 7-substituted hydroxyl of genistein lost its proton and turned to be anion. The resulting hydroxyl anion was involved in O—H····O- hydrogen bonding with 4'-substituted hydroxyl, which gave rise to an one-dimensional hydrogen-bonded chain-like structure. Two water molecules formed a chain-like structure through hydrogen-bonding interactions and further connected the 1D chain of genistein into a 2D hydrogen-bonded network. The hydrate turned to be amorphous form after losing water molecules by heating. The amorphous form could transform into crystalline organic salt hydrate after suspending in ethanol-water for 24 h. After forming berberine-genistein salt hydrate, the solubility of genistein in water increased slightly.
2019, 36(2): 236-244
doi: 10.11944/j.issn.1000-0518.2019.02.180144
Abstract:
Carbon fiber cloth supported three-dimensional polyaniline networks were synthesized by electrochemical polymerization. Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer were applied to characterize the morphology of the electrode and analyze the characteristic groups on the electrode surface. The capacitive performance of the as-prepared electrode in four RCl(R=H, Li, Na, K) aqueous solutions was systematically compared. The electrochemical tests show that KCl electrolyte gives a wider potential window(1.8 V) than the HCl or LiCl electrolyte, and also exhibits a superior specific capacitance(501 F/g@0.5 A/g) to the NaCl electrolyte. The energy density under the current density of 10 A/g in the KCl electrolyte is even larger than that in the HCl electrolyte under 2.0 A/g. As a result, KCl is the most suitable electrolyte for the polyaniline-based capacitor. The potential window is widened and the energy density of electrochemical capacitor is remarkably improved just simply by altering the electrolyte in the aqueous solution, which avoids the issues of poor physico-chemical stability and severe environment contamination originated from the organic solutions.
Carbon fiber cloth supported three-dimensional polyaniline networks were synthesized by electrochemical polymerization. Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer were applied to characterize the morphology of the electrode and analyze the characteristic groups on the electrode surface. The capacitive performance of the as-prepared electrode in four RCl(R=H, Li, Na, K) aqueous solutions was systematically compared. The electrochemical tests show that KCl electrolyte gives a wider potential window(1.8 V) than the HCl or LiCl electrolyte, and also exhibits a superior specific capacitance(501 F/g@0.5 A/g) to the NaCl electrolyte. The energy density under the current density of 10 A/g in the KCl electrolyte is even larger than that in the HCl electrolyte under 2.0 A/g. As a result, KCl is the most suitable electrolyte for the polyaniline-based capacitor. The potential window is widened and the energy density of electrochemical capacitor is remarkably improved just simply by altering the electrolyte in the aqueous solution, which avoids the issues of poor physico-chemical stability and severe environment contamination originated from the organic solutions.
