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2017 Volume 34 Issue 11
2017, 34(11): 1221-1239
doi: 10.11944/j.issn.1000-0518.2017.11.170305
Abstract:
It is extremely urgent to look for new and clean energy because fossil fuels are consumed rapidly and release harmful gas in the combustion process. Hydrogen has the advantages of high combustion value and high efficiency, so it has become one of the most promising new energy. Using solar energy to produce hydrogen is a method which conforms to "green chemistry". According to the current exploration of photocatalyst, perovskite photocatalyst has become a popular research system because of its diversity, characteristic and variability. Titanium based perovskite materials and its derivatives show many excellent photocatalytic activities and it is a research hotspot in the field of solar photocatalytic studies. In this paper, the structure, modification method and the research progress of titanium-based perovskite materials and their derivatives are briefly reviewed.
It is extremely urgent to look for new and clean energy because fossil fuels are consumed rapidly and release harmful gas in the combustion process. Hydrogen has the advantages of high combustion value and high efficiency, so it has become one of the most promising new energy. Using solar energy to produce hydrogen is a method which conforms to "green chemistry". According to the current exploration of photocatalyst, perovskite photocatalyst has become a popular research system because of its diversity, characteristic and variability. Titanium based perovskite materials and its derivatives show many excellent photocatalytic activities and it is a research hotspot in the field of solar photocatalytic studies. In this paper, the structure, modification method and the research progress of titanium-based perovskite materials and their derivatives are briefly reviewed.
2017, 34(11): 1240-1249
doi: 10.11944/j.issn.1000-0518.2017.11.170264
Abstract:
Controllable fabrication of functional microfibers with diverse structures and compositions are important for their innovation and application. This review summarizes the recent progress on controllable fabrication of functional microfibers with solid, hollow, compartmental, and helical structures from diverse jet templates generated by microfluidics, and hopes to provide scientific guidelines for the design and controllable fabrication of novel functional microfibers.
Controllable fabrication of functional microfibers with diverse structures and compositions are important for their innovation and application. This review summarizes the recent progress on controllable fabrication of functional microfibers with solid, hollow, compartmental, and helical structures from diverse jet templates generated by microfluidics, and hopes to provide scientific guidelines for the design and controllable fabrication of novel functional microfibers.
2017, 34(11): 1250-1258
doi: 10.11944/j.issn.1000-0518.2017.11.170329
Abstract:
As one of the important anisotropic particles, ellipsoidal particles have widespread range of applications in biology, chemical engineering and materials. Further research on the diffusion dynamics of ellipsoidal particles not only contributes to our understanding of the diffusion dynamics of anisotropic particles, but also provides theoretical guidance for the design of materials containing anisotropic particles. Therefore, the diffusion dynamics of ellipsoidal particles has been a research focus in the diffusion of particles over 100 years and extensive theoretical, experimental and simulation studies have been conducted. Although significant progress has been made, systemic reviews on this field are rarely published up to now. In this review, we summarize the diffusion dynamics of ellipsoidal particles, including the relationship between size and diffusion properties of ellipsoidal particles under different hydrodynamic boundary conditions and the coupling effect of translational and rotational motion. Furthermore, we analyze the existing problems in this field and discuss the research trends briefly.
As one of the important anisotropic particles, ellipsoidal particles have widespread range of applications in biology, chemical engineering and materials. Further research on the diffusion dynamics of ellipsoidal particles not only contributes to our understanding of the diffusion dynamics of anisotropic particles, but also provides theoretical guidance for the design of materials containing anisotropic particles. Therefore, the diffusion dynamics of ellipsoidal particles has been a research focus in the diffusion of particles over 100 years and extensive theoretical, experimental and simulation studies have been conducted. Although significant progress has been made, systemic reviews on this field are rarely published up to now. In this review, we summarize the diffusion dynamics of ellipsoidal particles, including the relationship between size and diffusion properties of ellipsoidal particles under different hydrodynamic boundary conditions and the coupling effect of translational and rotational motion. Furthermore, we analyze the existing problems in this field and discuss the research trends briefly.
2017, 34(11): 1259-1264
doi: 10.11944/j.issn.1000-0518.2017.11.170236
Abstract:
The introduction of side arm soft donors(S or P) is an efficient method to improve catalytic performance of the complexes. A series of NNP-tridentate nickel(Ⅱ) complexes bearing pyridyl/quinolyl-imine ligands(2a~2d) was synthesized and characterized by Fourier transform infrared spectroscopy(FTIR) and elemental analysis. X-ray diffraction analysis(XRD) reveals that complexes 2a and 2d adopt square-pyramidal and trigonal bipyramid geometries, respectively. Activated by ethylaluminum sesquichloride(EASC), all complexes are highly active for butadiene polymerization to afford liquid polybutadienes having number-average relative molecular masses of 4200~7700 and medium cis-1, 4 mole fraction(74.5%~79.9%). The ligand has little influence on the catalytic behaviors. The catalytic activity increases with the increment of polymerization temperature, and the catalytic system still exhibits high activity even at 90℃, indicating high thermal stability of the generated active species.
The introduction of side arm soft donors(S or P) is an efficient method to improve catalytic performance of the complexes. A series of NNP-tridentate nickel(Ⅱ) complexes bearing pyridyl/quinolyl-imine ligands(2a~2d) was synthesized and characterized by Fourier transform infrared spectroscopy(FTIR) and elemental analysis. X-ray diffraction analysis(XRD) reveals that complexes 2a and 2d adopt square-pyramidal and trigonal bipyramid geometries, respectively. Activated by ethylaluminum sesquichloride(EASC), all complexes are highly active for butadiene polymerization to afford liquid polybutadienes having number-average relative molecular masses of 4200~7700 and medium cis-1, 4 mole fraction(74.5%~79.9%). The ligand has little influence on the catalytic behaviors. The catalytic activity increases with the increment of polymerization temperature, and the catalytic system still exhibits high activity even at 90℃, indicating high thermal stability of the generated active species.
2017, 34(11): 1265-1272
doi: 10.11944/j.issn.1000-0518.2017.11.170042
Abstract:
A series of novel polynaphthalimides(PNIs) was synthesized from 1, 4, 5, 8-naphthalenetracarboxylic dianhydride and several diamines containing alkyl substituents in the o-position. Almost all the PNIs with alkyl substituents in the o-position are readily soluble in polar solvents and can be solution-cast to transparent and tough films. The films have tensile strengths, elongations at break, and tensile module in the range of 54~77 MPa, 6.4%~8.1%, and 1.3~2.2 GPa, respectively. The PNIs exhibit excellent thermal stabilities with the onset decomposition temperature ranging from 448 to 501℃. The glass transition temperatures of the PNIs are in the range of 382 to 391℃. The CO2 permeability coefficients and permeability selectivities of CO2 to CH4 of the PNIs are in the range of 37.2~151 barrer and 20.9~31.7, respectively, making these novel polynaphthalimides potentially useful candidate materials for membranes in natural gas purification.
A series of novel polynaphthalimides(PNIs) was synthesized from 1, 4, 5, 8-naphthalenetracarboxylic dianhydride and several diamines containing alkyl substituents in the o-position. Almost all the PNIs with alkyl substituents in the o-position are readily soluble in polar solvents and can be solution-cast to transparent and tough films. The films have tensile strengths, elongations at break, and tensile module in the range of 54~77 MPa, 6.4%~8.1%, and 1.3~2.2 GPa, respectively. The PNIs exhibit excellent thermal stabilities with the onset decomposition temperature ranging from 448 to 501℃. The glass transition temperatures of the PNIs are in the range of 382 to 391℃. The CO2 permeability coefficients and permeability selectivities of CO2 to CH4 of the PNIs are in the range of 37.2~151 barrer and 20.9~31.7, respectively, making these novel polynaphthalimides potentially useful candidate materials for membranes in natural gas purification.
2017, 34(11): 1273-1278
doi: 10.11944/j.issn.1000-0518.2017.11.160516
Abstract:
The viscosities of the dilute solutions containing chlorinated polypropylene(CPP) and the coating resins, such as petroleum resin(PTR), acrylic resin(ALR) and alkyd resin(SAR), with different compositions were measured. The miscibilities of PTR/CPP blends, ALR/CPP blends and SAR/CPP blends were discriminated by the miscibility criterion α which was calculated from the experimental data by dilute solution viscosity. The results show that PTR/CPP blends are miscible and ALR/CPP blends are immiscible, while the miscibilities of SAR/CPP blends are determined by their compositions. SAR/CPP blends are compatible when the mass ratios of SAR to CPP are less than 1:1, while the blends are incompatible when the mass ratios are greater than 1:1, which are consistent with the results of the stability of the mixtures, the clarity and the related glossiness of the films. Therefore, the dilute solution viscosity can be used in the determination of coating polyblend miscibility by determining polymer-polymer interactions in solution.
The viscosities of the dilute solutions containing chlorinated polypropylene(CPP) and the coating resins, such as petroleum resin(PTR), acrylic resin(ALR) and alkyd resin(SAR), with different compositions were measured. The miscibilities of PTR/CPP blends, ALR/CPP blends and SAR/CPP blends were discriminated by the miscibility criterion α which was calculated from the experimental data by dilute solution viscosity. The results show that PTR/CPP blends are miscible and ALR/CPP blends are immiscible, while the miscibilities of SAR/CPP blends are determined by their compositions. SAR/CPP blends are compatible when the mass ratios of SAR to CPP are less than 1:1, while the blends are incompatible when the mass ratios are greater than 1:1, which are consistent with the results of the stability of the mixtures, the clarity and the related glossiness of the films. Therefore, the dilute solution viscosity can be used in the determination of coating polyblend miscibility by determining polymer-polymer interactions in solution.
2017, 34(11): 1279-1286
doi: 10.11944/j.issn.1000-0518.2017.11.160502
Abstract:
A series of new 2-substituted-3, 8-diphenyl-5-aryl-6-methyl-5, 8-dihydropyrazolo[4', 3':5, 6]pyrano[2, 3-d]pyrimidine derivatives was designed and synthesized via tandem aza-Wittig reaction. The structures of target compounds were confirmed by 1H NMR, IR spectra and elemental analysis. The structure of 2-dipropylamino-3, 8-diphenyl-5-(4-methylphenyl)-6-methyl-5, 8-dihydropyrazolo[4', 3':5, 6]pyrano[2, 3-d]pyrimidin-4(3H)-one was determined by single crystal X-ray diffraction. The results of preliminary bioassay indicate that some compounds possess good inhibition activities against Botrytis cinereapers at a dosage of 5.0×10-5 g/mL, and the inhibition rates against Botrytis cinereapers are above 90%. Target compounds possess no insecticidal activity against Nilaparvatalegen, but show obvious insecticidal activity against Mythimaseparata, and the inhibihition rates against Mythimaseparata are above 60%.
A series of new 2-substituted-3, 8-diphenyl-5-aryl-6-methyl-5, 8-dihydropyrazolo[4', 3':5, 6]pyrano[2, 3-d]pyrimidine derivatives was designed and synthesized via tandem aza-Wittig reaction. The structures of target compounds were confirmed by 1H NMR, IR spectra and elemental analysis. The structure of 2-dipropylamino-3, 8-diphenyl-5-(4-methylphenyl)-6-methyl-5, 8-dihydropyrazolo[4', 3':5, 6]pyrano[2, 3-d]pyrimidin-4(3H)-one was determined by single crystal X-ray diffraction. The results of preliminary bioassay indicate that some compounds possess good inhibition activities against Botrytis cinereapers at a dosage of 5.0×10-5 g/mL, and the inhibition rates against Botrytis cinereapers are above 90%. Target compounds possess no insecticidal activity against Nilaparvatalegen, but show obvious insecticidal activity against Mythimaseparata, and the inhibihition rates against Mythimaseparata are above 60%.
2017, 34(11): 1287-1294
doi: 10.11944/j.issn.1000-0518.2017.11.170054
Abstract:
A visible light induced desulfonylative cyclization cascade of N-sulfonylmethacrylamides toward perfluoroalkylated oxindoles and α-arylamides was developed. Under light-emitting diode(LED) irradiation, in the presence of fac-tris-2-phenylpyridine iridium(Ⅲ)(fac-Ir(ppy)3) and perfluoroalkyl iodides or bromides, N-butyl-N-(tolylsulfonyl)methacrylamides underwent tandem radical addition/β-arylmigration/desulfonylation to construct two-fold of C-C bonds in single step, leading to a series of perfluoroalkylated oxindoles and α-aryl-β-perfluoroalkyl amide in 41%~78% yield. This mild catalytic protocol exhibits a broad substrate scope and therefore, provides a green and efficient approach to fluorinated oxindoles with potential biological activities.
A visible light induced desulfonylative cyclization cascade of N-sulfonylmethacrylamides toward perfluoroalkylated oxindoles and α-arylamides was developed. Under light-emitting diode(LED) irradiation, in the presence of fac-tris-2-phenylpyridine iridium(Ⅲ)(fac-Ir(ppy)3) and perfluoroalkyl iodides or bromides, N-butyl-N-(tolylsulfonyl)methacrylamides underwent tandem radical addition/β-arylmigration/desulfonylation to construct two-fold of C-C bonds in single step, leading to a series of perfluoroalkylated oxindoles and α-aryl-β-perfluoroalkyl amide in 41%~78% yield. This mild catalytic protocol exhibits a broad substrate scope and therefore, provides a green and efficient approach to fluorinated oxindoles with potential biological activities.
2017, 34(11): 1295-1300
doi: 10.11944/j.issn.1000-0518.2017.11.170005
Abstract:
The synthesis of coumarin-3-carboxylic acids in a more convenient way has attracted considerable attention from organic and medicinal chemists. In this paper, a simple and effective method was described through a Knoevenagel-intramolecular cyclization tandem reaction of 2-hydroxyarylaldehydes with Meldrum's acid at room temperature. Employing commercially available, mild, and nontoxic choline chloride as the accelerant and using the mixture of water and ethanol as solvent is highly applicable to get a satisfactory outcome from 88% to 96%. This approach expands the method for the preparation of coumarin-3-carboxylic acids and also provides other advantages such as mild reaction conditions, tolerant the substrates with diverse functional groups, and simple post-treatment process.
The synthesis of coumarin-3-carboxylic acids in a more convenient way has attracted considerable attention from organic and medicinal chemists. In this paper, a simple and effective method was described through a Knoevenagel-intramolecular cyclization tandem reaction of 2-hydroxyarylaldehydes with Meldrum's acid at room temperature. Employing commercially available, mild, and nontoxic choline chloride as the accelerant and using the mixture of water and ethanol as solvent is highly applicable to get a satisfactory outcome from 88% to 96%. This approach expands the method for the preparation of coumarin-3-carboxylic acids and also provides other advantages such as mild reaction conditions, tolerant the substrates with diverse functional groups, and simple post-treatment process.
2017, 34(11): 1301-1306
doi: 10.11944/j.issn.1000-0518.2017.11.170011
Abstract:
Design and development of high activity ultra-deep oxidation of desulfurization catalyst is one of the most important ways to meet the increasing stringent requirements of petrochemical industry for cleaning fuel standards in the future. Catalysts with Keggin structure aluminum hydroxide polyoxocations(Al13), Al13-SDS and HPW-Al13-SDS(HPW=Keggin structure phosphotungstic acid, SDS=sodium dodecylsulfate) were prepared. The structures of these catalysts were characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD), ultraviolet visible spectroscopy(UV-Vis), Brunauer-Emmett-Teller(BET) and thermogravimetry(TG). The preservation of the Keggin structure on HPW-Al13-SDS catalyst was confirmed by IR and UV-Vis spectra. Catalytic oxidation desulfurization(ODS) reaction over HPW-Al13-SDS with a model of oil(n-hexan solution of organic sulfur) was studied. In optimized condition, up to 99.5% conversion of sulfur was achieved. The efficiencies of ODS decrease from dibenzothiophene to benzothiophene. IR and XRD characterizations of HPW-Al13-SDS catalyst after the reaction show that the catalysts form peroxo-tungsten complexes. The catalytic activity of the recycled HPW-Al13-SDS is almost the same as freshly prepared, and can be recycled via easy separation. The catalyst used herein is an ideal model for ODS of organic sulfide.
Design and development of high activity ultra-deep oxidation of desulfurization catalyst is one of the most important ways to meet the increasing stringent requirements of petrochemical industry for cleaning fuel standards in the future. Catalysts with Keggin structure aluminum hydroxide polyoxocations(Al13), Al13-SDS and HPW-Al13-SDS(HPW=Keggin structure phosphotungstic acid, SDS=sodium dodecylsulfate) were prepared. The structures of these catalysts were characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD), ultraviolet visible spectroscopy(UV-Vis), Brunauer-Emmett-Teller(BET) and thermogravimetry(TG). The preservation of the Keggin structure on HPW-Al13-SDS catalyst was confirmed by IR and UV-Vis spectra. Catalytic oxidation desulfurization(ODS) reaction over HPW-Al13-SDS with a model of oil(n-hexan solution of organic sulfur) was studied. In optimized condition, up to 99.5% conversion of sulfur was achieved. The efficiencies of ODS decrease from dibenzothiophene to benzothiophene. IR and XRD characterizations of HPW-Al13-SDS catalyst after the reaction show that the catalysts form peroxo-tungsten complexes. The catalytic activity of the recycled HPW-Al13-SDS is almost the same as freshly prepared, and can be recycled via easy separation. The catalyst used herein is an ideal model for ODS of organic sulfide.
2017, 34(11): 1307-1313
doi: 10.11944/j.issn.1000-0518.2017.11.170251
Abstract:
This work presents a novel approach for the electrochemical determination of butylated hydroxyanisole(BHA) and tert-butylhydroquinone(TBHQ) in real cosmetic samples using the indium tin oxide(ITO) electrodes modified with vertically aligned mesoporous silica channels retaining micelles of cetyltrimethylammonium bromide(CTAB). The ultra-small pore size of the channels, namely 2.3 nm in diameter, rendered the size screening capability of the electrode. Meanwhile, the hydrocarbon tails of CTAB provided a hydrophobic microenvironment, which enabled the rapid extraction and preconcentration of lipophilic organic analytes from sample solutions. An excellent analytical sensitivity, a wide dynamic range and a low limit of detection were obtained for both antioxidants under optimized conditions. Recovery values between 96.4% and 104% indicate the practical usefulness of the proposed sensor.
This work presents a novel approach for the electrochemical determination of butylated hydroxyanisole(BHA) and tert-butylhydroquinone(TBHQ) in real cosmetic samples using the indium tin oxide(ITO) electrodes modified with vertically aligned mesoporous silica channels retaining micelles of cetyltrimethylammonium bromide(CTAB). The ultra-small pore size of the channels, namely 2.3 nm in diameter, rendered the size screening capability of the electrode. Meanwhile, the hydrocarbon tails of CTAB provided a hydrophobic microenvironment, which enabled the rapid extraction and preconcentration of lipophilic organic analytes from sample solutions. An excellent analytical sensitivity, a wide dynamic range and a low limit of detection were obtained for both antioxidants under optimized conditions. Recovery values between 96.4% and 104% indicate the practical usefulness of the proposed sensor.
2017, 34(11): 1314-1320
doi: 10.11944/j.issn.1000-0518.2017.11.160509
Abstract:
In order to study the sensitization mechanism of chlorophyll, ethanol extract of spinach chlorophyll served as sensitizers of TiO2 nanotubes electrodes, and the aqueous solution of Na2SO4 was used as electrolyte to measure the photocurrent activity of the as-obtained electrodes. Photocurrent response results show that the TiO2 nanotubes electrode changes its photocurrent value after sensitizing, while the pristine Ti electrode has weak photocurrent response. Cyclic voltammetry curves indicate that the oxidation of sensitized TiO2 electrodes is more reactive than unsensitized ones. The incident photocurrent conversion efficiency(IPCE) of TiO2 electrodes sensitized by extracts from different chlorophyll concentrations was tested. The result shows that, at optimized concentration(7.123~71.23 μg/L), sensitizers can increase the IPCE value of electrodes over 2 times than that before sensitizing, while at high concentration(7123 μg/L), the IPCE value decreases obviously. It is found that the characteristic peak positions of the IPCE spectra change very little between sensitized and unsensitized electrodes. The absorption spectrum of spinach pigment and the sensitization efficiency(SEλ) spectra reveal the mechanism of the enhancement of photoelectric activity as chlorophyll molecules react with photo-generated hole of TiO2 and reduce the rate of electron-hole recombination, resulting in an increased IPCE value of TiO2 nanotube electrodes.
In order to study the sensitization mechanism of chlorophyll, ethanol extract of spinach chlorophyll served as sensitizers of TiO2 nanotubes electrodes, and the aqueous solution of Na2SO4 was used as electrolyte to measure the photocurrent activity of the as-obtained electrodes. Photocurrent response results show that the TiO2 nanotubes electrode changes its photocurrent value after sensitizing, while the pristine Ti electrode has weak photocurrent response. Cyclic voltammetry curves indicate that the oxidation of sensitized TiO2 electrodes is more reactive than unsensitized ones. The incident photocurrent conversion efficiency(IPCE) of TiO2 electrodes sensitized by extracts from different chlorophyll concentrations was tested. The result shows that, at optimized concentration(7.123~71.23 μg/L), sensitizers can increase the IPCE value of electrodes over 2 times than that before sensitizing, while at high concentration(7123 μg/L), the IPCE value decreases obviously. It is found that the characteristic peak positions of the IPCE spectra change very little between sensitized and unsensitized electrodes. The absorption spectrum of spinach pigment and the sensitization efficiency(SEλ) spectra reveal the mechanism of the enhancement of photoelectric activity as chlorophyll molecules react with photo-generated hole of TiO2 and reduce the rate of electron-hole recombination, resulting in an increased IPCE value of TiO2 nanotube electrodes.
2017, 34(11): 1321-1328
doi: 10.11944/j.issn.1000-0518.2017.11.170015
Abstract:
2-Aminoterephthalic acid and 4, 4'-bipyridine ligand with Cu2+ ion was used to prepared three-dimensional(3D) anionic metal-organic framework, namely Cu(BDC-NH2)(4, 4'-Bipy)0.5(BDC=terephthalicacid, Bipy=bipyridine)by hydrothermal method. By X-ray powder diffraction pattern(XRD), Fourier transform infrared spectrum(FT-IR), scanning electron micrographs(SEM), thermogravimetry(TG), N2 absorption-desorption experiment, the composition, structure, morphology, stability and toleration of Cu(BDC-NH2)(4, 4'-Bipy)0.5 were characterized. The adsorption property of the composites on methyl violet(MV) from aqueous solution was investigated. The effects of experimental parameters including the temperature, initial pH value and initial concentration of MV solution were discussed. The experiment data could be well described by the Langmuir equations with pseudo-second-order kinetic model. Thermodynamic parameters ΔG < 0, ΔH < 0 and ΔS < 0 indicate that the MV adsorption onto Cu(BDC-NH2)(4, 4'-Bipy)0.5 is spontaneous and endothermic, and the maximum adsorption capacity value reaches 60.09 mg/g at 193 K and pH=9, indicating that the adsorption ability of Cu(BDC)(4, 4'-Bipy)0.5 towards dyes can be improved by using amino modification..
2-Aminoterephthalic acid and 4, 4'-bipyridine ligand with Cu2+ ion was used to prepared three-dimensional(3D) anionic metal-organic framework, namely Cu(BDC-NH2)(4, 4'-Bipy)0.5(BDC=terephthalicacid, Bipy=bipyridine)by hydrothermal method. By X-ray powder diffraction pattern(XRD), Fourier transform infrared spectrum(FT-IR), scanning electron micrographs(SEM), thermogravimetry(TG), N2 absorption-desorption experiment, the composition, structure, morphology, stability and toleration of Cu(BDC-NH2)(4, 4'-Bipy)0.5 were characterized. The adsorption property of the composites on methyl violet(MV) from aqueous solution was investigated. The effects of experimental parameters including the temperature, initial pH value and initial concentration of MV solution were discussed. The experiment data could be well described by the Langmuir equations with pseudo-second-order kinetic model. Thermodynamic parameters ΔG < 0, ΔH < 0 and ΔS < 0 indicate that the MV adsorption onto Cu(BDC-NH2)(4, 4'-Bipy)0.5 is spontaneous and endothermic, and the maximum adsorption capacity value reaches 60.09 mg/g at 193 K and pH=9, indicating that the adsorption ability of Cu(BDC)(4, 4'-Bipy)0.5 towards dyes can be improved by using amino modification..
2017, 34(11): 1329-1335
doi: 10.11944/j.issn.1000-0518.2017.11.160507
Abstract:
Traditional surfactant-hydrotalcite-like(HTlc) nanocomposites can effectively adsorb the main organic pollutants, such as phenolic pollutants, in water. With high performance Gemini surfactant instead of traditional surfactant, an improved removal efficiency of surfactant-HTlc nanocomposites for organic pollutants is expected. In this paper, Gemini surfactant(MXC6)-HTlc nanocomposite was prepared by delamination/reassembling method. The material was characterised by powder X-ray diffraction, Fourier transform infrared spectroscopy, specific surface area, atomic absorption spectrometry, and elemental analysis. The results show that MXC6 anions are reassembled in the layers of HTlc. The adsorption behavior of p-cresol on MXC6-HTlc nanocomposite was then investigated. The adsorption kinetics and adsorption isotherm of p-cresol on MXC6-HTlc nanocomposite well fitted pseudo-first order kinetics and Linear equation, respectively. These results indicate that the adsorption amount of p-cresol on MXC6-HTlc nanocomposite, is much higher than that on HTlc, and is decreased by increasing either pH(5.00~10.00) or temperature. The adsorption mechanism was discussed in detail. It is confirmed that MXC6-HTlc nanocomposite can be as a new kind of highly effective adsorbent for phenolic pollution from water.
Traditional surfactant-hydrotalcite-like(HTlc) nanocomposites can effectively adsorb the main organic pollutants, such as phenolic pollutants, in water. With high performance Gemini surfactant instead of traditional surfactant, an improved removal efficiency of surfactant-HTlc nanocomposites for organic pollutants is expected. In this paper, Gemini surfactant(MXC6)-HTlc nanocomposite was prepared by delamination/reassembling method. The material was characterised by powder X-ray diffraction, Fourier transform infrared spectroscopy, specific surface area, atomic absorption spectrometry, and elemental analysis. The results show that MXC6 anions are reassembled in the layers of HTlc. The adsorption behavior of p-cresol on MXC6-HTlc nanocomposite was then investigated. The adsorption kinetics and adsorption isotherm of p-cresol on MXC6-HTlc nanocomposite well fitted pseudo-first order kinetics and Linear equation, respectively. These results indicate that the adsorption amount of p-cresol on MXC6-HTlc nanocomposite, is much higher than that on HTlc, and is decreased by increasing either pH(5.00~10.00) or temperature. The adsorption mechanism was discussed in detail. It is confirmed that MXC6-HTlc nanocomposite can be as a new kind of highly effective adsorbent for phenolic pollution from water.
2017, 34(11): 1336-1342
doi: 10.11944/j.issn.1000-0518.2017.11.160522
Abstract:
In order to discuss the possibility of application of Biluochun tea to the adsorption of brilliant green(BG), the optimum adsorption of BG by Biluochun green tea was studied. When the initial solution pH is 4.1, the mass ratio of BG/tea is 833:1, contact time is 45 min and the temperature is (25±1)℃, the adsorption rate of BG by the tea reaches 80%, and the adsorption capacity is 0.96 mg/g. Studies on three desorption agents, sodium hydorxide, acetic acid, and hydrochloric acid show that sodium hydroxide is the optimal desorption agent and the highest desorption rate reaches 93.20% in 1.5 h. The adsorption process fits the Langmuir isotherm adsorption equation in a single molecular layer adsorption mode. The thermodynamic parameters of adsorption process, free energe change ΔG < 0, the enthalpy change ΔH=102.32 kJ/mol>0, the entropy change ΔS=0.33 kJ/(mol·K)>0, indicate that the adsorption process is a spontaneous endothermic process with increasing entropy.
In order to discuss the possibility of application of Biluochun tea to the adsorption of brilliant green(BG), the optimum adsorption of BG by Biluochun green tea was studied. When the initial solution pH is 4.1, the mass ratio of BG/tea is 833:1, contact time is 45 min and the temperature is (25±1)℃, the adsorption rate of BG by the tea reaches 80%, and the adsorption capacity is 0.96 mg/g. Studies on three desorption agents, sodium hydorxide, acetic acid, and hydrochloric acid show that sodium hydroxide is the optimal desorption agent and the highest desorption rate reaches 93.20% in 1.5 h. The adsorption process fits the Langmuir isotherm adsorption equation in a single molecular layer adsorption mode. The thermodynamic parameters of adsorption process, free energe change ΔG < 0, the enthalpy change ΔH=102.32 kJ/mol>0, the entropy change ΔS=0.33 kJ/(mol·K)>0, indicate that the adsorption process is a spontaneous endothermic process with increasing entropy.
