Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separat...Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separation and purification process was evaluated by measuring the concentration of total flavonoid in the fractions with UV spectrophotometer. Results The SP70 macroporous resin was the most effective compared with other macroporous resins. The optimum conditions were screened, which were 0.5 g· mL^- 1 corresponding to crude drug for concentration of extract, pH 5 - 6, and appended 60 times the volume of the resin bed （BV） with the adsorption speed 2 BV·h^-1, and the volume of aq. 70% （V/V） ethanol as eluant was 5 BV with desorption speed 2 BV·h^-1. By this method, the final contents of total flavonoids exceeded 80%. Conclusion The SP70 macroporous resin is the most effective one for large-scale isolation and purification of flavonoids from Radix Pueraria, which meets industrial needs.展开更多
A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibi...A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied （e.g., Ts0 = 331 ~C and Smco2 = 95.3%）. The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot （〈400 ℃） were well within the exhaust temperature range （175-400 ℃）, which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.展开更多
[Objective] This study was conducted to develop a method for rapidly separating macranthoidin B and dipsacoside B from Flos Lonicerae. [Method] HP-20 and HP-SS macroporous resin were applied to separate and purify mac...[Objective] This study was conducted to develop a method for rapidly separating macranthoidin B and dipsacoside B from Flos Lonicerae. [Method] HP-20 and HP-SS macroporous resin were applied to separate and purify macranthoidin B and dipsacoside B from Flos Lonicerae. The extract of Flos Lonicerae was first loaded onto an HP-20 column to enrich saponins, which were then separated by an HP-SS macroporous resin column to get pure macranthoidin B and dipsacoside B.[Result] The optimal HP-20 purification conditions included： a concentration of sample liquid at 4.8 mg/ml, a sample volume of 2 BV, an adsorption flow rate at 1.5BV/h, an ethanol concentration for desorption at 60%, a desorption volume of 3 BV,and a desorption flow rate at 1.5 BV/h. Total saponins were then separated by an HP-SS macroporous resin column which was eluted sequentially by water, 20%ethanol, 30% ethanol, 40% ethanol and 50% ethanol. Two purified compounds were obtained in fractions eluted by 40% ethanol and 50% ethanol, respectively. The two compounds were identified as macranthoidin B and dipsacoside B by13 C and1H nuclear magnetic resonance spectroscopy. [Conclusion] The combination of HP-20 and HP-SS macroporous resin could efficiently separate macranthoidin B and dipsacoside B from Flos Lonicerae.展开更多
Herein, we reported the synthesis of well-defined Co_3O_4 nanoarrays(NAs) supported on a monolithic three-dimensional macroporous nickel(Ni) foam substrate for use in highefficiency CO oxidation. The monolithic Co_3O_...Herein, we reported the synthesis of well-defined Co_3O_4 nanoarrays(NAs) supported on a monolithic three-dimensional macroporous nickel(Ni) foam substrate for use in highefficiency CO oxidation. The monolithic Co_3O_4 NAs catalysts were obtained through a generic hydrothermal synthesis route with subsequent calcination. By controlling the reaction time,solvent polarity and deposition agent, these Co_3O_4 NAs catalysts exhibited various novel morphologies(single or hybrid arrays), whose physicochemical properties were further characterized by using several analytical techniques. Based on the catalytic and characterization analyses, it was found that the Co_3O_4 NAs-6 catalyst with nanobrush and nanomace arrays displayed enhanced catalytic activity for CO oxidation, achieving an efficient 100% CO oxidation conversion at a gas hourly space velocity(GHSV) 10,000 hr^(-1) and 150°C with longterm stability. Compared with the other Co_3O_4 NAs catalysts, it had the highest abundance of surface-adsorbed oxygen species, excellent low-temperature reducibility and was rich in surface-active sites(Co^(3+)/Co^(2+)= 1.26).展开更多
A facile procedure was carried out to prepare macroporous perovskite-type complex oxide catalysts of La1–xKxCo1–yFeyO3(x=0,0.1,y=0,0.1) by using the combined method of organic ligation and solution combustion.This m...A facile procedure was carried out to prepare macroporous perovskite-type complex oxide catalysts of La1–xKxCo1–yFeyO3(x=0,0.1,y=0,0.1) by using the combined method of organic ligation and solution combustion.This method could ensure the formation of the desired macroporous structures and the desired crystal phases of the prepared catalysts.It was found that the macroporous catalysts showed higher catalytic activities for soot combustion than that of the corresponding nanometric samples,and the macroporous ...展开更多
This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure...This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure and polymer properties. The spherical support with the chemical composition of CH3CH2 OMg OCH(CH2Cl)2 has been synthesized from a new dispersion system and is used as the supporting material to prepare Ziegler-Natta catalyst. The XRD analysis indicates that the catalyst is fully activated with δ-Mg Cl2 in the active catalyst. The far-IR spectrometric results confirm again the presence of δ-Mg Cl2 in the active catalyst. Textural property of the active catalyst exhibits high surface area coupled with high porosity. The high activity in propylene polymerization is mainly ascribed to the full activation and the porous structure of the catalyst. Scanning electron microscopy/energy dispersive spectrometer mapping results indicate a uniform titanium distribution throughout the catalyst particles. Particle size analysis shows that the catalyst has a narrow particle size distribution. The perfect spherical shape, uniform titanium distribution and narrow particle size distribution of the catalyst confirm the advantage of polymer particles production with less fines. The solid state 13 C NMR and mid-IR spectroscopic analyses indicate that there exists strong complexation between diisobutyl phthalate and Mg Cl2, which leads to the high isotacticity of polypropylene.展开更多
An aminated hypercrosslinked macroporous polymeric adsorbent was synthesized and characterized. Adsorption isotherms for 1 amino 2 naphthol 4 sulfonic acid(1, 2, 4 acid) and 2 naphthol obtained from various bin...An aminated hypercrosslinked macroporous polymeric adsorbent was synthesized and characterized. Adsorption isotherms for 1 amino 2 naphthol 4 sulfonic acid(1, 2, 4 acid) and 2 naphthol obtained from various binary adsorption environments can be well fitted by Freundlich equation, which indicated a favorable adsorption process in the studied range. Adsorption for 1, 2, 4 acid was an endothermic process in comparison with that for 2 naphthol of an exothermic process. 2 naphthol molecules put a little influence on the adsorption capacity for 1, 2, 4 acid. However, the adsorption to 1, 2, 4 acid depressed that to 2 naphthol in a large extent for the stronger electrostatic interaction between 1, 2, 4 acid and adsorbent. The predominant mechanism can be contributed to the competition for adsorption sites. And the simultaneous environment was confirmed to be helpful to the selective adsorption towards 1,2,4 acid based on the larger selectivity index.展开更多
Arabinogalactan （AG） obtained from Larix gmelinii R. waS purified with the method of macroporous resin adsorption. Effects of various parameters on the adsorption, including adsorption time and temperature, the conc...Arabinogalactan （AG） obtained from Larix gmelinii R. waS purified with the method of macroporous resin adsorption. Effects of various parameters on the adsorption, including adsorption time and temperature, the concentration and the dosage of raw AG the reused numbers of resin, were investigated. The effect of purification was tested through the removal rate of impurity and the contents of AG and impurity. The optimal condition was determined as follows： adsorbed at 30℃ for 2 h with the concentration of raw AG 〈0.1 g·mL^-1 and its dosage 〈 7 mL, the dose of resin was 3 g and reused for 4 times. On the basis of these, macroporous resin column was used for AG purification. The result showed that the AG yield could reach 68.28% with sugar content of 95.02%. The analysis of IR and UV showed that the effect of macroporous resin characteristics on the purification of AG was significant. The obtained product had the same functional groups with standard sample.展开更多
Flavonoids are one main kind of effective components in Houttuynia cordata Thunb., which display a wide range of pharmacological activity. In this study supercritical fluid extraction （SFE） with carbon dioxide was f...Flavonoids are one main kind of effective components in Houttuynia cordata Thunb., which display a wide range of pharmacological activity. In this study supercritical fluid extraction （SFE） with carbon dioxide was first used as preparat ion step to remove the volatile components, which are also active components, from Hout-tuynia cordata Thunb. Then ultrasound-assisted extraction was used to obtain the crude flavonoids and the macro-porous resin adsorption technology was further employed to purify the flavonoids. Nine kinds of macroporous resins with different properties were tested through static adsorption, and one macroporous resin labeled as D101 was selected. The effect of several factors, such as the ratio of column height to diameter, initial concentration and pH, on both flavonoids yield and content were explored by dynamic adsorption to obtain reasonable conditions of adsorption and desorption. The experimental results show that the content of fiavonoids can be above 60% with fia- vonoids recovery of 93.3 % under the optimum conditions of purification. HPLC analysis of the final flavonoids product shows it contains quercitrin, hypefin, rutin and quercetin.展开更多
Three-dimensionally ordered（3DOM） macroporous phosphotungstic acid/SiO_2（HPW/SiO_2） materials were prepared by using colloidal crystal as templates and applied for oxidative desulfurization（ODS） of the model fue...Three-dimensionally ordered（3DOM） macroporous phosphotungstic acid/SiO_2（HPW/SiO_2） materials were prepared by using colloidal crystal as templates and applied for oxidative desulfurization（ODS） of the model fuel oil. The obtained HPW/SiO_2 materials were characterized through scanning electron microscopy, powder X-ray diffraction, N_2 sorption, and Fourier transform infrared spectroscopy. The results indicated that 3 DOM HPW/SiO_2 possessed hierarchical pore architectures which contained ordered macropores and disordered mesopores, with the Keggin type HPW embedded in the framework of pore structure. The removal rate of dibenzothiophene（DBT） could reach 100% under the optimum conditions, moreover. The performance was only slightly decreased for the regenerated catalyst after 7 cycles.展开更多
Macroporous magnetic poly(GMA-EGDMA-DVB) microspheres synthesized by suspension polymerization were used as supports for palladium catalyst.The results showed the novel magnetic catalyst can promote Heck reaction of a...Macroporous magnetic poly(GMA-EGDMA-DVB) microspheres synthesized by suspension polymerization were used as supports for palladium catalyst.The results showed the novel magnetic catalyst can promote Heck reaction of aryl halides with acrylic acid efficiently without an inert atmosphere.In addition,the novel catalyst can be conveniently recovered by applying an external magnet and reused at least five times without significant loss of its activity.展开更多
Monolithic macroporous Pt/CeO2/Al2O3 and zirconia modified Pt/CeO2/Al2O3 catalysts were prepared by using concentrated emulsions synthesis route. The catalytic performances over the platinum-based catalysts were inves...Monolithic macroporous Pt/CeO2/Al2O3 and zirconia modified Pt/CeO2/Al2O3 catalysts were prepared by using concentrated emulsions synthesis route. The catalytic performances over the platinum-based catalysts were investigated by water-gas shift （WGS） reaction in a wide temperature range （180–300 oC）. The samples were characterized with thermogravimetry （TG）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, high resolution transmission electron microscopy （HRTEM） and temperature programmed reduction （TPR） techniques as well. The SEM and HRTEM results indicated that the monoliths possessed macroporosity, in size of 5–50 μm, and platinum particles were homogeneously dispersed on macroporous materials. XRD and TPR results showed that the interaction between ceria and zirconia oxide was formed and the addition of zirconia could promote the reducibility of platinum oxide on the interface of ceria and zirconia particles, which led to an improvement of catalytic activity in WGS reaction. The results indicated that zirconia modified monolithic macroporous Pt/CeO2/Al2O3 could be fabricated in small size （from millimeter lever to centimeter） and had good reaction activity, which was a potential new route for miniaturization of the WGS reactor.展开更多
The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microsp...The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microspheres were prepared by emulsifier-free emulsion polymerization using methacrylic acid(MAA) as the functional monomer. PS microspheres were self-assembled into close packing colloidal crystals of facecentered cubic arrays to the substrate with vertical deposition method. These colloidal crystals were modified using dopamine(DA) to form poly-dopamine(PDA) during its oxidative polymerization. Through electrostatic interaction, the silver nanoparticles were deposited and adsorbed onto the surfaces of colloidal crystals templates by exposing [Ag(NH_3)_2]^+solution to infrared irradiation. Removal of the polymeric template by etching with methylbenzene solvent resulted in 3D ordered macroporous silver films. The structural and properties of the ordered silver-coated arrays and macroporous silver films were characterized by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD), UV-vis spectroscopy and surface-enhanced Raman spectroscopy(SERS). The results indicate that the prepared silver-coated arrays and macroporous silver films possess the features of ordered multilayer arrangement, uniformity and repeatability as well as an ideal SERS effect.展开更多
In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. Wit...In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. With an orthogonal test the optimal conditions of synthesis were determined： the concentration of sodium hydroxide solution 1.0 mol.L^-1; the reaction time is one hour and the mass concentration of tannins 5%. With single factorial experiment the optimal conditions of adsorption were confirmed： a solidified pH of 5.0; an adsorption temperature of 25℃ and a cation dye concentration of 100 mg.L^-1. The adsorption for cation dye can be similar to Langmuir isotherms.展开更多
Tje adsorption bchavior and mechanism of a novel chelate resin,macroporous phosphonic acid resin（PAR）for Ni（Ⅱ）were imestigated.The stotically saturated adsorption capacity is 64.3mg·g^-1 resin at 298K in HAc...Tje adsorption bchavior and mechanism of a novel chelate resin,macroporous phosphonic acid resin（PAR）for Ni（Ⅱ）were imestigated.The stotically saturated adsorption capacity is 64.3mg·g^-1 resin at 298K in HAc-NaAc medium.The Ni（Ⅱ）adsorbed on PAR can be eluted by 0.5mal·L^-1 HCl and the elution percentage reaches 96.6%.The resin can be regenerated and reused without abvious decrease in adsorption capacity.The apparent adsorption rate constant is k298=2.6×10^-5s^-1.The adsorption behavior of PAR for Ni（Ⅱ）obeys the Freundllich isotherm.The thermodynamie adsorption parameters.enthalpy change △H,free energy change △G and entropy change △S of PAR for Ni（Ⅱ）are 3.36kJ·mol^-1,-5.47kJ·mol^-1 and 29.6J·mol^-1·K^-1,respectively.The apparent activation energy is Ea=12.2kJ·mol^-1,The molar coordination ratio of the functional group of PAR to Ni（Ⅱ）is about 4：1.The adsorption mechanism of PAR for Ni（Ⅱ）was examined by a chemical method and IR spectrometry.展开更多
A novelty method,frontal polymerization(FP),was employed to directly produce a series of polyacrylamide (PAM),poly(N-isopropylacrylamide)(PNIPAM) and acrylamide-N-isopropylacrylamide copolymer macroporous monoliths. F...A novelty method,frontal polymerization(FP),was employed to directly produce a series of polyacrylamide (PAM),poly(N-isopropylacrylamide)(PNIPAM) and acrylamide-N-isopropylacrylamide copolymer macroporous monoliths. Field emission scanning electronic microscope and mercury intrusion method were adopted to measure some parameters of these monoliths,such as frame,pore size distribution as well as porosity.Effects of types of monomer,thicker and surfactant on porous structure of monoliths were studied.A variet...展开更多
AIM： To prepare high-purity ginseng total saponins from a water decoction of Chinese ginseng root.METHOD： Total saponins were efficiently purified by dynamic anion-cation exchange following the removal of hydrophili...AIM： To prepare high-purity ginseng total saponins from a water decoction of Chinese ginseng root.METHOD： Total saponins were efficiently purified by dynamic anion-cation exchange following the removal of hydrophilic impurities by macroporous resin D101. For quality control, ultrahigh-performance liquid chromatography with a charged aerosol detector （CAD） was applied to quantify marker components. The total saponin content was estimated by a colorimetric method using a vanillin-vitriol system and CAD response. RESULTS： D201, which consisted of a cross-linked polystyrene matrix and -]N＋（CI-13）3 functional groups, was the best of the four anion exchange resins tested. However, no significant difference in cation exchange ability was observed between D001 （strong acid） and D 113 （weak acid）, although they have different functional groups and matrices. After purification in combination with D101, D201, and D 113, the estimated contents of total saponins were 107% and 90% according to the colorimetric method and CAD response, respectively. The total amount of representative ginsenosides Re, Rd, Rgl, and compound K was approximately 22% based on ultrahigh-performance liquid chromatography-CAD quantitative analysis. CONCLUSION： These findings suggest that an ion exchange resin, combined with macroporous adsorption resin separation, is a promising and feasible purification procedure for neutral natural polar components.展开更多
Chemical-looping steam methane reforming （CL-SMR） is a novel process towards the production of pure hydrogen and syngas, consisting ofa syngas production reaction and a hydrogen production reaction. Macroporous CeQ-...Chemical-looping steam methane reforming （CL-SMR） is a novel process towards the production of pure hydrogen and syngas, consisting ofa syngas production reaction and a hydrogen production reaction. Macroporous CeQ-ZrO2 oxygen carders with different pore sizes prepared by colloidal crystal templating method and characterized by techniques of scalming electron microscopy （SEM）, transmission electron microscopy （TEM）, Brunauer-Emmett-Teller （BET）, X-ray diffraction （XRD） and temperature pro- grammed reduction （H2-TPR） were tested in CL-SMR process. For comparison, nonporous CeO2-ZrO2 oxygen carrier prepared by precipitation method was also investigated. It was found that macroporous CeO2-ZrO2 oxygen carriers owned higher reducibility and reactivity in CL-SMR process than nonporous samples. For the macroporous CeO2-ZrO2 sample, the decline of pore size could im- prove the reducibility and reactivity. The macroporous sample with a pore size of 100 nm （labeled as Ce-Zr-100） showed the highest performance for the co-production of syngas and hydrogen during the successive CL-SMR redox cycles. After 10 redox cycles, it still retained good porous structure and reducibility. It was found that the porous structure could accelerate the oxygen release from bulk to surface, leading to a good mobility of oxygen and higher reducibility. In addition, it was also favorable for diffusion and penetration of methane and water steam into the sample particles to accelerate the reaction rate.展开更多
Oridonin,one of the active ingredients in Rabdosia rubescens(R.rubescens),has been reported to induce cell apoptosis and cell cycle arrest in many cancers.Conventional extraction methods tend to result in unsatisfied ...Oridonin,one of the active ingredients in Rabdosia rubescens(R.rubescens),has been reported to induce cell apoptosis and cell cycle arrest in many cancers.Conventional extraction methods tend to result in unsatisfied enrichment and poor quality of oridonin present in a given biomass.This paper aims to evaluate the performance and separation characteristics of four different macroporous resins to arrive at the most suitable methodology for the isolation and purification of highquality oridonin.Static absorption kinetics,thermodynamic and dynamic adsorption were evaluated.HP20 was selected for further study due to its high adsorption capacity of 32 mgg 1 and desorption ratio with 98.5%.The pseudosecondorder model was considered to be the most suitable for kinetic results,and Langmuir model was chosen to better describe the absorption thermodynamics.Under optimum conditions(flow rate of 4 ml min 1,bed depth with 6 cm and initial concentration of 2.15 mg·ml^1),the effective content of oridonin increased from 33.9%to 79.1%in the dry extract with a recovery of 81%and the purity of oridonin improved from 76%to 93%.The results confirm that HP20 provides an efficient method to purify most oridonin from R.rubescens.展开更多
A series of macroporous CuO-ZnO-ZrO2 （CZZ） catalysts with different Zn/Zr ratios were successfully prepared by template method and characterized by X-ray diffraction （XRD）, N2 adsorption, reactive N2O adsorption, ...A series of macroporous CuO-ZnO-ZrO2 （CZZ） catalysts with different Zn/Zr ratios were successfully prepared by template method and characterized by X-ray diffraction （XRD）, N2 adsorption, reactive N2O adsorption, scanning electron microscopy （SEM）, H2 temperature-pro- grammed reduction （H2-TPR）, and transmission electron microscopy （TEM）. The activity of the catalysts was tested for methanol synthesis from CO2 hydrogenation. It is found that the increase in the Zn/Zr ratio could lead to the sintering of the catalysts, destroying the macroporous structure integrity. The macroporous CZZ catalysts own lower Zn/Zr ratio, exhibiting a better morphology and activity. For comparison, the conventional nonporous CZZ catalysts were also investigated. The results show that the CZZ catalysts with macroporous structure own smaller particles, higher CO2 conversion, and CH3OH yield. It reveals that the macroporous structure could inhibit the growth of the par- ticle size, and the special porous structure is favorable for diffusion and penetration of CO2, which could improve the catalytic activities.展开更多
基金Science and Technology Committee of Chongqing inChina(CSTC.2004BB5122).
文摘Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separation and purification process was evaluated by measuring the concentration of total flavonoid in the fractions with UV spectrophotometer. Results The SP70 macroporous resin was the most effective compared with other macroporous resins. The optimum conditions were screened, which were 0.5 g· mL^- 1 corresponding to crude drug for concentration of extract, pH 5 - 6, and appended 60 times the volume of the resin bed （BV） with the adsorption speed 2 BV·h^-1, and the volume of aq. 70% （V/V） ethanol as eluant was 5 BV with desorption speed 2 BV·h^-1. By this method, the final contents of total flavonoids exceeded 80%. Conclusion The SP70 macroporous resin is the most effective one for large-scale isolation and purification of flavonoids from Radix Pueraria, which meets industrial needs.
基金supported by the National Natural Science Foundation of China(21177160,21303263,21477164)Beijing Nova Program(Z141109001814072)+1 种基金Specialized Research Fund for the Doctoral Program of High Education of China(20130007120011)the Science Foundation of China University of Petroleum-Beijing(2462013YJRC13,2462013BJRC003)~~
文摘A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied （e.g., Ts0 = 331 ~C and Smco2 = 95.3%）. The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot （〈400 ℃） were well within the exhaust temperature range （175-400 ℃）, which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.
基金Supported by Guangxi Scientific Research and Technological Development Planning Project(20130403-2)Technology Research and Development Program of Guangxi Province(GKH15104001-15)+1 种基金Special Fund for Bagui Scholars of the Guangxi Zhuang Autonomous RegionDirector Fund Project of Guangxi Key Laboratory of Functional Phytochemicals Research and Utilization(ZRJJ2016-4)~~
文摘[Objective] This study was conducted to develop a method for rapidly separating macranthoidin B and dipsacoside B from Flos Lonicerae. [Method] HP-20 and HP-SS macroporous resin were applied to separate and purify macranthoidin B and dipsacoside B from Flos Lonicerae. The extract of Flos Lonicerae was first loaded onto an HP-20 column to enrich saponins, which were then separated by an HP-SS macroporous resin column to get pure macranthoidin B and dipsacoside B.[Result] The optimal HP-20 purification conditions included： a concentration of sample liquid at 4.8 mg/ml, a sample volume of 2 BV, an adsorption flow rate at 1.5BV/h, an ethanol concentration for desorption at 60%, a desorption volume of 3 BV,and a desorption flow rate at 1.5 BV/h. Total saponins were then separated by an HP-SS macroporous resin column which was eluted sequentially by water, 20%ethanol, 30% ethanol, 40% ethanol and 50% ethanol. Two purified compounds were obtained in fractions eluted by 40% ethanol and 50% ethanol, respectively. The two compounds were identified as macranthoidin B and dipsacoside B by13 C and1H nuclear magnetic resonance spectroscopy. [Conclusion] The combination of HP-20 and HP-SS macroporous resin could efficiently separate macranthoidin B and dipsacoside B from Flos Lonicerae.
基金supported by Science and Technology Planning Project of Guangdong Province China (No.2015B0202236002)the National Natural Science Foundation of China (Nos.21401200,51108187,51672273,B5151050)+2 种基金the National Key R & D Plan (No.2017YFC0211503)the Open Research Fund of State Key Laboratory of Multi-phase Complex Systems (No.MPCS-2017-D-06)the Guangdong Natural Science Foundation (No.2016A030311003)
文摘Herein, we reported the synthesis of well-defined Co_3O_4 nanoarrays(NAs) supported on a monolithic three-dimensional macroporous nickel(Ni) foam substrate for use in highefficiency CO oxidation. The monolithic Co_3O_4 NAs catalysts were obtained through a generic hydrothermal synthesis route with subsequent calcination. By controlling the reaction time,solvent polarity and deposition agent, these Co_3O_4 NAs catalysts exhibited various novel morphologies(single or hybrid arrays), whose physicochemical properties were further characterized by using several analytical techniques. Based on the catalytic and characterization analyses, it was found that the Co_3O_4 NAs-6 catalyst with nanobrush and nanomace arrays displayed enhanced catalytic activity for CO oxidation, achieving an efficient 100% CO oxidation conversion at a gas hourly space velocity(GHSV) 10,000 hr^(-1) and 150°C with longterm stability. Compared with the other Co_3O_4 NAs catalysts, it had the highest abundance of surface-adsorbed oxygen species, excellent low-temperature reducibility and was rich in surface-active sites(Co^(3+)/Co^(2+)= 1.26).
基金supported by the National Natural Science Foundation of China (20833011 and 20803093)the 863 Project of China (2006AA06Z346)
文摘A facile procedure was carried out to prepare macroporous perovskite-type complex oxide catalysts of La1–xKxCo1–yFeyO3(x=0,0.1,y=0,0.1) by using the combined method of organic ligation and solution combustion.This method could ensure the formation of the desired macroporous structures and the desired crystal phases of the prepared catalysts.It was found that the macroporous catalysts showed higher catalytic activities for soot combustion than that of the corresponding nanometric samples,and the macroporous ...
基金the financial support by the National Natural Science Foundation of China (No. 20973022 and No. 11472048)
文摘This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure and polymer properties. The spherical support with the chemical composition of CH3CH2 OMg OCH(CH2Cl)2 has been synthesized from a new dispersion system and is used as the supporting material to prepare Ziegler-Natta catalyst. The XRD analysis indicates that the catalyst is fully activated with δ-Mg Cl2 in the active catalyst. The far-IR spectrometric results confirm again the presence of δ-Mg Cl2 in the active catalyst. Textural property of the active catalyst exhibits high surface area coupled with high porosity. The high activity in propylene polymerization is mainly ascribed to the full activation and the porous structure of the catalyst. Scanning electron microscopy/energy dispersive spectrometer mapping results indicate a uniform titanium distribution throughout the catalyst particles. Particle size analysis shows that the catalyst has a narrow particle size distribution. The perfect spherical shape, uniform titanium distribution and narrow particle size distribution of the catalyst confirm the advantage of polymer particles production with less fines. The solid state 13 C NMR and mid-IR spectroscopic analyses indicate that there exists strong complexation between diisobutyl phthalate and Mg Cl2, which leads to the high isotacticity of polypropylene.
文摘An aminated hypercrosslinked macroporous polymeric adsorbent was synthesized and characterized. Adsorption isotherms for 1 amino 2 naphthol 4 sulfonic acid(1, 2, 4 acid) and 2 naphthol obtained from various binary adsorption environments can be well fitted by Freundlich equation, which indicated a favorable adsorption process in the studied range. Adsorption for 1, 2, 4 acid was an endothermic process in comparison with that for 2 naphthol of an exothermic process. 2 naphthol molecules put a little influence on the adsorption capacity for 1, 2, 4 acid. However, the adsorption to 1, 2, 4 acid depressed that to 2 naphthol in a large extent for the stronger electrostatic interaction between 1, 2, 4 acid and adsorbent. The predominant mechanism can be contributed to the competition for adsorption sites. And the simultaneous environment was confirmed to be helpful to the selective adsorption towards 1,2,4 acid based on the larger selectivity index.
基金This research was supported by Important Tackle Key Problem of Heilongjiang Province (GB05B601-02)Youth Fund of Northeast Forestry University (200403-10).
文摘Arabinogalactan （AG） obtained from Larix gmelinii R. waS purified with the method of macroporous resin adsorption. Effects of various parameters on the adsorption, including adsorption time and temperature, the concentration and the dosage of raw AG the reused numbers of resin, were investigated. The effect of purification was tested through the removal rate of impurity and the contents of AG and impurity. The optimal condition was determined as follows： adsorbed at 30℃ for 2 h with the concentration of raw AG 〈0.1 g·mL^-1 and its dosage 〈 7 mL, the dose of resin was 3 g and reused for 4 times. On the basis of these, macroporous resin column was used for AG purification. The result showed that the AG yield could reach 68.28% with sugar content of 95.02%. The analysis of IR and UV showed that the effect of macroporous resin characteristics on the purification of AG was significant. The obtained product had the same functional groups with standard sample.
文摘Flavonoids are one main kind of effective components in Houttuynia cordata Thunb., which display a wide range of pharmacological activity. In this study supercritical fluid extraction （SFE） with carbon dioxide was first used as preparat ion step to remove the volatile components, which are also active components, from Hout-tuynia cordata Thunb. Then ultrasound-assisted extraction was used to obtain the crude flavonoids and the macro-porous resin adsorption technology was further employed to purify the flavonoids. Nine kinds of macroporous resins with different properties were tested through static adsorption, and one macroporous resin labeled as D101 was selected. The effect of several factors, such as the ratio of column height to diameter, initial concentration and pH, on both flavonoids yield and content were explored by dynamic adsorption to obtain reasonable conditions of adsorption and desorption. The experimental results show that the content of fiavonoids can be above 60% with fia- vonoids recovery of 93.3 % under the optimum conditions of purification. HPLC analysis of the final flavonoids product shows it contains quercitrin, hypefin, rutin and quercetin.
基金the National Nature Science Foundation of China(No.21476177)
文摘Three-dimensionally ordered（3DOM） macroporous phosphotungstic acid/SiO_2（HPW/SiO_2） materials were prepared by using colloidal crystal as templates and applied for oxidative desulfurization（ODS） of the model fuel oil. The obtained HPW/SiO_2 materials were characterized through scanning electron microscopy, powder X-ray diffraction, N_2 sorption, and Fourier transform infrared spectroscopy. The results indicated that 3 DOM HPW/SiO_2 possessed hierarchical pore architectures which contained ordered macropores and disordered mesopores, with the Keggin type HPW embedded in the framework of pore structure. The removal rate of dibenzothiophene（DBT） could reach 100% under the optimum conditions, moreover. The performance was only slightly decreased for the regenerated catalyst after 7 cycles.
文摘Macroporous magnetic poly(GMA-EGDMA-DVB) microspheres synthesized by suspension polymerization were used as supports for palladium catalyst.The results showed the novel magnetic catalyst can promote Heck reaction of aryl halides with acrylic acid efficiently without an inert atmosphere.In addition,the novel catalyst can be conveniently recovered by applying an external magnet and reused at least five times without significant loss of its activity.
文摘Monolithic macroporous Pt/CeO2/Al2O3 and zirconia modified Pt/CeO2/Al2O3 catalysts were prepared by using concentrated emulsions synthesis route. The catalytic performances over the platinum-based catalysts were investigated by water-gas shift （WGS） reaction in a wide temperature range （180–300 oC）. The samples were characterized with thermogravimetry （TG）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, high resolution transmission electron microscopy （HRTEM） and temperature programmed reduction （TPR） techniques as well. The SEM and HRTEM results indicated that the monoliths possessed macroporosity, in size of 5–50 μm, and platinum particles were homogeneously dispersed on macroporous materials. XRD and TPR results showed that the interaction between ceria and zirconia oxide was formed and the addition of zirconia could promote the reducibility of platinum oxide on the interface of ceria and zirconia particles, which led to an improvement of catalytic activity in WGS reaction. The results indicated that zirconia modified monolithic macroporous Pt/CeO2/Al2O3 could be fabricated in small size （from millimeter lever to centimeter） and had good reaction activity, which was a potential new route for miniaturization of the WGS reactor.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50873085 and 21375116)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microspheres were prepared by emulsifier-free emulsion polymerization using methacrylic acid(MAA) as the functional monomer. PS microspheres were self-assembled into close packing colloidal crystals of facecentered cubic arrays to the substrate with vertical deposition method. These colloidal crystals were modified using dopamine(DA) to form poly-dopamine(PDA) during its oxidative polymerization. Through electrostatic interaction, the silver nanoparticles were deposited and adsorbed onto the surfaces of colloidal crystals templates by exposing [Ag(NH_3)_2]^+solution to infrared irradiation. Removal of the polymeric template by etching with methylbenzene solvent resulted in 3D ordered macroporous silver films. The structural and properties of the ordered silver-coated arrays and macroporous silver films were characterized by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD), UV-vis spectroscopy and surface-enhanced Raman spectroscopy(SERS). The results indicate that the prepared silver-coated arrays and macroporous silver films possess the features of ordered multilayer arrangement, uniformity and repeatability as well as an ideal SERS effect.
文摘In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. With an orthogonal test the optimal conditions of synthesis were determined： the concentration of sodium hydroxide solution 1.0 mol.L^-1; the reaction time is one hour and the mass concentration of tannins 5%. With single factorial experiment the optimal conditions of adsorption were confirmed： a solidified pH of 5.0; an adsorption temperature of 25℃ and a cation dye concentration of 100 mg.L^-1. The adsorption for cation dye can be similar to Langmuir isotherms.
文摘Tje adsorption bchavior and mechanism of a novel chelate resin,macroporous phosphonic acid resin（PAR）for Ni（Ⅱ）were imestigated.The stotically saturated adsorption capacity is 64.3mg·g^-1 resin at 298K in HAc-NaAc medium.The Ni（Ⅱ）adsorbed on PAR can be eluted by 0.5mal·L^-1 HCl and the elution percentage reaches 96.6%.The resin can be regenerated and reused without abvious decrease in adsorption capacity.The apparent adsorption rate constant is k298=2.6×10^-5s^-1.The adsorption behavior of PAR for Ni（Ⅱ）obeys the Freundllich isotherm.The thermodynamie adsorption parameters.enthalpy change △H,free energy change △G and entropy change △S of PAR for Ni（Ⅱ）are 3.36kJ·mol^-1,-5.47kJ·mol^-1 and 29.6J·mol^-1·K^-1,respectively.The apparent activation energy is Ea=12.2kJ·mol^-1,The molar coordination ratio of the functional group of PAR to Ni（Ⅱ）is about 4：1.The adsorption mechanism of PAR for Ni（Ⅱ）was examined by a chemical method and IR spectrometry.
基金supported by the National Natural Science Foundation of China(No50772013)
文摘A novelty method,frontal polymerization(FP),was employed to directly produce a series of polyacrylamide (PAM),poly(N-isopropylacrylamide)(PNIPAM) and acrylamide-N-isopropylacrylamide copolymer macroporous monoliths. Field emission scanning electronic microscope and mercury intrusion method were adopted to measure some parameters of these monoliths,such as frame,pore size distribution as well as porosity.Effects of types of monomer,thicker and surfactant on porous structure of monoliths were studied.A variet...
基金supported by the Jiangsu Provincial Natural Science Foundation of China(No.BK2011815)Specialized Research Fund for the Doctoral Program of Higher Education(No.20103237120011)the"Qing Lan"Project from Jiangsu Provincial Framework Teacher Support Scheme
文摘AIM： To prepare high-purity ginseng total saponins from a water decoction of Chinese ginseng root.METHOD： Total saponins were efficiently purified by dynamic anion-cation exchange following the removal of hydrophilic impurities by macroporous resin D101. For quality control, ultrahigh-performance liquid chromatography with a charged aerosol detector （CAD） was applied to quantify marker components. The total saponin content was estimated by a colorimetric method using a vanillin-vitriol system and CAD response. RESULTS： D201, which consisted of a cross-linked polystyrene matrix and -]N＋（CI-13）3 functional groups, was the best of the four anion exchange resins tested. However, no significant difference in cation exchange ability was observed between D001 （strong acid） and D 113 （weak acid）, although they have different functional groups and matrices. After purification in combination with D101, D201, and D 113, the estimated contents of total saponins were 107% and 90% according to the colorimetric method and CAD response, respectively. The total amount of representative ginsenosides Re, Rd, Rgl, and compound K was approximately 22% based on ultrahigh-performance liquid chromatography-CAD quantitative analysis. CONCLUSION： These findings suggest that an ion exchange resin, combined with macroporous adsorption resin separation, is a promising and feasible purification procedure for neutral natural polar components.
基金Project supported by National Natural Science Foundation of China(51104074,51204083,51174105,51374004)the Applied Basic Research Program of Yunnan Province(2012FD016)the Candidate Talents Training Fund of Yunnan Province(2012HB009)
文摘Chemical-looping steam methane reforming （CL-SMR） is a novel process towards the production of pure hydrogen and syngas, consisting ofa syngas production reaction and a hydrogen production reaction. Macroporous CeQ-ZrO2 oxygen carders with different pore sizes prepared by colloidal crystal templating method and characterized by techniques of scalming electron microscopy （SEM）, transmission electron microscopy （TEM）, Brunauer-Emmett-Teller （BET）, X-ray diffraction （XRD） and temperature pro- grammed reduction （H2-TPR） were tested in CL-SMR process. For comparison, nonporous CeO2-ZrO2 oxygen carrier prepared by precipitation method was also investigated. It was found that macroporous CeO2-ZrO2 oxygen carriers owned higher reducibility and reactivity in CL-SMR process than nonporous samples. For the macroporous CeO2-ZrO2 sample, the decline of pore size could im- prove the reducibility and reactivity. The macroporous sample with a pore size of 100 nm （labeled as Ce-Zr-100） showed the highest performance for the co-production of syngas and hydrogen during the successive CL-SMR redox cycles. After 10 redox cycles, it still retained good porous structure and reducibility. It was found that the porous structure could accelerate the oxygen release from bulk to surface, leading to a good mobility of oxygen and higher reducibility. In addition, it was also favorable for diffusion and penetration of methane and water steam into the sample particles to accelerate the reaction rate.
基金the National Natural Science Foundation of China(21676145)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD,China).
文摘Oridonin,one of the active ingredients in Rabdosia rubescens(R.rubescens),has been reported to induce cell apoptosis and cell cycle arrest in many cancers.Conventional extraction methods tend to result in unsatisfied enrichment and poor quality of oridonin present in a given biomass.This paper aims to evaluate the performance and separation characteristics of four different macroporous resins to arrive at the most suitable methodology for the isolation and purification of highquality oridonin.Static absorption kinetics,thermodynamic and dynamic adsorption were evaluated.HP20 was selected for further study due to its high adsorption capacity of 32 mgg 1 and desorption ratio with 98.5%.The pseudosecondorder model was considered to be the most suitable for kinetic results,and Langmuir model was chosen to better describe the absorption thermodynamics.Under optimum conditions(flow rate of 4 ml min 1,bed depth with 6 cm and initial concentration of 2.15 mg·ml^1),the effective content of oridonin increased from 33.9%to 79.1%in the dry extract with a recovery of 81%and the purity of oridonin improved from 76%to 93%.The results confirm that HP20 provides an efficient method to purify most oridonin from R.rubescens.
基金financially supported by the National Key Technologies Research & Development Program of China(No.2011BAC01B03)the National Natural Science Foundation of China(No.51304099)+1 种基金the Applied Basic Research Program of Yunnan Province(No.2013FZ035)the Testing and Analyzing Foundation of Kunming University of Science and Technology(No. 2010213)
文摘A series of macroporous CuO-ZnO-ZrO2 （CZZ） catalysts with different Zn/Zr ratios were successfully prepared by template method and characterized by X-ray diffraction （XRD）, N2 adsorption, reactive N2O adsorption, scanning electron microscopy （SEM）, H2 temperature-pro- grammed reduction （H2-TPR）, and transmission electron microscopy （TEM）. The activity of the catalysts was tested for methanol synthesis from CO2 hydrogenation. It is found that the increase in the Zn/Zr ratio could lead to the sintering of the catalysts, destroying the macroporous structure integrity. The macroporous CZZ catalysts own lower Zn/Zr ratio, exhibiting a better morphology and activity. For comparison, the conventional nonporous CZZ catalysts were also investigated. The results show that the CZZ catalysts with macroporous structure own smaller particles, higher CO2 conversion, and CH3OH yield. It reveals that the macroporous structure could inhibit the growth of the par- ticle size, and the special porous structure is favorable for diffusion and penetration of CO2, which could improve the catalytic activities.
