壳聚糖凝胶球的制备及对银离子的吸附

以壳聚糖(CTS)为基材、硝酸银为印迹物,提出了一种新的CTS水凝胶球的制备方法.采用Ag+吸附容量作为评价指标,对凝胶球的制备条件进行了优化,并进行了吸附试验.结果显示,当CTS用量为质量分数2.5%、交联剂用量为体积分数3.0%、凝固浴三乙醇胺的质量分数为10.0%、制备温度为25℃,热处理温度为60℃,洗脱剂硫代...     

Constructing a Carbon-Encapsulated Carbon Composite Material with Hierarchically Porous Architectures for Efficient Capacitive Storage in Organic Supercapacitors

Hierarchical porous activated carbon (HPAC) materials with fascinating porous features are favored for their function as active materials for supercapacitors. However, achieving high mass-loading of the HPAC electrodes remains challenging. Inspired by the concepts of carbon/carbon (C/C) composites and hydrogels, a novel hydrogel-derived HPAC (H-HPAC) encapsulated H-HPAC (H@H) composite material was successfully synthesized in this study. In comparison with the original H-HPAC, it is noticed that the specific surface area and pore parameters of the resulting H@H are observably decreased, while the proportions of nitrogen species are dramatically enhanced. The free-standing and flexible H@H electrodes with a mass-loading of 7.5 mg/cm² are further prepared for electrochemical measurements. The experiments revealed remarkable reversible capacitance (118.6 F/g at 1 mA/cm²), rate capability (73.9 F/g at 10 mA/cm²), and cycling stability (76.6% of retention after 30,000 cycles at 5 mA) are delivered by the coin-type symmetric cells. The cycling stability is even better than that of the H-HPAC electrode. Consequently, the findings of the present study suggest that the nature of the HPAC surface is a significant factor affecting the corresponding capacitive performances.     

多孔二氧化硅对酸性橙吸附性能的研究

以水玻璃和盐酸为原料,采用化学沉淀法制备出多孔、高比表面积的SiO2。改变灼烧温度,得到不同灼烧温度下SiO2对酸性橙的吸附曲线,找出了最佳灼烧温度。在此温度下制备出SiO2并对一定浓度的酸性橙溶液进行"吸附-灼烧-吸附"的反复吸收试验。实验结果表明400℃灼烧的SiO2的吸附性最好,并且随着循环次数的增多吸附能力慢慢下降。     

Preparation of Porous Polymethyl Methacrylate/Organo-Montmorillonite Composite Membranes for Phenolic Compound Adsorption

The preparation of porous poly(methyl methacrylate)/organo-montmorillonite composite membranes for adsorption application was carried out via entrapment methods. The sponge-like membrane structure was characterized by a scanning electron microscope, whereas the X-ray diffraction, Fourier transform infrared, and thermogravimetric analyses confirmed the incorporation of organo-clays inside the composite membranes. To investigate the applicability of the composite membranes on phenolic compound adsorption, batch-mode adsorption of p-nitrophenol at 0.025 mg/mL was conducted. The optimum feed organo-clay/polymer ratio was 0.3 for the membrane prepared by the emulsion polymerization method, and in this case 75% of p-nitrophenol was adsorbed after 34 h. 80% methanol was selected as the desorbent for its high ability to desorb p-nitrophenol from the composite membrane. The membrane performance in the flow process was similar to the batch result, and the adsorption/desorption cycle was successfully repeated three times.     

Activated-Carbon Nanofibers/Graphene Nanocomposites and Their Adsorption Performance Towards Carbon Dioxide

Activated-carbon nanofibers (ACNFs) provide a relatively new, modified structure of carbon-based adsorbents that have the ability to adsorb carbon dioxide due to their high specific surface area, wide distribution of porous structures, and high volume of active sites. In this study, cost-effective agricultural waste-based graphene synthesized from rice husk ashes was used as additive to enhance the ACNF properties. ACNF/graphene (gACNF) is still a relatively unexplored adsorbent. The resultant gACNF exhibited better thermal stability properties, with higher yield, larger specific surface area, and higher micropore volume. These properties are the main factors contributing to their enhanced adsorption performance towards CO₂.     

Preparation of Silk Sericin/Lignin Blend Beads for the Removal of Hexavalent Chromium Ions

In the present study, novel adsorbents having high adsorption capability and reusability were prepared using agricultural by-products: silk sericin and lignin. Silk sericin and lignin blend beads were successfully prepared using simple coagulation methods for the removal of hexavalent chromium (Cr(VI)) from aqueous solution. A 1 M lithium chloride (LiCl)/dimethyl sulfoxide (DMSO) solvent system successfully dissolved both sericin and lignin and had sufficient viscosity for bead preparation. Compared to the conventional sericin bead adsorbent, sericin/lignin blend beads showed higher Cr(VI) adsorption capacity. The amount of lignin added to the adsorbent greatly affected the adsorption capacity of the beads, and a 50:50 sericin/lignin blend ratio was optimal. Adsorption behavior followed the Freundlich isotherm, which means the adsorption of Cr(VI) occurred on the heterogeneous surface. Cr(VI) adsorption capability increased with temperature because of thermodynamic-kinetic effects. In addition, over 90% of Cr(VI) ions were recovered from the Cr(VI) adsorbed sericin/lignin beads in a 1 M NaOH solution. The adsorption-desorption recycling process was stable for more than seven cycles, and the recycling efficiency was 82%. It is expected that the sericin/lignin beads could be successfully applied in wastewater remediation especially for hazardous Cr(VI) ions in industrial wastewater.     

氨基功能化聚苯乙烯纳米微球的制备及其CO2吸附性能研究

以苯乙烯(St)和甲基丙烯酸缩水甘油酯(GMA)为共聚单体,通过细乳液聚合法制备出聚苯乙烯纳米微球,并研究了单体配比与反应条件对纳米微球粒径大小与分布的影响。然后利用GMA上的活性环氧基团将有机胺接枝到纳米微球表面,并将其应用于CO2吸附。采用动态激光散射、扫描电子显微镜、红外光谱、元素分析等方法对纳米微球进行了结构表征。结果表明,所制备的纳米微球最小粒径为67 nm,粒径大小均一可控,而且纳米微球表面成功地接枝上有机胺;乙二胺改性纳米微球的CO2吸附量为2.45 mmol/g,并且吸附循环稳定性较好。     

Hierarchically porous N-doped carbon nanofibers derived from ZIF-8/PAN composites for benzene adsorption

Coupling with electrospinning technique, metal–organic-frameworks (MOFs)-derived porous carbon fibers exhibit a great potential application in the adsorption of volatile organic compounds (VOCs) because of their huge surface area, high porosity, as well as sufficient heteroatom-doped active sites. In this work, the hierarchically porous N-doped carbon nanofibers are obtained after the pyrolysis of zeolite imidazole framework-8 and polyacrylonitrile (ZIF-8/PAN) composite fibers synthesized by electrospinning method. The N-doped carbon nanofibers fabricated in N₂ atmosphere (N-CF-N₂) present an enhanced adsorption capacity of 694 mg/g for benzene because of the synergistic effect of the hierarchically porous structure and the abundant N-species-containing active sites. It is also interesting that the N-doped hierarchical carbon nanofibers fabricated in Ar atmosphere (N-CF-Ar) exhibit a low benzene adsorption as compared with the N-CF-N₂, which can be attributed to the porous structure damage caused by the bombardment of heavy Ar atoms on the pore shells during the pyrolysis. These results not only show a promising application of the as-fabricated N-CF-N₂ in adsorption of VOCs for air purification due to its merit of cost-efficient, large-scale production, and excellent adsorption capacity, but also expand the potential of electrospinning technology and composite fibers in volatile organic gas adsorption.     

球形纤维素-钛白粉复合基质的扩张床流体混合特性

Expanded bed adsorption (EBA) has been widely used in industrial downstream bioprocessing,Solid matrix is the principal pillar supporting the successful application of EBA.A novel spherical ceelulose-titanium dioxide composite matrix was prepared through the method of water-in-oil suspension thermal regeneration.Its typical physical properties were wet density 1.18g.cm^-3,,diameters in the range of 100-300μm ,porosity 85.5%,and water content 72.3%.Expansion characteristics and liquid mixing performance of the matrix in expanded bed were investigated using water and 10% (by mass )glycerol solution as mobile phases,The results indicate that the custom-assembled matrix has a stable flow hydrodynamics and exhibits the same degree of liquid-phase mixing or column efficiency as the commercially available Streamline adsorbent.     

吸附聚硫化物的高性能g-C_3N_4/大孔碳复合材料及其在锂硫电池中的应用

为提高碳材料对聚硫化物的吸附能力,将三聚氰胺-二甲亚砜(DMSO)混合溶液真空灌注至大孔碳(MPC)孔道,并通过干燥和煅烧,在MPC孔道内壁均匀担载氮化碳(g-C_3N_4),得到复合材料g-C_3N_4/MPC。研究表明,g-C_3N_4/MPC中由于g-C_3N_4和MPC的协同作用,强化了聚硫化物的吸附,有效抑制了聚硫化物穿梭,改善了以其为载硫材料的锂硫电池循环性能。另外,MPC和三聚氰胺的较佳质量比为1:1,所得g-C_3N_4/MPC具有良好的聚硫化物穿梭抑制效果,而且硫电极的导电性也得到有效改善,所制备的电池表现出优异的循环性能和倍率放电性能。     

Application of Comparative Method for Estimating Microporosity of Porous Solids in Adsorption from Solutions

The concept of a comparative method in terms of the liquid adsorption on solids is presented. This method is based on comparison of the excess adsorption isotherm on a porous solid with that measured on a reference nonporous adsorbent. It is proved that proposed approach gives the possibility for separating a total excess adsorption isotherm into partial isotherms, proper for micro- and mesopores. Several experimental systems are analyzed to illustrate the usefulness of the comparative method for evaluating the surface phase capacity, which presents an important quantity in the study of adsorption from solution in the whole concentration region. The comparative method examined for adsorption systems of microporous active carbons seems to be useful for investigating other porous materials as silica gels, zeolites or metal oxides.     

膨润土／活性炭复合吸附剂对土霉素的吸附性能研究

研究了一定条件下低品位钙基膨润土／活性炭复合吸附剂对土霉素废水的吸附作用。结果表明：活化温度在140℃、pH=6.5时复合吸附剂对土霉素最大吸附容量为21．78mg／g，明显大于原土的14．16mg／g，讨论并合理地解释了影响吸附的因素，适宜条件下对吸附剂多次再生，最大吸附容量仍可达到21mg／g以上。     

Swelling,Protein Adsorption,and Biocompatibility In Vitro of Gel Beads Prepared from Pectin of Hogweed Heracleum sosnówskyi Manden in Comparison with Gel Beads from Apple Pectin

The study aims to develop gel beads with improved functional properties and biocompatibility from hogweed (HS) pectin. HS4 and AP4 gel beads were prepared from the HS pectin and apple pectin (AP) using gelling with calcium ions. HS4 and AP4 gel beads swelled in PBS in dependence on pH. The swelling degree of HS4 and AP4 gel beads was 191 and 136%, respectively, in PBS at pH 7.4. The hardness of HS4 and AP4 gel beads reduced 8.2 and 60 times, respectively, compared with the initial value after 24 h incubation. Both pectin gel beads swelled less in Hanks’ solution than in PBS and swelled less in Hanks’ solution containing peritoneal macrophages than in cell-free Hanks’ solution. Serum protein adsorption by HS4 and AP4 gel beads was 118 ± 44 and 196 ± 68 μg/cm² after 24 h of incubation. Both pectin gel beads demonstrated low rates of hemolysis and complement activation. However, HS4 gel beads inhibited the LPS-stimulated secretion of TNF-α and the expression of TLR4 and NF-κB by macrophages, whereas AP4 gel beads stimulated the inflammatory response of macrophages. HS4 gel beads adsorbed 1.3 times more LPS and adhered to 1.6 times more macrophages than AP4 gel beads. Thus, HS pectin gel has advantages over AP gel concerning swelling behavior, protein adsorption, and biocompatibility.     

Ordered Mesoporous Carbon CMK-3 Modified with Cu(I) for Selective Ethylene/Ethane Adsorption

Ordered mesoporous carbon CMK-3 was modified with cuprous chloride (CuCl) by a spontaneous thermal dispersion approach. A new kind of π-complexation adsorbent was thus obtained and characterized by X-ray diffraction, N₂ adsorption, and transmission electron microscopy. The results show that the mesostructure of CMK-3 is well preserved after the introduction of CuCl. In comparison with parent CMK-3, the selectivity of ethylene over ethane increases from 0.93 on CMK-3 to 2.67 on CuCl/CMK-3. All of the adsorption isotherms can be well fitted with the corresponding models. The fitting parameters along with the heat of adsorption demonstrate that the introduction of CuCl improve the interaction of ethylene with adsorbent apparently. The present adsorbents may provide useful candidates for the separation of ethylene and ethane as well as other alkene-containing systems.     

Porous Silica Beads Supported TEMPO and Adsorbed NOx (PSB‐TEMPO/NOx): An Efficient Heterogeneous Catalytic System for the Oxidation of Alcohols under Mild Conditions

The combination of NO_x gas which is stored in the pore canals of porous silica beads (PSB) with a heterogeneous catalyst, PSB‐supported 2,2,6,6‐tetramethylpiperdine 1‐oxyl (PSB‐TEMPO, 1 ), afforded a highly efficient, widely applicable, and efficiently recyclable approach for the selective aerobic oxidation of alcohols. This novel catalytic system (PSB‐TEMPO/NO_x) can be employed in the oxidation of a wide range of alcohols to their corresponding aldehydes and ketones with selectivities as high as 99% at complete conversions under mild conditions. O₂ is the terminal oxidant. PSB‐TEMPO can be recycled for more than 10 times without significant loss of activity.     

坡缕石-活性炭-壳聚糖负载环糊精对硝基苯酚的吸附性质

研究了坡缕石-活性炭-壳聚糖负载环糊精吸附剂对对硝基苯酚、邻硝基苯酚的吸附行为以及pH、温度等对吸附的影响。在pH=5.0-7.5时,自制吸附剂对对硝基苯酚,邻硝基苯酚具有较好的吸附作用。等温吸附曲线拟合结果显示,吸附剂对硝基苯酚的吸附更符合Langmu ir方程。热力学函数计算表明,吸附剂对硝基酚的吸附是自发的放热过程,对硝基苯酚的吸附热和熵变分别为-27.49 kJ/mol和-70.39 J/(mol.K),邻硝基苯酚的吸附热和熵变分别为-29.06 kJ/mol和-78.87 J/(mol.K),吸附自由能均随温度的升高而增加。     

Polyurethane membrane prepared via a dry/wet phase inversion method for protein adsorption

Hydroxyl‐terminated polybutadiene (HTPB)‐ and 4,4′‐dicyclohexyl‐methane (H₁₂MDI)‐based polyurethanes (PUs) were synthesized by solution polymerization. PU membranes were prepared by a dry/wet phase inversion method. Protein adsorption ratio of fibrinogen to albumin (F/A molar ratio) was measured. Low F/A molar ratio was found on these PUs. It was found that surface composition of these PUs has a subtle effect on F/A adsorption molar ratio. The F/A molar ratio was increased as the increase of hard segment content distributed on the surface. The variation of surface composition of these membranes and the effect on the F/A molar ratio were investigated by the difference in surface energy between nonpolar HTPB soft segment and polar hard segment, concentration, and temperature of coagulation medium, polymer content, and alcohol type. The CO/CC ratio, frequency shift, and difference (Δν) as a measure of polymer homogeneity and the average strength of interpolymer hydrogen bonds were utilized to study the surface composition. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1334–1340, 1999     

蒙脱土壳聚糖复合材料对活性艳红KE-3B的吸附行为研究

采用壳聚糖和蒙脱土合成了纳米复合材料,在静态条件下,研究了蒙脱土壳聚糖对活性艳红KE-3B的吸附,探讨了蒙脱土壳聚糖吸附活性艳红KE-3B的最佳吸附条件。结果表明,蒙脱土壳聚糖对活性艳红具有较好的吸附性能,吸附的最佳pH值为6.0,最佳吸附时间为40 m in,最佳吸附温度为30℃,最佳吸附剂用量为50 mg,活性艳红KE-3B的最佳初始浓度为50 mg/L,吸附率最高可达91.6%以上。计算得出蒙脱土壳聚糖对活性艳红KE-3B的吸附符合Freund lich吸附等温式。实验表明,蒙脱土壳聚糖的吸附性能好,具有良好的应用价值。     

Waste-to-Resource Strategy to Fabricate Functionalized MOFs Composite Material Based on Durian Shell Biomass Carbon Fiber and Fe3O4 for Highly Efficient and Recyclable Dye Adsorption

Recently, metal–organic frameworks (MOFs), which are porous inorganic–organic hybrid materials consisting of metal ions (clusters or secondary building units) and organic ligands through coordination bonds, have attracted wide attention because of their high surface area, huge ordered porosity, uniform structural cavities, and excellent thermal/chemical stability. In this work, durian shell biomass carbon fiber and Fe₃O₄ functionalized metal–organic framework composite material (durian shell fiber-Fe₃O₄-MOF, DFM) was synthesized and employed for the adsorption removal of methylene blue (MB) from wastewater. The morphology, structure, and chemical elements of the DFM material were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM), and X-ray photoelectron spectroscope (XPS) techniques. Adsorption conditions such as pH, adsorption time, and temperature were optimized. The adsorption isotherm and kinetics results show that the adsorption process of DFM material to MB is more in line with the Freundlich model and pseudo-second-order kinetic model. Using these models, the maximum adsorption capacity of 53.31 mg/g was obtained by calculation. In addition, DFM material could be easily reused through an external magnet and the removal rate of MB was still 80% after five adsorption cycles. The obtained results show that DFM composite material, as an economical, environmentally friendly, recyclable new adsorbent, can simply and effectively remove MB from wastewater.     

亚氨乙酸型螯合吸附材料IAA-PEI/SiO2对重金属离子的螯合吸附行为

将聚胺大分子聚乙烯亚胺(PEI)接枝于微米级硅胶微粒表面,制得接枝微粒PEI/SiO2,然后使氯乙酸与PEI大分子中的伯、仲胺基发生亲核取代反应,形成亚氨乙酸(IAA)型螯合吸附材料IAA-PEI/SiO2. 研究了IAA-PEI/SiO2对重金属离子的螯合吸附行为和吸附机理. 结果表明,由于亚氨乙酸基团与重金属离子之间的静电作用与配位螯合作用,IAA-PEI/SiO2对重金属离子可产生强的螯合吸附作用,对Ni2+的吸附容量可达1.4 mmol/g;吸附过程为放热过程;在可抑制重金属离子水解的pH范围内,pH值越高,吸附能力越强;IAA-PEI/SiO2对重金属离子的吸附容量顺序为Ni2+> Pb2+>Cu2+>Cd2+.