Reversible adsorption of thiophene on copper chromite

Adsorption isotherms of thiophene on copper chromite catalyst have been obtained under catalytic conditions using the gas chromatographic technique. The isotherms were found to follow the Freundlich adsorption equation. The isosteric heat of adsorption has been determined from the isotherms and found to be dependent on surface coverage.     

Anodically grown films on copper and copper–nickel alloys in slightly alkaline solutions

Surface oxides grown on copper and copper–nickel alloys (UNS 72000 and UNS 70600) in aerated borax-borate buffer solution of pH 7.7 were characterized using various experimental techniques. Their influence on the mechanism of oxygen reduction was also investigated. The composition of the passive films formed in situ on the different materials was studied using differential reflectance spectroscopy. Electrochemical techniques such as voltammetry and potentiodynamic reductions, as well as hydrodynamic tools such as the rotating disk electrode were used to characterize the kinetic parameters of the oxygen reduction reaction. The results show that the addition of Ni to Cu to form copper–nickel alloys changes the composition of the surface film. As the amount of Ni in the alloy increases, the proportion of Cu(I) compounds decreases, and Ni(II) compounds are incorporated into the film structure. The films anodically grown at 0.5 V on Cu70Ni30 tend to be thinner but more resistive. This is supported by results from reflectance and impedance spectroscopy. The kinetics of oxygen reduction follows a four-electron path on surface-free films, independently of the Ni-content in the alloy.     

FTIR evidence for surface azides formed upon ammonia adsorption on copper catalysts

The adsorption of ammonia on an alumina supported copper catalyst and on unsupported copper powder was studied by diffuse reflectance FTIR spectroscopy in the temperature range 423–643 K. Bands in the region between 1950 and 2350 cm^–1 were identified as being due to surface-bound azides. These species are suggested to be possible precursors in the copper nitride formation observed earlier.     

Mechanism of copper(II) adsorption by polyvinyl polyacrylate

The mechanism of copper adsorption by polyvinyl polyacrylate (PVPA) was examined using ESR and magnetic measurements. The copper adsorption by PVPA obeyed Langmuir adsorption isotherm with the maximum adsorption amounts of 4.17 mmol g^?1 adsorbent, being larger than those of uranium adsorption. Though copper in the solution was completely adsorbed by the resin above pH 4, the ESR intensity was remained low level and only increased above pH 8. The ESR spectrum of Cu(II) ion in PVPA are axial type with tetragonally distorted octahedral symmetry, having parameters of g_⊥ = 2.361, g_? = 2.057, |A_⊥| = 14.0 m cm^?1 (pH 5), and g_⊥ = 2.329, g_? = 2.058, |A_⊥| = 16.2 m cm^?1, |A_?| = 2.7 m cm^?1 (pH 9). The absorption peaks originated from Cu(II)–Cu(II) dimer was also observed (pH 5). The paramagnetic susceptibility of PVPA adsorbed Cu(II) ion at pH 5 explained by the dimer model with |J| = 220 K. These results suggested that most of copper was adsorbed and formed dimer in PVPA, being similar to that in Cu(II)‐acetate monohydrate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5372–5377, 2006     

乙二胺螯合细菌纤维素的制备及其吸附Cu~(2+)研究

以细菌纤维素为原料制备乙二胺螯合细菌纤维素.通过红外光谱仪、元素分析仪对产物进行了表征.研究了乙二胺螯合细菌纤维素对铜离子的吸附动力学、等温吸附等特征.结果表明,吸附动力学可用拟二级速度方程来描述,吸附平衡符合Freundlich等温吸附方程,并对其吸附与解吸性能进行了分析.     

Investigation of inhibiting properties of self-assembled films of 4-aminothiophenol on copper in 3.5% NaCl

A self-assembled monolayer (SAM) of 4-aminothiophenol (4-ATP) was formed on copper surface which was characterized using cyclic voltammetry, Fourier transform infrared spectroscopy, and Raman spectroscopic techniques. The surface morphology of the monolayer was examined by scanning electron microscopy. The anticorrosive property of the SAM was investigated using electrochemical impedance spectroscopy and polarization studies. The electrochemical measurements showed that the inhibition efficiency increased with the immersion time of copper in ethanolic solution of 4-ATP in 3.5% NaCl. The significant corrosion protection efficiency of SAM could be due to the compact and dense monolayer on metallic surfaces.     

The detailed kinetics of the adsorption of hydrogen on polycrystalline copper studied by reactive frontal chromatography

The coverage-dependent sticking probabilities of molecular hydrogen on polycrystalline copper supported on alumina have been determined in the temperature range 213–273 K by analysis of the hydrogen frontal adsorption line shape. In this temperature range the initial sticking probabilities increase from 8× 10^–13 (213 K) to 1.3× 10^–10 (273 K). The overall activation energy to adsorption has been found to be 42 kJ mol^–1. The application of reactive frontal chromatography for the measurement of hydrogen sticking probabilities on copper is a novel variant of the N₂O reactive frontal chromatographic method, developed for the measurement of copper surface areas. Its use here shows that reactive frontal chromatography may be applied generally to any adsorbate/adsorbent system involving activated adsorption and low sticking probabilities.     

水分子对HKUST-1甲烷吸附性能的影响

以三水合硝酸铜和均苯三甲酸为反应物、N,N’-二甲基甲酰胺为溶剂,采用溶剂热法合成金属有机骨架材料HKUST-1。将HKUST-1浸渍于等体积去离子水中,考察浸渍时间对其理化性能的影响,并通过XRD、SEM、BET和高压气体吸附表征研究了水分子对HKUST-1吸附甲烷性能的影响。结果表明,水分子易于吸附在HKUST-1中不饱和金属活性位点且对其骨架结构产生影响,浸渍72 h后,HKUST-1的BET比表面积和孔容分别从1 478.8 m2·g~(-1)和0.700 cm3·g~(-1)降至53.6 m~2·g~(-1)和0.005 cm3·g~(-1),在298 K和3.5 MPa条件下,甲烷吸附量从203.91 cm3·g~(-1)降至13.74 cm3·g~(-1)。但24 h浸渍后的HKUST-1骨架中生成一定数量的介孔,有利于较大的气体或液体分子吸附存储,值得深入研究。     

Relationship between thickness of polymer films and their oxidation on copper substrate

This research was undertaken to understand how the thickness of polyethylene films oxidized on a copper substrate influences the accumulation of carbonyl groups (measured by an IR‐spectroscopy technique) and of metal from the substrate (determined by polarography analysis). It was found that the whole polymer became inhibited by the time the copper stopped transferring into the specimen. Plots of copper concentration versus film thickness have two thickness sections: section I is found between 0 and 70 μm and section II between 80 and 170 μm. Between these two sections the metal concentration varies drastically. This situation can be explained by two schemes by which PE changes to inhibited condition. According to Scheme I (for section I, short oxidation time) this change has only one step: the inhibited layer gradually becomes thicker beginning from the interface and moving toward the outer surface. The second scheme (for section II) shows that the polymer becomes inhibited in two steps. It is typical of thicker films. In this case the oxidation process shifts and localizes in the outer surface because of longer treatment. As a result, transfer of metal and formation of an inhibited layer are interrupted for some time. The metal accumulation in the film only resumes when low‐molecular‐weight products of thermooxidative degradation—formed in the specimen outer surface—enter the region of adhesional contact. A so‐called second transfer stage for metal is realized during which the whole polymer becomes inhibited. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 671–675, 2003     

Preparation and specific adsorption of dual antibacterial BSA surface imprinted GO-PEI/MXene wrinkled microspheres

Molecular imprinting technology has gained increasing attention and application in protein adsorption and separation. Bacterial growth on the imprinted material would reduce the adsorption selectivity and shorten the service life. To solve the above problems, carrier materials (GO-PEI/MXene wrinkled microspheres) with dual antibacterial ability are constructed for the first time. BSA surface imprinted GO-PEI/MXene (GO-PEI/MXene@MIPs) are constructed in this study. The large exterior surface area increases the number of imprinting sites, thereby enhancing the adsorption capacity. The adsorption capacity of GO-PEI/MXene@MIPs reaches 312.63 ± 22 mg/g with an imprinting factor (IF) of 3.15 within 90 min. Meanwhile, GO-PEI/MXene@MIPs can separate BSA from mixed protein solution and fetal bovine serum (FBS) and only loses 14.1% of saturation adsorption after eight cycles. In addition, antibacterial tests show that the material has excellent broad-spectrum antibacterial effects, which will significantly extend the service life of the material in real-world environments.     

对羟基苯甲酸自组装膜对铜的缓蚀作用

利用自组装技术将对羟基苯甲酸在铜表面形成自组装单分子膜,利用电化学阻抗谱和极化曲线研究了自组装膜对铜的缓蚀作用及其吸附行为。结果表明,对羟基苯甲酸分子易在铜表面形成稳定的自组装单分子膜,该膜抑制了铜的阳极氧化过程,改变了电极表面的双电层结构,固/液界面双电层电容明显降低,有良好的缓蚀效果。研究结果还表明,对羟基苯甲酸在铜表面的吸附行为符合Langmuir吸附等温式,吸附机理是典型的物理吸附。     

Study on EDTA‐chelated copper adsorption by granular activated carbon

Equilibrium and kinetic experiments on uptake of single‐species copper, EDTA, and EDTA‐chelated copper by an H‐type granular activated carbon under various factors, such as pH, ionic strength and EDTA concentration were carried out in this study. Adsorption of copper ions was increased with an increase in solution pH when the solution contained single‐species or EDTA‐chelated copper ions. The solution pH increased significantly from its lower initial value, which resulted from the adsorption of hydrogen ions by the carbon. The efficiency for the single‐species metal ion removal was increased from 5 to 95% when the solution pH was increased from 2 to 7.5. EDTA‐chelated metal ion removal, however, was increased from 7 to 97% as the pH was increased from 1.5 to 7.5. EDTA adsorption percentages increased when the solution pH was increased and the initial concentration was decreased. Slightly higher EDTA‐chelated copper removal was observed when the ionic strength was higher and the ratio of EDTA to copper concentrations was 1:1. Kinetic experiments demonstrated that the copper adsorption occurred rapidly in the first hour. No further change in the removal was observed after 3 and 6 h for single‐species or EDTA‐chelated, respectively. The EDTA‐chelated copper adsorption kinetics was enhanced with an increase in EDTA concentration and a decrease in ionic strength. © 2000 Society of Chemical Industry     

防腐剂吸附效应与润滑油防腐性能的关系

引言润滑油中添加剂的性质决定了润滑油的性能,防腐剂的存在对润滑油的防腐性能起到了决定性作用,为开发适合于海洋环境条件下防腐型轴承润滑油,防腐剂对润滑油防腐性能的影响规律和影响机理等问题均亟需解决。添加剂在摩擦副界面的吸附是液-固吸附,目前对于两相吸附的研究主要针对于气-液[1]、气-固间的吸附[2-3]和离子流体中的液-固吸附研究[4-6],防腐剂的缓蚀机理研究主要针对     

Removal of copper ions from aqueous solution by adsorption using LABORATORIES-modified bentonite (organo-bentonite)

Equilibrium, kinetic and thermodynamic aspects of the adsorption of copper ions from an aqueous solution using linear alkylbenzene sulfonate (LABORATORIES) modified bentonite (organo-bentonite) are reported. Modification of bentonite was performed via microwave heating with a concentration of LABORATORIES surfactant equivalent to 1.5 times that of the cation exchange capacity (CEC) of the raw bentonite. Experimental parameters affecting the adsorption process such as pH, contact time and temperature were studied. Several adsorption equations (e.g., Langmuir, Freundlich, Sips and Toth) with temperature dependency were used to correlate the equilibrium data. These models were evaluated based on the theoretical justifications of each isotherm parameter. The Sips model had the best fit for the adsorption of copper ions onto organo-bentonite. For the kinetic data, the pseudo-second order model was superior to the pseudo-first order model. Thermodynamically, the adsorption of copper ions occurs via chemisorption and the process is endothermic (ΔH⁰>0), irreversible (ΔS⁰>0) and nonspontaneous (ΔG⁰>0).     

Comparison study of copper ion adsorption on chitosan,Dowex A-1, and Zerolit 225

The adsorption of copper ions by chitosan, Dowex A-1, and Zerolit 225 has been investigated. The uptake of copper was determined from changes in concentration as measured by atomic absorption spectrometry. A preliminary investigation on the adsorption was conducted by batch-wise examining the effects on pH and the initial copper ion concentration. It was found that chitosan has an excellent loading capacity of copper, compared with Dowex A-1 and Zerolit 225. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1067–1070, 1998     

氧化铈-二氧化硅介孔材料制备及对铜离子的吸附性能

采用共沉淀法和沉淀浸渍法制备了纳米氧化铈-二氧化硅（CeO₂-SiO₂）介孔材料吸附剂,主要考察了其对水中铜离子（Cu²⁺）的吸附行为。通过X射线衍射（XRD）、扫描电镜（SEM）和氮吸附（BET）等手段对合成的介孔材料进行了性能表征,并通过静态吸附实验分析了溶液pH、溶液初始金属离子质量浓度、吸附剂用量、吸附时间等条件对介孔材料吸附Cu²⁺性能的影响。结果表明：共沉淀法制备的纳米CeO₂-SiO₂介孔材料对Cu²⁺的去除效果较沉淀浸渍法要好;当溶液pH=7.0时CeO₂-SiO₂介孔材料对Cu²⁺的吸附效果最好,20 min时基本达到吸附平衡;溶液初始Cu²⁺浓度增大Cu²⁺去除率降低,Cu²⁺累计吸附量增大;随着吸附剂用量增加Cu²⁺去除率增大,当CeO₂-SiO₂吸附剂用量为0.15 g/L时对Cu²⁺的去除率趋于稳定;CeO₂-SiO₂吸附剂对不同金属离子吸附性能由大到小的顺序为Cu²⁺、Fe²⁺、Mn²⁺,该吸附过程均符合准二级动力学模型。     

磁性生物吸附剂对Cu2+吸附性能的研究

以环氧氯丙烷为交联剂,用壳聚糖、纳米磁粉悬浮液(Fe3O4)和纯菌丝体制备了磁性生物吸附剂,用XRD对该吸附剂进行了结构表征.研究了溶液pH、吸附时间和Cu2 初始浓度对其吸附性能的影响,结果表明,在pH为5～5.5,Cu2 初始质量浓度为0.1 g/L,吸附时间为8 h的条件下,它的Cu2 去除率为88.73%,吸附容量为16.530 mg/g.该磁性生物吸附剂经5次重复使用后,对Cu2 去除率仍然达到79%以上,具有良好的重复使用性.     

安吉蒙脱石对抗菌金属离子的吸附容量研究

研究了安吉蒙脱石对抗菌金属离子Ag 、Zn2 及Cu2 的吸附反应容量 ,发现安吉蒙脱石对抗菌金属离子的吸附等温线可用Freundlich方程加以拟合。抗菌金属离子按照其吸附容量大小的排列次序为Cu2 >Zn2 >Ag ,此次序由三种离子的水化热、离子半径及价态所决定。     

纳米纤维素基无机复合抗菌膜材料的研究进展

纳米纤维素作为一种高值绿色天然聚合物，因其兼具优异的机械性能、可成膜性、高透明度、可生物降解性、生物相容性好等特性，成为无机抗菌原料良好的载体或者基材，这类复合抗菌材料不仅成膜具有一定的机械强度和透明性，而且可提高无机抗菌剂的稳定性，在抗菌功能膜材料领域具有潜在的应用前景。近年来，以纳米纤维素为基体，引入无机抗菌纳米粒子制备纳米纤维素基无机复合抗菌材料成为抗菌新材料的研究热点。基于此，该文着重从纳米纤维素在复合抗菌膜材料制备中的作用与功效，综述了不同无机抗菌纳米粒子与纳米纤维素复合制备纳米纤维素基无机复合抗菌膜材料的研究进展，分析了各类纳米纤维素基无机复合抗菌膜材料的制备及应用优势，最后对纳米纤维素基复合抗菌材料的未来进行了总结和展望，以期为纳米纤维素基有机-无机复合材料的研究提供参考。     

焦粉基碳吸附材料对含铜废水处理研究

用硝酸预氧化焦粉、氯化锌化学活化法制备了焦粉基碳吸附材料。静态法考察了焦粉基碳吸附材料对水中铜离子的吸附工艺参数、吸附模型、温度对吸附过程的影响。研究表明：焦粉基碳吸附材料对水中铜离子的吸附工艺参数为：铜离子溶液浓度80mg／L、吸附平衡时间50min、吸附温度为40℃、pH为5．0～6．0;该吸附过程符合Langmuir型吸附模型;温度升高有利于焦粉基碳吸附材料对铜离子的吸附,表明该吸附为吸热过程。