雷尼镍催化剂的吸附量热研究

雷尼镍催化剂的吸附量热研究王益沈俭一（南京大学化学系，南京２１００９３）ＨａｎｓＷａｒｌｉｍｏｎｔ（ＩｎｓｔｉｔｕｔｅｆｏｒＳｏｌｉｄＳｔａｔｅａｎｄＭａｔｅｒｉａｌｓＲｅｓｅａｒｃｈ，ＤｒｅｓｄｅｎＤ０１０６９，Ｇｅｒｍａｎｙ）关键词雷尼镍...     

ORGANIC CHELATING REAGENT ON REDOX ADSORPTION OF ACTIVATED CARBON FIBER TOWARDS Au^3+

Organic chelating reagent influences upon the redox adsorption of activated carbon fibertowards Au3- were systematically investigated. The experimental results indicated that the presenceof organic chelating reagent on activated carbon fiber strongly affects adsorption capacity ofactivated carbon fiber towards Au3+. The reduction-adsorption amount of Au3+ increased three timesby the presence of 8-quinolinol. Furthermore, The reduction-adsorption amount of Au3+ depended onthe pH value of adsorption and temperature.     

笼形聚偕胺肟树脂的研究──酸处理树脂吸附H_2PdCl_4

考查了无机酸、羧酸和酚类化合物处理的笼形聚偕胺肟树脂吸附酸性溶液中H_2PdCl_4的能力，其中H_3BO_3/ACAO、HSCH_2CO_2H/ACAO和p－NH_2C_6H_4H/ACAO树脂对H_2PdCl_4的吸附容量分别是2．023、2．368和2．083mmol/g-R或215、252和222mgPd／g－R。优于相同条件下的碱处理树脂（BCAO吸附容量为1．828mmol/g-R）。研究了吸附动力学，讨论了吸附机理。     

Hydrogen Oxidation on a Platinum Microelectrode: Effect of Carbon Monoxide Impurities

The kinetics of the hydrogen oxidation and the CO adsorption on a Pt (ultra)microelectrode is studied in a 0.5 M H₂SO₄ solution saturated with a mixture of gaseous H₂ and CO at partial CO pressures p _CO = 10–500 ppm. The balance between rates of diffusion and adsorption of CO at different adsorption times is studied. Studied is the effect of CO impurities in H₂ on steady-state polarization curves for the hydrogen ionization and nonsteady-state curves of the oxidation current decay with time at 0.02–0.05 V. Conditions under which in a certain time interval and at a certain CO concentration the slope of an I vs. t curve is proportional to p _CO are determined. The obtained dependence may be used when designing a technique for monitoring CO impurities in technical hydrogen.     

Early-stage flocculation kinetics of polystyrene latex particles with polyelectrolytes studied in the standardized mixing: Contrast of excess and moderate polyelectrolyte dosage

Standardized mixing procedure was applied to the analysis of flocculation of polystyrene latex (PSL) particles with polyelectrolytes. After confirming the initial enhancement of flocculation rate in the very beginning followed by abrupt stop with excess dosage, attention was shifted to the system of moderate dosage. In the former, effects of ionic strength were further analyzed to find the consistency with adsorption isotherm. In the latter, flocculation started slowly in the beginning, sometime slower than salt-induced rapid coagulation, however, the rate gradually increases in the middle stage. Often, the increased rate exceeds that of salt-induced rapid coagulation. This behavior emerged more clearly in the case of lower ionic strength. This is the indication that the rate of relaxation of polymer on the colloidal surface is a function of surface coverage and ionic strength. The ultimate degree of flocculation is usually higher than that observed for excess dosage. The size distribution of flocs was also examined, however, no clear difference between different experimental conditions was confirmed for the same degree of flocculation.     

FCC硫转移剂MgAlCuFe复合氧化物的结构与性能:金属盐前体的影响

分别以硝酸盐、盐酸盐和硫酸盐为金属盐前体,采用共沉淀法合成了MgAlCuFe类水滑石前驱体,经过700℃焙烧6h后,制得三种新型FCC硫转移剂.运用X射线衍射、热重、氮气吸附和红外光谱对这三种硫转移剂的结构和性能进行了表征,并采用改装的WRP-3热重天平评价了其氧化吸硫和还原脱硫的性能.结果表明,三种金属盐均可得到结构规整的类水滑石前驱体,经过焙烧后得到复合氧化物MgAlCuFe.与采用盐酸盐和硫酸盐作前体相比,由硝酸盐制得的硫转移剂具有较大的比表面积,其饱和吸附硫容和氧化吸硫速率均较高,6min可达到1.54g/g的饱和吸附能力,同时具有较强的还原脱硫能力.     

胶原-单宁树脂的制备及其对水溶液中UO2+2的吸附特性研究

以天然牛皮为原料,经胃蛋白酶处理制得水解胶原;通过胶原-黑荆树单宁-醛反应制备了胶原-单宁树脂(C-TR)吸附材料,并表征了材料的形貌,测定了材料的比表面积、热变形温度等性质。系统研究了C-TR对水溶液中UO22 的吸附特性。结果表明,C-TR对UO22 有较强的吸附能力。当温度为303K、pH=5.0、UO22 的初始浓度2.5mmol.L-1时,吸附容量达到1.49mmolU/g。升高温度,平衡吸附量增大。pH对吸附容量的影响较大,适宜的pH范围为5.0-6.0。C-TR对UO22 的吸附平衡符合Freundlich方程。吸附动力学可用拟二级速度方程来描述。C-TR对UO22 的吸附基本不受NaCl影响,该吸附材料可望用于海水中铀的富集和分离。     

偏最小二乘法用于研究酚类物质的竞争吸附

将偏最小二乘法(PLS)用于紫外-可见分光光度分析,同时测定水溶液中苯酚、对甲氧基苯酚和α-萘酚三种组分,并将此方法用于研究苯酚、对甲氧基苯酚和α-萘酚在水溶液中的竞争吸附.结果表明:合成样本的回收率在96%~107.6%之间,结果比较令人满意.采用PLS法计算三种酚类物质吸附后的平衡浓度和吸附量,其结果与采用LCA(Langmuir Competitive Adsorption)模型预测的结果较为接近.     

Adsorption Equilibrium and Kinetics of Egg-White Proteins on Immobilized Metal Ion Affinity Gels for Designing Fractionation

Designing an Immobilized Metal ion Affinity (IMA) chromatographic process on large scale demands a thorough understanding to be developed regarding the adsorption behaviour of proteins on metal loaded IMA (IMA-M(II)) gels and the characteristic adsorption parameters to be evaluated. This research investigation illustrates the significance of these aspects for the proposed fractionation of chicken egg-white proteins on these gels. Consequently, a systematic investigation of the adsorption characteristics of three chicken egg-white proteins viz., ovalbumin, conalbumin and lysozyme on Cu(II) and Ni(II) loaded IMA gels, iminodiacetate (IDA) and tris(2-aminoethyl)amine (TREN), has been undertaken. These gels differ in their selectivity towards the proteins of interest under the identical sets of experimental conditions. While TREN-Ni(II) was selective only for lysozyme, IDA-Cu(II), IDA-Ni(II) and TREN-Cu(II) showed varying affinities for all the three proteins. The equilibrium and kinetic data were analysed using various theoretical models and adsorption parameters were quantified. On the basis of these investigations, various strategies have been proposed for the efficient large-scale fractionation of chicken egg-white proteins on these gels.     

Molecular simulation of water behaviors on crystal faces of hydroxyapatite

The water behavior on (001) and (100) crystal faces of hydroxyapatite (HAP) were studied using molecular dynamics (MD) simulations. The study showed that the water molecules between the HAP faces were under conditions of strong electrical field and high pressure, and hence formed 2–3 well-organized water layers on the crystal surfaces. These structured water layers had ice-like features. Compared with the crystallographic [100] direction of HAP, the polarity along the [001] direction was stronger, which resulted in more structured water layers on the surface. The interaction of water molecules with the calcium and phosphate sites at the HAP-water interface was also studied. The results indicated the multiple pathways of water adsorption onto the HAP surfaces. This study revealed the formation and the detailed structure of water layers on HAP surfaces and suggested that the interfacial water played an important role in stabilizing the HAP particles in aqueous solutions. Translated from Chinese Journal of Inorganic Chemistry, 2006, 22(8): 1392–1400 (in Chinese)