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1.
有机试剂键合硅胶对牛血清白蛋白的吸附行为 总被引:3,自引:0,他引:3
介绍几种偶氮,卟啉,三苯甲烷类有机试剂键合硅胶的合成方法,研究其吸附牛血清白蛋白(BSA)的行为,研究结果表明:TPP.SG吸附性能最佳,对BSA吸附平衡1h即可达到,最大吸附率为90%,最大吸附容量为12.2mg/g。 相似文献
2.
Formation of mixed adsorbed layers was tested for ternary liquid mixtures containing methanol or acetone and the binary solvent benzene+n — heptane. The specific excess adsorption isotherms from the liquid phase were measured on silica gel, silanized silica gel and aluminium oxide. The experimental adsorption data are discussed on the basis of the changes in the mixed solvent composition. 相似文献
3.
Copper and mercury ion adsorption on chitosan membranes was investigated in batch systems (with both single and binary solutions).
The Langmuir model and its extensions (extended Langmuir, Jain-Snoeyink, and Langmuir-Freundlich models) were tested for the
modeling of experimental data. Chitosan membranes presented more affinity for Hg ions than for Cu ions. The decrease of the
amount of metal adsorbed on natural chitosan in binary systems (compared to single-metal solutions) showed the competition
effects between the two metal ions. For glutaraldehyde-crosslinked chitosan and epichlorohydrin-crosslinked chitosan, the
mixture effect was present, producing unexpected result such as higher adsorption capacities, when compared to the monocomponent
solution of each metal. The desorption of the metals was also investigated, and copper and mercury ions could be selectively
recovered using a combined process by using NaCl and H2SO4 as eluant. 相似文献
4.
以γ-氯丙基三氯硅烷为偶联剂,将乙二胺偶合接枝在硅胶表面,合成对锌离子具有吸附作用的乙二胺硅胶复合材料(EDA/SiO2),考察了Zn2+溶液pH值、初始浓度、吸附温度和吸附时间等因素对复合材料吸附性能的影响。 结果表明,在研究的溶液浓度及温度范围内,Zn2+溶液pH值对EDA/SiO2的吸附量影响显著,吸附的最佳pH值范围在3.0~5.5;Zn2+的吸附平衡数据符合Langmuir吸附模型,热力学数据显示,EDA/SiO2对Zn2+的吸附行为为一吸热且自发进行的过程,升高温度有利于吸附,并对此吸附行为作了解释;吸附动力学数据可用拟二级吸附动力学方程描述,得到的吸附速率常数与溶液初始浓度有关。 相似文献
5.
A new, simple and sensitive method for the simultaneous determination of mercury(II) and methylmercury chloride at sub-ng l−1 levels in river waters is described. Inorganic and organic mercury were preconcentrated from fresh water samples simultaneously on a laboratory-made column containing 2-mercaptobenzimidazol loaded on silica gel and then quantitatively eluted with 0.05 M KCN solution and 2.0 M HCl to desorp inorganic and methylmercury species, respectively. After irradiation with an intensive UV source, MeHg+ was decomposed and mercury vapours were generated from inorganic and organic mercury using an acidic SnCl2 solution in a continuous flow system and were subsequently determined with a cold vapour atomic fluorescence (CV-AFS) spectrometer. Detection limits (3σ) were 0.07 and 0.05 ng l−1 (as Hg) for mercury(II) chloride and methylmercury chloride, respectively. Relative standard deviations of method (%R.S.D.) were 8.8 and 10 for inorganic and organomercuric species in the river water, respectively. The analysis of real samples, taken from different rivers, showed that inorganic mercury levels ranged from 4.0±0.6 to 12±1 ng l−1 (as Hg and 95% confidence limit) and methylmercury levels at 0.2±0.02 ng l−1(as Hg). 相似文献
6.
7.
Shushi Chen 《中国化学会会志》2020,67(9):1661-1667
Three selected flavonoids, commonly found in spices, red-purple fruits, and vegetables, were adsorbed on humic fraction-modified silica gel in hexane. The percentage of adsorption in hexane for all examined analytes was nearly 100% after 1 hr, as a result of the strong dipole–dipole interaction. The increasing amount of adsorbent involved in the process improved the percentage of adsorption, which in turn shortened the time needed to reach the maximum by providing more binding sites. However, adsorption was not observed in other liquid phases under the same conditions, such as acetonitrile and ethyl ether. The mechanism leading to the adsorption was explored chromatographically, as well as by fourier transform infrared spectroscopy (FTIR) and theoretical simulations. 相似文献
8.
The formation of mixed adsorbed layers has been tested for ternary mixtures containing a specifically adsorbed component—acetone and binary solvent benzene +n-hepane. The specific excess adsorption isotherms from the liquid phase were measured on silica gel samples partially dehydroxylated. The competition of liquid components for silica surface is discussed on the basis of changes in the mixed solvent composition. 相似文献
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10.
2-Thiophenecarboxaldhyde is chemically bonded to silica gel surface immobilized monoamine, ethylenediamine and diethylenetriamine by a simple Schiff’s base reaction to produce three new SP-extractors, phases (I-III). The selectivity properties of these phases toward Hg(II) uptake as well as eight other metal ions: Ca(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) were extensively studied and evaluated as a function of pH of metal ion solution and equilibrium shaking time by the batch equilibrium technique. The data obtained clearly indicate that the new SP-extractors have the highest affinity for retention of Hg(II) ion. Their Hg(II) uptake in mmol g−1 and distribution coefficient as log Kd values are always higher than the uptake of any other metal ion along the range of pH used (pH 1.0-10.0). The uptake of Hg(II) using phase I was 2.0 mmol g−1 (log Kd 6.6) at pH 1.0 and 2.0. 1.8 mmol g−1 (log Kd 4.25), 1.6 mmol g−1 (log Kd 3.90) and 1.08 mmol g−1 (log Kd 3.37) at pH 3.0, 5.0 and 8.0, respectively. Selective separation of Hg(II) from the other eight coexisting metal ions under investigation was achieved successfully using phase I at pH 2.0 either under static or dynamic conditions. Hg(II) was completely retained while Ca(II), Co(II) and Cd(II) ions were not retained. Ni(II), Cu(II), Zn(II), Pb(II) and Fe(III) showed very low percentage retention values to be 0.74, 0.97, 3.5 and 6.3%, respectively. Moreover, the high recovery values (95.5 ± 0.5, 95.8 ± 0.5 and 99.0% ± 1.0) of percolating two liters of doubly distilled water, drinking tap water and Nile river water spiked with 5 ng/l of Hg(II) over 100 mg of phase I packed in a minicolumn and used as a thin layer enrichment bed demonstrate the accuracy and validity of the new SP-extractors for preconcentration of the ultratrace amount of spiked Hg(II) prior to the determination by borohydride generation atomic absorption spectrometry (AAS) with no matrix interference. The detection limit (3σ) for Hg(II) based on enrichment factor 1000 was 4.75 pg/ml. The precision (R.S.D.) obtained for different amounts of mercury was in the range 0.52-1.01% (N = 3) at the 25-100 ng/l level. 相似文献
11.
《中国化学快报》2020,31(10):2835-2838
In this paper, a novel mesoporous silica gel evenly doped by Prussian blue nanoparticles (PBMSG) was successfully synthesized by using N,N-dimethylamide as template with a large Barrett-Emmett-Teller (BET) surface area of 505 m2/g and an average pore size of 2.9 nm. The static adsorption experiments showed that the equilibration time of PBMSG for Cs+ was about 30 min. The adsorption isotherm of PBMSG for Cs+ accorded with Langmuir model and the theoretical maximum adsorption capacity was 80.0 ± 2.9 mg/g. When the initial concentration of Cs+ was 1.00 mg/L, the adsorption partition coefficient Kd could reach 3.5 × 104 mL/g After adsorption, Cs+ could be eluted by dilute hydrochloric acid (pH 2) with an efficiency of 89.8%, while no K+, Fe3+, Fe2+ was eluted. PBMSG exhibited good selectivity toward Cs+ and Rb+. In the presence of high concentration of K+, the selective adsorption of PBMSG could change the mass ratio of K+, Rb+ and Cs+ from 96.63:0.83:1.00–1.12:0.73:1.00. The separation of Cs+ and Rb+ from K+ with similar concentration (100 mg/g) was realized by column experiment. This indicated that PBMSG was suitable for rapid recovery of low concentration of rubidium and cesium from complex matrixes, such as wastewater and salt lake brine, etc. 相似文献
12.
用甲基氯硅烷蒸气或溶液处理硅胶,均可制成憎水硅胶。关于憎水硅胶的吸附性能和热稳定性的研究,文献中时有报道。本文主要探讨以下3个问题:(1)在水蒸气吸附中,硅胶表面自由羟基和缔合羟基究竟哪种起主要作用;(2)从吸附水蒸气等数据讨论硅胶表面有机基团—OSi(CH_3)_3的热稳定性;(3)用二甲基二氯硅烷(DMCS)和三甲基氯硅烷(TMCS)处理的憎水硅胶,哪种硅胶的热稳定性较高。这些基本问题,不仅具有学术意义,对研究氧化物表面改性也有参考价值。 相似文献
13.
《Analytical letters》2012,45(12):1125-1133
Abstract Selective adsorption of trace arsenite- and arsenate anions in an aqueous solution by ferric hydroxyde supported on silica gel particles was investigated. Silica gel particles were loaded with ferric hydroxide of the range of 1 – 3 wt. % in terms of Fe based on the dry gel, and the extent of adsorption of arsenite or arsenate ion measured by batch- and column processes, being the highest at pH 6 in the presence of diverse foreign ions. With the use of silica gel containing 3.3 wt. % Fe, as much as 0.07 m mol of arsenic per gram of dry gel was adsorbed. 相似文献
14.
The applicability of silica gels for the application in solid-phase extraction was tested. Silica was modified with ketoimine
groups. Surface characteristics of the modified silica were determined by elemental analysis, NMR spectra of solid phases
(29Si CP MAS NMR), analysis of pore size distribution of the silica support, and nitrogen adsorption-desorption. Newly proposed
sorbents with ketoimine groups were applied in the preconcentration of trace amounts of the Cu (II) ions from lake water,
post-industrial water, and demineralized water unburdened back to the lake.
Presented at the 34th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 21–25 May
2007. 相似文献
15.
The efficiency for the extraction of U(VI) of new modified silica gels, namely N-tripropionate (or N-triacetate)-substituted tetraazamacrocycles-bound silica gels, has been studied. The effect of the nature of the ligand, the pH and the temperature was studied both in batch experiments as well as in continuous extraction. These silica gels are good candidates for the extraction of U(VI) when compared to a commercially available acid-type chelating resin. The breakthrough and regeneration tests showed that the total removal of U(VI) from a contaminated solution can be achieved by using a column packed with such tetraazamacrocycles-bound silica gels. Finally, the use of a modified silica gel in a pilot device allowed the total decontamination of 50 m3 of real effluents containing traces of uranium, plutonium, and americium. 相似文献
16.
Surface characterization of silica gels prepared at different gelation pH from water glass and sulphuric acid were made by argon adsorption at 77 K using continuous volumetric method. While microporous silica gels prepared in the pH range of 1–3 had BET surface areas of 504–571 m2 g–1, total pore volumes of 0.26–0.31 cm3 g–1 and micropore volumes of 0.16–0.23 cm3 g–1, mesoporous silica gels prepared in the pH range of 3.36–0.65 had BET surface areas of 374–530 m2 g–1 and pore volumes of 0.61–0.79 cm3 g–1. 相似文献
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18.
阴、阳离子表面活性剂混合体系在硅胶/水及硅胶/矿化水界面上的吸附 总被引:3,自引:1,他引:3
研究阴、阳离子表面活性剂混合体系(十二烷基氯代吡啶,辛基磺酸钠,辛基三乙基溴化铵/十二烷基苯磺酸钠)在硅胶,纯水和硅胶,矿化水界面上的吸附作用,探讨阴(阳)离子表面活性剂的存在对阳(阴)离子表面活性剂吸附作用的影响.结果表明,阴离子表面活性剂的存在基本不影响阳离子表面活性剂在带负电固体表面的吸附;而阳离子表面活性剂的存在却使本来吸附量就不大的阴离子表面活性剂在带负电的固体表面上不再吸附.在矿化水中阳离子表面活性剂的吸附量比在纯水中明显降低.从硅胶表面吸附机制解释了所得结果. 相似文献
19.
M. Odlyha R. P. W. Scott C. F. Simpson 《Journal of Thermal Analysis and Calorimetry》1993,40(3):1197-1212
Thermogravimetric analysis of silica gel has shown that the loss in weight between 30° and 910°C can be quantitatively explained on the basis of water being lost from three distinct and different populations of sites on the silica gel surface. The results indicate that the site energies of the three different populations are randomly distributed and, consequently, the resulting weight loss steps from each population can be described by the integral of a simple normal distribution with temperature. The calculated weight loss obtained by assuming three different site-groups having randomly distributed adsorption energies is, within experimental error, coincident with the experimental data. It is also shown that the water evolved from the second population of sites originates from strongly bound water and may also contain water generated by the condensation of (geminal) silanol groups contained in the overlapping and neighbouring population. 相似文献
20.
Summary The chromatographic technique of frontal analysis is applied to measuring adsorption from binary liquid mixtures by silica gel. The complete adsorption isotherm of a solvent mixture is obtained by measuring the break-through curves for a series of small concentration steps of the mobile phase. This method offers a direct way to determine the composition of the stationary phase in liquid-solid chromatography with mixed mobile phases. The surface excess isotherms of all binary systems formed by benzene, cyclohexane, and 1,2-dichloroethane, at the solution-silica gel interface at 25 °C are presented. The data of the three systems are shown to be thermodynamically mutually consistent. 相似文献