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1.
In this paper, the adsorption behaviors of phenol on polymeric adsorbents (Amberlite XAD4, NDA101, and D301)were investigated in batch system at 293, 303, and 313K, respectively. As the results shown, the adsorption isotherms of phenol on all adsorbents can be well fitted by Langmuir and Freundlich equations, which indicate a favorable and exothermic process. The adsorption capacity on a newly developed aminated adsorbent, NDA101, on which adsorption could be achieved by both hydrogen bonding interaction and π-π interaction, are higher than that on a weak base adsorbent, D301, on which adsorption could be achieved by hydrogen bonding interaction only, and on a nonpolar adsorbent, XAD4, on which adsorption could be achieved by π-π interaction only. The results of this paper indicate that the synergistic effect of some weak interactions, which occur simultaneously would contribute more to the adsorption than that occur individually. 相似文献
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苯酚和苯胺在超高交联吸附树脂上的共吸附行为 总被引:12,自引:0,他引:12
研究了水溶液中苯酚和苯胺在超高交联吸附树脂NDA103、NDA101、NDA100上的竞争吸附和协同吸附行为.实验结果表明,单组分苯酚或苯胺水溶液和双组分共存水溶液中吸附质分子在超高交联吸附树脂上的吸附等温线均符合Langmuir模型.当双组分摩尔比为1∶1时,在较低平衡浓度范围内苯酚和苯胺在树脂上呈现竞争吸附行为,其主导机制是两种吸附质分子对树脂内外表面上π-π作用吸附位点的直接竞争;而在较高平衡浓度范围内呈现协同吸附行为,其主导机制是两种吸附质分子之间的氢键作用.吸附温度由293K升至313K时,苯酚和苯胺在NDA103上的协同吸附作用加强,而在NDA101和NDA100上的协同吸附作用变化不明显. 相似文献
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水介质中氢键吸附与疏水吸附协同作用的研究 总被引:7,自引:0,他引:7
研究了丙烯酸型树脂(D152)在水、乙醇和正己烷中对苯胺、N-甲基苯胺和N,N-二甲基苯胺的吸附行为.在水中D152树脂对3种吸附质的吸附亲合性随N上甲基数的增加而增大,说明疏水作用是主要的吸附机理,但其吸附焓己超出范德华力的范围而在氢键的键能范围内,故氢键吸附也同时在起作用.在正己烷中,D152树脂对3种吸附质的吸附亲合性随N上甲基数的增加而减小,与水中呈相反的趋势,说明氢键作用是主要的吸附机理.在乙醇中,D152树脂对3种吸附质均无吸附,因为疏水作用和氢键作用均受到的乙醇抑制.在水中,吸附质与树脂间的氢键作用同样受到水的抑制,但氢键吸附却依然存在,说明水介质中氢键吸附和疏水吸附可能存在一种协同作用.在热力学上对水介质中氢键吸附和疏水吸附的协同作用给于合理的解释. 相似文献
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Weiming Zhang Qiong Du Bingcai Pan Lu Lv Changhong Hong Zhengmao Jiang Deyang Kong 《Colloids and surfaces. A, Physicochemical and engineering aspects》2009,346(1-3):34-38
Aminated polystyrene resins (NDA-101 and NDA-103) were synthesized, and their adsorption performances for phenol in aqueous solution were investigated and compared with the commercial polystyrene resin (Amberlite XAD-4) and weakly basic polystyrene resin (Amberlite IRA-96). All the associated adsorption isotherms are well described by Freundlich and Langmuir equations. The results indicated that all the four resins spontaneously adsorb phenol driven mainly by enthalpy change, and their adsorption capacities, free energy changes, enthalpy changes, and entropy changes for phenol followed the same order as: NDA-101 > NDA-103 > XAD-4 > IRA-96. Surface energy heterogeneity analysis by Do's model also suggested that the surfaces of XAD-4 and IRA-96 were more homogeneous, and the better adsorption capacity and affinity of the aminated resins (NDA-101 and NDA-103) are probably due to their multiple hydrogen bonding and π–π stacking interactions with phenol molecule. 相似文献
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HUANG Jiangou XU Mancai ** LI Haitao SHI Zuoqing HE Binglin College of Chemistry Chemical Engineering Hunan Normal University Changsha The State Key Laboratory of Functional Polymer Materials for Adsorption Separation Institute of Polymer Chemistry Nankai University Tianjin 《Chinese Journal of Reactive Polymers》2002,(2)
1. INTRODUCTION Adsorption capacity and selectivity are improved when some ion exchange groups or hydrogen bonding acceptor or/and donors are introduced into common polymeric adsorbents [1~5]. R. F. Shi et al have synthesized a series of bifunctional ads… 相似文献
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Three polymeric adsorbents with hydrogen bonding acceptors, methylamine,N-methyl-acetamide and aminotri(hydroxymethyl)methane modified resins are synthesized fromchloromethylated X-5 resin. Adsorption isotherms of phenol and theophylline onto the three modifiedresins and the original X-5 resin from aqueous solution are measured. The results show thatadsorption of compounds with hydrogen bonding donor onto methylamine and N-methylacetamidemodified resins is enhanced as compared with that onto X-5 resin, and adsorption mechanismbetween the adsorbents and the adsorbates is mainly based on hydrogen bonding and hydrophobicinteraction. While adsorption of compounds with hydrogen bonding donor ontoaminotri(hydroxymethyl)methane modified resin is lowered as compared with that onto X-5 resin, andadsorption mechanism between the adsorbent and the adsorbates is mainly based on hydrophobicinteraction. 相似文献
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A kind of new multi-layer adsorbent including Tenax TA/multi-walled carbon nanotubes (MWCNTs)/Carboxen 564 was developed for collecting volatile organic compounds. The adsorption and desorption efficiencies of 11 kinds of adsorbents (including Activated charcoal, Tenax TA, Carboxen 564, Chromosorb 101, Chromosorb 102, Chromosorb 103, Chromosorb 105, Porapak Q, GDX 301, XAD-2, and MWCNTs) were compared. By combining the advantages of Tenax TA, MWCNTs, and Carboxen 564, new type of multi-layer adsorbents was developed. The adsorption and desorption efficiency, the sampling reproducibility, and the effect of water were improved using multi-layer adsorbents, Tenax TA/MWCNTs/Carboxen 564. New multi-layer adsorbents were successfully applied to the determination of volatile organic compounds (VOCs) in ambient air. 相似文献
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胺基化超高交联吸附树脂对苯酚和苯胺吸附行为的研究 总被引:4,自引:1,他引:3
在超高交联吸附树脂上负载不同胺基后,无论是在非水体系还是在水体系中,树脂对苯酚的吸附选择性大大增强.非水体系中,树脂对苯胺和苯酚的吸附是靠氢键作用,水体系中,树脂对苯酚的吸附是表面吸附和基团吸附综合作用的结果.动态吸附表明,树脂胺基化前(Rf18)树脂与季铵化后(Rs6 ) ,对苯胺和苯酚混合水溶液的动态吸附泄漏曲线差别较大.对Rf18树脂,苯酚首先在14 7BV(床体积)处泄漏,其泄漏液浓度上升很快,在2 12BV处达吸附饱和,苯胺在184BV处才开始泄漏,且其泄漏液浓度上升缓慢;在14 7~184BV之间可收集到苯酚溶液.对Rs6树脂,苯胺先泄漏(17BV处) ,其泄漏浓度很快趋于水平,在4 7BV处达吸附饱和;苯酚在4 4BV处开始泄漏,其泄漏曲线也上升很快,在79BV处趋于水平,在17~4 4BV之间可收集到苯胺水溶液. 相似文献
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Isotherm analysis of phenol adsorption on polymeric adsorbents from nonaqueous solution 总被引:1,自引:0,他引:1
Macroporous poly(methyl methacrylate-co-divinylbenzene) (PMMA), interpenetrating polymer adsorbent based on poly(styrene-co-divinylbenzene) (PS) and poly(methyl methacrylate-co-divinylbenzene) (PMMA/PS), and macroporous cross-linked poly(N-p-vinylbenzyl acetylamide) (PVBA) were prepared for the adsorption of phenol from cyclohexane. The sorption isotherms of phenol on the three polymeric adsorbents were measured and fitted to Langmuir and Freundlich isotherms. It is shown that the Langmuir isotherm, which is based on a homogeneous surface model, is unsuitable to describe the sorption of phenol on the adsorbents from nonaqueous solution and the Freundlich equation fits the tested three adsorption systems well. The isosteric enthalpy was quantitatively correlated with the fractional loading for the sorption of phenol onto the three polymeric adsorbents. The surface energetic heterogeneity patterns of the adsorbents were described with functions of isosteric enthalpy. The results showed that the tested three polymeric adsorbents exhibited different surface energetic heterogeneity patterns. The initial isosteric enthalpy of phenol sorption on polymeric adsorbent has to do with the surface chemical composition and is free from the pore structure of the polymeric adsorbent matrix. Forming hydrogen bonds between phenol molecules and adsorbent is the main driving force of phenol sorption onto PVBA and PMMA adsorbent from nonaqueous solution. When phenol is adsorbed on PMMA/PS, pi-pi interaction resulting from the stacking of the benzene rings of the adsorbed phenol molecules and the pendant benzene ring of adsorbent is involved. 相似文献
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Adsorption behavior, thermodynamics, and mechanism of phenol on polymeric adsorbents with amide group in cyclohexane 总被引:4,自引:0,他引:4
Macroporous cross-linked poly(N-methyl-N-p-vinylbenzylacetamide) (PMVBA), poly(N-methyl-N-p-vinylbenzylcaprolactam) (PMVBC), and poly(N-methyl-N-p-vinylbenzylurea) (PMVBU) were synthesized and their adsorption behavior for phenol in cyclohexane was investigated. The results indicated that the adsorption capacities of phenol on the three adsorbents followed the order PMVBU > PMVBA > PMVBC. Adsorption isotherms of phenol on the three polymeric adsorbents were measured and correlated to a Freundlich isotherm. Adsorption enthalpy, adsorption Gibbs free energy, and adsorption entropy were calculated using thermodynamic function relationships. It was found that the adsorption enthalpy of phenol on PMVBU was almost twice that on PMVBA and PMVBC. Analysis of the adsorption mechanism suggested that hydrogen bonding was the primary driving force for phenol adsorbed on the adsorbents in cyclohexane, and multiple hydrogen bonding was involved for PMVBU with phenol. 相似文献
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利用Davankov后交联反应,合成了一类兼具高比表面积和高功能基含量的季铵基(—N+(CH)3)吸附树脂,考察了树脂比表面积和功能基含量的调控规律,并将其用于三七叶总皂甙的进一步纯化.结果表明,当树脂比表面积为692m2/g,交换量为2.1mmol/g时,树脂具有最佳的纯化效果,只通过吸附—解吸一步工艺,产品纯度即可从32.0%提高到90%以上,皂甙的回收率高于95%.最后,初步探讨了树脂对皂甙和色素的吸附机理,认为树脂对皂甙的吸附是单纯的疏水性作用力,而对色素的吸附应为疏水-离子交换双重作用的协同效应. 相似文献
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A comparison of the adsorption of benzoic acid and p-nitrobenzoic acid on the new hypercrosslinked polymeric adsorbent AM-I, with that by macroporous Amberlite XAD-4, including the equilibrium adsorption isotherms, the dynamic adsorption behaviors through column and the adsorption thermodynamics were studied. Results show that Freundlich equation gives a fitting adsorption isotherm. The specific surface of AM-l is only 67% of that of Amberlite XAD-4, but the adsorption capacities on AM-1 are much higher about 125%~166% than that on Amberlite XAD-4,which is contributed to the micropore mechanism and polarity. The negative values of the adsorption enthalpy are indicative of an exothermic process. Enthalpy and free energy changes of adsorption both manifest a physic-sorption process. The negative values of the adsorption entropy indicate that the adsorption is well consistent with the restricted mobilities and the configurations of the adsorbed benzoic acid molecules on the surface of studied adsorbents with superficial heterogeneity. Both adsorbents were used in mini-column experiments for adsorbing benzoic acid expecting to elucidate the higher breakthrough adsorption capacity of the new hypercrosslinked polymeric adsorbent AM-1 as compared with that of Amberlite XAD-4. 相似文献
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1.INTRODUCTIONThepolymericadsorbentAmberliteXAD-4isconsideredoneofthemostsuitablepolymericadsorbentsforremovingphenoliccompoundsfromwaterstreams[1,2]becauseitischemicallystable,notsolubleinsolventsandmoreselectiveforaromaticringsduetoitshydrophobicproperties.However,methanol,acetoneoracetonitrile,hastobeusedtoenhancethesurfacecontactbetweenadsorbentandthesolute.DavankovandTsyurupadescribedanewseriesofadsorbents[3,4].Thistechniqueyieldedpolystyrenesorbentsofunusualhypercrosslinkedstructu… 相似文献
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The adsorption behavior of benzoic acid onto a water-compatible hypercrosslinked polymeric adsorbent NJ-8 wascompared with that onto macroporous Amberlite XAN-4. This paper focuses on the static equilibrium adsorption behaviors,the adsorption thermodynamics and the column dynamic adsorption profiles. Five isotherm models are used to fit the results.This shows that the Freundlich equation can give a perfect fit. The specific surface area of NJ-8 is about as high as that ofAmberlite XAD-4, but the adsorbing capacity for benzoic acid on NJ-8 is about 14.9%-64.8% higher than that on AmberliteXAD-4, which is attributed to its microporous mechanism and partial polarity. The negative values of the adsorptionenthalpy are indicative of an exothermic process. Both enthalpy and free energy changes of adsorption manifest a physicalsorption process. The negative values of the adsorption entropy indicate that adsorption is well consistent with the restrictedmobilities and the configurations of the adsorbed molecules on the surface of the studied adsorbents with superficialheterogeneity. Both adsorbents were used in mini-column experiments to demonstrate the higher breakthrough adsorbing capacity of the hypercrosslinked polymeric adsorbent NJ-8 to benzoic acid, as compared with that of Amberlite XAD-4. 相似文献
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B. R. Saifutdinov A. A. Pimerzin N. S. Emel’yanova S. V. Kurbatova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(2):289-297
Adsorption in Henry’s range of structurally related aryl- and hetaryl-substituted 1,3,4-oxadiazoles from n-hexane-dichloromethane and water-acetonitrile solutions on the surface of porous graphitic carbon (PGC) under the conditions
close to equilibrium is studied by high-performance liquid chromatography. The characteristics of sorption of 1,3,4-oxadiazoles
from solutions on the surface of this adsorbent, octadecyl silica gel, and on hypercrosslinked polystyrene are compared. It
is shown that the structure of the molecules and their Van der Waals surface area and polarity affect adsorption on a PGC
surface. A variant of the mechanism of adsorption of the polar molecules on the PGC surface, explaining the anomalously high
values of their Henry constants of adsorption and based on the planar location of the 1,3,4-oxadiazoles molecules with respect
to the adsorbent surface and the specific adsorbate-adsorbent intermolecular interaction in addition to the background dispersion
interactions, is proposed. It is established that the linear the Gibbs energy relationship upon the adsorption of the studied
compounds from n-hexane-dichloromethane and water-acetonitrile solutions on the PGC surface holds. 相似文献
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《Arabian Journal of Chemistry》2022,15(11):104293
This study aimed to get an insight into the adsorption of three synthetic dyes onto chitin using experimental and computational approaches. The successful preparation of α-chitin was confirmed using the Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD). In addition, the presence of porous and fiber on the surface of the extracted chitin was revealed by the Scanning Electron Microscopy (SEM) analysis. The extracted α-chitin was then used as an adsorbent to remove synthetic dyes, namely Malachite green, Basic red 18, and Alizarin yellow R. The kinetic study showed that the adsorption of dyes was well-described using a pseudo-second-order model, whereas the isotherm adsorption obeyed the Freundlich model. The Frontier Molecular Orbital (FMO) revealed several locations of dyes and chitin molecules that are potentially active sites for adsorption. The adsorption trend could be related to the Highest Occupied Molecular Orbital (HOMO) – Lowest Unoccupied Molecular Orbital (LUMO) energy gap and electrophilicity index of the dyes. The Conductor-like Model for Real Solvent (COSMO-RS) model demonstrated, for the first time, that several interactions occurred during the adsorption of dyes onto α-chitin. For the Malachite green and Basic Red 18, the Van der Waals forces of the dyes controlled its adsorption behavior. In contrast, the hydrogen bonding interaction governed the adsorption behavior of Alizarin yellow R dye onto α-chitin. The gathered insight from this work might guide us better to understand the molecular level of dyes–chitin interactions and, ultimately, to design adsorbents to remove synthetic dyes from wastewater. 相似文献
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Zhang WM Zhang QJ Pan BC Lv L Pan BJ Xu ZW Zhang QX Zhao XS Du W Zhang QR 《Journal of colloid and interface science》2007,306(2):216-221
The adsorption equilibria of phenol and aniline on nonpolar polymer adsorbents (NDA-100, XAD-4, NDA-16 and NDA-1800) were investigated in single- and binary-solute adsorption systems at 313 K. The results showed that all the adsorption isotherms of phenol and aniline on these adsorbents can be well fitted by Freundlich and Langmuir equations, and the experimental uptake of phenol and aniline in all binary-component systems is obviously higher than predicted by the extended Langmuir model, arising presumably from the synergistic effect caused by the laterally acid-base interaction between the adsorbed phenol and aniline molecules. A new model (MELM) was developed to quantitatively describe the synergistic adsorption behavior of phenol/aniline equimolar mixtures in the binary-solute systems and showed a marked improvement in correlating the binary-solute adsorption of phenol and aniline by comparison with the widely used extended Langmuir model. The newly developed model confirms that the synergistic coefficient of one adsorbate is linearly correlated with the adsorbed amount of the other, and the larger average pore size of adsorbent results in the greater synergistic effect of phenol/aniline equimolar mixtures adsorption. 相似文献