共查询到20条相似文献,搜索用时 31 毫秒
1.
Hai-ling Wang Zheng-hao Fei Jin-long Chen Quan-xing Zhang 《高分子科学》2007,(3):235-244
In the present study the adsorptive properties of p-aminobenzoic acid with hypercrosslinked and multi-functional polymeric adsorbents at different solution pHs were systematically investigated in accordance with the particular physicochemical characteristics of the aromatic amphoteric compound involving both Lewis acid and Lewis base functional groups. It was found that the equilibrium adsorption data of the three polymeric adsorbents fitted well in the Langmuir and Freundlich isotherm equations. Studies at various pH levels indicate that the capacity of the adsorbents for adsorption of the ionic forms of adsorbate is less than that for the corresponding neutral species. At pH 3.78, the adsorption capacities of the three adsorbents are the highest. Whereas the adsorption property of multi-functional polymeric adsorbent NJ-99 is the largest, which may be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of p-aminobenzoic acid. The trend of the adsorption capacities of the three adsorbents towards p-aminobenzoic acid with the solution pH is in accord with the dissociation curve of the neutral molecular p-aminobenzoic acid. The adsorption forces include π-π interaction, hydrogen-bonding interaction and electrostatic attraction or repulsion when there exist the molecular and ionic adsorbing species at different pHs in aqueous solution. 相似文献
2.
合成了用邻羧基苯甲酰基或苯甲酰基修饰的新型聚苯乙烯-二乙烯苯吸附树脂ZH-01, ZH-02和ZH-03, 利用瓶点法研究了它们和Amberlite XAD-4对288~318 K下水溶液中2,4,6-三氯苯酚的静态吸附和静态脱附特征以证实吸附质与吸附剂之间存在化学吸附, 并利用半经验分子轨道法(AM1)计算的几种吸附剂和2,4,6-三氯苯酚的前线轨道近似能级进行了解释. 结果表明: 经邻羧基苯甲酰基或苯甲酰基化学修饰后的树脂ZH-01, ZH-02和ZH-03对水溶液中2,4,6-三氯苯酚的吸附过程在合适温度时会使酚羟基和吸附剂表面的羰基发生作用, 对吸附剂进行适当的化学修饰后, 对2,4,6-三氯苯酚的穿透吸附容量均为Amberlite XAD-4树脂的150%, 饱和吸附容量是Amberlite XAD-4树脂的114%~128%. 相似文献
3.
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
4.
5.
6.
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
7.
超高交联树脂对苯胺的吸附机理研究 总被引:11,自引:0,他引:11
在静态条件下,研究了水溶液中超高交联树脂AM-1和NJ-8及大孔吸附树脂Amberlite XAD-4吸附苯胺的热力学特性,测定了不同温度下的吸附等温线。结果表明,在稀溶液中3种树脂吸附苯胺都符合Langmuir和Freundlich模型,其中AM-1和NJ-8对苯胺的吸附是一个吸热过程;由于AM-1和NJ-8的微孔结构和表面存在酸性基团的吸附中心,对苯胺的吸附是物理吸附和化学吸附共同作用的结果。 相似文献
8.
比较两种超高交联聚苯乙烯吸附树脂NJ-8、AM-1与Amberlite XAD-4(以下简称XAD-4)对对硝基苯乙酮的静态吸附行为,根据吸附等温线研究了吸附热力学性质.在298~318K和研究的浓度范围内,NJ-8,AM-1、XAD-4对对硝基苯乙酮的吸附平衡数据符合Freundlich吸附等温方程.结果表明:吸附为放热过程,适当降低温度有利于吸附.计算了对硝基苯乙酮在NJ-8,AM-1、XAD-4树脂上的吸附焓变、自由能变,吸附熵变.对吸附行为作了合理的解释。 相似文献
9.
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
10.
In this research, naphthalene was adopted as the representative model compound of PAHs, and static adsorption of naphthalene from aqueous solution onto three commercial polymeric adsorbents with different pore structure was investigated. Nonlinear isotherms models, i.e., Freundlich, Langmuir, and Polanyi-Dubinin-Manes (PDM) models were tested to fit experimental data, and the experimental data were found to fit well by the PDM model. Through both isotherm modeling and constructing "characteristic curve," Polanyi theory was useful to describe the adsorption process of naphthalene by polymeric adsorbents, providing evidence that a micropore filling phenomenon was involved during the adsorption process. In addition, a good linear correlation was obtained between the naphthalene adsorption capacities and the micropore volume of adsorbents (Vmicro), whereas no linear relationship was found between the naphthalene adsorption capacities and the specific surface area of adsorbents. Based on the PDM model, the micropore volumes of adsorbents was introduced to normalize the equilibrium adsorbed volume (qv), plots of qv/V(micro) vs adsorption potential density for naphthalene on three different polymeric adsorbents were collapsed to a single correlation curve, which would be of great benefit to predict the adsorption capacity of adsorbent for the purpose of adsorption engineering design. 相似文献
11.
根据原花青素含有疏水性的苯环和酚羟基的特点,设计合成了含有苯环和酰胺基的大孔二乙烯苯-异氰酸三烯丙基酯-丙烯腈(DTA)共聚物吸附树脂,DTA树脂通过疏水作用和氢键吸附原花青素.比较了DTA吸附树脂和3种商品化吸附树脂ADS-5(非极性)、ADS-8(弱极性)和ADS-17(中极性)对原花青素的吸附性能.结果表明,DTA、ADS-8、ADS-17对原花青素的吸附既包含疏水作用又有氢键参与.在合适的单体和致孔剂配比情况下合成的DTA吸附树脂对原花青素有很好的吸附性能. 相似文献
12.
13.
The adsorptive removal of trihalomethanes (THMs) from spiked water samples was evaluated with a series of modified polysaccharide adsorbents that contain β-cylodextrin or chitosan. The uptake properties of these biodegradable polymer adsorbents were evaluated with a mixture of THMs in aqueous solution. Gas chromatography employing a direct aqueous injection (DAI) method with electrolytic conductivity detection enabled quantification of THMs in water at 295 K and at pH 6.5. The adsorption isotherms for the polymer-THMs was evaluated using the Sips model, where the monolayer adsorption capacities ranged between 0.04 and 1.07 mmol THMs/g for respective component THMs. Unique adsorption characteristics were observed that vary according to the polymer structure, composition, and surface chemical properties. The modified polysaccharide adsorbents display variable molecular recognition and selectivity toward component THMs in the mixed systems according to the molecular size and polarizability of the adsorbates. 相似文献
14.
15.
16.
17.
The presence of sulfonamide antibiotics in aquatic environments poses potential ecological risks and dangers to human health. In this study, porous resins as adsorbents for the removal of two sulfonamides, sulfadiazine and sulfadimidine, from aqueous solutions were evaluated. Activated carbon F-400 was included as a comparative adsorbent. Despite the different surface properties and pore structures of the three resins, similar patterns of pH-dependent adsorption were observed, implying the importance of sulfonamide molecular forms to the adsorption process on the resins. Sulfonamide adsorption to the three resins exhibited different ionic strengths and temperature dependence consistent with sulfonamide speciation and the corresponding adsorption mechanism. Adsorption of sulfadiazine to F-400 was relatively insensitive to pH and ionic strength as micropore-filling mainly contributed to adsorption. The adsorption mechanism of sulfadiazine to the hypercrosslinked resin MN-200 was similar to that of the macroporous resin XAD-4 at lower pH values, whereas it was almost identical to the aminated resin MN-150 at higher pH. This work provided an understanding of adsorption behavior and mechanism of sulfonamide antibiotics on different adsorbents and should result in more effective applications of porous resin for antibiotics removal from industrial wastewater. 相似文献
18.
19.
The adsorption mechanism of a series of macroporous adsorption resins (p-(CH3NH)PhL (L = NH2, OH, COOH)) with rutin have been investigated using density functional theory calculations at B3LYP/6-31G(d,p) level of theory. Solvent effects on these species were explored using calculations that included a polarizable continuum model for the aqueous solvent. In this article, the geometry structure, interaction energies and the infrared spectra for the stable reactants and the adsorption complexes were obtained and analyzed. The results show that the hydrogen-bonding have been formed in the adsorption complexes. The higher interaction energy is calculated for the carboxyl group, while the resin with amino group has the highest adsorption capacity for rutin. The adsorption complexes become more and more stable as increasing the number of adsorbents. Our theoretical study is in good explanation for the experimental results. 相似文献
20.
Adsorption behaviors of phenol from aqueous solutions have been investigated in batch systems at 303 K and 318 K respectively, using hypercrosslinked polymeric adsorbent (CHA111), aminated hypercrosslinked polymeric adsorbents (NDA101, NDA103, NDA105) and weakly basic polymeric adsorbent (D301) with a view to studying the effect of hydrogen bonding and Van der Waals interactions between adsorbate and the adsorbent. All adsorption isotherms can be well fitted by Langmuir and Freundlich equations. Compared with D301 driven by hydrogen bonding interaction only and CHA111 driven by Van der Waals interaction only, phenol adsorption on aminated adsorbents driven by both hydrogen bonding and Van der Waals interactions were apparently different, i.e., negative effect for NDA105, positive effect for NDA101 and synergistic effect for NDA103. In this synergistic action, some weak interactions would contribute more or less to the adsorption than they work individually. 相似文献