大孔交联聚苯乙烯吸附树脂的合成及其对叶绿素铜的吸附…

通过改变苯乙烯－二乙烯苯共聚物的交联度和使用不同结构的二乙烯苯，合成了树脂Ｉ－Ⅵ，在工业二乙烯苯共聚体系中加入少量丙烯酸甲酯合成了树脂Ⅶ；交联聚苯乙烯经Ｆｒｉｅｄｅｌ－Ｇｒａｆｔｓ酰化反应在其苯环上引入乙酰基制备树了树脂Ⅷ，用物理技术和化学方法表征了树脂的结构。树脂对叶绿素铜的吸附量不仅与其二乙烯苯含量胶有关，还与二乙烯基的位置（间－，对－）异构有关，树脂骨架极性的增加，不利于树脂对叶绿素铜的吸附     

一种极性吸附树脂的合成研究

低交联苯乙烯—二乙烯苯共聚物在Friedel—Crafts催化剂存在下,与二氯亚砜发生反应而产生了后交联,形成大孔树脂,因为树脂中引入了极性的亚矾基团,此树脂可作为极性吸附树脂。树脂通过元素分析。孔结构测定、红外光谱等,证实发生了反应。研究了反应条件对树脂孔结构的影响。     

中极性高交联大孔吸附树脂的合成及其对绞股蓝皂甙的吸附性能

二乙烯苯分别与甲基丙烯酸甲酯、丙烯酸甲酯、顺丁烯二酸二甲酯、乙酸烯丙酯、丙烯腈、甲基乙烯基甲酮和N-乙烯基吡咯烷酮进行悬浮共聚合,制备了一系列交联度为40％的大孔吸附树脂。并表征了这些树脂的结构,测定了树脂对绞股蓝皂甙的吸附量。结果说明,所用单体的极性等因素对树脂的孔结构及吸附量有重要影响。     

三嗪树脂对生物碱的分子识别研究

合成了丙烯腈-二乙烯苯交联共聚物,对其进行化学修饰得到二氨基三嗪树脂.尝试了该三嗪树脂对脲嘧啶和胸腺嘧啶在甲醇中的吸附情况,初步研究了该三嗪树脂在质子性溶剂中对生物碱的分子识别作用.     

单宁酸修饰的后交联吸附树脂的制备及对氯酚的吸附性能

采用氯甲基化的低交联苯乙烯-二乙烯苯共聚物,通过交联反应和化学修饰反应制备了单宁酸修饰的后交联吸附树脂TAMR-1和TAMR-2,并对其进行了红外光谱分析、比表面及孔径分析和热重分析。通过静态吸附实验,比较了TAMR-1和TAMR-2对2-氯酚、4-氯酚和2,4-二氯苯酚的吸附去除率。通过小柱吸附-脱附实验,探讨了TAMR-1对3种氯酚的吸附性能。结果表明,与TAMR-2相比,TAMR-1的比表面积较高,氯残留量低,后交联反应与化学修饰反应更完全。TAMR-1和TAMR-2的外推起始分解温度均超过680K。TAMR-1树脂对3种氯酚(C0均为200mg/L)的吸附去除率均超过85%,明显高于TAMR-2树脂,且对2,4-二氯苯酚的吸附量最大。4%的NaOH溶液对吸附氯酚饱和后的TAMR-1树脂具有良好的再生效果。     

中极性高交联大孔吸附树脂的合成及其对绞股蓝皂甙的吸附性能

 二乙烯苯分别与甲基丙烯酸甲酯、丙烯酸甲酯、顺丁烯二酸二甲酯、乙酸烯丙酯、丙烯腈、甲基乙烯基甲酮和N-乙烯基吡咯烷酮进行悬浮共聚合,制备了一系列交联度为40％的大孔吸附树脂。并表征了这些树脂的结构,测定了树脂对绞股蓝皂甙的吸附量。结果说明,所用单体的极性等因素对树脂的孔结构及吸附量有重要影响。     

中国离子交换与吸附科学技术文摘(1986年)

苯乙烯、二乙烯苯在致孔剂存在下进行悬浮聚合反应制得大孔交联聚苯乙烯,然后进行氯甲基化反应和付氏交联反应,制备了一系列吸附树脂,分别测定了它们的比表面积、孔容、平均孔径等结构性能。实测结果表明,共聚体的交联度、致孔剂的种类和用量对吸附树脂的孔结构性能有明显的影响。     

不同长度酰胺基手臂吸附树脂对罗布麻黄酮吸附纯化研究

二乙烯苯交联的酯基树脂分别与乙二胺、二乙烯三胺、三乙烯四胺、四乙烯五胺发生胺解反应,将其胺端与乙酸酐进行酰化得到不同长度手臂的酰胺树脂,研究了其对罗布麻黄酮的纯化,发现二乙烯三胺手臂的酰胺树脂对黄酮选择性最好,将罗布麻黄酮纯度从17%提高到80%。利用吸附热力学研究其吸附机理,树脂对黄酮的等量吸附焓在氢键吸附范围内。通过红外光谱测定,发现树脂吸附罗布麻黄酮前后,酰胺基团的伸缩振动峰由1624.5cm~(-1)移动到了1619.6cm~(-1),移动了5个波长,说明酰胺树脂的酰胺基团与多酚类的黄酮分子之间形成了氢键作用,增强了其对黄酮化合物吸附选择性。     

阴离子交换树脂骨架结构对吸附单宁酸与五倍子酸的影响

选用聚丙烯酸系D730、FPA98和聚(苯乙烯-二乙烯苯)系的D201强碱型阴离子交换树脂作为吸附剂,系统研究单宁酸、五倍子酸在上述3种阴离子交换树脂上的吸附行为与机理。吸附等温线表明,聚丙烯酸系阴离子交换树脂对单宁酸的吸附性能优于聚苯乙烯-二乙烯苯系阴离子交换树脂,而聚(苯乙烯-二乙烯苯)系阴离子交换树脂对五倍子酸有较高的吸附容量。虽然3种阴离子交换树脂对单宁酸的吸附均为熵推动的自发吸附过程,静电引力是主要吸附作用力,但是在吸附过程中除离子交换作用外,D730和FPA98骨架上的羰基与单宁酸有较强的氢键作用,而D201骨架上的苯环与五倍子酸也存在着"π-π"共轭作用,从而提升离子交换树脂对鞣酸类物质的吸附性能。因此,影响离子交换树脂吸附性能的不仅是交换容量,其骨架结构对吸附性能也有较大影响。另外,上述吸附作用也会影响树脂吸附饱和后的脱附性能,相比较聚(苯乙烯-二乙烯苯)系强碱型阴离子交换树脂,聚丙烯酸系强碱型阴离子交换树脂有更好脱附性能。     

交联聚苯乙烯吸附树脂的修饰及其对天然皂甙的吸附性能

交联聚苯乙烯氯甲基化后,将氯转化为羟基、氨基、甲氧基、苯氧基、4-羟基苯氧基和4-乙酰苯氧基,合成了不同极性的吸附树脂Ⅰ—Ⅵ。同时由交联聚苯乙烯经Friedel-Crafts酰化反应在其苯环上引入乙酰基,制备了树指Ⅶ。用物理技术和化学方法表征树脂Ⅰ—Ⅶ的结构,然后测定了它们对天然皂甙如甜菊甙和绞股蓝皂甙的吸附量。结果说明,这些树脂亲水性较好,均能吸附天然皂甙,但只有中极性的酮基树脂Ⅵ和Ⅶ的吸附量较大。     

Development of Composite Adsorbents of Carbon and Intercalated Clay for N2and O2Adsorption: A Preliminary Study

Composite adsorbents of carbon and alumina intercalated montmorillonite were prepared and characterized by adsorption of N₂and O₂at various temperatures. The effects of pyrolysis, temperature, heating rate, subsequent degassing, and doping of cations and anions were investigated. The adsorption capacities of the composite adsorbents developed at higher temperatures (0 and −79°C) are found to be larger than those of normal alumina pillared clays. The experimental results showed that the framework of these adsorbents is made of alumina particles and clay sheets while the pyrolyzed carbon distributes in the space of interlayers and interpillars. The pores between the carbon particles, clay sheets, and alumina pillars are very narrow with very strong adsorption forces, leading to enhanced adsorption capacities at 0 and −79°C. The composite adsorbents exhibit features similar to those of carbonaceous adsorbents. Their pore structures, adsorption capacities, and selectivities to oxygen can be tailored by a controlled degassing procedure. Meanwhile, ions can be doped into the adsorbents to modify their adsorption properties, as usually observed for oxide adsorbents like zeolite and pillared clays. Such flexibility in pore structure tailoring is a potential advantage of the composite adsorbents developed for their adsorption and separation applications.     

Evaluation of new high-density ion exchange adsorbents for expanded bed adsorption chromatography

New adsorbents Q HyperZ and CM HyperZ composed of hydrogel-filled porous zirconium oxide particles were evaluated for expanded bed adsorption applications in the present work. The HyperZ adsorbents have wet density of 3.16 g ml(-1), particle size of 44.5-100.8 microm and average sphere diameter of 67 microm. The bed expansion as the function of flow velocity and fluid viscosity was measured and correlated with Richardson-Zaki equation. The suitable expansion factor was considered less than 2.5, while the corresponding flow velocity was about 450 cmh(-1). Liquid mixing in the bed was determined to evaluate the stability of expanded bed. The Bodenstein numbers tested were higher than 40 and the axial mixing coefficients (D(ax)) were between 0.5 and 9.7x10(-6)m(2)s(-1), which demonstrated that a stable expanded bed could be formed under suitable operation conditions. Bovine serum albumin (BSA) and lysozyme were used as model proteins to estimate the adsorption capacities of Q and CM HyperZ, respectively. The maximum equilibrium adsorption of Q and CM HyperZ could reach 45.7 and 27.2 mg g(-1) drained adsorbents, respectively. It was found that yeast cells had little influence on the adsorption capacities of the two adsorbents tested. The dynamic adsorption capacity of BSA at 10% breakthrough with Q HyperZ was 35.9 mg g(-1) drained adsorbent at flow velocity of 100 cm h(-1) for packed bed adsorption. The values for expanded bed adsorption were 34.4 mg g(-1) drained adsorbent at flow velocity of 200 cm h(-1), 33.6 mg g(-1) drained adsorbent at 300 cm h(-1) and 31.7 mg g(-1) drained adsorbent 400 cm h(-1). The results demonstrated that Q HyperZ and CM HyperZ are suitable for expanded bed adsorption of biomolecules.     

DNA binding during expanded bed adsorption and factors affecting adsorbent aggregation

DNA-induced aggregation and contraction of expanded bed adsorption chromatography beds have been examined using strong anion exchanger Q HyperZ and calf thymus DNA in buffers containing added NaCl. Two batches of adsorbent with different ionic capacities were used allowing the effects of different ligand densities to be examined. Very high dynamic binding capacities at 10% breakthrough were found in the absence of added salt. However, the highest binding capacities ( approximately 10 and approximately 19mgDNAml(-1) gel) were found in buffers containing added salt at concentrations of either 0.25 or 0.35M, for the low and high ligand density adsorbents, respectively. Bed contraction was observed, but did not correlate with dynamic binding capacity or with the amount of DNA loaded. No differences in bed contraction were seen by varying the concentration of DNA loaded in the range of 20-80mugml(-1) even though the dynamic binding capacity was reduced as DNA concentration was increased. The extent of bed contraction during DNA loading was found to be a function of added salt concentration and ligand density of the adsorbent. The results imply that ligand density significantly affects the salt tolerance of anion exchangers when binding DNA. However, more importantly, with the adsorbents examined here, attempts to reduce bed aggregation by feedstock conditioning with added salt may increase DNA binding leading to a reduction in expanded bed adsorption performance compromising protein capture in real feedstocks.     

Ionic silica based hybrid material containing the pyridinium group used as an adsorbent for textile dye

The present study reports the development of an ionic silica based hybrid material containing the cationic pyridinium group, which was employed for the removal of the Reactive Red 194 textile dye from aqueous solution. Three hybrid material samples were prepared with planned textural and chemical properties, varying the inorganic precursor molar percentage in the sol-gel synthesis. The obtained samples were defined as Py/Si-90, Py/Si-92 and Py/Si-94, where the number specifies the inorganic molar percentage. The hybrid samples were characterized by elemental, infrared, (13)C and (29)Si NMR, N(2) adsorption-desorption isotherms and thermogravimetric analyses. The dye-removing ability of these adsorbents was determined by the batch contact adsorption procedure. Effects such as pH value and adsorbent dosage on the adsorption capacities were studied. Four kinetic models were applied. The adsorption was best fitted to Avrami fractional-order kinetic model for the three hybrid material samples. The kinetic data were also adjusted to an intra-particle diffusion model resulting three linear regions, indicating that the adsorption kinetics follows multiple sorption rates. The equilibrium data were fitted to Langmuir, Freundlich and Liu isotherm models. The maximum adsorption capacities were 165.4, 190.3 and 195.9 mg g(-1) for Py/Si-90, Py/Si-92 and Py/Si-94, respectively. Simulated dye-house effluents were used to check the applicability of the proposed adsorbents for effluent treatment. Dye loaded adsorbents were regenerated (>98.2%) by using 0.4 mol L(-1) of NaOH solution as an eluent.     

Polanyi-based models for the adsorption of naphthalene from aqueous solutions onto nonpolar polymeric adsorbents

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.     

The adsorption properties of organic sulfur compounds on zeolite-based sorbents impregnated with rare-earth metals

Dimethyl disulfide (DMDS) and dimethyl sulfide (DMS) are non-polar, stable, organic sulfur compounds found in liquefied petroleum gas, and their oxidation in the atmosphere results in the formation of tropospheric sulfur dioxide, which is subsequently converted into sulfuric acid, as the main factor of acid rain. In the present study, adsorption processes were devised based on the use of modified zeolite impregnated with rare-earth metals (Ce, La or Pr) for the adsorption of DMDS and DMS, and their sorption capacities were compared with that of commercial zeolite [Zeolite-Y, Ultra Stable Y(USY)]. The adsorption capacities of adsorbents were tested using a micro liquid flow reactor at room temperature. USY impregnated with cerium oxide (UC-10) had excellent DMDS and DMS adsorption capacities as compared with the other adsorbents tested. It was found that impregnation of USY with rare-earth metal such as Ce improved the sulfur adsorption capacity of zeolite. The form of the Ce promoter impregnated into USY was determined by FT-Raman spectroscopy. Adsorbents were characterized by X-ray fluorescence spectrometer, X-ray diffraction, and BET and the results obtained are discussed.     

Comparative study of thiophilic functionalised matrices for polyclonal F(ab')2 purification

Thiophilic adsorbents have been developed using divinyl sulfone or epoxy activated Streamline quartz base matrix. Their capacity and selectivity for binding polyclonal F(ab')2 fragments generated by whole serum proteolysis was tested. Except for epoxy activated guanidine, all the adsorbents displayed high selectivity for F(ab')2 with dynamic binding capacities ranging from 3 to 10 mg/ml of adsorbent. Thiol immobilised ligands adsorbed more F(ab')2 and the recovery was equal to or more than that from amino immobilised ligands. All adsorbents showed good selectivity for IgG and the dynamic binding capacities were better than for F(ab')2.     

Biosorption of Cr(VI) ions from aqueous solutions: kinetics, equilibrium, thermodynamics and desorption studies

Cr(VI) is a major water pollutant from industrial effluent whose concentration is to be reduced within the permissible limit. Present study reports a systematic evaluation of six different natural adsorbents for the removal of Cr(VI) from aqueous solutions in batch process. The adsorption kinetic data were best described by pseudo-second order model. The values of mass transfer coefficient for Cr(VI) adsorption indicated that the velocity of the adsorbate transport from the bulk to the solid phase was quite fast. The effective diffusivity of Cr(VI) removal for all the adsorbents were of the order of 10(-10) m(2)/s which suggested chemisorption of the process. The adsorption process was jointly controlled by film diffusion and intraparticle diffusion. Maximum monolayer adsorption capacities onto the natural adsorbents used were comparable to the other natural adsorbents used by other researchers. The thermodynamic studies and sorption energy calculation using Dubinin-Radushkevich isotherm model indicated that the adsorption processes were endothermic and chemical in nature. FT-IR studies were carried out to understand the type of functional groups responsible for Cr(VI) binding process. Desorption study was carried out with different concentration of NaOH solutions. Application study was carried out using electroplating industrial wastewater.     

低交换量混胺树脂的合成及其对绞股蓝皂甙的吸附性能

高交联聚苯乙烯型树脂S-008(Ⅰ)氯甲基化后,以不同比例的三甲胺/二甲胺混合胺或三甲按/二乙醇胺混合胺胺化,合成了同时含有季铵和叔氨基的混胺树脂Ⅱ-Ⅺ,研究了它们对绞股蓝皂甙的吸附性能,发现树脂的比表面和极性基团对其吸附量均有明显影响,此外,这些树脂对绞股蓝皂甙呈现出一定的吸附选择性和良好的解吸选择性。     

A comparative adsorption study of β-naphthol on four polymeric adsorbents from aqueous solutions

Adsorptive removal of aromatic compounds from aqueous solutions by polymeric adsorbents has attracted many concerns in recent years. A comparative adsorption study including equilibria, kinetics and column dynamics of β-naphthol from aqueous solutions was carried out using two hypercrosslinked polymeric adsorbents (HJ-1 and TEPA) we developed and two commercial polymeric adsorbents (XAD-4 and XAD-7). The adsorption isotherms could be well described by the Freundlich equation, and the adsorption equilibrium capacities of β-naphthol followed an order of q(e)((TEPA))>q(e)((HJ-1))>q(e)((XAD-4))>q(e)((XAD-7)). The isosteric adsorption enthalpies on HJ-1 and TEPA decreased with increasing adsorption fractional loading, while a constant enthalpy was observed for XAD-4 and XAD-7, implying that HJ-1 and TEPA had a heterogeneous surface while XAD-4 and XAD-7 possessed a homogenous surface. The surface energetic heterogeneity of HJ-1 and TEPA could be well characterized by the Do's model. The adsorption kinetics were fitted by both pseudo-first-order and pseudo-second-order rate equations, and the intra-particle diffusion was found to be the rate-limiting step. The adsorption breakthrough data were well correlated by the Thomas and Clark models, and the dynamic capacities for TEPA, HJ-1, XAD-4 and XAD-7 adsorbents were calculated to be 341.7, 321.6, 268.0 and 173.8 mg/g dry resin, which were within 90% of the corresponding equilibrium capacities obtained in the batch experiments.