基于环糊精的高度支化聚合物*

环糊精（CD）与高度支化聚合物都存在空腔结构,若将两者结合起来可构筑出含有两种不同疏水空腔且具有特异物理化学功能的高分子体系,并有望在分子包合与识别、药物控释、基因传输等领域得到新的应用。本文根据高度支化聚合物与环糊精结合方式的不同,从以环糊精为核的高度支化聚合物、外端悬挂环糊精的高度支化聚合物、高度支化聚合物的结构单元与环糊精包合、环糊精与客体分子包合后自组装成高度支化聚合物,以及用功能化的环糊精单体合成超支化聚合物等5个方面对其研究进展进行了总结和评述,并在此基础上展望了该类聚合物的研究方向和发展趋势。     

基于环糊精的农药吸附剂的研究进展

农药的研发与使用极大地提高了农作物的产量,为解决人类温饱、改善人类生活品质做出了贡献。但是,农药广泛残留于农副产品以及土壤和水体中,造成的污染日趋严重。残留的农药通常具有微量致毒、难生物降解、生物累积等特性,对生物健康与生态系统造成了巨大威胁。高效检测微量农药、减小污染危害是亟待解决的问题。吸附法具有成本低、操作简单、稳定性强、可重复性强的特点,在农药分离预富集领域得到了广泛关注。作为一种常用的农药吸附剂材料,环糊精是一类具有空腔的超分子化合物,能够作为主体通过主客体作用形成包合物;另外,可以通过醚化、酯化、氧化等化学反应对环糊精进行后修饰以提高其吸附性能。疏水作用、静电作用、范德华力、氢键作用、立体效应协同促进对农药的吸附。环糊精在农药吸附领域已经取得了一定进展,但是目前还没有基于环糊精的农药吸附剂的综述。该文针对杀菌剂、杀虫剂、除草剂、植物生长调节剂这4类农药,系统性地评述了基于环糊精的农药吸附剂的制备、吸附机理及应用,目前存在个别吸附剂吸附容量不高、降解机理不明确、降解产物对环境不友好、容易造成二次污染的问题,研发高吸附容量、易回收、易分离、易再生的基于环糊精的农药吸附剂是未来的主要研究方向。     

大环吸附剂在离子污染物去除中的应用

水污染已对人类健康和生态系统构成了严重的威胁。很多污染物,包括重金属、染料、抗生素等在水体中以离子形式存在。吸附被认为是去除离子污染物的有效手段之一,但目前针对离子污染物的吸附剂在吸附容量、强度以及速率上还难以满足工业化净水要求。近年来,有机大环分子在离子识别领域表现出独特优势。大环分子上丰富的氧、氮原子,可与离子产生静电吸引、配位、氢键等相互作用;其疏水空腔可进一步通过离子-π作用、π-π作用、疏水作用等增强与有机离子的结合能力。因此,将大环分子引入吸附剂有望改善离子吸附性能。本文对近3年来关于大环吸附剂的工作进行总结。本文将分别对大环基多孔有机聚合物和大环修饰固态材料两类主要的大环吸附剂进行介绍。本文不仅归纳这两类材料的构筑方法,而且介绍其典型代表在吸附金属离子、非金属离子以及有机离子中所表现的应用性能。本文在结尾对该领域的发展现状以及所面临的挑战进行了简要的总结与展望。     

聚合物海绵吸附剂用于水处理的研究进展

在目前水处理方法中,吸附法以其吸附剂来源多样、成本低、效率高、操作容易、环境友好等优点而被广泛研究和应用。聚合物海绵吸附剂不仅具有高分子链分子设计的多样性,还因存在羟基、羧基、氨基等活性基团而具有金属配位能力,同时兼具海绵这一软质泡沫材料的多孔性和高弹性,这些特点赋予其高的吸附容量和优异的可回收性。通过物理共混或化学改性的方法引入纳米材料(如纳米颗粒、纳米线等),可以极大地改善聚合物海绵吸附剂的力学性能和吸附性能。本文介绍了聚合物海绵吸附剂的分类及制备原理,重点综述了其在重金属、油及有机溶剂、染料等水中污染物去除领域的应用,最后对其不足和发展前景作出了展望。     

基于羧甲基-β-环糊精功能材料的研究进展北大核心CSCD

羧甲基-β-环糊精(CM-β-CD)由于具有"内疏水、外亲水"的中空结构,可包结其它化合物分子,而且空腔边缘的羧基也可增加与其它分子间的静电、氢键、偶极等相互作用。通过对CM-β-CD进行修饰,可使其成为具有优异性能的功能材料,因而在医药、分离分析、生物科学、环境保护、污水处理等方面具有很好的应用价值,引起了人们越来越多的关注。本文在分析了CM-β-CD特性的基础上,详细综述了近年来设计开发的CM-β-CD功能材料,主要包括CM-β-CD聚合物、纳米磁性复合材料以及接枝生物分子化合物的制备方法,及其作为吸附剂对有机分子、生物分子、金属离子的分离和吸附性能等相关方面的应用研究,通过分析总结文献内容,对CM-β-CD功能材料的发展进行了展望并提出建议。     

基于羧甲基-β-环糊精功能材料的研究进展

羧甲基-β-环糊精(CM-β-CD)由于具有"内疏水、外亲水"的中空结构,可包结其它化合物分子,而且空腔边缘的羧基也可增加与其它分子间的静电、氢键、偶极等相互作用。通过对CM-β-CD进行修饰,可使其成为具有优异性能的功能材料,因而在医药、分离分析、生物科学、环境保护、污水处理等方面具有很好的应用价值,引起了人们越来越多的关注。本文在分析了CM-β-CD特性的基础上,详细综述了近年来设计开发的CM-β-CD功能材料,主要包括CM-β-CD聚合物、纳米磁性复合材料以及接枝生物分子化合物的制备方法,及其作为吸附剂对有机分子、生物分子、金属离子的分离和吸附性能等相关方面的应用研究,通过分析总结文献内容,对CM-β-CD功能材料的发展进行了展望并提出建议。     

环糊精分子管道的制备与应用

环糊精分子管道是一种基于环糊精制备的中空管状聚合物,因其特殊的空腔结构及与客体分子间的选择性组装现象而引起广泛关注。本文综述和比较了环糊精分子管道的主要制备方法,着重阐述了环糊精分子管道与客体分子间的选择性组装现象、机理及影响因素方面的研究成果。对环糊精分子管道的应用现状和潜在的应用价值进行了概括,最后提出了应予以重视...     

分子印迹球状β-环糊精聚合物的合成及性能研究

利用分子印迹技术,以β-环糊精为功能单体,甲苯-2,4-二异氰酸酯为交联剂,茶碱为模板分子,合成了分子印迹β-环糊精聚合物。采用反相悬浮聚合的方法,以戊二醛为交联剂,用聚乙烯醇(PVA)包埋环糊精聚合物合成了分子印迹球状β-环糊精聚合物(MI-CDPs)吸附剂,对聚合物的合成条件进行了考察,并利用静态吸附方法对球状MI-CDPs的吸附性能进行研究,结果表明,球状MI-CDPs对水溶液中的茶碱分子表现出良好的分子识别能力,实现了对水溶液中茶碱的分子识别,证实在pH=9时,球状MI-CDPs的吸附性能最佳。     

多孔有机聚合物吸附分离水体系中有机污染物研究和应用进展

有机物对水体的污染严重威胁生态环境安全和人类健康。 如何有效控制和消除水体系中的有机污染物是当前全球性热点问题之一,基于多孔材料的高效吸附是处理水体有机污染的有效方法。 多孔有机聚合物(Porous Organic Polymers,POPs)具有比表面积高、物理化学稳定性好、易修饰等特点,作为新型吸附剂在处理水体系有机污染方面具有广阔的应用前景。 本文综述了近10年来新型多孔有机聚合物对水体系中有机溶剂、农药与杀虫剂、有机染料等污染物的吸附分离研究进展。     

分子印迹β-环糊精聚合物选择性识别水中的双酚A

以双酚A为模板分子, β-环糊精为功能单体, 六亚甲基二异氰酸酯为交联剂, 二甲基亚砜为溶剂, 采用沉淀聚合法合成了分子印迹β-环糊精聚合物. 用傅里叶变换红外光谱仪、 扫描电子显微镜对聚合物的结构进行表征. 从选择性、 吸附容量、 结合特性对吸附剂的性能进行了评价. 底物类似物的机会均等与机会不均等竞争吸附实验证明了β-CD-MIPs对底物的结合容量远大于对类似物的结合容量. 用热力学参数对实验数据进行拟合, 发现β-CD-MIPs对BPA的吸附为自发的放热过程, 温度低对吸附有利.     

Advances in cyclodextrin polymers adsorbents for separation and enrichment: Classification,mechanism and applications

Over the past few decades, supramolecular chemistry has entered the field of scientific research and attracted extensive attention. Among supramolecular macrocycles, cyclodextrins(CDs) are widely applied in the field of adsorption due to their unique structure and properties. This review focuses on the important role of cyclodextrin polymers(CDPs) as adsorbents in the adsorption of different substances. It covers the category of CDPs adsorbents(including crosslinked CDPs, grafted CDPs, CD-based ...     

ADSORPTION OF PHENOL AND Pb^2＋ FROM AQUEOUS SOLUTIONS BY A NEW DI-FUNCTION ADSORBENT WITH SULFHYDRYL GROUPS

A new di-function adsorbent （JN-3） was prepared by sulfhydryl modified. Comparing with Amberlite XAD-4 and NDA-150, the equilibrium adsorption for phenol on the JN-3 from aqueous solutions was tested, perfect adsorption capacity was shown. Pb^2＋ can be also removed by JN-3 because of the chelate interaction between sulfhydryl groups and metal ions. This adsorbent could be used in removal of combine pollutants such as phenolic compounds and heavy metal ions from waste streams.     

多孔氧化物块体材料的制备及其对重金属离子吸附研究进展

目前去除重金属离子的方法较多,其中吸附法因操作简单、经济性好而被广泛使用。多孔氧化物块体材料作为新兴的吸附材料具有比表面积高、机械强度高及可回收性好等特点,但吸附选择性差以及孔结构单一的缺陷限制了其在水体重金属处理中的应用。本文详细叙述了多孔氧化物块体材料的多种制备方法,并分别讨论了各方法的优势及其不足。介绍了近几年研究较多的多孔氧化物块体材料及其制备方法与特性。最后,对多孔氧化物块体材料对Pb、Cd及Cr等重金属离子吸附性能的影响因素及改善措施方面进行了总结分析,并指出多种材料的复合、材料表面的接枝改性及分级多孔结构的构建会增强对重金属离子的吸附性能。期望本文为多孔氧化物块体材料的制备及其在重金属离子吸附方面的应用提供参考。     

Kinetic, equilibrium and thermodynamic studies of cadmium (II) adsorption by modified agricultural wastes

Agricultural wastes have great potential for the removal of heavy metal ions from aqueous solution. The contamination of water by toxic heavy metals is a worldwide environmental problem. Unlike organic pollutants, the majority of which are susceptible to biological degradation, heavy metals do not degrade into harmless end products. Discharges containing cadmium, in particular, are strictly controlled because of the highly toxic nature of this element and its tendency to accumulate in the tissues of living organisms. This work aims to develop inexpensive, highly available, effective metal ion adsorbents from natural wastes as alternatives to existing commercial adsorbents. In particular, Tamrix articulata wastes were modified chemically by esterification with maleic acid to yield a carboxyl-rich adsorbent. The adsorption behavior of treated Tamrix articulata wastes toward cadmium ions in aqueous solutions in a batch system has been studied as a function of equilibration time, adsorbent dose, temperature and pH. Results showed that the maximum adsorption capacity was 195.5 mg/g in a pH 4 solution at 30 °C with a contact time of 120 min, an initial concentration of 400 mg/L and an adsorbent dose of 0.3 g/L. The kinetic data were analyzed using pseudo-first-order and pseudo-second-order kinetic models. It was shown that the adsorption of cadmium could be described by a pseudo-second-order equation. The experimental data were also analyzed using the Langmuir and Freundlich models of adsorption. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° have been evaluated and it has been found that the sorption process was spontaneous and exothermic in nature. From all of our data, we conclude that the treated Tamrix articulata wastes investigated in this study showed good potential for cadmium removal from aqueous solutions.     

Graphene Oxides Prepared by Hummers’, Hofmann’s,and Staudenmaier’s Methods: Dramatic Influences on Heavy‐Metal‐Ion Adsorption

Graphene oxide (GO), an up‐and‐coming material rich in oxygenated groups, shows much promise in pollution management. GO is synthesised using several synthetic routes, and the adsorption behaviour of GO is investigated to establish its ability to remove the heavy‐metal pollutants of lead and cadmium ions. The GO is synthesised by Hummers’ (HU), Hofmann’s (HO) and Staudenmaier’s (ST) methodologies. Characterisation of GO is performed before and after adsorption experiments to investigate the structure–function relationship by using Fourier‐transform infrared spectroscopy and X‐ray photoelectron spectroscopy. Scanning electron microscopy coupled with elemental detection spectroscopy is used to investigate morphological changes and heavy‐metal content in the adsorbed GO. The filtrate, collected after adsorption, is analysed by inductively coupled plasma mass spectrometry, through which the efficiency and adsorption capacity of each GO for heavy‐metal‐ion removal is obtained. Spectroscopic analysis and characterisation reveal that the three types of GO have different compositions of oxygenated carbon functionalities. The trend in the affinity towards both Pb^II and Cd^II is HU GO>HO GO>ST GO. A direct correlation between the number of carboxyl groups present and the amount of heavy‐metal ions adsorbed is established. The highest efficiency and highest adsorption capacity of heavy‐metal ions is achieved with HU, in which the relative abundance of carboxyl groups is highest. The embedded systematic study reveals that carboxyl groups are the principal functionality responsible for heavy‐metal‐ion removal in GO. The choice of synthesis methodology for GO has a profound influence on heavy‐metal‐ion adsorption. A further enrichment of the carboxyl groups in GO will serve to enhance the role of GO as an adsorbent for environmental clean‐up.     

纤维素吸附剂相关进展

随着工业化进程加快,人类活动加剧,各种环境问题日益突出,水污染首当其冲。工业生产和日常生活排放的有毒重金属离子和有机废物等造成了严重的水体污染。因此,开发出一种实用有效的吸附剂迫在眉睫。研究发现,天然纤维素可以用作吸附剂,通过化学改性可以显著增强其吸附性能。本文主要概述了纤维素吸附剂的物理化学性质、吸附机理及化学改性研究。从现有文献发现纤维素吸附剂具有十分广阔的应用前景,但工业化生产应用还存在一定的困难,需做进一步的研究。     

Adsorption of some bivalent heavy metal ions from aqueous solutions by manganese nodule leached residues

The leached residue, generated after selective extraction of Cu, Ni, and Co in sulfur dioxide-ammonia leaching of manganese nodules, was characterized and batch isothermal adsorption experiments were conducted at ambient temperature to evaluate the effectiveness of the water-washed leached residue for removal of different bivalent metal ions from aqueous synthetic solutions. The effects of pH, initial metal ion concentrations, amount of adsorbent, interfering ions, and heat treatment were also investigated. The uptake of metal ions increased with increasing pH. Under identical conditions the adsorption capacity increased in the order Cd(2+)相似文献   

金属组学方法识别水中络合态重金属形态及其吸附净化技术研究进展

Cu²⁺、Pb²⁺和Ni²⁺等重金属离子可与水中乙二胺四乙酸、柠檬酸、酒石酸等有机分子形成络合态重金属。相比于游离态离子,络合态重金属具有更高的水溶性和环境毒性,在广泛的pH值范围内稳定存在且形态复杂,难以通过化学沉淀等常规方法高效去除。对近年来基于金属组学方法的水中络合态重金属复杂形态分析方法进行总结,对吸附净化技术在络合态重金属废水处理中的研究进展进行综述,并对上述领域需要解决的问题进行了探讨和展望。     

Modifying the surface of TEOS xerogel by metal ion Zn(II)

The removal of 2,4-dichlorophenol from aqueous solution by modified TEOS xerogel has been studied in batch experiments at varying pH (2.0–8.0). Tetraethyl orthosilicate (TEOS) xerogel recently has been considered as an adsorbent which is more active. Surface of the adsorbent due to the outward oxygen atoms in the molecular structure, is negatively charged, so this solid, shows good ability to adsorb metal ions. But because of the negative charge on the surface of the adsorbent, the anions, particularly organic anion compounds are not absorbed. To fix this problem, it can set the metal ions on the surface of the solid. By placing Zn ions on the xerogel, a positive charge on the surface of the adsorbent is made, which increases the ability of the adsorbent to attract 2, 4-dichlorophenol from aqueous solutions. Results show an increase in the adsorption by about 17% on empty xerogel, by about 60% in xerogel modified with metal Zn (II) ion.

     

水杨酸型螯合吸附材料对重金属离子的吸附性能

将5-氨基水杨酸接枝到PGMA/SiO2微粒的聚甲基丙烯酸缩水甘油酯(PGMA)大分子链上,成功制备了一种新型螯合吸附材料ASA-PGMA/SiO2。采用静态法研究了ASA-PGMA/SiO2对重金属离子Cu2+、Cd2+、Zn2+、Pb2+的吸附性能,结果表明其对Cu2+、Cd2+、Zn2+、Pb2+具有很强的螯合吸附能力,吸附容量分别可以达到0.42、0.40、0.35、0.31mmol/g。体系的pH对吸附容量影响较大,吸附行为服从Langmuir和Freundlich吸附模型。使用0.1mol/L的盐酸溶液就可实现重金属离子的解吸。通过反复吸附-解吸实验证明ASA-PGMA/SiO2具有良好的重复使用性能。