壳聚糖及其衍生物对金属离子的吸附研究(上)

壳聚糖是一种天然高分子,在其分子结构的重复单元中有-NH2和-OH,因而对金属离子有较好地吸附和配位能力.本文较全面地综述了壳聚糖及其衍生物对金属离子的吸附性能,简述了它们与金属离子形成配合物的结构及吸附机理,并对其发展前景作了展望.其中上篇主要讲述了壳聚糖及其衍生物对金属离子吸附性能的研究进展.     

改性磁性壳聚糖微球对Cu2+、Cd2+和Ni2+的吸附性能

Fe3O4/ chitosan magnetic microspheres of 50 to 80 滋m were prepared using the inverse phase emulsion dispersion and chemical crosslinking technology, and then modified with ethylenediamine for use in the adsorption of heavy metal ions. The adsorption properties of the modified Fe3O4/chitosan toward Cu2+, Cd2+ and Ni2+ were investigated. It was found that the adsorption capacities of Cu2+ and Ni2+ increased with pH, and a maximum adsorption for Cd2+ occurred at pH=3. The saturated adsorption capacities calculated by Langmuir isotherms were 54.3 mg·g-1 for Cu2+, 20.4 mg·g-1 for Cd2+, and 12.4 mg·g-1 for Ni2+, respectively. The adsorption kinetics were well described by pseudo-second-order equation models. The experimental results showed that the Fe3O4/chitosan modified with ethylenediamine presented higher adsorption selectivity for Cu2+ than for Cd2+ and Ni2+ in all studied pH ranges.     

交联酚醛型咪唑啉树脂的合成与吸附性能研究

以苯酚及一氯醋酸为原料,合成了新型交联酚醛咪唑啉树脂.合成树脂对Au3 、Pt2 、Cu2 、Ag 、Hg2 、Co2 、Ni2 具有良好的吸附性能,其静态吸附容量分别为2.278mmol/g,1.530mmol/g,2.692mmol/g,2.390mmol/g,1.901mmol/g,1.644mmol/g,1.488mmol/g(25℃).吸附Cu2 、Hg2 、Ag 、Co2 的表观速率常数(k/min)分别为3.2659×10-2,1.7124×10-2,1.9611×10-2,2.8175×10-2.吸附Cu2 ,Ni2 ,Co2 和Ag 的最佳pH值分别为6.0～6.5,6.0～6.5,6.0～6.5和5.5～6.0.     

基于壳聚糖及其衍生物的金属离子吸附剂的研究进展

综述了近年来以壳聚糖和壳聚糖衍生物为原料的金属离子吸附剂的研究进展．重点介绍了壳聚糖及其衍生物的交联和功能化反应，以及交联后的树脂对多种金属离子的吸附情况．常用的交联剂包括戊二醛、甲醛及环氧氟丙烷，(聚)乙二醇双缩水甘油醚等，壳聚糖树脂的功能化主要包括向其中引入冠醚、羧甲基等功能团，其中羧甲基化是最常用最有效的方法．另外，还介绍了金属离子模板壳聚糖树脂以及基于壳聚糖衍生物的蛇笼树脂的合成。     

壳聚糖及其衍生物对金属离子的吸附研究(下)

壳聚糖是一种天然高分子,在其分子结构的重复单元中有-NH2和-OH,因而对金属离子有较好地吸附和配位能力。本文较全面的综述了壳聚糖及其衍生物对金属离子的吸附性能,简述了它们与金属离子形成配合物的结构及吸附机理。其中下篇主要讲述了壳聚糖及其衍生物与金属离子形成配合物后的结构以及吸附机理,并对其发展前景作了展望。     

Recent advances on hydrogels based on chitosan and alginate for the adsorption of dyes and metal ions from water

In contemporary times, water resources have become increasingly scarce and suffer from anthropogenic pollution sources with an organic and inorganic origin that are products of industrial, agricultural, and everyday waste. Contamination with heavy metals and dyes in wastewater is considered a risk for water sources that can leak into underground and surface sources, leading to increased biological and chemical contamination. The pollutant removal process is performed by adsorption treatment methods, which is the most common method, and it is considered an effective method with a high and economical removal rate.In this review, we discuss the use of biobased hydrogel adsorbents in the removal of organic dyes and metal ions from water. The literature indicates that hydrogels exhibit rapid absorption kinetics and a dye removal absorption capacity that can reach more than 100 mg/g and sometimes more than 2000 mg/g, with a metal adsorption capacity ranging from 38 mg/g to more than 440 mg/g. These results are discussed and compared by taking into account hydrogel materials that contain biopolymers such as alginate, chitosan or both. In general, absorption depends mainly on biobased materials, which have a natural origin and can be utilized to synthesize hydrogels to remove pollutants, dyes and heavy metals. Chitosan and alginate are prominent materials for this use and they can be incorporated with other components to obtain hydrogels or nanocomposite materials with different efficacies to remove dyes and metal ions.     

新型胺基壳聚糖树脂的合成及其对胆红素吸附性能的研究

以壳聚糖为原料，经羟丙基氯化、胺基化，制备了一种新型胺基壳聚糖树脂，研究了该树脂对胆红素的吸附性能。结果表明：胺基壳聚糖树脂的胺基含量比壳聚糖高，该树脂对游离胆红素的吸附在3h基本达到平衡，吸附量随着胺基含量增加而增加，树脂的吸附性能受温度、离子强度影响。胺基壳聚糖树脂对血清白蛋白结合胆红素的吸附量大于壳聚糖，但低于对游离胆红素的吸附。     

螯合树脂S930对Cu(Ⅱ)、Pb(Ⅱ)、Cd(Ⅱ)的吸附性能与作用机理研究

通过静态吸附和动态吸附研究系统分析了螯合树脂S930对单组分与双组分体系中Cu(Ⅱ)、Pb(Ⅱ)、Cd(Ⅱ)的吸附行为,经结构表征(FT-IR、XPS)与软硬酸碱理论(HASB)深入探讨了3种金属离子在S930树脂上的作用机理。结果表明,树脂吸附金属离子的最佳pH值为5.0左右,且对Cu(Ⅱ)、Pb(Ⅱ)的吸附过程符合Langmuir方程,而对Cd(Ⅱ)的吸附过程符合Freundlich方程。吸附过程在6h左右达到平衡,且符合Lagergren二级吸附动力学模型,表明化学作用是吸附速率决定步骤。Cu(Ⅱ)、Pb(Ⅱ)的动态吸附过程符合Thomas模型。FT-IR、XPS及HASB同时证明树脂对Cu(Ⅱ)、Pb(Ⅱ)的作用包括离子交换与配位作用,而对Cd(Ⅱ)的作用以离子交换为主,是树脂对Cd(Ⅱ)吸附选择性较差的主要原因。     

萃淋树脂和螯合树脂在金属元素分离及试剂纯化中的应用

作者等就多年来在萃淋树脂及螯合树脂在金属元素分离及试剂纯化方面所取得的经验和成果作了总结。在萃淋树脂方面,概要地叙述了此类树脂的制备方法,其选择性及应用等内容。就螯合树脂方面几种突出实例,如Chelex 100树脂应用于从碱金属及碱土金属离子溶液中选择性地分离两价重金属;Amberlite 743硼选择性树脂用于选择性分离以BO33-或BF4-形式存在的硼(Ⅲ)离子;LZ 85树脂用于制备高纯度含钴试剂及353E树脂用于吸附分离金属离子与氰根形成的络合离子如Au(CN)4-、Ag(CN)2-等作了介绍。此外,还对应用阴离子交换树脂,如Dowex 1-X8,分离金属离子与氯离子生成的络阴离子,如[AuCl6]3-、[FeCl4]-等;对阳离子交换树脂用于制备高纯铀等特例作了简述。     

交联聚氨基壳聚糖螯合树脂的制备及吸附性能研究

以壳聚糖为原料合成了交联聚氨基球状螯合树脂,并考察了其对Hg(Ⅱ)、Pb(Ⅱ)、Zn(Ⅱ)的吸附性能及影响因素。结果表明,对高浓度金属离子(约0.01mol/L)吸附量的大小为Hg(Ⅱ)>Pb(Ⅱ)>Zn(Ⅱ),对Zn(Ⅱ)几乎不吸附;而在低浓度时(约20ug/ml)树脂对三种离子均具有较高的吸附率(>55%)。     

硅胶负载壳聚糖树脂的制备及其对金属离子的吸附性能

将壳聚糖（ＣＴＳ）负载于层析硅胶上，然后于乙二醇中用Ｂ－６３树脂对其进行化学交联，合成了标题化合物（Ｓｉ－ＢＣＴＳ）。研究了ＣＴＳ的浓度、碱的浓度、交联剂的用量及时间等条件对树脂的负载率及时间等因素对金属离子的吸附性能的影响。考察了时间对上述树脂对 Ｃｕ２＋、 Ｎｉ２＋、 Ｚｎ２＋、 Ｃｏ２＋的吸附量的影响。结果表明：１）最佳合成条件是：温度为１２０℃，反应时间为５ｈ，－ＮＨ２与环氧基的比例为１～２： ２～１． ２）上述树脂具有吸附速度快、沉降迅速和对金属离子吸附性能好等特点，其对Ｃｕ２＋、Ｎｉ２＋、Ｚｎ２＋、Ｃｏ２＋的吸附量分别可达到０．４５～０．７５，０．３４～０．６４， ０．０１～０．０２，０．０８～０．２１ｍｍｏｌＭ２＋／ｇ ｒｅｓｉｎ．     

电化法研究壳聚糖树脂与游离酸的相互作用

利用电化实验技术，跟踪观察交联壳聚糖树脂吸附低浓度游离酸的行为，讨论了酸和甲醇浓度等因素对吸附的影响，利用固-液相互作用方程，求取吸附剂一吸附质相互作用能。实验结果表明，交联壳聚糖树脂吸附低浓度游离酸的过程是遵循单分子层机制进行的，表观吸附速率常数随着吸附质浓度和外加甲醇含量的增大而减小，表观吸附速率常数与吸附剂一吸附质相互作用能（U）存在线性相关。     

几种吸附树脂对五氯酚钠吸附性能的研究

研究了几种树脂对五氯酚钠的吸附能力,其中戊二醛交联的壳聚糖树脂不仅有较好的吸附效果,动态吸附容量为187.5mg/g干树脂,而且易洗脱,洗脱率高达90%以上。     

Adsorption of graphene oxide/chitosan porous materials for metal ions

Porous graphene oxide/chitosan（PGOC） materials were prepared by a unidirectional freeze-drying method.Their porous structure,mechanical property and adsorption for metal ions were investigated.The results show that the incorporation of graphene oxide（GO） significantly increased the compressive strength of the PGOC materials.The saturated adsorption capacity of Pb²⁺ increased about 31%,up to 99 mg/g when 5 wt%GO was incorporated These biodegradable,nontoxic,efficient PGOC materials will be a potential adsorbent for metal ions in aqueous solution.     

外加盐对壳聚糖树脂吸附游离酸的影响

利用电化实验技术,跟踪观察交联壳聚糖树脂在不同环境体系吸附低浓度游离酸的行为。讨论了在三元体系（酸 水 盐）和四元体系（酸 水 有机物 盐）中,交联壳聚糖树脂吸附游离酸的规律。利用固-液相互作用方程,求取吸附剂-吸附质相互作用能。实验结果表明,交联壳聚糖树脂在三元体系和四元体系中吸附游离酸,表观吸附速率常数（k)随着外加盐浓度的增大而减小。发现表观吸附速率常数（k)与吸附剂-吸附质相互作用能（U）存在线性关系。     

Preparation and metal binding behavior of poly(4-vinylbenzyl 2-hydroxyethyl) sulfoxide and sulfone

In order to explore the reuse properties of oxidized chelating resin containing sulfur after adsorption, two kinds of novel chelating resins, poly[4-vinylbenzyl-(2-hydroxyethyl)] sulfoxide (PVBSO) and poly[4-vinylbenzyl-(2-hydroxyethyl)] sulfone (PVBSO₂), were synthesized using poly[4-vinylbenzyl-(2-hydroxyethyl)] sulfide (PVBS) as material. Their structures were confirmed by FTIR and XPS. The adsorption properties and mechanism for metal ions such as Au³⁺, Pt⁴⁺, Pd²⁺, Hg²⁺, Cu²⁺, Ni²⁺, Fe³⁺, Pb²⁺, Cd²⁺, and Zn²⁺ were investigated. Experimental results showed that PVBSO had good adsorption and selective properties for Au³⁺, Pd²⁺ and Cu²⁺ when the coexisting ion was Pt⁴⁺, Ni²⁺, Pb²⁺ or Cd²⁺. In the aqueous system containing Cu²⁺ and Pb²⁺ or Cu²⁺ and Cd²⁺, PVBSO₂ only adsorbed Cu²⁺. The selective coefficients of PVBSO and PVBSO₂ were α_Au/Pt = 4.8, α_Au/Pd = 11.8, α_Pd/Pt = 10.9, α_Cu/Ni = 2.5, α_Cu/Cd = 41.2, α_Cu/Pb = ∞, α_Cu/Ni = 3.0, α_Cu/Cd = ∞, α_Cu/Pb = ∞, respectively.     

Adsorption properties of the double-imprinted electrospun crosslinked chitosan nanofibers

Pb(II)-Cd(II) double-imprinted electrospun crosslinked chitosan nanofibers (Pd/Cd-DIECCNs) were prepared by combining electrospinning and ion-imprinting methods, which showed excellent adsorption capacity for both Pb(II) and Cd(II).     

流动注射分光光度法研究壳聚糖树脂吸附阴离子染料

利用流动注射分光光度法技术，跟踪观察交联壳聚糖树脂吸附阴离子染料的行为，讨论了外加氯化钠或甲醇以及温度等因素对吸附的影响。利用固－液相互作用方程，求取了吸附剂－吸附质相互作用能。实验结果表明，交联壳聚糖树脂吸附 子染料，其表观吸附速率常数随体系中氯化钠浓度或甲醇含量的增大而减小，随温度的升高而增大；交联壳聚糖树脂吸附酸性铬蓝K染料的表观活化能力26.095kJ/mol。     

Preparation of crosslinked polystyrene-supported ethylenediamine via a S-containing spacer and adsorption properties towards metal ions

Two novel chelating resins were prepared by anchoring ethylenediamine to crosslinked polystyrene via a spacer containing sulfide. Their structures were characterized by Fourier transform-infrared spectra (FTIR) and scanning electron microscopy (SEM). Porous structure parameters of the resins were measured by ASAP 2020 using BET and BJH methods. Their adsorption capacities for several heavy metal ions especially Hg²⁺ were investigated. The results showed that for the two resins, the more N contents did not mean the better adsorption capacity and the saturated adsorption capacity of poly(2-ethylenediamidomercaptomethylstyrene) (PSM-EDA) for Hg²⁺ could reach to 3.0 mmol/g at room temperature. Isothermal adsorptions of the resins for Hg²⁺ could be described by Langmuir formula. The adsorption mechanism of the resins for Hg²⁺, Cu²⁺ and Ag⁺ was confirmed by X-ray photoelectron spectroscopy (XPS) and FTIR.     

交联壳聚糖预富集分离-石墨炉原子吸收光谱法测定痕量银(Ⅰ)

研究了交联壳聚糖(CCTS)对银(Ⅰ)的吸附性能,提出了用CCTS作为富集剂预富集分离水样中痕量银的新方法。研究结果表明:在pH 3.0时,CCTS对银的吸附率达99%以上,其饱和吸附量为0.6 mg/g;采用8 mL 0.5 moL/L的氨水可将吸附在CCTS上的银定量洗脱。用CCTS将水中痕量银(Ⅰ)富集20倍,石墨炉原子吸收光谱法(GFAAS)进行检测,检出限(3σ,n=6)为0.406μg/L,相对标准偏差(RSD)小于6.8%。该方法也适合贵金属银的回收利用。