香草醛接枝壳聚糖的制备及其吸附性能

以壳聚糖和香草醛为原料,乙醇为溶剂,采用超声波辐射技术制备了香草醛接枝壳聚糖,用红外光谱对产物的结构进行了表征,同时研究了接枝壳聚糖的吸附性能。结果表明:采用超声波辐射法,大大提高了壳聚糖的接枝反应速度,反应2 h时接枝率达到32.85%。香草醛接枝壳聚糖对Cr6+、Cu2+的吸附容量和吸附速度大于壳聚糖。在25℃下,它对Cu2+、Cr6+的吸附容量分别达到145.68 mg/g和56.75 mg/g,并且对Cu2+、Cr6+的吸附在2 h内即可达到饱和。     

微波辐射下甲醛交联壳聚糖的制备及其吸附性能的研究

报道了微波辐射下甲醛交联改性壳聚糖衍生物的制备及其对铜(Ⅱ)的吸附性能,考察了不同溶剂交联度的影响,并测定了交联壳聚糖和壳聚糖对铜(Ⅱ)的吸附量。结果表明,交联后的壳聚糖对铜(Ⅱ)有较好的吸附,并对微波作用进行了探讨。     

壳聚糖Schiff碱的制备及其对金属离子吸附性能研究

文章采用微波辐射技术制备戊二醛交联壳聚糖水杨醛Schiff碱,探究其对铜离子的吸附性能。通过红外光谱仪,热分析仪和扫描电子显微镜对其结构及性能进行一系列表征,同时通过正交实验法考察其反应温度、时间、吸附动力学等影响因素对交联产物吸附性能的影响。扫描电镜分析表明交联改性后壳聚糖的表面明显发生变化,比壳聚糖更加松散,在吸附完成后改性壳聚糖的表面变得严密。由分析热失重可知改性壳聚糖热分解反应是258℃。由吸附动力学曲线可以得出改性壳聚糖对铜离子的吸附符合二级吸附动力学方程。     

香草醛改性壳聚糖对水中Cu2＋，Pb2＋的吸附性能探讨

研究了香草醛与壳聚糖在pH值为6．8和5．5时,分别对水中Cu2＋,Pb2＋的吸附容量达到476．7mg／g和382．94mg／g。当吸附剂的用量小时,其吸附效果令人满意,可以作为自来水中祛除金属离子,净化水质的吸附剂。     

改性壳聚糖在重金属离子吸附方面的研究进展

本文综述了近年来壳聚糖在金属离子吸附方面的研究进展,主要介绍了壳聚糖的改性方法和各种改性壳聚糖对金属离子的吸附情况。     

微波辐射制备壳聚糖

用质量分数34％的NaOH在微波辐射下对甲壳素进行非均相脱乙酰以快速制备壳聚糖，并测定了不同条件下制得的壳聚糖的相对分子质量和脱乙酰度，该反应时间短，重复性好，产品质量易控制。     

壳聚糖对金属离子的吸附选择性

壳聚糖是一种天然高分子化合物,高分子链段中含有-NH2,-OH活性基团,与重金属离子形成配位化合物,可制成高分子吸附剂吸附重金属离子。以Cu^2＋、Zn^2＋和Pb^2＋为研究对象,通过等温吸附的分析,讨论壳聚糖吸附重金属离子的选择性。     

羧甲基壳聚糖对金属离子吸附的研究进展

羧甲基壳聚糖及其改性产品的吸附性能主要体现在对各种金属离子的的吸附上.为了有选择性地吸附某些金属离子,人们通过修饰、交联、接技等方法对羧甲基壳聚糖进行了各种改性研究.文章综述了1992年以来羧甲基壳聚糖及其衍生物在金属离子吸附方面的研究进展.展望了吸附剂存重金属离子废水处理过程中的巨大优势和良好的发展前景.     

壳聚糖对金属离子吸附性能改性的研究进展

壳聚糖以其优良的理化性质和吸附特性在工业废水处理中已得到广泛的应用.目前对壳聚糖进行化学改性已经成为壳聚糖开发研究的热点.本文结合国内外研究成果对壳聚糖吸附金属离子性能的改性进行了评述和展望.     

壳聚糖对重金属离子吸附作用的研究

本文了研究了壳聚糖对水中Ｃｄ＾２＋,Ｐｂ＾２＋,Ｍｎ＾２＋,Ｚｎ＾２＋,Ｆｅ＾３＋,Ｃｒ＾３＋七种离子的吸附作用。结果表明,重金属离子的吸附率与溶液的ＰＨ值,壳聚糖用量,吸附时间等有关。     

壳聚糖及其衍生物去除金属离子的研究进展

壳聚糖具有来源广泛、无毒无害、功能基团丰富、化学活性强等特点,广泛应用于化工、环保、医药、食品等领域.围绕壳聚糖分子链上活性基团对金属离子的吸附能力,综述了壳聚糖及其衍生物在去除溶液中金属离子方面的研究工作及进展.介绍了对壳聚糖单体进行官能团置换或重组的化学改性法和改变壳聚糖物理形态的物理改性法,详细阐述了交联改性法、接枝改性法、磁化改性法、分子印迹法的基本原理、应用效果和优缺点,并对壳聚糖微球、壳聚糖膜的制备方法和材料性能进行了归纳.结合壳聚糖及其衍生物在制备和应用过程中存在的问题,提出了将化学改性和物理改性相结合制备新型印迹壳聚糖基聚合物,从而实现高效和选择性去除金属离子的研究方向.     

羧甲基壳聚糖对稀土离子吸附性能的研究

以壳聚糖为原料,在碱性条件下合成了标题化合物,考察了其对稀土离子La3+、Nd3+、Sm3+的吸附性能.讨论了时间、溶液的酸度、初始离子浓度、羧甲基取代度对吸附性能的影响.发现羧甲基壳聚糖对稀土离子有较强的吸附性,吸附性满足Langmuir等温式.     

Synthesis and adsorption properties for metal ions of crosslinked chitosan acetate crown ethers

Two novel chitosan derivatives—crosslinked chitosan dibenzo‐16‐c‐5 acetate crown ether (CCTS‐1) and crosslinked chitosan 3,5‐di‐tert‐butyl dibenzo‐14‐c‐4 diacetate crown ether (CCTS‐2)—were synthesized by the reaction of crosslinked chitosan with dibenzo‐16‐c‐5 chloracetate crown ether and 3,5‐di‐tert‐butyl dibenzo‐14‐c‐4 dichloracetate crown ether with the intent of forming polymers that could be used in hazardous waste remediation as toxic metal‐binding agents in aqueous environments. Their structures were confirmed with elemental analysis, infrared spectral analysis, and X‐ray diffraction analysis. In the infrared spectra of CCTS‐1 and CCTS‐2, the characteristic peaks of aromatic backbone vibration appeared at 1595 cm⁻¹ and 1500 cm⁻¹; the intensity of the N H and O H stretching vibration in the region of 3150–3200 cm⁻¹ decreased greatly. The X‐ray diffraction analysis showed that the peak at 2θ = 20° decreased greatly in CCTS‐1 and CCTS‐2. The adsorption and selectivity properties of CCTS‐1 and CCTS‐2 for Pb²⁺, Cu²⁺, Cr³⁺, and Ni²⁺ were studied. Experimental results showed that the two crosslinked chitosan derivatives had not only good adsorption capacities for Pb²⁺, Cu²⁺, but also high selectivity for Pb²⁺, Cu²⁺ in the coexistence of Ni²⁺. For aqueous systems containing Pb²⁺, Ni²⁺, or Cu²⁺, Ni²⁺, CCTS‐1 only adsorbed Pb²⁺ or Cu²⁺. For aqueous systems containing Pb²⁺, Cr²⁺ and Ni²⁺, CCTS‐2 had high adsorption and selectivity properties for Pb²⁺. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2069–2074, 1999     

Preparation and adsorption behavior for metal of chitosan crosslinked by dihydroxy azacrown ether

A new type of crosslinked chitosan was prepared using Dihydroxy azacrown ether as the crosslinking agent. Its structure was confirmed by elemental analysis, Fourier transform infrared (FTIR) spectra analysis, solid‐state ¹³C nuclear magnetic resonance (NMR) analysis, and X‐ray diffraction analysis. Its static adsorption properties for Ag⁺, Cd²⁺, Hg²⁺, and Co²⁺ were studied. The experimental results showed that the Dihydroxy azacrown ether crosslinked chitosan has good adsorption capacities and high selectivity for adsorption of Ag⁺ with the coexistence of Hg²⁺ and Co²⁺. The selectivity coefficients of crosslinked chitosan are k/ = 5.47, k/ = 4.64, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 530–535, 2002     

Preparation and adsorption properties of metal ions of crosslinked chitosan azacrown ethers

The novel azacrown ether chitosan derivatives (CCAE‐I, CCAE‐II) were prepared by reaction between crosslinked chitosan with epoxy‐activated azacrown ethers. Their structures were confirmed by elemental FTIR spectra analysis and X‐ray diffraction analysis. The adsorption and selectivity properties of the crosslinked chitosan azacrown ethers for Pb²⁺, Cu²⁺, Cr³⁺, Cd²⁺, and Hg²⁺ were also investigated. The experimental results showed that they have high adsorption capacity for Cu²⁺, Cd²⁺, and Hg²⁺. The adsorption capacity of CCAE‐II is higher than CCAE‐I for Cd²⁺ and Hg²⁺. The selectivity properties of CCAE are better than chitosan and crosslinked chitosan. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3053–3058, 1999     

Adsorption for metal ions of chitosan coated cotton fiber

A kind of adsorbent for metal ions, cotton fiber coated by high loading of chitosan (SCCH) was prepared. Its structure was characterized by elemental analysis, scanning electronic microscopy (SEM), Fourier transform infrared spectrum (FTIR), and wide‐angle X‐ray diffraction (WAXD). The adsorption properties of SCCH for Cu²⁺, Ni²⁺, Pb²⁺, Cd²⁺, such as saturated adsorption capacities, static kinetics, and isotherm were investigated. The adsorption for Ni²⁺, Pb²⁺, and Cd²⁺ was controlled by liquid film diffusion, but by particle diffusion for Cu²⁺. The adsorption process for Cu²⁺, Ni²⁺, Cd²⁺ could be described with Langmuir or Freundlich equation, but only with Freundlich equation for Pb²⁺. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Adsorption behaviour of metal ions on imprinted chitosan resin

A new method for preparation of metal ion imprinted chitosan resin, which can considerably enhance the adsorption capacity and selectivity of the metal ion is presented in this paper. The conditions influencing the preparation of chitosan imprinted resin such as the cross‐linking agent, epichlororohydrin and ethylene glycol diglycidyl ether, and metal ion concentration are optimized. The chemical and the physical stability are also discussed and the imprinted chitosan resin can be used many times without losing adsorption capacity. The adsorption isotherms were studied and a new model was suggested to correlate the relationship of adsorption with pH and metal ion concentration. © 2001 Society of Chemical Industry