偕胺肟基纤维的合成及对铀的吸附性能研究

以聚丙烯腈纤维为原料,通过与羟胺反应制得偕胺肟基纤维,考察了合成条件对铀吸附性能的影响.结果表明,用二甲基亚砜(DMSO)作添加剂,温度为70℃时合成的偕胺肟基纤维中偕胺肟基的含量可高达11.45mmol·g-1.考察了吸附温度、溶液的pH和浓度对吸附性能的影响.结果表明,温度较高、浓度较大时吸附速率较快.当pH为5时,吸附量可高达24.82mg·g-1.由对UO22+、Mg2+,Ca2+3种离子的吸附数据可知,铀/镁,铀/钙的选择性系数分别为20.26和4.01,表明该偕胺肟基纤维对铀具有较强的吸附选择性.     

吸附法海水提铀材料研究进展

吸附法是海水提铀的最适宜方法之一,选择性好且吸附效率高的吸附材料是从海水中提取铀的最佳材料。本文回顾了到目前为止吸附法海水提铀的无机、有机、无机/有机杂化材料的制备方法、结构、吸附性能和铀吸附机理,介绍了不同海水提铀装置的结构和吸附性能。由于有机/无机杂化材料具有高机械强度、高铀吸附量、低共存离子干扰等优点,是一种理想的海水提铀材料;而且膜式吸附装置由于操作流程简单、可连续化等优点,是一种较佳的吸附方式。开展高铀吸附量、高选择性的吸附剂和处理量大的吸附方式是今后吸附法海水提铀的重要研究方向。     

高氟高氯含铀废水中偕胺肟基改性聚丙烯腈纤维螯合铀的研究

以聚丙烯腈纤维（PANF）为基体与盐酸羟胺反应制得偕胺肟基改性纤维（AO-PANF）,并通过扫描电镜、红外光谱和批次吸附,探究了AO-PANF对高氟高氯含铀废水中铀的螯合行为。结果表明,偕胺肟化反应将PANF中的氰基成功转化为偕胺肟基团,转化率随盐酸羟胺浓度增加而增大,氰基转化率为22.34%时,AO-PANF对铀的吸附量最大。随废水pH增加,AO-PANF对铀的吸附量先增大后减小,pH为5时,其值最大。F^-和Cl^-浓度变化对AO-PANF的吸附量影响较小。当处理100 ml铀初始浓度为100 mg·L^-1,pH为5的废水,温度为45℃,吸附剂投加量为0.40 g时,转化率为22.34%的AO-PANF对铀的吸附量为19.53 mg·g^-1,3 h左右吸附达到平衡。AO-PANF通过偕胺肟基团中-NH₂与废水中UO₂F₄^2-螯合实现对铀的吸附。该吸附过程符合Freundlich等温吸附模型和准二级动力学方程。研究表明AO-PANF可以有效地螯合高氟高氯含铀废水中的铀,具有良好的应用前景。     

偕胺肟基乙烷桥键介孔二氧化硅对铀的吸附研究

采用水热法合成了氰基化乙烷桥键的介孔材料,经胺肟功能化后制备出偕胺肟基介孔SiO_2材料(AO-PMOs)。利用AO-PMOs对铀溶液进行吸附实验,探讨了铀溶液初始质量浓度、pH值以及吸附时间对AO-PMOs吸附铀的影响,并采用FTIR,SEM,EDS技术进行表征分析。结果表明:在溶液初始pH值为5,铀质量浓度为10 mg/L,吸附剂投加量为20 mg,反应温度为303 K的条件下,吸附效果较佳,吸附率最大为99.04%,吸附量可达25 mg/g。该吸附过程与准二级动力学模型(R~20.99),Langmuir和Freundlich等温吸附模型(R~20.98)能较好地拟合。偕胺肟基在AO-PMOs吸附铀过程起主要作用。     

偕胺肟基改性纤维在含铀废水处理中的应用研究

偕胺肟基改性纤维对水中铀离子具有良好的选择性和吸附性,是一种新型的含铀废水处理技术.对偕胺肟基改性纤维的发展情况进行了研究,结果表明偕胺肟基改性纤维对低浓度含铀废水具有非常好的吸附效果和减容率,分析了吸附操作对铀去除效果的影响因素,表明该技术在含铀废水处理和低浓度铀浓缩行业有良好的应用前景.     

偕胺肟基腈纶螯合纤维制备的研究

腈纶偕胺肟化反应可采用湿法、松弛浸渍焙烘法和紧张浸渍焙烘法三种工艺。本文分析了各种制备工艺条件对制得螯合纤维性能的影响,指出焙烘法工艺较湿法工艺先进,尤以紧张浸渍焙烘法更好,它克服了前两种工艺中无法解决的偕胺肟基含量与纤维强度的逆相关性,可制得偕胺肟基含量高于7.0mmol/g,并使强度大于3.0cN/dtex的腈纶螯合纤维。     

螯合纤维的制备——聚丙烯腈纤维改性

聚丙烯腈纤维与羟胺试剂通过化学反应,腈基转变为偕胺肟基团,使聚丙烯腈纤维改性成为对金属离子具有螯合能力的螯合纤维。系统地探讨和研究了聚丙烯腈纤维改性的实验参数:反应温度、时间、反应物浓度、酸度等。并用红外光谱对螯合纤维进行表征。     

偕胺肟基Cu(Ⅱ)、Hg(Ⅱ)配合物纤维的抗菌性能研究

偕胺肟基聚丙烯腈纤维(AOCF)分别与Cu2+和Hg2+通过配位反应,得到AOCF-Cu(Ⅱ)、AOCF-Hg(Ⅱ)配合物纤维,研究了这两种纤维对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌和白色念珠菌等4种微生物的抗菌性能。实验表明:配合物纤维中金属离子含量越高,作用时间越长,灭菌效果越好;金属配合物纤维对4种菌的杀灭有选择性;AOCF-Hg(Ⅱ)的抗菌能力强于AOCF-Cu(Ⅱ)。     

纳米硫化银/偕胺肟复合纤维的制备及抑菌性能研究

以聚丙烯腈纤维(PAN)为原料,化学改性制得含有偕胺肟基团的螯合纤维(AOCF),使其与纳米硫化银反应,制得标题化合物.运用扫描电镜(SEM)及X-衍射能谱仪(EDX)对样品进行了相应的表征,并研究纤维对大肠杆菌和枯草芽孢杆菌的抑菌性能.结果表明,在纤维表面生成了纳米硫化银,0.1g的nano-Ag2S/AOCF对大肠杆菌的抑菌能力与0.5万单位的青霉素相当,而对枯草芽孢杆菌的抑菌能力与1.0万单位的青霉素相当.     

新型偕胺肟基修饰杯8]芳烃材料的制备及其吸附性能研究

一种新型杯芳烃衍生物偕胺肟基修饰亚甲基桥杯[8]芳烃(C8A-AO)首次成功合成,并通过处理得到C8A-AO纳米颗粒。使用核磁氢谱和碳谱、红外光谱、扫描电镜、X射线光电子能谱等方法对其进行了表征。考察了C8A-AO在不同pH值、接触时间和温度等条件下对铀酰离子的吸附能力,研究了其在模拟海水中对铀酰离子的选择性吸附能力,以期C8A-AO在核工业海水提铀领域发挥其应用价值。     

Adsorption properties of poly(acrylaminophosphonic-carboxyl-hydrazide)type chelating fiber for heavy metal ions

In this article, the adsorption properties of poly(acrylaminophosphonic-carboxyl-hydrazide) chelating fibers for Cu(II), Cd(II), Co(II), Mn(II), Pb(II), Zn(II), Ni(II), and Cr(III) are investigated by a batch technique. Based on the research results of binding capacity, adsorption isotherm, effect of pH value on sorption, and adsorption kinetics experiments, it is shown that the poly(acrylaminophosphonic-carboxyl-hydrazide) chelating fibers have higher binding capacities and good adsorption kinetic properties for heavy metal ions. The sorption of the metal ions on the chelating fibers is strongly dependent on the equilibrium pH value of the solution. The adsorption isotherms of Cu(II) and Cd(II) on the chelating fiber exhibit a Langmuir-type equation. The adsorbed Cu(II), Cd(II), Zn(II), and Pb(II) could be eluted by diluted nitric acid. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 7–14, 1998     

多配位基螯合纤维对Ag~+的吸附性能研究

以聚(N-乙烯基甲酰胺/丙烯腈)纤维为原料,依次与二乙烯三胺交联反应、盐酸羟胺水溶液偕胺肟化反应和氢氧化钾水溶液水解反应,制备了多配位螯合纤维,研究了纤维对Ag+的吸附性能。用红外光谱法探讨了纤维对Ag+的吸附机理。结果表明:多配位鳌合纤维具有较好的吸附动力学特性,吸附速率常数和表观吸附活化能分别为3.337×10-4s-1和3.99kJ/mol;等温吸附曲线服从Langmuir和Freundlich经验式;测得吸附热力学参数焓变、熵变、自由能变分别为0.25kJ/mol,18.39J/mol.K,-5.24kJ/mol。     

Adsorption and desorption properties of the chelating membranes prepared from the PE films

The chelating membranes for adsorption of metal ions were prepared by the photografting of glycidyl methacrylate (GMA) onto a polyethylene (PE) film and the subsequent modification of the resultant GMA‐grafted PE (PE‐g‐PGMA) films with disodium iminodiacetate in an aqueous solution of 55% DMSO at 80°C. The adsorption and desorption properties of the iminodiacetate (IDA) group‐appended PE‐g‐PGMA (IDA‐(PE‐g‐PGMA)) films to Cu²⁺ ions were investigated as functions of the grafted amount, pH value, Cu²⁺ ion concentration, and temperature. The amount of adsorbed Cu²⁺ ions increased with an increase in the pH value in the range of 1.0–5.0. The time required to reach the equilibrium adsorption decreased with an increase in the temperature, although the degree of adsorption stayed almost constant. The amount of Cu²⁺ ions desorbed from the (IDA‐(PE‐g‐PGMA)) films increased and the time required to reach the equilibrium desorption decreased with an increase in the HCl concentration. About 100% of Cu²⁺ ions were desorbed in the aqueous HCl solutions of more than 0.5M. The amounts of adsorbed and desorbed Cu²⁺ ions were almost the same in each cyclic process of adsorption in a CuCl₂ buffer at pH 5.0 and desorption in an aqueous 1.0M HCl solution. These results indicate that the IDA‐(PE‐g‐PGMA) films can be applied to a repeatedly generative chelating membrane for adsorption and desorption of metal ions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99:1895–1902, 2006     

三唑硫酮基螯合纤维的制备及其吸附性能研究

以聚丙烯腈纤维为原料,分别经水合肼、乙二胺、二乙烯三胺预交联后,以N,N-二甲基甲酰胺(DMF)作溶剂,加入催化剂金属钠,与硫代氨基脲反应,合成了3种携三唑硫酮功能基的螫合纤维。利用红外光谱、热重分析等手段表征了该螯合纤维的结构,研究了纤维对金属离子的吸附性能。结果表明:以DMF作溶剂,金属钠为催化剂,控制温度100℃反应8h,得到的产品质量较好。纤维对Au~(3+),Pd~(2+)等贵金属离子具有良好的吸附性,对Au~(3+),Pd~(2+)的吸附量分别为437.1 mg/g和203.7 mg/g。     

Vegetable composts for sea water uranium extraction

Composting wood or crop residues by the addition of tanneries sludge as nitrogen supplement yields products having lower polysaccharides and protein content, but higher relative concentration of lignin material than the starting mixture. When used as sea water uranium adsorbents, the compost products exhibit higher uranium uptake (3.0–100 μg g^?1) than parent ligno-cellulosic materials (0.3–9 μg g^?1), thus achieving over 10⁴-fold uranium concentration relative to sea water. An additional distinguishing feature is the strong pH effect observed on uptake by products. The results are consistent with the expected change of parent lignin to lignin-humus in the compost product.     

Adsorption behavior of metal ions by amidoxime chelating resin

The adsorption properties of poly(acrylamidoxime) chelating resin for Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), Cr(III), and U(VI) are investigated by the batch technique. Based on the research results of the binding capacity effect of the pH value on sorption kinetic experiments, it is shown that this resin has higher binding capacity to uranyl ions, fast kinetics, and very good selectivity from binary metal ion mixtures with Cu(II) and Pb(II). The uranyl ion sorption strongly depends on the pH value of the solution. The highest value of 99% is at pH 5, but at pH 1 there is no retention. The adsorbed UO can be eluted by sulfuric acid and sodium carbonate. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1994–1999, 2000     

Preparation and adsorption properties of poly(N‐vinylformamide/acrylonitrile) chelating fiber for heavy metal ions

In this article we report a new chelating fiber that was prepared from a hydrolyzate of poly(N‐vinylformamide/acrylonitrile) by a wet‐spinning method. This fiber contains chelating groups, such as amidine groups, amino groups, cyano groups, and amide groups, with high densities. We examined the chelating abilities for several metal ions with this fiber, and present the morphological merit of the fibrous product compared with the globular resin. Based on the research results, it is shown that the fiber has higher binding capacities and better adsorption properties for heavy metal ions than the resin. The pH value of the metal ion solution shows strong influences on the adsorption of the metal ions. The maximum adsorption capacities of the fiber for Cu²⁺, Cr³⁺, Co²⁺, Ni²⁺, and Mn²⁺ are 112.23, 88.11, 141.04, 108.06, and 73.51 mg/g, respectively. In mixed metal ions solution, the fiber adsorbs Cr³⁺, Cu²⁺ and Co²⁺ efficiently. The adsorbed metal ions can be quantitatively eluted by hydrochloric acid. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1378–1386, 2002     

螯合树脂对有机胺脱硫液中Fe2+的吸附平衡

研究了4种螯合型树脂对有机胺脱硫液中Fe2+的吸附及解吸特性,发现D751型螯合树脂具有较高的吸附选择性和良好的脱附性能,采用静态吸附实验研究了D751型螯合树脂对Fe2+的吸附平衡,并用红外光谱的方法探讨了树脂吸附Fe2+的机理。结果表明,Langmuir模型和Freundlich模型均能较好地描述D751树脂对Fe2+的吸附行为;吸附自由能变G<0,熵变S>0,吸附为自发的熵增过程,升高温度有利于吸附的进行。红外光谱表明,D751树脂通过离子交换和配位双重作用与Fe2+结合。     

Studies of syntheses and adsorption properties of chelating resin from thiourea and formaldehyde

Chelating resins are useful substances in industry because of their extraordinary adsorption properties for specific metal ions. In this study, a new type of chelating resin is synthesized simply by reaction between thiourea and formaldehyde. The synthetic conditions and the structure of the product are approached and the adsorbing capacities for 11 metal ions, adsorbing rates, and selectivities investigated. The results of the experiments show that the resin has high adsorbing capacities for Ag(I): 13.1 mmol/g, and for Au(III): 6.95 mmol/g. Adsorbing rates are close to 100% in dilute solution. Isothermal adsorbing study reveals that the adsorption is monomolecular layer adsorption process. It is hopeful for the resin to be used for concentrating and retrieving Ag(I) and Au(III) ions from their dilute solutions in industry. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3127–3132, 2001