偕胺肟基螯合氧化硅的合成及其Cu2+亲和性能

以氯化钾为晶体结构导向剂, 以正硅酸乙酯和2-氰乙基三乙氧基硅烷为硅源, 聚(乙二醇)-聚(丙二醇)-聚(乙二醇)三嵌段共聚物为模板剂, 合成了偕胺肟基螯合氧化硅(AO-SBA-15)。通过X射线衍射(XRD)、低温氮气吸附-脱附、傅里叶红外光谱(FT-IR)、Zeta电位分析和元素分析技术对样品的结构、孔性质和螯合官能团等进行了表征。XRD分析结果表明, 偕胺肟基螯合氧化硅材料具有有序的二维六方结构, 通过氮气物理吸附数据计算得到材料的平均孔径和比表面积分别为3.96 nm和435 m²/g。FT-IR分析表明将氰基成功地引入材料中并转化为偕胺肟基螯合官能团, 元素分析发现材料的偕胺肟基含量约为1.6 mmol/g, 此外, Zeta电位分析表明材料呈现电负性。相对未改性的氧化硅材料(SBA-15), AO-SBA-15对铜离子吸附容量提高了2倍; 相对氰基功能化氧化硅(CN-SBA-15), AO-SBA-15吸附容量提高了3.6倍。这表明通过引入偕胺肟基螯合官能团, SBA-15对铜离子的亲和力得到显著提高。     

偕胺肟螯合材料合成与应用研究进展

偕胺肟的特殊结构使其可以交换吸附诸多重金属离子,且具有高选择性和大吸附量。综述了以纤维、树脂、硅胶以及生物材料为基体的偕胺肟螯合材料的研究进展,详细论述了其合成方法与路径及应用,对偕胺肟螯合材料的研究现状进行了评述,展望了偕胺肟螯合树脂的应用前景。     

偕胺肟基螯合吸附分离材料研究进展

偕胺肟型螯合树脂以其特殊的官能团结构、优良的吸附性能而成为从海水中提取铀的最佳材料.综述了近几年通过预辐照接枝法和化学接枝法在高聚物基材上制备偕胺肟基螯合吸附分离材料的研究现状,并展望了利用辐照接枝合成新型材料的前景.     

偕胺肟基螯合纳米纤维的制备

以静电纺聚丙烯腈(PAN)纳米纤维为原料,与盐酸羟胺的水溶液反应,将腈基转化为偕胺肟基团,从而制备出偕胺肟基螯合纤维。探讨了盐酸羟胺浓度、pH值、反应时间及温度对转化率的影响,并分别采用扫描电子显微镜和傅里叶变换红外光谱(FT-IR)对PAN纳米纤维膜反应前后的形貌和分子基团进行分析。结果表明:PAN在pH值为7时,腈基转化率最高;-CN转化率随着浓度、反应时间及温度的增大而提高。红外光谱分析表明,PAN分子中有部分腈基转化为偕胺肟基团。     

偕胺肟基螯合树脂的研究进展

偕胺肟螯合树脂对重金属离子有高的选择性和较大的吸附量,可用于污水处理和回收利用废矿、废液中的重金属离子。本文介绍了偕胺肟螯合树脂的合成方法,阐述了偕胺肟基螯合树脂的物理化学性质及其表征手段,对偕胺肟螯合树脂作为吸附分离材料的研究现状进行了评述,展望了偕胺肟螯合树脂的应用前景。     

聚丙烯腈纤维改性条件优化及其对模拟电镀废水的净化作用

为了寻求低价、环保的电镀废水处理方案,将廉价的聚丙烯腈(PAN)纤维与羟胺试剂反应对PAN纤维进行改性,使其上氰基螯合获得偕胺肟基纤维。通过改变各种改性条件,探讨了改性条件对PAN改性纤维在重金属单离子溶液和多离子混合溶液中吸附性能的影响。结果表明:最佳改性条件为21.2 g/L PAN纤维,27.0 g/L盐酸羟胺,pH值为7.0,70℃下反应2 h;改性PAN纤维对模拟电镀废水中的Cu2+,Zn2+,Ni2+,Pb2+,Cd2+等重金属离子均有较好吸附性能,其中对Cd2+吸附效果最好,吸附量为55 mg/g;在多离子混合溶液中优先选择吸附Cd2+;改性PAN纤维再生效果优良,可重复利用。     

聚乙烯醇胺肟螯合纤维的合成及对钯的吸附

利用＾６０Ｃｏ－γ射线预辐照接枝和胺肟化反应合成了聚乙烯醇胺肟螯合纤维。预辐照剂量支液的组成对接枝率,胺肟基因含量和吸附容量有影响。研究了ＰＶＡＡＯ螯合纤维对钯的吸附性能。     

含羧基的聚丙烯胺肟型螯合纤维的合成及性能

利用预辐照接枝法合成了含羧基的聚丙烯胺肟（ＰＰＡＯ－ＡＡｃ）型螯合纤维。研究了影响接枝率和胺肟基团含量的因素。该纤维对铜（Ⅲ）离子的吸附容量达１．２３ｍｇＮ／ｇ干纤维。     

交联型偕胺肟型凝胶的制备及对镓离子的吸附性能

以水合联胺为交联剂,利用"热致相分离"原理制备了聚丙烯腈/二甲亚砜(PAN/DMSO)交联(C-PAN)凝胶,将其进一步与羟胺(NH2OH)反应后得到交联型偕胺肟(C-PAO)凝胶,交联型偕胺肟凝胶可用于吸附强碱性模拟拜耳溶液中的镓离子(Ga~(3+))。文中采用了超临界CO_2萃取干燥法取代真空干燥,并探讨了不同溶度参数的交换溶剂对凝胶孔径的影响。红外测试结果表明,凝胶成功偕胺肟化且偕胺肟基团与镓离子发生了螯合作用;扫描电镜照片显示,当交换溶剂的溶度参数与PAN基体的差值(Δδ)增加,得到的凝胶孔径减小;吸附测试结果显示,偕胺肟凝胶对模拟拜耳溶液中镓离子的饱和吸附量为15.8 mg/g,平衡时间为140 min。     

偕胺肟基功能材料对铀的吸附研究进展

随着核能发电技术的发展,对铀的需求也越来越多。核能发电的过程中会产生含铀的污染废水,如何有效去除污染废水中的金属铀是当前比较热门的研究课题。偕胺肟基团对铀具有较强选择吸附性,可以对吸附剂进行功能化改性而形成对铀具有较强吸附能力的偕胺肟基功能材料。采用吸附法处理含铀废水时,发现经偕胺肟基团修饰后的吸附剂,表现出对铀高效的选择吸附能力。综述了偕胺肟基功能材料对铀的吸附性能、吸附影响因素及吸附机理,并对它们在水体中富集铀的应用前景和发展趋势进行展望,以期为后续相关研究及实际应用提供参考依据。     

活性碳纤维SACF的制备和对金属离子的吸附性能

研究了以天然纤维制备新型的活性碳纤维(SACF)的制备条件以及 SACF 对水溶液中金属离子的吸附性能。实验结果表明,活化反应条件如反应温度、时间、活化剂流速等对 SACF 的比表面积有较大的影响。SACF 对水溶液中的La~(+++),Cu~(++),Co~(++),Ni~(++),Cd~(++),Pb~(++)等离子基本上不吸附,而对贵金属 Au~(+++)具有吸附率高、吸附选择性好、吸附速度快、吸附量大等优异性能。     

超小型Fe3O4/Au纳米复合微粒的制备与表征

用反向微乳液法成功制备了超小型Fe3O4/Au磁性纳米复合微粒,并利用3-巯基丙酸将复合微粒直接从微乳液分离到有机溶剂中.用UV-Vis、VSM和TEM对产物进行了鉴定与表征,结果表明复合微粒分散良好,平均粒径为6.7nm,饱和磁化强度为9.7A·m2/kg.     

DO1细菌吸附还原金离子特性的谱学表征

在用细菌还原法制备高分散度负载型金催化剂的研究中,经自然界广泛筛选获得了对Au~(3+)具有强吸附和还原能力的DO1细菌,该菌易培养有应用价值。本文对这细菌吸附、还原Au~(3+)的特性,采用红外、光电子能谱、透射电镜等实验方法进行较系统、深入的谱学表征,获得了良好的实验结果;将这些表征结果与DO1还原法所制得Au/α-Fe_2O_3催化剂的催化性能相联系并讨论。     

Passively Q-switched Tm(3+)-doped silica fiber lasers

By splicing on a length of Ho(3+)-doped silica fiber onto a diode-pumped double-clad Tm(3+)-doped silica fiber, stable passive Q switching of the Tm(3+)-doped silica fiber laser is demonstrated. The formation of Q-switched pulses was found to depend on both the length and the position of the Ho(3+)-doped silica fiber that was inserted into the fiber laser cavity. For stable Q-switched pulse generation, Ho(3+)-doped silica fiber lengths shorter than twice the absorption depth must be used. For long Ho(3+)-doped silica fiber lengths, randomly generated pulses are observed at operating wavelengths longer than 2090 nm, which are attributed to intracavity pumping of the Ho(3+)-doped silica fiber.     

Copper-iron bimetal modified PAN fiber complexes as novel heterogeneous Fenton catalysts for degradation of organic dye under visible light irradiation

A series of Cu-Fe bimetal amidoximated polyacrylonitrile (PAN) fiber complexes with different molar ratios of Cu(2+) to Fe(3+) ions was prepared using a simple exhaustion method, and characterized using FTIR, DRS and XPS, respectively. Then they were tested as the heterogeneous Fenton catalysts for Rhodamine B degradation with H(2)O(2) in the dark and under visible light irradiation. The results indicated that Cu-Fe bimetal amidoximated PAN fiber complexes could more effectively catalyze the dye degradation in water than Fe amidoximated PAN fiber complex, especially in the dark. And introduction of Cu(2+) ions significantly increased their catalytic performance. 0.56 was the optimum molar ratio of Cu(2+) to Fe(3+) ions to achieve the best catalytic activity and stability. This was mainly due to the synergetic effect in the bimetal complexes. Visible light irradiation improved the catalytic activity of the complexes, especially with a low molar ratio of Cu(2+) to Fe(3+) ions.     

Sequence lasing in a gain-switched Yb3+,Er(3+)-doped silica double-clad fiber laser

Experimental results relating to the gain-switched operation of a double-clad Yb3+,Er(3+)-doped silica fiber laser that is pulse pumped with the output from a flash-lamp-pumped Ti:sapphire laser are presented. For all the configurations of the fiber laser that we studied, the 2F5/2-->2F7/2 laser transition of the Yb3+ ion lased prior to laser emission from the 4I13/2-->4I15/2 transition of the Er3+ ion. To the best of our knowledge, this is the first reported operation of sequence lasing in the Yb3+,Er(3+)-codoped system. This succession of laser pulses deduced from the measurements of this investigation is a consequence of both the short intense pump pulse and the short 900-nm wavelength of the pump that does not overlap with any important excited-state absorption transitions. We believe that the predominant interionic interaction during the course of the pump pulse is the double-energy transfer to the Er3+ ion acting twice from the 2F5/2 energy level of the Yb3+ donor ion. A maximum total output of 1.65 mJ is obtained (1.38 mJ from the 2F5/2-->2F7/2 transition of Yb3+ and 0.27 mJ from the 4I13/2-->4I15/2 transition of Er3+) from a nonoptimized configuration of the fiber laser. The wavelength of the output from the fiber laser was measured to vary approximately linearly with fiber length from 1040 to 1046 nm for the Yb(3+)-based laser and 1535 to 1541 nm for the Er(3+)-based laser.     

Sapphire-fiber thermometer ranging from 20 to 1800 degrees C

A novel, to our knowledge, sapphire-fiber thermometer ranging from 20 degrees to 1800 degrees C is presented that combines the radiance detection and the fluorescent lifetime detection schemes into one system. The thermal probe is a sapphire fiber grown from the laser-heated pedestal growth method. Its end part is doped with Cr(3+) ion and coated with some radiance material to constitute a minifiber cavity. The sapphire fiber is coupled with a Y-shaped silica fiber bundle for signal transmission. Radiance and fluorescence signal processing schemes are also set up within one thermometer system. A sandwich two-band p-i-n detector is used that may respond to both the radiation and the fluorescence. Preliminary experimental results show that the thermometer is suitable for practical application with potential long-term stability and a high-temperature resolution.     

Linearly polarized er(3+)-doped fiber laser by use of a fiber loop polarizer and a wavelength-selective fiber loop reflector

We demonstrate a novel single-polarization Er(3+)-doped fiber Fabry-Perot laser. The all-fiber Fabry-Perot cavity is simple inasmuch as it is formed by only two fiber-based components, a fiber loop polarizer and a wavelength-selective fiber loop reflector. The threshold power is 6.5 mW, the slope efficiency is 12.2%, and the extinction ratio is approximately 25 dB.     

Polarization effects in a high-birefringence elliptical fiber laser with a Bragg grating in a low-birefringence fiber

The polarization characteristics of a fiber laser cavity that combines a high-birefringence Er(3+)-doped elliptical core fiber with a Bragg grating fabricated in a low-birefringence (Low-Bi) fiber are studied. It is shown that, by use of an adequate length of Low-Bi fiber and an intracavity polarization controller, the dependence of the fiber laser's state of polarization on the pump's state of polarization can be altered. This fiber laser cavity design allows for the realization of a double-frequency, orthogonally polarized single-mode fiber laser source insensitive to the polarization parameters of the pump source.     

Scanning electrochemical microscopy. 56. Probing outside and inside single giant liposomes containing Ru(bpy)32+

Giant liposomes containing Ru(bpy)(3)(2+) (bpy = 2,2'-bipyridine) were prepared as model systems for biomembranes and cells and studied by scanning electrochemical microscopy (SECM). Conical carbon fiber tips of submicrometer size were used to approach, image, and puncture individual liposomes immobilized on glass substrates. SECM images of the liposomes were obtained, and the leakage of Ru(bpy)(3)(2+) through the lipid membrane was probed. The tip was also pushed into liposomes and characteristic breakthrough transients, corresponding to liposomes with different compartmental configurations, were obtained. Voltammograms were obtained with the tip inside a single liposome after breaking through the membrane, and the influx of mediator and efflux of encapsulant after puncture could be observed.