离子交换树脂对马尾松松针中草酸的分离纯化

比较4种吸附树脂对马尾松松针提取液中莽草酸的静态吸附和解吸效果,从中筛选出适合该提取液中莽草酸分离纯化的树脂,并对其动态吸附-解吸性能进行研究.结果表明,331阴离子交换树脂最适合马尾松松针提取液中莽草酸的纯化.当上样液的质量浓度为1.5mg/mL,上样流速为2mL/min,上样液体积为4BV时,331阴离子交换树脂达到动态吸附饱和.再用8BV 2％的氢氧化钠溶液,以4mL/min的流速可以完全洗脱.经过331阴离子交换树脂的纯化,莽草酸的纯度由原来的25％提高到90％,纯化提取率为90.9％.     

A novel cross-linked polyzwitterion/anion having pH-responsive carboxylate and sulfonate groups for the removal of Sr2+ from aqueous solution at low concentrations

A novel cross-linked polyzwitterion (CPZ) was synthesized via cycloterpolymerization of N,N-diallyl-N-sulfopropylammonioethanoic acid (92.5 mol%), a cross-linker 1,1,4,4-tetraallylpiperazinium dichloride (7.5 mol%), and sulfur dioxide (100 mol%) in the presence of azoisobutyronitrile in dimethylsulfoxide at 60 °C. CPZ, upon treatment with NaOH, was converted into a cross-linked polyzwitterion/anion (CPZA). The experimental data for the adsorption of Sr²⁺ on CPZA fitted the pseudo-second-order kinetic model and Freundlich as well as Temkin isotherm models. The adsorption process was spontaneous and exothermic in nature with negative values for both ΔG and ΔH. The low activation energy of 7.18 kJ/mol indicated the adsorption as a favorable process. The removal for the initial concentrations of 200 ppb and 1000 ppb (i.e., 1 ppm) of Sr²⁺ ions was observed to be 87% and 92%, respectively. An efficient synthetic access to the resin and excellent adsorption capacity and desorption would enable its use in the treatment of radioactive nuclear waste containing Sr²⁺ ions. The CPZA provided an opportunity to test the efficacy of a zwiiterionic/anionic group in the removal of Sr²⁺ ions in low concentrations.     

利用D-900树脂对巴戟天多糖脱色工艺进行优化

研究D-900阴离子交换树脂对巴戟天多糖的最佳脱色工艺。采用D-900阴离子交换树脂对巴戟天多糖进行静态和动态吸附试验,考察不同温度、树脂用量、流速和pH值等因素对吸附过程的影响,以脱色率和多糖保留率综合评价其脱色效果。最佳工艺参数为：采用动态吸附,柱溶液温度45℃、流速1.0BV/h、上样液pH6.0。使用D-900阴离子交换树脂对巴戟天多糖脱色可以获得较好的脱色率以及较高的多糖保留率。     

超临界水氧化处理核电站废阴离子交换树脂研究

在间歇式超临界水氧化(SCWO)设备中,对粉碎处理后的阴离子交换树脂水悬浮液在超临界条件下进行了氧化降解处理。实验研究了反应温度、反应压力、反应时间、过氧系数对COD去除率的影响,同时考察了催化剂种类、反应压力和反应温度对氨氮去除率的影响。通过正交试验,得到主要因素对处理效果影响的显著程度排序为:反应温度>反应压力>反应时间>过氧系数。结果表明:在反应温度540 ℃、反应压力26 MPa、反应时间8 min、过氧系数3的条件下,COD去除率为99.65%。针对阴离子树脂中NH₃-N含量高难以去除的问题,选用不同的催化剂CuSO₄、MnO₂、CeO₂添加到反应体系中,结果表明对NH₃-N的氧化效果顺序为CuSO₄>CeO₂>MnO₂,对NH₃-N的最高降解率达到96.53%。     

Metal–Organic Framework Hybrid‐Assisted Formation of Co3O4/Co‐Fe Oxide Double‐Shelled Nanoboxes for Enhanced Oxygen Evolution

Rational design of complex metal–organic framework (MOF) hybrid precursors offers a great opportunity to construct various functional nanostructures. Here, a novel MOF‐hybrid‐assisted strategy to synthesize Co₃O₄/Co‐Fe oxide double‐shelled nanoboxes is reported. In the first step, zeolitic imidazolate framework‐67 (ZIF‐67, a Co‐based MOF)/Co‐Fe Prussian blue analogue (PBA) yolk–shell nanocubes are formed via a facile anion‐exchange reaction between ZIF‐67 nanocube precursors and [Fe(CN)₆]^3? ions at room temperature. Subsequently, an annealing treatment is applied to prepare Co₃O₄/Co‐Fe oxide double‐shelled nanoboxes. Owing to the structural and compositional benefits, the as‐derived Co₃O₄/Co‐Fe oxide double‐shelled nanoboxes exhibit enhanced electrocatalytic performance for oxygen evolution reaction in alkaline solution.     

Self‐Activating,Capacitive Anion Intercalation Enables High‐Power Graphite Cathodes

Developing high‐power cathodes is crucial to construct next‐generation quick‐charge batteries for electric transportation and grid applications. However, this mainly relies on nanoengineering strategies at the expense of low scalability and high battery cost. Another option is provided herein to build high‐power cathodes by exploiting inexpensive bulk graphite as the active electrode material, where anion intercalation is involved. With the assistance of a strong alginate binder, the disintegration problem of graphite cathodes due to the large volume variation of >130% is well suppressed, making it possible to investigate the intrinsic electrochemical behavior and to elucidate the charge storage kinetics of graphite cathodes. Ultrahigh power capability up to 42.9 kW kg^?1 at the energy density of >300 Wh kg^?1 (based on graphite mass) and long cycling life over 10 000 cycles are achieved, much higher than those of conventional cathode materials for Li‐ion batteries. A self‐activating and capacitive anion intercalation into graphite is discovered for the first time, making graphite a new intrinsic intercalation‐pseudocapacitance cathode material. The finding highlights the kinetical difference of anion intercalation (as cathode) from cation intercalation (as anode) into graphitic carbon materials, and new high‐power energy storage devices will be inspired.     

吡啶硫酮锌/蒙脱土的制备及其抗菌性能研究

以载锌蒙脱土为前驱体,在蒙脱土的层间,引入吡啶硫酮阴离子,原位制备了新型的吡啶硫酮锌/蒙脱土(ZPT/MMT)抗菌材料.采用XRD、FT-IR、TG、DSC和UV-VisDRS对材料的插层结构、耐光、耐热性能进行分析,结果表明,蒙脱土层间的吡啶硫酮阴离子以吡啶硫酮锌的形式存在,致使层间距d001值由1.29nm增至1.85nm,并且ZPT/MMT具有较好的耐光性和耐热性(热分解温度高于240℃).抗菌试验结果表明,ZPT/MMT对大肠杆菌和金黄色葡萄球菌具有较好的抗菌活性.     

阴离子交换膜渗析法回收含硫酸钠的高浓度硫酸废水

根据Fick扩散定律 ,提出了测定H2 SO4和Na2 SO4在阴离子交换膜中扩散速度的方法 .静态法测定结果显示 ,对含 2 5 0～ 3 5 0g/LH2 SO4、1 0 0～ 1 2 0g/LNa2 SO4的废水 ,常温下 ,A2 0 和 3 3 62BW膜中H 平均扩散速度分别为 8.0× 1 0 -4m/h和 7.8× 1 0 -4m/h,Na 平均扩散速度分别为 5 .9× 1 0 -5m/h和 6.6× 1 0 -5m/h,这预示两膜都能实现废酸中H2 SO4和Na2 SO4的有效分离 .动态法分离废酸结果表明 ,H2 SO4回收率达 83 .4% ,回收酸中Na2 SO4含量下降至 5 .2 g/L     

Composition‐Graded Cesium Lead Halide Perovskite Nanowires with Tunable Dual‐Color Lasing Performance

Cesium lead halide (CsPbX₃) perovskite has emerged as a promising low‐threshold multicolor laser material; however, realizing wavelength‐tunable lasing output from a single CsPbX₃ nanostructure is still constrained by integrating different composition. Here, the direct synthesis of composition‐graded CsPbBr_xI_3?x nanowires (NWs) is reported through vapor‐phase epitaxial growth on mica. The graded composition along the NW, with an increased Br/I from the center to the ends, comes from desynchronized deposition of cesium lead halides and temperature‐controlled anion‐exchange reaction. The graded composition results in varied bandgaps along the NW, which induce a blueshifted emission from the center to the ends. As an efficient gain media, the nanowire exerts position‐dependent lasing performance, with a different color at the ends and center respectively above the threshold. Meanwhile, dual‐color lasing with a wavelength separation of 35 nm is activated simultaneously at a site with an intermediate composition. This position‐dependent dual‐color lasing from a single nanowire makes these metal halide perovskites promising for applications in nanoscale optical devices.     

降冰片烯类季铵型阴离子交换膜的制备

通过环状烯烃双键打开, 首尾相接形成聚合物的方法, 设计合成了含有季铵阳离子作为功能化基的降冰片烯衍生物单体QRPhNB, 通过开环异位聚合(ROMP)制备得到阴离子交换膜材料, 流延成膜后的分析结果表明:当单体与降冰片二烯1:2投料时所得到的阴离子交换膜的IEC值为1.26 mequiv·g^-1, 其最高离子传导率为20.05 mS·cm^-1;吸水率为14.3%。