表面活性剂和四烷基溴化铵的复配 Ⅲ.四烷基溴化铵碳氢链长对离子型表面活性剂在气/液表面吸附行为的影响

本文考察了四烷基澳化铵(TAAB)碳氢链长对离子型表面活性剂SDS和DTAB在气/液表面吸附行为的影响.实验结果表明,与表面活性剂离子对应的添加剂反离子是影响其水溶液表面活性的主要因素,因而TAAB对SDS表现出明显的效应,对DTAB影响效果则和同浓度的NaBr类似.除了对表面活性离子头基电荷的静电屏蔽外,TAA+的碳氢基团和SD-碳氢链间还可能发生疏水相互作用,但后者受TAA+离子体积制约.TAAB对SDS在气/液表面吸附行为的影响是上述几个因素的综合作用结果.     

硫敏化中心中的银原子簇的增感作用

采用一定电位范围内的氧化还原缓冲液处理单分散立方溴化银乳剂颗粒表面上的硫敏化中心和由曝光生成的潜影中心,考察银原子簇的漂白和再生后的曝光响应曲线.实验结果再一次确认硫敏化中心中存在的银原子簇对硫敏化起重要作用,而且敏化效果也与银原子簇的含量有关.为此,提出硫敏化中心是由硫化银簇与银簇组成,它们在潜影形成的过程中各起不同的作用,但都有利于提高潜影的生成效率,因而共同产生敏化效应.     

灿烂绿新体系催化动力学分光光度法测定痕量铜

铜是人体必需的微量元素之一。缺铜将引发各种疾病 ,因而对水中痕量铜的检测是十分必要的。催化动力学分析法是一种高灵敏度的分析方法 [1-6] ,用于铁的测量已有不少报道 [1-4 ] ,但用灿烂绿作指示剂催化动力学光度法测定铜还未见报道。本文发现在 p H=4 .5的 HAc- Na Ac缓冲介质中 ,Cu2 对过氧化氢氧化灿烂绿有明显的催化作用。据此研究了适宜的催化条件 ,建立了催化动力学光度法测定痕量铜的新方法。该反应可表示为灿烂绿 H2 O2Cu2 ,H 氧化产物反应速率方程为 :- dc灿烂绿 /dt=kca灿烂绿 cb Cu2 cm H2 O2 cn H 但由于缓冲溶…     

Alkylation mechanism of benzene with 1-dodecene catalyzed by Et_3NHCl-AlCl_3

The isotope exchange method was employed to investigate the catalytic mechanism of ionic liquid in alkylation of benzenes with olefins.It is proposed that alkylation was induced by the Lewis acid AlCl3 which attracted π electrons of 1-dodecene to shift toward 1-carbon,thus forming a carbonium ion.The carbonium ion further reacted with benzenes to form a complex.Due to unstabilit of the complex,a deuterated ring proton was transferred into an electronegative 1-carbon of the side chain to substitute for the A...     

海蜇中微量汞的微波消解-原子荧光光谱法测定

以冷冻干燥和微波消解相结合的方式处理样品 ,采用冷原子荧光光谱法测定了新鲜海蜇和腌制海蜇不同部位的汞含量。通过试验 ,确定了最佳的样品处理条件和仪器的工作条件。方法简便、快速、准确。检出限为0.015ng·mL -1 ,RSD(n=5)为2.3%～4.2 %,回收率为95%～104%。     

反射式薄层可见光谱电解池的制作与性能测试

设计制作了一种反射式薄层可见光谱电解池。该电解池采用光亮铂片作为工作电极,将铂丝辅助电极和Ag AgCl参比电极组装在一起。薄层池中间的溶液薄层是通过光亮铂片和覆盖其上的玻璃片之间的塑料薄膜垫圈加以控制,当液层厚度为0.2mm时,液层容积为16μL。由于采用双平行反射的光路,使入射光与出射光保持在一直线上,可以在不变更光路系统下的各种光度计上使用。在K3Fe(CN)6 K4Fe(CN)6体系中,用循环伏安法、恒电位现场光度法进行性能测试。实验结果表明,该电池具有良好的薄层光谱电化学性能,可用于薄层可见光谱电化学研究。     

ZnCl2/粘土-SA01催化剂上二苯甲烷的合成

在环境友好ZnCl2/粘土-SA01催化剂上合成了二苯甲烷,较系统地考察了负载量、苯/苄基氯摩尔比、催化剂用量、反应温度、反应时间对该傅克反应的影响,并与催化剂的表面性质关联.实验结果表明,该催化剂具有良好的催化活性和稳定性并易于回收重复使用.     

液液萃取-气相色谱-质谱法同时测定水中46种半挥发性有机物

半挥发性有机物主要包括多环芳烃类(PAHs)、邻苯二甲酸酯类(PAEs)、有机氯农药类(OCPs)和硝基苯类(NBs)等化合物,这些物质多具有致癌、致畸、致突变作用,以及内分泌干扰效应.因此,快速准确测定水中半挥发性有机物非常重要,目前国内尚无水中半挥发性有机物的检测标准.该研究从氮吹温度、水样pH值和萃取时间3个方面...     

Growth of Single-walled Carbon Nanotubes on Substrates Using Carbon Monoxide as Carbon Source

The growth of single-walled carbon nanotubes(SWCNTs) on substrates has attracted great interests because of the potential applications in various fields. Carbon monoxide(CO) was used as the carbon source for the growth of SWCNTs on silicon substrates. Random or oriented SWCNTs can be produced by varying the CO flow rate. When the flow rate of CO was as low as 20 sccm(sccm:standard cubic centimeter per minute), dense SWCNT networks with clean surface were produced. When the flow rate was above 50 sccm, vertically aligned SWCNT(VA-SWCNT) arrays were grown. Well-aligned VA-SWCNT arrays were obtained in the temperature range of 650-800℃ and the content of large-diameter(above 1.7 nm) tubes in the array increased with the temperature. The height of the array was affected by the growth temperature, the CO flow rate, and the growth time. These findings indicate CO can be used as an efficient carbon source for the growth of SWCNTs on substrates under low flow rates.     

Design and Construction of 3D Porous Na3V2(PO4)3/C as High Performance Cathode for Sodium Ion Batteries

An easy and delicate approach using cheap carbon source as conductive materials to construct 3D sequential porous structural Na3V2(PO4)3/C(NVP/C)with high performance for cathode materials of sodium ion battery is highly desired.In this paper,the NVP/C with 3D sequential porous structure is constructed by a delicate approach named as“cooking porridge”including evaporation and calcination stages.Especially,during evaporation,the viscosity of NVP/C precursor is optimized by controlling the adding quantity of citric acid,thus leading to a 3D sequential porous structure with a high specific surface area.Furthermore,the NVP/C with a 3D sequential porous structure enables the electrolyte to interior easily,providing more active sites for redox reaction and shortening the diffusion path of electron and sodium ion.Therefore,benefited from its unique structure,as cathode material of sodium ion batteries,the 3D sequential porous structural NVP/C exhibits high specific capacities(115.7,88.9 and 74.4 mA·h/g at current rates of 1,20 and 50 C,respectively)and excellent cycling stability(107.5 and 80.4 mA·h/g are remained at a current density of 1 C after 500 cycles and at a current density of 20 C after 2200 cycles,respectively).