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1.
2-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚(5-Br-PADAP)在极谱和伏安分析中的应用已有一些报道。陈林林等曾经研究过Ti(Ⅳ)-5-Br-PADAP络合物在稀H2SO4-H2C2O4溶液中的极谱行为,但灵敏度不高(1.0×10-7mol/L)。我们发现,在pH4.1左右的HAc-NaAc底液中,Ti(Ⅳ)-5-Br-PADAP-NaClO3体系产生一灵敏的极谱吸附催化波,二次导数峰电位在-0.86V(vs.SCE)左右,波形良好,波高稳定,检测限可达4×10-10mol/L。1 实验部…  相似文献   

2.
吸附络合物体系的示波分析   总被引:5,自引:0,他引:5  
In(Ⅲ)在pH457HAcNaAc0.1%VC0.06%HCuP溶液中,用示波计时电位法可获得良好示波图,其切口电位为E=090(Vs.SCE),切口高度与In(Ⅲ)浓度在800×10-7~14×10-5mol/L范围内成正比,检出限可达50×10-7mol/L吸附络合物组成为In(Ⅲ):铜铁试剂(HCup)=1∶1,条件稳定常数为59×103  相似文献   

3.
SYNTHESIS OF 4-S-(1"-ARYL-TETRAZOLE-5"-YL)-4-DEOXY-4'-DEMETHYL-EPIPODOPHYLLOTOXIN ANALOGUES¥KuanKeLU;FangMinLIUandYaoZuCHEN(D...  相似文献   

4.
高效液相色谱法测定血清中茶碱浓度   总被引:2,自引:0,他引:2  
采用高效液相色谱,分析柱:3μm,3.3cm*4.6mm,I.D(Perkin Elmer,USA);预柱:10μm,1cm*2.1mm,I.D(Perkin ELmer,USA);以乙酰氨基酚为内标对氯仿-异丙醇(95:5,V/V)提取样品进行了分析,流动相:0.1mol/L醋酸缓冲液(PH=4.5)-甲醇(70:30,V/V);检测波长:270nm;流速0.5mL/min,3min即完成一次茶  相似文献   

5.
系统地研究了钼-羟胺(HY)-邻苯二酚紫(PV)-溴化十二烷基吡啶(DPB)体系的四元胶束混配物协同增敏显色反应。在pH4 ̄5的弱酸性条件下,Mo-PV二元配合物生成速率很慢,须加热才能完成,最大吸收波长λmax=510nm,表观摩尔吸光系数εmax=6.1×10^4L·mol^-1·cm^-1;Mo(Ⅵ)-PV-DPB配合物在室温下缓慢形成1:1:1的配合物,最大吸收波长为590nm,表观摩尔吸  相似文献   

6.
5-Br-PADAB分光光度法测定钯   总被引:8,自引:0,他引:8  
研究了4-(5-溴-2-吡啶偶氮)-1,3-二氨基苯(简称5-Br-PADAB)分光光度法测定微量钯的反应,在乙酸介质中Pd(Ⅱ)与5-Br-PADAB生成紫红色络合物,确定了分光光度法测定钯的新体系。在实验条件下试剂的最大吸收峰位于438nm处,络合物的最大吸收峰位于564nm处,表观摩尔吸光系数ε=5.20×10-4L/mol.cm,用等摩尔连续变化法、摩尔比法测得络合比n(Pd(Ⅱ))∶n(5-Br-PADAB)=1∶1,钯离子的量浓度在4.27×10-8~1.54×10-5mol/L时,服从Beer定律。试验了30种离子在一定量下不干扰测定。  相似文献   

7.
用改性PVA树脂,从水中富集痕量合成非离子型表面活性剂(SNS),进一步用SNS与钡盐和磷钼酸定量地形成难溶缔合物沉淀,使SNS与共存物分离浓缩。用Mo-邻苯二酚紫-溴化十二烷基吡啶(DPB)显色反应(表面摩尔吸光系数εmax值为3.1×10^5L.mol^-1.cm^_1)体系分光光度测定与SNS定量缔合的Mo,从而间接测定水中痕量SNS。方法用于江,湖水中痕量SNS的测定,获得较好结果。  相似文献   

8.
该研究合成了一种新型水溶性大π共轭高分子-聚吡咯-{2,5-〔二(对二甲氨基苯甲烯)〕}(PPDMAB),它地强酸的水溶液,在1mol/L的盐酸中溶解度为0.5~1.0g/100mL,通过EA、XPS、FT-IR、UV-Vis-NIR、In-situUV-Vis-NIR对PPDMAB进行了结构表征。通过质子化、碘掺杂、浓硫酸(98%)掺杂等处理,PPDMAB的电导率提高2~4个数量组(&=1-^-7  相似文献   

9.
SYNTHESISOF4-S-(5″-ALKYL-4″-AMINO-1″,2″,4″-TRIAZOLE-3″-YL)-4-DEOXY-4′-DEMETHYL-EPIPODOPHYLLOTOXINANALOGUES¥KuanKeLU;FangMinLI...  相似文献   

10.
脱氧核糖核酸变性和损伤的吸附伏安法研究   总被引:2,自引:0,他引:2  
陆宗鹏  卢莠芬 《分析化学》1996,24(4):463-466
本文用汞电极(HMDE)二次导数阴极吸附伏安(SD-AdCSV)和碳电极(GCE、CPE)导数循环伏安(FD-CV)法研究了核酸受热、紫外线、超声波和丝裂霉素C(MMC)作用下的变性作用。在0.1mol/L(K2HPO4+KH2PO4)-0.1mol.L NaCl(pH7.0)底液中,吸附的单股(ss-)和双螺旋(ds-)DNA分别在HMDE上得到特征还原峰P3和P2,和在碳电极上得到氧化峰A。物  相似文献   

11.
Polymerizable surfactants (surfmers) 12-acryloyloxy-dodecanoic acid and 11-acrylamidoundecanoic acid and their respective sodium salts were prepared and then polymerized to form their corresponding oligomers using reversible addition-fragmentation chain transfer (RAFT). Different concentrations of both the surfmers, their sodium salts, and their RAFT oligomers were used as polysoaps in the emulsion polymerization of styrene. Stabilities of the pre-emulsions before polymerization were determined and compared. After polymerization, particle sizes and polydispersities of the resulting polystyrene latices were determined. Sodium dodecyl sulfate (SDS) was used as a reference surfactant to compare the particle sizes and stabilities of the pre-emulsions prepared using surfmers and polymeric surfactants (polysoaps) as particle stabilizers. Emulsion polymerization of styrene using these surfmers and polysoaps all led to latices which were stable for a period of more than six months, as indicated by constant particle sizes, whereas latices prepared using the conventional surfactant, SDS, were not as stable.  相似文献   

12.
较系统地综述了聚皂的性质和研究进展,侧重介绍了近年来利用荧光探针技术研究聚皂在水溶液中的聚集特性,以及利用紫外/可见光探针技术,从动力学催化反应、与甲基橙的相互作用来研究聚皂形成胶束的机理及结构。同时介绍了聚皂在某些些方面的应用。  相似文献   

13.
Existing Janus filters cannot separate oil from emulsions stabilized by nonionic surfactants. Reported herein are universal Janus filters that separate oil from emulsions stabilized by not only ionic but also nonionic surfactants. To prepare such a filter, poly(dimethyl siloxane) (PDMS) is grafted onto one side of a fabric. The other side is then grafted with a copolymer polysoap bearing pendant oligo(ethylene glycol) monolaurate (EL) chains. Upon contact with an emulsion, the grafted polysoap competes with free surfactants, ionic or nonionic, for adsorption onto the emulsified droplets, drawing them to the surfaces of the fabric fibers, and causes them to coalesce locally. The coalesced oil then migrates to the PDMS‐coated side of the fabric and selectively permeates it. These novel filters possess enhanced versatility and showcase a new application for polysoaps.  相似文献   

14.
As-synthesized single-walled carbon nanotubes (SWNTs) are bundled mixtures of different species. The current challenge in the field of carbon nanotube research lies in the processing and separation of SWNTs, which first require efficient dispersion of individual SWNTs in solvents. We report DNA-mimicking polysoap surfactants that disperse SWNTs in aqueous solutions more effectively than DNA. The polysoaps are synthesized by functionalizing the side chain of poly(styrene-alt-maleic acid) with aminopyrene. The synthetic nature of the polysoap opens a new approach to further optimization of not only SWNT dispersion efficiency but also multi-functional SWNT dispersing surfactant.  相似文献   

15.
Amphiphilic hyperbranched polyelectrolytes: a new type of polysoap   总被引:2,自引:0,他引:2  
Hyperbranched hydrophobized polyelectrolytes of the ionene type are prepared. They are investigated as a new type of polysoap, with respect to viscosifying behaviour, surface activity and solubilization power. Compared to linear analogues, the viscosifying effect is reduced. Compared to classical polysoap architectures, such as analogous “tail-end-type” and “head-type” polysoaps, the hyperbranched polysoaps behave rather similarly to the “head-type” ones: they exhibit notable surface activity, whereas the solubilization capacity is moderate only. Received: 10 November 1998 Accepted in revised form: 21 January 1999  相似文献   

16.
The effects of different alkyl chains of nonionic surfactants and solubilized polar oily material on the solubilizing capacity of binary anionic‐nonionic mixed surfactant systems were studied. This system includes surface tension measurements to determine the critical micelle concentration. Results were analyzed using regular solution theory to obtain the mixed micelle and the interaction parameter β, in order to evaluate the type of interactions of surfactants in the mixed micelle. Solubilizing capacity has been investigated by measuring the optical density of solubilized polar oily materials like octanol, decanol, and dodecanol. The solubilizing phenomenon exhibited by mixed surfactants systems showed better results than that of the individual surfactant system. The amount of solubilization in mixed surfactant increases with increase in carbon chain length of alkyl polyglucoside.  相似文献   

17.
The interactions between fluorocarbon‐modified poly (sodium acrylate) and various kinds of added surfactants have been studied by means of viscometric measurement. Association behavior was found in both hydrogenated and fluorinated anionic, nonionic and cationic surfactants. Among them, the interactions between fluorocarbon‐modified poly (sodium acrylate) and cationic surfactants are the strongest, owing to the cooperation of both electrostatic attractions and hydrophobic associations. The anionic surfactants have the weakest effects on the solution properties because of the existence of unfavorable electrostatic repulsion. The hydrophobic interactions between copolymers and fluorinated surfactants are much stronger than those between copolymers and hydrogenated surfactants.  相似文献   

18.
The kinetics of the adsorption at the air-water interface and the processes of the structure formation inside the adsorption layers of hydrophobically modified systems [alkylated chitosans and sodium dodecyl sulfate (SDS)–chitosan (Ch) complexes] have been studied by the tensiometric method based on the axisymmetric rising-bubble-shape analysis as a function of the bulk concentration of polymers and the ageing time of their adsorption layers. The kinetics of the adsorption of chitosan, alkylated chitosans (ChC3, ChC8, and ChC12), and surfactant–polyelectrolyte (PE) complexes formed by the chitosan and the polysoaps with oppositely charged anionic surfactant SDS is characterized by an induction time (the so-called lag time), τlag, corresponding to the diffusion stage of the formation of adsorption layers. During this time, the decrease in the surface tension (or the increase in the surface pressure π) does not exceed several millinewtons per meter that corresponds to the “gaseous” state of adsorption layers. The postlag stage of the formation of the adsorption layer is characterized by the remarkable rate of increase in the surface pressure π that corresponds to the conformational rearrangement of PEs inside the adsorption layer by increasing the number of hydrophobic groups (adsorbing centres) in contact with the non-polar phase at the interface. It has been found that during the lag time, the adsorption of alkylated chitosans (cationic polysoaps) increases with increasing alkyl chain length, whereas during the postlag time, the adsorption of the ChC3 is maximal with regard to other polysoaps. It has been confirmed that at equal content of alkyl groups in the system, the surface activity of the SDS–Ch complexes is much higher with regard to that of the polysoaps. The viscoelasticity of adsorption layers of individual PEs and their complexes continuously increases with the ageing time, giving evidence for the interaction between the polymers inside the adsorption layers. It has been found that the rate of increase in the dilational storage module E′ of the adsorption layers of SDS–Ch complexes is much higher than for the polysoaps that correlates with the higher surface activity of the former with regard to the latter. For the mentioned systems, the module E′ is much higher than the loss module E″ that confirms the solid-like properties of their adsorption layers. On the other hand, the adsorption layers of the chitosan are liquid-like, while E′<<E′′.  相似文献   

19.
利用荧光探针法研究了双子型阳离子表面活性剂与明胶的相互作用,考察了此类表面活性剂的分子结构和明胶对临界胶团浓度(cmc)、胶团聚集数(Nagg)和胶团微极性的影响.结果表明,当双子型阳离子表面活性剂的疏水基增长时,cmc减少,Nagg增加,胶团的微极性降低;加入明胶后,双子型阳离子表面活性剂的Nagg减少,cmc和胶团微极性增加.  相似文献   

20.
《Analytical letters》2012,45(12):2687-2700
Abstract

The interaction of 38 nonionic surfactants containing various hydrophobic moieties with dimethyl-β-cyclodextrin (DIMEB) was studied by charge transfer chromatography. DIMED modified the retention behaviour of each surfactant, however, the strength of interaction varied considerably. Both the lipophilicity and specific hydrophobic surface area of surfactants significantly influenced the strength of interaction. The presence of ester bond and double bond in the hydrophobic moiety of surfactants has impact on the complex formation.  相似文献   

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