Salinity Controlled Vesicle Formation and Growth in Aqueous Mixture of Aerosol OT/Triton X‐100

Mixed vesicles can be formed spontaneously from aqueous mixture of the double‐tailed anionic surfactant sodium bis(2‐ethylhexyl) sulfosuccinate (AOT) and the nonionic surfactant octylphenoxypolyethoxyethanol (Triton X‐100) under the inducement of salt, the formation mechanism of which should be attributed to the compression of salt on the electric bilayers of the head groups. The stability and the polydispersity of the vesicles are superior to single‐component AOT vesicles, which can be proved by the TEM image and visual observation. The vesicle region was presented in a pseudo‐ternary diagram of AOT/TX‐100/brine. The size of the vesicle was measured using dynamic light scattering. It is found that the vesicle size increases with the salinity but decreases with the content of TX‐100 in the mixture at the same salinity. Especially, the vesicle size is independent of the surfactant concentration at fixed salinity.     

Interfacial Tension of Aqueous Three‐Phase Systems Formed by Triton X‐100/PEG/Dextran

A novel aqueous three‐phase system was formed spontaneously when a nonionic surfactant (Triton X‐100) and two polymers (PEG and dextran) were mixed. The interfacial tension between the phases was measured by the spinning drop method. It was shown that the values of interfacial tension were extremely small. The interfacial tensions of the top/middle phases were much lower than those of the middle/bottom phases. The interfacial tension was affected by component concentrations, temperature, added salts, and the density difference between two phases. Temperature exhibited a special effect on interfacial tension: with the increase of temperature, interfacial tension increases significantly.     

Triton X—100—DPSA法测定血铅

着重研究了在微分电位溶出法测定血铅中加入ＴｒｉｔｉｏｎＸ－１００非离子型表面活性剂的效果，发现它能改善溶出峰形，减少误差，明显地提高分析的灵敏度，铅溶出峰与浓度在０．００２～０．０１ｍｇ／Ｌ范围呈线性关系，回归方程式和相关系数为ｙ＝１４．５７＋７５７．１４ｘ，ｒ＝１，其相关系数比原法稍有提高，变异系数７．１％，回收率９６．８％～１０３．９％，本法取血量少，血样经微汉消解即可测定，简便快速准确，便基     

Effect of Triton‐X‐100 Solvent in the Micellar Catalysis of the Aquation of Tris(2‐nitroso‐1‐naphtholate) Ferrate (II)

The effect of triton‐X‐100 micelles on the aquation of Fe(C₁₀H₆N₂O)₃ ²⁺ has been investigated with triton‐X‐100 as solvent. In liquid triton‐X‐100, over a range of [H₂O] _T (0.0–3 M), significant rate enhancement factors of 50–150 are observe. Acid inhibits the rate of aquation at fixed [H₂O] _T . A mechanism based on effective solvent participation in a chemical environment similar to that in reversed micelles is proposed in liquid triton‐X‐100 with dispersed water pockets. This mechanism predicts direct H₂O substitution into the coordination sphere of Fe(C₁₀H₆N₂O)₃ ²⁺ in the highly polar water pockets or cavities where the Fe (II) complex molecules are solubilized. Changes in the tumbling rate, structure, and activity of water are suggested to account for the observed changes in the rate of aquation as a function OH [H₂O] _T . All k _ψ–[H₂O] _T profiles are structured and exhibit maxima with k _ψ(max) shifted to progressively higher [H₂O] _T as the fixed concentration [H⁺] _T is increased.     

Steric Considerations in Supramolecular Inclusion of Modified β-cyclodextrins with Triton X-100 and α-bromonaphthalene

Supramolecular inclusion of modified β-cyclodextrin (β-CD) with Triton X-100 (TX) and α-bromonaphthalene (BN) was studied by fluorescence and phosphorescence measurements. Major differences were observed in the magnitude of the apparent stability constants and quenching constants of the inclusion complexes. Methyl substitution on the rims of β-CD increased the binding of TX with β-CD but was unfavorable to the protection of the phenyl group of TX from fluorescence quenching and further accommodation of BN for steric considerations. According to the overall molecular size of β-CD, TX and BN, further inclusion of BN in the cavity of β-CD occupied by TX may force the flexible tert-octyl chain of TX to deform to a greater extent and close packing complexes were obtained. Phosphorescence of BN arising from intermolecular energy transfer between BN and the phenyl group of TX was observed when the phenyl group of TX was irradiated. In the case of heptakis(2,6-di-O-methyl)-β-CD, BN failed to penetrate into the cavity because of the steric hindrance of the methyl substituents at the rim of the β-CD cavity.     

Synthesis and characterization of nanosized NiO2 and NiO using Triton® X-100

Nanosized NiO₂ particles with an average diameter of 15 nm are prepared by treating of Ni(NO₃)₂ · 6H₂O with an aqueous solution of KClO in the presence of Triton® X-100. This black fine powder of nickel peroxide was characterized by XRD diffraction, energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). The as-prepared NiO₂ can be easily transformed to nanosized NiO merely by washing it with acetone. The obtained NiO has an average diameter of 40 nm and was characterized by the same means used for NiO₂. The nanoparticles of NiO₂ and NiO were obtained in high yields and purities.      

PAN—Triton X—100吸光光度法连续测定铝合金中铜镍

用PAN-OP乳化剂吸光光度法测定人发和血清中铜和锌,以及用PAN作显色剂同时测定WO_3和MoO_3中的铜、钻、镍已有报道,但未见用PAN显色连续测定铝合金中铜和镍的研究.PAN可与多种金属离子显色,如何避开基体元素和其他共存元素的干扰,实现对铝合金中铜、镍的连续测定,是本文研究的目的.试验表明,在pH=3.0酸度下,加上柠檬酸铵和氟化钠的掩蔽作用,可消除基体铝的影响和共存离子的干扰.在Triton X-100存在下,配合物Cu-PAN和Ni-PAN的最大吸收波长分别为550nm和565nm,摩尔     

Determination of Trace Titanium by Solid Substrate－Room Temperature Phosphorimetry with 4,5－Dibromophenylfluorone as Luminescent Ligand and Triton X－100 as Sensitizer

A new highly sensitive solid substrate room temperature phosphorimetry for the determination of trace titanium is proposed based on the sensitization of Triton X-100 to the SS-RTP intensity of 4, 5-dibro-mophenylfluorone-titanium complex adsorbed on the filter paper substrate modified by gelatin. When Triton X-100 was added into the luminescence system, the RTP intensity was raised 3 times stronger than that of the system without Triton X-100. The linear dynamic range of the new method is 0. 64 ～ 3.2 fg/spot (0. 4 μL) with a detection limit of 12.8 ag/spot, and the regression equation of the working curve is △Ip = 482. 0 119.5mTi（Ⅳ) (fg/spot), the correlation coefficient r= 0. 9992, n = 6. The phosphorescence lifetime (r= 0. 85 ms) was also determined. The recoveriesCand RSD) for the determinations of titanium in human hair and tea samples were 101.0% (3. 0%) and 99. 97% (4. 2%), respectively.     

Synthesis and Biological Evaluation of Novel Isonucleosides with 1,2,4‐Triazole‐3‐Carboxamide

Novel 1,2,4‐triazole isonucleosides (1 and 2) were efficiently synthesized starting from D‐ribose and D‐xylose, respectively. The key steps were condensation of cyclic sulfate 8 with methyl‐1,2,4‐triazole‐3‐carboxylate and nucleophilic displacement of the tosylate 15 with methyl‐1,2,4‐triazole‐3‐carboxylate, respectively.     

铬天青S,Triton X—100分光光度法测定微量锆

前言 近年来表面活性剂用于分光光度法测定微量金属离子浓度有很大发展,但发表的论文以阳离子型居多。鹤见近夫用阳离子活性剂测定微量锆,对测定条件做了系统研究,并对干扰离子的掩蔽进行了讨论。本文报导了用非离子型表面活性剂(TritonX-100)和铬天青S测定微量锆,所生成络合物的最大吸收波长在605nm左右,摩尔吸收系数为     

Spectrophotometric Determination of Gold in Water and Ore with 2‐Carboxyl‐1‐Naphthalthiorhodanine

Abstract

This paper reports on the synthesis of a new chromogenic reagent, 2‐carboxyl‐1‐naphthalthiorhodanine (CNTR). A high sensitive, selective, and rapid method for the determination of gold based on the rapid reaction of gold with CNTR and the solid phase extraction of the colored chelate with a reversed phase polymer‐based C₁₈ cartridge was developed. In the presence of 0.05–0.5 mol L^?1 of phosphoric acid solution and emulsifier‐OP medium, CNTR reacts with gold to form a red chelate of a molar ratio 1∶3 (gold to CNTR). This chelate was enriched by the solid phase extraction with a polymer‐based C₁₈ cartridge and the retained chelate was eluted from the cartridge with dimethyl formamide (DMF). The enrichment factor of 100 was achieved. In the DMF medium, the molar absorptivity of the chelate is 1.35×10⁵ L · mol^?1 · cm^?1 at 540 nm. Beer's law is obeyed in the range of 0.01～2 µg mL^?1 in the measured solution. The relative standard deviation for 11 replicates sample of 0.5 µg L^?1 level is 2.05%. The detection limit, based on three times the standard deviation is 0.02 µg L^?1 in the original sample. This method was applied to the determination of gold in water and ore with good results.     

Synthesis and Characterization of Alkyl and Aryl‐(4‐methyl‐6‐nitro‐quinolin‐2‐yl)amines: X‐Ray Structures of Ethyl and Cyclohexyl‐(4‐methyl‐6‐nitro‐quinolin‐2‐yl)amine

Abstract

We have synthesized and characterized a series of alkyl and aryl‐(4‐methyl‐6‐nitro‐quinolin‐2‐yl)amines through a high‐yield, three‐step procedure starting from 4‐methylquinolin‐2‐ol. Nitration using concentrated nitric/sulfuric acids, followed by chlorination in phosphorus oxychloride, yielded 2‐chloro‐4‐methyl‐6‐nitro‐quinoline. All of the intermediates and aminated products have been characterized by multinuclear (¹H and ¹³C) NMR spectroscopy, elemental analysis, and, in the case of the two title compounds (ethyl and cyclohexyl‐(4‐methyl‐6‐nitro‐quinolin‐2‐yl)amine), a single crystal X‐ray structure was obtained to verify the nature of the new materials.     

Micellization and surface activity of Triton X-100 in water–orthophosphoric medium

The adsorption isotherms of Triton X-100 for air/water–orthophosphoric acid interfaces were determined by the stripping method. The surface chemical parameters, Γ_max, F and ΔG°_A, and the aggregation ones, CMC and the ΔG_M, are determined in different H₂O/H₃PO₄ mixtures. For concentrations higher than 4 M, the values of the CMC, ΔG_M, Γ_max and ΔG°_A increase with increasing acid concentrations due to the occurring changes in the medium structure. ©2000 Académie des sciences / Éditions scientifiques et médicales Elsevier SASsurface tension / non-ionic surfactant / micellization / orthophosphoric acid     

X‐Ray Photoelectron‐ and Auger‐Spectroscopic Study of Superstoichiometric Fluorographite‐Like Materials

Xray photoelectron spectroscopy (XPS) and Auger spectroscopy methods were used to study industrial fluorographitelike fluorocarbon materials (FCMs) of superstoichiometric CF_1.25–1.33 composition [fluorosibunite (FS) and T900 fluorinated soot (FT)] and fluorinated graphites of CF_0.88–1.08 composition. Based on XPS analysis, models were proposed for the surface layer structures in nanofragments of the FCMs and fluorographite. The main structural element of the FCMs and fluorographites studied here is a corrugated carbon network with CF and CF₂ groups of several types. The CF networks of the FCM structures contain holes formed upon fluorination of the initial carbon materials and filled with alternating CF and CF₂ groups. The bond energies of the inner C1s and F1s levels and the kinetic energies of F KLL Auger spectra suggest a covalent nature of all types of bonds between the carbon and fluorine atoms. Calculations using XPS data revealed common and specific features in correlations between the volume stoichiometry of the FCMs and fluorographites and the atomic F/C ratios in the surface layers of the materials.     

Ring‐Opening of Benzocyclobutenol with Mild Bases and Trapping with Dieneophiles

The treatment of benzocyclobutenol with a mild base has been investigated. This reaction results in an electrocyclic opening of the cyclobutene to the corresponding o‐quinodimethane, which has been successfully treated with aldehydes and electron‐deficient alkenes to form benzolactols and benzocyclohexenes respectively.