Sulfonate solution

Ito and Matsuda studied the y-radiolysis of 2-methyltetrahydrofuran (MTHF) solutions of diphenyl sulfone and dibenzothiophene-S,S-dioxide (DBTSD) at 77 K. They found that the radical anions of these sulfone compounds are formed and have intense absorption bands at 1030 nm and 850 nm, respectively. The blue glassy solution of y-irradiated diphenyl sulfone has absorption bands at both 1030 nm and 360 nm while the absorption spectrum of the benzenesulfonyl radical formed by UV irradiation of diphenyl sulfone solution at 77 K showed only a peak at 382 nm. Gamma-irradiated phenyl methyl sulfone solution showed an absorption band only at 385 nm. Consequently the appearance of the absorption bands in 800-1030 nm of diphenyl sulfone and DBTSD may suggest that the unpaired electron is delocalized on two phenyl rings. The same authors studied the radiolysis of MTHF solutions of disulfones (diphenyl and dihexyl disulfones). They found a blue coloring of the solution by the y-radiolysis of diphenyl disulfone and dihexyl disulfone due to absorption peaks at 695 nm and 690 nm respectively, besides smaller absorptions at 300-400 nm. Comparing these results to the previous observation, that phenyl methyl sulfone solution absorbs only at 398 nm, results in the conclusion that the absorption band at 690 nm is due to the linked two sulfone moieties. The authors found that substituents on the phenyl ring lead to shifts in the absorption maxima of the... 

The presence of pre-adsorbed polyacrylic acid significantly reduces the adsorption of sodium dodecylsulfonate on hematite from dilute acidic solutions. Nonionic polyacrylamide was found to have a much lesser effect on the adsorption of sulfonate. The isotherm for sulfonate adsorption in absence of polymer on positively charged hematite exhibits the typical three regions characteristic of physical adsorption in aqueous surfactant systems. Adsorption behavior of the sulfonate and polymer is related to electrokinetic potentials in this system. Contact angle measurements on a hematite disk in sulfonate solutions revealed that pre-adsorption of polymer resulted in reduced surface hydrophobicity. 

Mobile phase 0.19% Na pentane sulfonate solution in MeOH-H20-acetic acid (67 32 1, v/v/v). 

Preliminary Oxidation with Cupric Oxide and Alkali. This first oxidation study under conditions used previously for evaluating ligno-sulfonate solutions (//) used the fractionation procedure developed recently for analyzing spent pulping liquors (75, 16). This procedure was used with little change for most of the oxidation experiments here. 

Dose level of melomine formaldehyde sulfonate solution %by wt cement... 

B Combinations that were not investigated are indicated by dashes b Water-propylene glycol solutions c Aqueous sodium dodecyl sulfonate solutions d Complexing only after heating... 

Dinonylnaphthalene Sulfonate. Solutions of this liquid cation exchanger in heptane were prepared and standardized as described elsewhere (9). 

B, Emulsified sodium poly(p vtnylbenzene sulfonate) solution... 

Hyoscyamine can be determined by fluorimetric technique as follows (100). A solution of hyoscyamine or an eluate of it from a LiChrosorb DIOL HPLC column is treated with 9,10-dimethoxy anthracene-2-sulfonate solution. The resulting derivative is determined fluorimetrically at 446 nm with excitation at 383 nm. 

Chan and Shah (26) proposed a unified theory to explain the ultralow interfacial tension minimum observed in dilute petroleum sulfonate solution/oil systems encountered in tertiary oil recovery processes. For several variables such as the salinity, the oil chain length and the surfactant concentration, the minimum in interfacial tension was found to occur when the equilibrated aqueous phase was at CMC. This interfacial minimum also corresponded to the partition coefficient near unity for surfactant distribution in oil and brine. It was observed that the minimum in ultralow interfacial tension occurs when the concentration of the surfactant monomers in aqueous phase is maximum. 

Phase Behavior of Aqueous Surfactant Solutions. The aqueous solu-tions contained 5 gm/dl TRS l0-4l0 as surfactant, and 3 gm/dl isobutyl alcohol as cosurfactant, unless otherwise indicated. The polymer concentration was varied from zero to 1500 ppm. The aqueous phase behavior in the absence of polymer is shown in Figure 2. The salinity is varied from 0.8 to 2.2 gm/dl NaCl in increments of 0.2 gm/dl. The phase behavior at lower salinities will be discussed later. The general trend is similar to the changes in textures reported for other commercial and model sulfonate solutions (26,27). 

Various additives have been added to PFSA membranes to either replace the water or to retain the water at higher temperatures. Nafion has been swollen with phosphoric acid and a conductivity of 0.05 S/cm has been achieved at 150°C. Unfortimately, the anode fails after a short period of time in these membranes so no successful FC tests have been run. 1-Butyl,3-methyl imidazolium triflate and tetrafluoroborate have also been used to swell Nafion giving a conductivity of 0.1 S/cm at 180°C. Nafion has also been swollen with heterocycle solutions, imidazole, and imidazolium salts in trifluoroacetate and trifluoro methane sulfonate solution, although the reported conductivities are more modest, 10 S/cm at 100°C. Acetic acid and tetra-n-butylammonium chloride solutions of the heteropoly acid (HPA), 12-phosphotungstic acid (PTA), have all been used with Nafion giving improved FC performance at 110°C and 120°C, respectively, vs. the undoped PFSA. ... 

Information on microviscosity is obtained by studying the excimer forming capabilities of suitable fluorescent probes. The excimer, which is a complex of a ground state and excited state monomer, has a characteristic emission frequency. The intramolecular excimer formation for example, of 1,3-dinaphthyl propane (DNP), is a sensitive function of the microviscosity of its neighborhood. This property, expressed as the ratio of the excimer and monomer yield (/e//m) for DNP, has been determined for dodecyl sulfonate solutions and its adsorbed layer for the various regions of the adsorption isotherm (Fig. 4.18) (Somasundaran et al., 1986). Comparing the ratios thus obtained to the /e//m values of DNP in mixtures of ethanol and glycerol of known viscosities, a microviscosity value of 90 to 120 cPs is obtained for the adsorbed layer in contrast to a value of 8 cPs for micelles. The constancy of microviscosity as reported by DNP is indicative of the existence of a condensed surfactant assembly (solloids) that holds the probe. 

The laminar flow of a certain aqueous polystyrene sulfonate solution can be represented by the Ostwald-de Waele model with an exponent of 0,500, The solution is contained in a tank that is a vertical cylinder. Solution flows out through a horizontal tube attached to the bottom of the tank, (a) If the time for the height of solution in the tank to fall from 10.00 to 9.90 m is 30,0 min, how much time will it take to half-empty the tank (from a height of 10.0 m down to a height of 5.0 m) (6) If the tank has a diameter of 2.0 m and the pipe has a diameter of 0.050 m with a length of 200 m, what is the flow consistency index of the solution The solution has a density of 1200 kg/m, ... 

Fig. 6.12 Concentration dependence of the effective dilational elasticity of hexadecyl dimethyl ammoniopropane sulfonate solutions at different frequencies f- 10 (A), 2(4), 1(D),...

Figure 8. Thin-film drainage tune (x) and dilatational modulus (m) at 10 s 1 bubbling frequency of a-olefin sulfonate solutions as a function of surfactant chain length. (Reproduced from reference 22. Copyright 1986 American Chemical Society.)...

If milder conditions are employed some trivalent phosphorus compound can be isolated 87), and when fluorination is carried out under nonoxidizing conditions, e.g., by sodium fluoride in tetramethylene sulfone solution, good yields of the alkyl- or aryldialkylaminofluorophosphines are obtained 288, 290). 

All nilralioiis were carried out in lelramelhylene sulfone solutions at temperatures between Oand -1-5 -... 

All nitrations were carried out in tetramethylene sulfone solutions. Halogen exchange to acid fluoride takes place with byproduct HF. 

In the course of our investigation, we found that homogeneous Friedel-Crafts type nitrations with N20i and Lewis acid catalyst such as TiCli, BF3, BCI3, PF and AsF can be carried out in tet-ramethylene sulfone solutions. It is not necessary to isolate the catalyst-N20i complex. Instead, a solution of N20j and the catalyst is prepared and this solution is added to a tetramethylene sulfone solution of the aromatic to be nitrated. 

Polyethylene imine acts as an adhesive layer and polystyrene sulfonate (an anionic polyelectrolyte) has been used according to Scheme 7.3. First a solution containing Au nanorods is prepared using seed-mediated growth. Then, the clean ITO shdes are immersed in polyethyleneimine solution followed by polystyrene sulfonate solution. After rinsing and drying, the slides are immersed in the Au nanorod solution. The Au rods self-assemble and deposit on substrate, as shown in Figure 7.11. 

A solution of a stable nitronium salt (generally the hexafluorophosphate NOa PF but also the hexafluoroantimonateNO SbFft ortetrafiuoroborate NO2BF4) in methylene chloride-tctramethylene sulfone solution was allowed to react with the alkane (cycloalkane), with usual precautions taken to avoid moisture and other impurities. Reactions were carried out at room temperature (25°C) in order to avoid or minimize the possibility of radical side reactions and/or protolytic cleavage reactions (tertiary nitroalkanes particularly readily undergo protolytic cleavage, even if the system initially is acid free but nitration forms acid). Data obtained are summarized in Table XXI. 

Figure 16.1 Electrochemical cycling in 2 M p-toluene sulfonic solution of a mild-steel electrode coated by a PPy/PANI bilayer (a) first cycle (b) after cycling for 2 h. The bilayer system exhibits the same stability under potentiodynamic cycling as a platinum electrode coated by a PANI film in acidic medium. (Reprinted with permission from Journal of Electroanalytical Chemistry, Aniline electropolymerization on mild steel and zinc in a two-step process by J.-C. Lacroix, J.L. Camalet, P.C. Lacaze et al., 481, 1, 76-81. Copyright (2000) Elsevier Ltd)...

---