NaCI concentration

Figure 44. Surface coverage of nickel passive film vs. NaCI concentration.91 300 K. (Reprinted from M. Asanuma and R. Aogaki, Nonequilibrium fluctuation theory on pitting dissolution. II. Determination of surface coverage of nickel passive film, J. Chem. Phys. 106, 9938, 1997, Fig. 14. Copyright 1997, American Institute of Physics.)...

Figure 12, Fractions of water in glycerol-NaCI-HjO solutions remaining unfrozen at various subzero temperatures. Glycerol molarities refer to the initial unfrozen solutions. The initial NaCI concentration in these solutions was 0.15 M. (From Mazur et al., 1981.)...

Figure 13.8 Calculated interaction energy curves for egg-PC on a surface-oxidized silicon substrate system.The NaCI concentration is 100mM (solid line), 10mM (broken line), and 1 mM (dotted line). Adapted from Ref [53] with permission.

At a given NaCI concentration, an increase in temperature resulted in an increase in interfacial tension. In contrast, for a narrow range of CaCI concentrations, interfacial tensions decreased with increasing temperatures. Changes of the amphiphile at the oil/water interface accounted for some of the experimental observations. Since the extent of oil desaturation is dependent on interfacial tension, the tension data could be used to assess the ability of surfactants to reduce oil saturations in the reservoir for application of surfactants and foams to thermal recovery processes. 

The interfacial tension behavior between a crude oil (as opposed to pure hydrocarbon) and an aqueous surfactant phase as a function of temperature has not been extensively studied. Burkowsky and Marx T181 observed interfacial tension minima at temperatures between 50 and 80°C for crude oils with some surfactant formulations, whereas interfacial tensions for other formulations were not affected by temperature changes. Handy et al. [191 observed little or no temperature dependence (25-180°C) for interfacial tensions between California crude and aqueous petroleum sulfonate surfactants at various NaCI concentrations. In contrast, for a pure hydrocarbon or mineral oil and the same surfactant systems, an abrupt decrease in interfacial tension was observed at temperatures in excess of 120°C 1 20]. Non ionic surfactants showed sharp minima of interfacial tension for crude... 

Effect of NaCI Concentration. The presence of surfactant in brine can have a dramatic effect on crude oil-aqueous surfactant tensions even at elevated temperatures r5,211. Figure 5 shows that the effect of sodium chloride concentration on Athabasca bitumen-D20 interfacial tensions measured at constant surfactant... 

In n-octane/aqueous systems at 27°C, TRS 10-80 has been shown to form a surfactant-rich third phase, or a thin film of liquid crystals (see Figure 1), with a sharp interfacial tension minimum of about 5x10 mN/m at 15 g/L NaCI concentration f131. Similarly, in this study the bitumen/aqueous tension behavior of TRS 10-80 and Sun Tech IV appeared not to be related to monolayer coverage at the interface (as in the case of Enordet C16 18) but rather was indicative of a surfactant-rich third phase between oil and water. The higher values for minimum interfacial tension observed for a heavy oil compared to a pure n-alkane were probably due to natural surfactants in the crude oil which somewhat hindered the formation of the surfactant-rich phase. This hypothesis needs to be tested, but the effect is not unlike that of the addition of SDS (which does not form liquid crystals) in partially solubilizing the third phase formed by TRS 10-80 or Aerosol OT at the alkane/brine interface Til.121. 

Figure 5 Effect of NaCI concentration on the Athabasca bitumen/DJ) interfacial tension for Enordet C18 18, Sun Tech IV and TRS 10-80. Closed triangle represents the data measured for Enordet C16 18 at concentrations up to 160 g/L NaCI.

Table III Interfacial tension data for the Athabasca bitumen/D20 and Enordet C1618 (2 g/L) system as a function of NaCI concentration and temperature...

Fig. 1.31. Behavior of a sucrose - NaCI solution at different sucrose - NaCI concentrations and temperatures after quick freezing (200 °C/min), during slow rewarming (Fig. 8 from [1.25]).

Fig. 17.14 NaCI concentration in the anolyte compartment of the ML32NCH cell operating at 6 kA rrf2, 32% NaOH and 90°C.

X and 4X the normal amount. The osmotic concentration was maintained constant by balancing the NaCI concentration. 

A mixture of 1.5-3.5 mmol of the a-alkylated benzylimino product and 10-25 mL of0.5 M hydroxylamine acetate in anhyd ethanol is stirred at 25 C for 4-10 h. concentrated, the residue is dissolved in 30-50 mL of benzene, the solution is washed with sat. aq NaHC03 and then NaCI, concentrated, acidified with 10-20 mL of 5% aq hydrochloric acid, the mixture is stirred for 0.5 h and extracted with six 10-mL portions of diethyl ether. Concentration of the ethereal layer gives the oxime. The aqueous layer is basified with Na2C03, extracted with six 10-mL portions of diethyl ether, dried over potassium carbonate. Concentration and distillation (bulb-lo-bulb) gives the product. The chiral auxiliary can be recovered and recycled39. 

By substituting the value of a0 into this expression and using the various NaCI concentrations given, values are readily calculated these are to be compared with Eobs - 200. The following values are obtained ... 

In Oil/Water Separation by Induced-Air Flotation by Sylvester and Byeseda, an induced-air flotation pilot unit was used to study the separation of oil from bnne solutions. Variations in the inlet oil concentration, vessel, residence time, air flow rate, bubble diameter, oil-drop diameter, temperature. NaCI concentration, and cationic polyelectrolyte concentration were evaluated. On a multistage unit, the majority of the oil removal occurred in the first stage. Oil-drop and air-bubble diameters have the most significant effects on oil-removal rates. 

The ability to separate the removal rates due to air bubbles from drop aggregation/coalcscencc for each oil drop size permitted a detailed study of the system variables. These variables and their ranges of variation are shown in Table I. Note that the first-order removal rate constants were independent of residence time and oil droplet population in the feed and effluent. The variables which may influence the rate constants are air flowrate, temperature, NaCI concentration, bubble diameter, cationic polymer concentration, and oil drop diameter. 

TABLE 4 - AIR BUBBLE PROPERTIES AS NaCI CONCENTRATION VARIES... 

Figure 3.3 Schematic map of crystallization kinetics as a function of lysozyme and NaCI concentration obtained from a matrix of dishes. Inserts show photographs of dishes obtained 1 month after preparation of solutions. From G. Feher and X. Kam, in Methods in Enzymology 114, H. W. Wyckoff, C. H. W. Hirs, and S. N. Timasheff, eds., Academic Press, Orlando, Florida, 1985, p. 90. Photo and caption reprinted with permission.

Nyquist plots recorded at an electrochemical cell with palladium electrodes or woven, non-woven or knitted textile electrodes with /4=180mm2 and d=103mm for a NaCI concentration of (1) 1x10 2, (2) 1 x10 3 and (3) 1 x10 4mol I- at T=298.0K. Part b is an enlargement of part a. 

Figure 5.19 The specific volume offilter cake, sediment volume, and Bingham yield stress of sodium montmorillonite sols as a function of the NaCI concentration. From van Olphen [1], Copyright 1977, Wiley-lnterscience.

Fig. 4.17 Signal broadening (Avlj/2, mm) of various spin systems of chlorphentermine (a-c) at constant liposome concentration (1.2mg/mL) as a function of increasing NaCI concentration (0-6 mg/mL). The lowest symbols at zero NaCI concentration represent the control line width of the different proton resonance signals in the absence of both lecithin liposomes and NaCI. (Reprinted from Fig. 4 of ref. 135 with permission from Elsevier Science.)...

The numerical solution for the surface potential as a function of pH is compared in Fig. 7, for various NaCI concentrations, with the experimental results provided by Li and Somasundaran [32], The potentials — ]i,s = — ]i(0) and — tyd= — t)t(t/E) are plotted as functions of distance, since the zeta potential determined by electrophoresis is not defined at the surface, but at an unknown location, the plane of slip . The magnitude of <-s is always larger than that of i >d, since the potential decays with the distance. The value dE=4 A, which is provided by the dependence of the surface tension of water on the NaCI concentration at high ionic strengths was employed. For the equilibrium constant, the value K ou= () 10 M, which is consistent with the experimental data for pH values between 3 and 6, was selected. A reasonable agreement with the data (which have a rather large error) was obtained by selecting A=5.0X 1016 sites/m2 and W1 = 0.5kT. 

FIGURE 12 Plots of the approach distance a (in angstroms) versus k for the protein human serum albumin (HSA) (pi = 5.85, Mr = 69,000) measured with the strong anion exchange sorbent, Mono-Q, under conditions of varying NaCI concentration to achieve smaller kf values at a flow rate of I mL/min and at a temperature of 298 K with (I) 20 mM piperazine buffer, pH 9.6 (2) 20 mM triethanolamine, pH 7.5 (3) bistris buffer, pH 6.5 and (4), 20 mM piperazine buffer, pH 5.5, as the eluents. Data selected from Ref. 542. 

Fig. 3.100. Plot of linear energy irof NBF and NaDoS solutions vs. NaCI concentration determined by Ihe...

Chemical Engineering Flow Models 89 Table 3.5 Evolution of the NaCI concentration at the reactor s exit. 

Membrane Mfr Volumetric flow rate H/m d) NaCI retention (%) Pressure (bars or -atm) NaCI concentration (%)... 

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