Sodium N-octanoate Research Articles

Lipid bioproduction from delignified native grass (Cyperus distans) hydrolysate by Yarrowia lipolytica

In the present study, native grass (Cyperus distans) was utilized for the production of lipid using Yarrowia lipolytica MTCC 9519. Initially, pretreatment methods using hydrothermal and alkaline delignification were performed to obtain cellulose rich liquid fractions. Delignified native grass biomass was enzymatically hydrolyzed to convert non fermentable sugars in to fermentable sugars. The growth of Y. lipolytica MTCC 9519 by utilizing pretreated native grass hydrolysate was evaluated. The yield and concentration of total reducing sugars after enzyme hydrolysis were found to be 378 ± 35 mg/g of pretreated biomass and 28.64 g/L ± 1.25 g/L, respectively. When pretreated, delignified native grass hydrolysate was used with (NH4)2SO4 (30C/N ratio) and sodium n-octanoate (0.4% w/w), the dry cell weight and lipid accumulation of Y. lipolytica MTCC 9519 reached about 19.88 ± 1.54 g/L and 53.62% (w/w) respectively after 96 h. Thus, native grass could become a promising substrate for biolipid production.

전기 전도도 및 광산란법에 의한 나트륨 도데카노에이트와 나트륨 옥타노에이트의 혼합미셀화 연구

The critical micelle concentration (CMC), the counter ion binding constant (B) and the aggregation number (N* ) for the mixed micellization of sodium dodecanoate and sodium n-octanoate as two anionic surfactants have been investigated by means of electric conductivity and light scattering. As its experimental results are found to be deviated from ideal mixed model, thus two different kinds of regular solution models such as Rubingh and Motomura are used for interpreting our experimental data. The stability of the mixed micelles has been confirmed from the negative values of the standard Gibbs energy of mixed micellization ΔGmicel,0 over all compositions and the measured values of ΔGmicel,0 agreed with the theoretical ones within the experimental error.

Sodium n-Octanoate(SOC)와 n-Octylammonium Chloride(OAC)의 혼합마이셀화에 관한 연구

The critical micelle concentration(CMC) and the counterion binding constant(B) for the mixed micel-lization of sodium n-octanoate(SOC) with n-octylammonium chloride(OAC) were determined as a function of the overall mole fraction of Various thermodynamic parameters(, , , $$, and ) for the mixed micellization of the SOC/OAC systems have been calculated and analyzed by means of the equations derived from the nonideal mixed micellar model. The results show that there are great deviations from the ideal behavior for the mixed micellization of these systems. And other thermodynamic parameters(, , and ) associated with the micellization of SOC,OAC, and their have been also estimated from the temperature dependence of CMC and B values, and the significance of these parameters and their relation to the theory of the micelle formation have been considered and analyzed by comparing each other.

Partial molar enthalpies of the components of a quaternary water/oil microemulsion system

The molar enthalpy of mixing has been determined calorimetrically for a large number of solutions of the quaternary w/o microemulsion system n-decanol- n-octane—water—sodium n-octanoate at 298.15 K. The system is of fundamental interest since it allows a direct comparison of the thermal properties of complex quaternary microemulsions with the simpler ternary and binary reference mixtures being a part of the same system. Such systems are the inverted micellar system water + sodium octanoate in decanol, the detergentless microemulsion water—decanol—octane, and the binary mixtures water in decanol and decanol—octane. When analyzing the thermal properties of complex multicomponent systems where all the components participate in the association process solution properties such as the apparent molar enthalpy are difficult to interpret. A method is therefore suggested to derive the partial molar enthalpies when mixing the components in order to successfully highlight the thermal interactions. In order to test the precision of the polynomial representation of the experimental material different sets applicable to each system are used in the partial derivation procedure and the resulting partial molar enthalpies are illustrated in the figures. The partial molar enthalpies indicate that the interaction between the water and the ionic groups primarily determines the capacity of the microemulsion to incorporate octane. Octane seems to influence the association equilibria by shifting the distribution of decanol between the micellar interface and the solvent. Despite the different properties of the water-rich (low octane solubility) and water-poor (high octane solubility) phase regions a variation in the degree of aggregation seems sufficient to explain the results qualitatively.

The role of the solvent in sodium n-octanoate solutions studied by self-diffusion and nuclear magnetic relaxation measurements

Three-component systems containing water, sodium n-octanoate, and ethylene glycol, 1,2-butandiol, 1-butanol or ethylene glycol monobutyl ether have been investigated by means of 23Na and 2H NMR relaxation rate and chemical shift measurements as well as FT NMR pulsed gradient spin echo measurements of self-diffusion coefficients. All systems exhibit an increase in the 23Na relaxation rate at decreasing water content. The increase is most pronounced in the 1,2-butandiol system and least accentuated in the butanol system. 23Na chemical shifts indicate that the sodium ions remain fully solvated in ethylene glycol, i.e., no contact ion-pair formation occurs. The water self-diffusion coefficient is high in all systems and proportional to the water concentration. In the systems containing diols, the water and diol self-diffusion coefficients are approximately proportional to each other indicating that no partitioning of these components occur. For sodium n-octanoate dissolved in water/ethylene glycol mixtures, 23Na and 2H relaxation measurements have been performed at varying concentration of the surfactant and constant composition of the solvent. In a 80:20 (w/w) mixture of water and ethylene glycol only small differences could be seen in the 23Na relaxation compared with the pure water system indicating a similar aggregation behavior. In the pure ethylene glycol system, the increase in relaxation rate is discussed in terms of a more gradual and less cooperative aggregation process than in water.

Solubilities of toluene and n-octane in aqueous protosurfactant and surfactant solutions

The solubilities of toluene and n-octane in aqueous protosurfactant and surfactant solutins were determined at 25/sup 0/C. The protosurfactants studied are sodium salts of cyclohexanecarboxylic acid, 2,5-diisopropylbenzenesulfonic acid, and 3,5-diisopropyisalicylic acid. Each of them has six alkyl carbons (S /SUB AC/ =6) and does not form micelles in water. The two micelle-forming surfactants used are sodium n-hexanoate with six alkyl carbons (S /SUB AC/ =6) and sodium n-octanoate with eight alkyl carbons (S /SUB AC/ =8). In three-component systems of toluene or n-octane with water and organic salt (either protosurfactant or surfactant), the solubility of the hydrocarbon in the aqueous phase increases as the number of alkyl carbons of the organic salt and as the aqueous concentration of the organic salt increases. However, in this study we found that sodium 3,5-diisopropyisalicylate causes much more pronounced increases in hydrocarbon solubility than these two surfactants. Sodium 2,5-diisopropylbenzenesulfonate, although not as effective in solubilization as the salicylate, has much stronger hydrotropic properties for hydrocarbons than either of these two surfactants. Sodium cyclohexanoate, with a compact arrangement of the six alkyl carbons, shows a higher hydrotropic effect than sodium n-hexanoate.

Aklyl Chain Order Parameters and Phase Diagrams for Systems Containing Sodium n-Octanoate, Water, and Different Alcohols

Abstract Lamellar liquid crystalline phases containing sodium n-octanoate, water, and an alcohol have been studied by means of 2H NMR. Order parameters have been determined for the octanoate alkyl chain in systems containing ethanol, 1-propanol, 1-butanol, 1-pentanol, benzyl alcohol or 1, 8-octandiol. The straight chain alcohols yield decreasing octanoate order parameters with decreasing chain length. With 1, 8-octandiol the octanoate order parameters are somewhat smaller than with 1-propanol, indicating quite flexible octanoate hydrocarbon chains. Using mono-deuteriated benzyl alcohol. C6H5CHDOH, the SCD as well as the SHD (= SHH ) order parameters were determined in the same measurement. A typical measurement yields |S HD|-|SCD | = 0.04 ± 0.04, where the error estimation includes the uncertainties in the quadrupole and the magnetic dipole-dipole coupling constants. It is stressed that in order to ascertain a significant difference between SHH and SCD , it is necessary to know the coupling constants with...

Solubility and thermodynamics of solution of argon in aqueous solutions of sodium octanoate and sodium dodecylsulfate

The ostwald absorption coefficient of argon was measured in aqueous solutions of two surfactants; sodium n-octanoate and in sodium dodecylsulfate, at several concentrations and at a few temperatures between 10–25°C. The free energies, entropies and enthalpies of solution were computed. A tentative interpretation of the results is given, based on a competition between the solubilization and the salting-out effects of the surfactants.

An infrared-spectroscopic study of reversed micellar solutions of sodium n-octanoate and water in n-decanol

The association process to reversed micelles in the system water/sodium n-octanoate/ n-decanol is studied by means of wave number shifts in the fundamental infrared region. It is found that the antisymmetric vibration band (σ 3), and the scissors vibration band (σ 2) of water, together with the antisymmetric stretching vibration band of the ionised carboxylic groups (σ COO−) are capable of detecting and visualising changes in the micellar association equilibria. The information is primarily qualitative, but some rough quantitative estimations are also made. A comparison between the intensities of the narrow σ 3-line corresponding to unassociated water OH-oscillators discernible at high dilutions in decanol, and the broad σ 3-band of the associated species reveals that the fraction of unassociated OH-groups in water is low, perhaps only a few percent.

Premicellar and micellar aggregation in sodium octanoate solutions

The premicellar association and the formation of micelles in sodium n-octanoate (NaB) solutions have been investigated by potentiometric titration at constant sodium concentration [3 M Na(Cl)] and by light-scattering photometry in 3 M NaCl, NaBr and NaI. The potentiometric results were treated using the Letagropvrid method. The following stability constants were found: B − + H 2 O = HB + OH − − logβ 1,1 = 8.965 ± 0.019 5B − + H 2 O = HB 5 4− + OH − − logβ 1,5 = 2.196 ± 0.027 9B − + H 2 O = HB 9 8− + OH − − log& = − 1.267 ± 0.199 9B − = B 9 9− − logβ 0,9 = −7.963 max − 8.319. The data can be reconciled satisfactorily, however, with any micellar aggregation number between 9 and 17. The light-scattering measurements followed Huisman's method and yielded a micellar weight of 4.62 ± 0.05 kg mole −1. To reconcile this result with the potentiometric aggregation numbers it is necessary to assume that the micelle binds 6–10 molecules of water per octanoate molecule. This assumption is supported by other investigations.