scholarly journals Spontaneous emulsification of pure xylene in an aqueous solution through mere adsorption of a detergent in the interface

1949 ◽  
Vol 198 (1055) ◽  
pp. 447-454 ◽  
Keyword(s):  
Aqueous Solution ◽  
Interfacial Tension ◽  
Pure Liquid ◽  
Detergent Solution ◽  
Liquid Hydrocarbons ◽  
Spontaneous Emulsification ◽  
Pure Solvent ◽  
Dodecylamine Hydrochloride ◽  
Spherical Droplets ◽  
Aqueous Detergent

Spontaneous emulsification of a pure liquid can occur. This is demonstrated when liquid hydrocarbons are quietly placed upon the surface of the solution of a suitable detergent. Here special attention has been given to xylene placed upon moderately dilute solutions of dodecylamine hydrochloride. In many cases violent disruption of the pure liquid occurs, when it is quietly placed upon a soap or detergent solution. Examination shows that the emulsitied droplets still consist of pure solvent stabilized by a coating of adsorbed protective colloid. The source of the required energy is the energy of adsorption, as well as solubilization of hydrocarbon in the aqueous detergent. The emulsion formed consists of spherical droplets which therefore retain a positive interfacial tension.

Enzymatic colorimetry of lecithin and sphingomyelin in aqueous solution.

1983 ◽  
Vol 29 (8) ◽  
pp. 1513-1517 ◽  
Author(s):  
M W McGowan ◽  
J D Artiss ◽  
B Zak
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Amniotic Fluid ◽  
Enzymatic Reaction ◽  
Detergent Solution ◽  
Enzymatic Determination ◽  
Red Color ◽  
Hydrolysis Of ◽  
Zwitterionic Detergent

Abstract A procedure for the enzymatic determination of lecithin and sphingomyelin in aqueous solution is described. The phospholipids are first dissolved in chloroform:methanol (2:1 by vol), the solvent is evaporated, and the residue is redissolved in an aqueous zwitterionic detergent solution. The enzymatic reaction sequences of both assays involve hydrolysis of the phospholipids to produce choline, which is then oxidized to betaine, thus generating hydrogen peroxide. The hydrogen peroxide is subsequently utilized in the enzymatic coupling of 4-aminoantipyrine and sodium 2-hydroxy-3,5-dichlorobenzenesulfonate, an intensely red color being formed. The presence of a non-reacting phospholipid enhances the hydrolysis of the reacting phospholipid. Thus we added lecithin to the sphingomyelin standards and sphingomyelin to the lecithin standards. This precise procedure may be applicable to determination of lecithin and sphingomyelin in amniotic fluid.

The Effect of Nanoparticles Crystallite Size on the Recovery Efficiency in Dielectric Nanofluid Flooding

2012 ◽  
Vol 21 ◽  
pp. 103-108 ◽  
Author(s):  
Hasnah Mohd Zaid ◽  
Noorhana Yahya ◽  
Noor Rasyada Ahmad Latiff
Keyword(s):  
Interfacial Tension ◽  
Crystallite Size ◽  
Oil Recovery ◽  
Zno Nanoparticles ◽  
Sodium Dodecyl ◽  
Substantial Reduction ◽  
Reservoir Rock ◽  
Recovery Efficiency ◽  
Spontaneous Emulsification ◽  
Emulsification Process

Application of nanotechnology in enhanced oil recovery (EOR) has been increasing in recent years. After secondary flooding, more than 60% of the original oil in place (OOIP) remains in the reservoir due to trapping of oil in the reservoir rock pores. One of the promising EOR methods is surfactant flooding, where substantial reduction in interfacial tension between oil and water could sufficiently displace oil from the reservoir. In this research, instability at the interfaces is created by dispersing 0.05 wt% ZnO nanoparticles in aqueous sodium dodecyl sulfate (SDS) solution during the core flooding experiment. The difference in the amount of particles adsorbed at the interface creates variation in the localized interfacial tension, thus induces fluid motion to reduce the stress. Four samples of different average crystallite size were used to study the effect of particle size on the spontaneous emulsification process which would in turn determine the recovery efficiency. From the study, ZnO nanofluid which consists of larger particles size gives 145% increase in the oil recovery as compared with the smaller ZnO nanoparticles. In contrast, 63% more oil was recovered by injecting Al2O3 nanofluid of smaller particles size as compared to the larger one. Formation of a cloudy solution was observed during the test which indicates the occurrence of an emulsification process. It can be concluded that ultralow Interfacial tension (IFT) value is not necessary to create spontaneous emulsification in dielectric nanofluid flooding.

Intermolecular Interactions of Pyridine in Liquid Phase and Aqueous Solution Studied by Soft X-ray Absorption Spectroscopy

2018 ◽  
Vol 232 (5-6) ◽  
pp. 705-722 ◽  
Author(s):  
Masanari Nagasaka ◽  
Hayato Yuzawa ◽  
Nobuhiro Kosugi
Keyword(s):  
Aqueous Solution ◽  
Quantum Chemical Calculations ◽  
Intermolecular Interactions ◽  
Absorption Spectroscopy ◽  
Quantum Chemical ◽  
Bulk Water ◽  
Pure Liquid ◽  
Rich Region ◽  
X Ray ◽  
X Ray Absorption

Abstract Intermolecular interactions of pyridine in liquid and in aqueous solution are studied by using soft X-ray absorption spectroscopy (XAS) at the C, N, and O K-edges. XAS of liquid pyridine shows that the N 1s→π* peak is blue shifted and the C 1s→π* peak of the meta and para sites is red shifted, respectively, as compared with XAS of pyridine gas. These shifts in liquid are smaller than those in clusters, indicating that the intermolecular interaction of liquid pyridine is weaker than that of pyridine cluster, as supported by the combination of quantum chemical calculations of the core excitation and molecular dynamics simulations of the liquid structure. On the other hand, XAS spectra of aqueous pyridine solutions (C5H5N)x(H2O)1−x measured at different molar fractions show that in the pyridine rich region, x>0.7, the C and N 1s→π* peak energies are not so different from pure liquid pyridine (x=1.0). In this region, antiparallel displaced structures of pyridine molecules are dominant as in pure pyridine liquid. In the O K-edge XAS, the pre-edge peaks sensitive to the hydrogen bond (HB) network of water molecules show the red shift of −0.15 eV from that of bulk water, indicating that small water clusters with no large-scale HB network are formed in the gap space of structured pyridine molecules. In the water rich region, 0.7>x, the N 1s→π* peaks and the O 1s pre-edge peaks are blue shifted, and the C 1s→π* peaks of the meta and para sites are red-shifted by increasing molar fraction of water. The HB network of bulk water is dominant, but quantum chemical calculations indicate that small pyridine clusters with the HB interaction between the H atom in water and the N atom in pyridine are still existent even in very dilute pyridine solutions.

Nuclear magnetic resonance studies of microemulsions and related systems: 2-butoxyethanol in water

1984 ◽  
Vol 62 (1) ◽  
pp. 56-63 ◽  
Author(s):  
O. Desrosiers ◽  
T. Van Dinter ◽  
J. K. Saunders
Keyword(s):  
Phase Transition ◽  
Aqueous Solution ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Pure Liquid ◽  
Population Changes ◽  
Magnetic Resonance Studies ◽  
Nmr Parameters ◽  
Dilute Aqueous Solution

The 13C chemical shift, T1 and 2H T1 data for 2-butoxyethanol (BE) in D2O as a function of concentration are presented. The nmr parameters are consistent with thermodynamic data for the same system in that it appears that 2-butoxyethanol in water undergoes a pseudo phase transition at about 1.2 M. The chemical shift for each carbon is different in the microphase relative to either aqueous solution or pure BE. The shift differences are due to a combination of factors, conformer population changes, changes in the polarity of the oxygen, and a solvent effect on chemical shift. The more organic the medium, the higher the population of trans relative to gauche conformers. The motion of BE is more restricted in the microphase than in either dilute aqueous solution or in the pure liquid. The number of adsorbed D2O molecules per molecule of BE is less in the microphase than in aqueous solution.

Photocontrolled self-assembly of azobenzene nanocontainers in water: light-triggered uptake and release of lipophilic molecules

2019 ◽  
Vol 55 (79) ◽  
pp. 11860-11863 ◽  
Author(s):  
Marco Villa ◽  
Giacomo Bergamini ◽  
Paola Ceroni ◽  
Massimo Baroncini
Keyword(s):  
Aqueous Solution ◽  
Small Molecules ◽  
Self Assembly ◽  
Spontaneous Emulsification ◽  
Uptake And Release

A simple azobenzene based photo-surfactant thanks to unique photo-triggerable spontaneous emulsification characteristics, allows a clean, reversible and fatigue resistant uptake and release of small molecules in aqueous solution.

Sign in / Sign up

Export Citation Format

Share Document