Novel Discrete Micellar Cubic Phase From a Mixture of GMO/Ethanol/Water

2005 ◽  
Vol 58 (11) ◽  
pp. 762 ◽  
Author(s):  
Rivka Efrat ◽  
Abraham Aserin ◽  
Dganit Danino ◽  
Ellen J. Wachtel ◽  
Nissim Garti

During the reconstruction the ternary phase diagram of glycerol monooleate (GMO)/ethanol/water, we detected a novel structure not previously seen. The new phase, denoted QL (micellar cubic liquid), is located within the 49–54 wt.-% water/41–33 wt.-% GMO binary mixture line and at 10–13 wt.-% EtOH in a small island within the phase diagram close to the cubic liquid-crystalline phase region. The QL phase is transparent (not tinted), of a low viscosity (36.6 Pa s), non-birefringent, and stable at room temperature. Evidence from severe centrifugation, synchrotron small-angle X-ray scattering (SAXS) measurements, and rheological behavior revealed that the sample is a single phase. SAXS reflections suggest that two types of domain may coexist. The symmetry of the QL phase is Pm3n. A cubic micellar structure is the dominant mesostructure of this unique sample. Cryo-TEM images show highly ordered domains with cubic symmetry, of lattice parameter 103 ± 2 Å. A possible transformation pathway to the QL phase is a ‘rupture and refusion’ mechanism, as the phase seems to have discontinuous symmetry.

2011 ◽  
Vol 90 (12) ◽  
pp. 1434-1438 ◽  
Author(s):  
Q. Ye ◽  
J. Park ◽  
J.S. Laurence ◽  
R. Parthasarathy ◽  
A. Misra ◽  
...  

When adhesives and/or composites are bonded to the tooth, water in the environment can interfere with proper interface formation. Formation of water blisters and phase separation at the adhesive/dentin interface have appeared as new types of bond defects. To better understand this problem, we determined the near-equilibrium partition of the hydrophobic/hydrophilic components when exposed to over-wet environments. Model methacrylate-based adhesives were mixed with different amounts of water to yield well-separated aqueous and resin phases. It was found that less than 0.1% BisGMA but nearly one-third of the HEMA diffused into the aqueous phase, leaving the remaining resin phase relatively hydrophobic. A partial phase diagram was created for the ternary BisGMA/HEMA/water system. All the experimental phase partitioning data were plotted, and the points lay on a binodal curve that separated the single-phase region from the two-phase region. We obtained the 3 tie lines by connecting the 2 points of each conjugate pair of the phase partitioning data from the 3 sets of tripartite mixtures. Information about solubility, water miscibility, distribution ratio, and phase partitioning behavior could be obtained quantitatively. This type of phase diagram will provide a more thorough understanding of current adhesive performance and elucidate directions for further improvement.


2002 ◽  
Vol 16 (26) ◽  
pp. 3959-3970 ◽  
Author(s):  
S. YILDIZ ◽  
İ. E. SERHATLI ◽  
Ö. PEKCAN ◽  
A. N. BERKER ◽  
H. ÖZBEK

The ultraviolet/visible photon transmission technique was applied to study the phase diagram of a mixture of 4-ethoxy-4′-(6-vinyloxyhexyloxyl) azobenzene (VE), a smectogen, and 4-hexoxy-3′-methyl-4′-(6-acryloyloxyhexyloxy) azobenzene (AH), which by itself exhibits no liquid crystalline behavior. It has been found that the N-Sm-A phase line terminates at either a tricritical point at about X VE = 0.9, where X VE is the weight percentage of VE in the binary mixture, or at least at a tricritical region 0.9 < X VE < 1 within the experimental resolution. For X VE = 1 the nematic phase region is not large enough to drive the transition second-order. It is found that the value of the critical exponent β for X VE = 0.9 is consistent with the tricritical value.


2015 ◽  
Vol 754-755 ◽  
pp. 944-949 ◽  
Author(s):  
Irwana Nainggolan ◽  
Shahidan Radiman ◽  
Ahmad Sazali Hamzah ◽  
Rauzah Hashim

Two glycolipids were synthesized to study the lyotropic behavior of these glycolipids in alkylglucoside/water/n-octane ternary system. These glycolipids have been distinguished based on the structure of alkyl chain (branched-alkyl chain and straight alkyl chain). 2-octyl-β-D-glucopyranoside (2-OG) and 2-ethylhexyl-β-D-glucopyranoside (2-EHG) were used as surfactants to perform two types of phase diagram. Phase behaviours investigated were phase behaviours of 2-OG/n-octane/water ternary system and 2-EHG/n-octane/water ternary system. Small angle x-ray (SAXS) and optical polarizing microscope were used as the instruments to study the lyotropic phase behaviour of these two surfactans in ternary phase diagram. Study the effect of branched-tail structure on the phase behaviour of glycolipids in ternary system is one of strategy to derive the structure-property relationship. For this purpose, 2-OG and 2-EHG were used as surfactants in the same ternary system. The phase diagram of 2-OG/water/n-octane ternary system showed rectangular ribbon phase and lamellar phase. The phase diagram of 2-EHG/water/n-octane ternary system showed wide region of lamellar lyotropic liquid crystalline in different ratio of weight composition. In 2-OG/water/n-octane ternary system, as more surfactant was added to the system, the interlayer spacing, d1 and scattering angle, a value increased, whereas in 2-EHG/water/n-octane ternary system, the d1 and a value decreased.


2013 ◽  
Vol 756 ◽  
pp. 85-90
Author(s):  
Rabiahtul Zulkafli ◽  
Norinsan Kamil Othman ◽  
Muhammad Azmi Abdul Hamid ◽  
Azman Jalar

The aim of the study was to synthesis the CdS nanoparticles via AOT-water-n-heptane microemulsion technique. Ternary phase diagram was constructed to obtain the concentration range of oil, surfactant and water. Three main phases form on the ternary phase diagram of AOT-water-n-heptane, which were gel, cloudy and clear phases. The clear phase was heptane rich region. Meanwhile, cloudy phase have consisted two phases and the gel phase was due to high concentration of AOT. The result showed that clear phase region shrink when the Cd2+ and S2-solvent was added or replaced the water component of the tertiary system.The existence of CdS nanoparticles with average size of 14.0 nm has been calculated by using UV-Vis Spectrometry meanwhile the TEM image showed that the size of CdS nanoparticles was about 49-89 nm. It also have concluded that the same concentration at solvents Cd2+ and S2- does not effected the size of nanoparticles.


Author(s):  
David M. Anderson ◽  
Tomas Landh

First discovered in surfactant-water liquid crystalline systems, so-called ‘bicontinuous cubic phases’ have the property that hydropnilic and lipophilic microdomains form interpenetrating networks conforming to cubic lattices on the scale of nanometers. Later these same structures were found in star diblock copolymers, where the simultaneous continuity of elastomeric and glassy domains gives rise to unique physical properties. Today it is well-established that the symmetry and topology of such a morphology are accurately described by one of several triply-periodic minimal surfaces, and that the interface between hydrophilic and hydrophobic, or immiscible polymer, domains is described by a triply-periodic surface of constant, nonzero mean curvature. One example of such a dividing surface is shown in figure 5.The study of these structures has become of increasing importance in the past five years for two reasons:1)Bicontinuous cubic phase liquid crystals are now being polymerized to create microporous materials with monodispersed pores and readily functionalizable porewalls; figure 3 shows a TEM from a polymerized surfactant / methylmethacrylate / water cubic phase; and2)Compelling evidence has been found that these same morphologies describe biomembrane systems in a wide range of cells.


Author(s):  
Md. Hamidul Kabir ◽  
Ravshan Makhkamov ◽  
Shaila Kabir

The solution properties and phase behavior of ammonium hexylene octyl succinate (HOS) was investigated in water and water-oil system. The critical micelle concentration (CMC) of HOS is lower than that of anionic surfactants having same carbon number in the lipophilic part. The phase diagrams of a water/ HOS system and water/ HOS/ C10EO8/ dodecane system were also constructed. Above critical micelle concentration, the surfactant forms a normal micellar solution (Wm) at a low surfactant concentration whereas a lamellar liquid crystalline phase (La) dominates over a wide region through the formation of a two-phase region (La+W) in the binary system. The lamellar phase is arranged in the form of a biocompatible vesicle which is very significant for the drug delivery system. The surfactant tends to be hydrophilic when it is mixed with C10EO8 and a middle-phase microemulsion (D) is appeared in the water-surfactant-dodecane system where both the water and oil soluble drug ingredient can be incorporated in the form of a dispersion. Hence, mixing can tune the hydrophile-lipophile properties of the surfactant. Key words: Ammonium hexylene octyl succinate, mixed surfactant, lamellar liquid crystal, middle-phase microemulsion. Dhaka Univ. J. Pharm. Sci. Vol.3(1-2) 2004 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website


Author(s):  
Rachel Orenstein ◽  
James P. Male ◽  
Michael Toriyama ◽  
Shashwat Anand ◽  
G. Jeffrey Snyder

A new understanding of the MgSi–MgSn miscibility gap is reached through phase boundary mapping the Mg–Si–Sn ternary phase diagram.


1984 ◽  
Vol 62 (3) ◽  
pp. 457-474 ◽  
Author(s):  
A. D. Pelton ◽  
C. W. Bale ◽  
P. L. Lin

Phase diagrams and thermodynamic properties of five additive molten salt ternary systems and nine reciprocal molten salt ternary systems containing the ions Li+, Na+, [Formula: see text], OH− are calculated from the thermodynamic properties of their binary subsystems which were obtained previously by a critical assessment of the thermodynamic data and the phase diagrams in these binary systems. Thermodynamic properties of ternary liquid phases are estimated from the binary properties by means of the Conformal Ionic Solution Theory. The ternary phase diagrams are then calculated from these thermodynamic properties by means of computer programs designed for the purpose. It is found that a ternary phase diagram can generally be calculated in this way with a maximum error about twice that of the maximum error in the binary phase diagrams upon which the calculations are based. If, in addition, some reliable ternary phase diagram measurements are available, these can be used to obtain small ternary correction terms. In this way, ternary phase diagram measurements can be smoothed and the isotherms drawn in a thermodynamically correct way. The thermodynamic approach permits experimental data to be critically assessed in the light of thermodynamic principles and accepted solution models. A critical assessment of error limits on all the calculated ternary diagrams is made, and suggestions as to which composition regions merit further experimental study are given.


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