2 edition of Ultrasonic relaxation studies of concentrated micellar solutions and lyotropic liquid crystals. found in the catalog.
Ultrasonic relaxation studies of concentrated micellar solutions and lyotropic liquid crystals.
Michael Francis Walsh
PhD thesis, Chemistry.
Finally, a couple of general books on the theory of diffusion and molecular transport in solution and complex fluids can be recommended Xis> 3. SCOPE OF THE PRESENT REVIEW Over the last ten years much attention has been devoted to the study of lipid membranes and lyotropic liquid crystals. Lyotropic liquid crystals are formed on the dissolution of most surfactants in water, and are more common than micellar solutions. Four major varieties of phase structures are known, these being hexagonal, lamellar, reversed hexagonal and cubic. The molecular arrangements within the .
Advances in Liquid Crystal Research and Applications, Volume 2 covers the proceedings of the Third Liquid Crystal Conference of the Socialist Countries. The book discusses several papers concerning the development and advancement of the research and application aspects of liquid crystals. Lyotropic liquid crystal phases of lithium perfluorinated fatty acid salts in aqueous solutions and molecular dynamics study of the lamellar phase. Journal of Fluorine Chemistry , , DOI: /em Natalia Hassan, Leandro R.S. Barbosa, Rosangela Itri, Juan M. Ruso.
COVID Resources. Reliable information about the coronavirus (COVID) is available from the World Health Organization (current situation, international travel).Numerous and frequently-updated resource results are available from this ’s WebJunction has pulled together information and resources to assist library staff as they consider how to handle coronavirus. Liquid crystals (LCs) are a state of matter which has properties between those of conventional liquids and those of solid instance, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many different types of liquid-crystal phases, which can be distinguished by their different optical properties (such as textures).
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Ultrasonic relaxation studies have been carried out on non-ionic, anionic and cationic surfactants in the micellar phase and in hexagonal and lamellar liquid crystal phases, over the frequency range 1– MHz. For all the surfactants, a relaxation process with similar absorption characteristics occurs in.
Ultrasonic relaxation measurements on a variety of surfactant solutions in the micellar and liquid crystalline phases show a relaxation process whose width is slightly broader than that expected for a single relaxation time, the origin of which is attributed to.
During the last 6 years, chemical relaxation studies of the kinetics of micelle formation in triblock copolymers such as L64 (EO13PO30EO13) and B40 (EO13BO10EO13) which behave as nonionic surfactants have been studied.
The micellar system is characterized by two well-defined relaxation times as predicted by Aniansson and Wall for the isodesmic model A1 + An-1 ⇌ An in Cited by: 7. This paper reports experimental results for the velocity and absorption of ultrasonic waves in the mesomorphic states of four cholesteric liquid crystals, namely, cholesteryl nonanoate, decanoate.
Reinsborough V.C. () Ultrasonic Pulse Spectroscopy in Micellar Solutions. In: Wyn-Jones E. (eds) Chemical and Biological Applications of Relaxation Spectrometry. NATO Advanced Study Institutes Series (Series C — Mathematical and Physical Sciences), vol Cited by: 1.
A lyotropic liquid crystalline system, the amphiphile n-octyl-amine and water, has been studied to investigate the dependence of velocity and absorption of ultrasound on the mechanisms of.
The alignment of lyotropic liquid crystals in a magnetic field has been studied by line shape analysis of the T-1 process and 2D H-2 double quantum filtered (DQF) NMR to investigate water dynamics. An investigation of chirality, twist and structures of micellar lyotropic cholesteric liquid crystals in comparison to the properties of chiralic thermotropic phases was presented.
The slow relaxation time (τ2) of SDS micelles, as measured by the pressure-jump technique, was in the range of 10−4 to s, depending on the surfactant concentration. A maximal relaxation time and thus a maximal micellar stability was found at mM SDS (5 s), corresponding to the least-foaming, largest bubble size, longest wetting time.
Control of Flow Properties in Surfactant Solutions via Photoreactions of Solubilizates Thomas Wolff Chap DOI: /bkch Publication Date (Print): December 9, Different methods are used to study the kinetics of such dynamic processes in micellar solutions and they usually involve relaxation techniques.
The most commonly used are stopped flow, temperature jump, pressure jump, ultrasonic relaxation, nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), etc. All those studies have revealed that two major relaxation processes exist in micellar dynamics.
They are simply ordered arrays of micelles in water. The liquid crystals occur above the concentration of the highest concentration micellar solution. Indeed, for some surfactants the micellar solution phase is absent and liquid crystals occur at the cmc. Lyotropic liquid crystals, built by amphiphilic molecules in presence of water, exhibit a very rich polymorphism: from crystalline structures with positional order along one, two or three dimensions to nematic structures with orientational order only and disordered concentrated micellar solutions.
Studies of Lyotropic Liquid Crystals that Align in Magnetic Fields. Fujiwara, L. Reeves, M. Suzuki, J. Vanin Ultrasonic Absorption Studies of Solutions of Ionic Amphiphiles in Organic Solvents. Zana. and one of its Sections was devoted to the topic of Solution Chemistry of Surfactants.
Although it was billed as the Section. The Letter presents an attempt to include the concentration dependence in the Landau–de Gennes theory for the nematic to isotropic phase transition for nematic lyotropic liquid crystals by.
Studies of Specific Adsorption Sites for Sodium Ion and Water on the Interface of Mixed Micelles of Novel Type II Lyomesophases. Molecular Crystals and Liquid Crystals53 (), DOI: / We here describe a first attempt of combining DNA origami nanostructures with a lyotropic chromonic liquid crystal (LCLC).
53, 54 In contrast to thermotropic liquid crystals, which are typically composed of rod‐like, hydrophobic organic molecules and are known for their electro‐optic application in flat panel displays, most lyotropic liquid.
Physicochemical Evaluation of Micellar Solution and Lyotropic Phases Formed by Self-Assembled Aggregates of Morpholinium Geminis. As the concentration of amphiphilic molecules is increased, several different type of lyotropic liquid crystal structures occur in solution.
Each of these different types has a different extent of molecular ordering within the solvent matrix, from spherical micelles to larger cylinders, aligned cylinders and even bilayered and multiwalled aggregates.
Studies of Lyotropic Liquid Crystals that Align in Magnetic Fields.- Use of Surfactant and Micellar Systems in Analytical Chemistry.- Micellar Systems Studied by Positron Annihilation Techniques.- Solubilization in Aqueous Micellar Systems.- Nonionic Surfactant Micelles and Mixed Micelles with Phospholipids.- Commercial Surfactants: An Overview.
Abstract. The main purpose of the ultrasonic absorption studies of micro-emulsions reported in this paper, as well as in a previous one (1) (referred to as Part I in the following) was to reach a better understanding of the dynamic properties of microemulsions.
Indeed, it has been put forward (2) that these properties may play an important role in determining the stability of microemulsions.This book gives a comprehensive description of the physical properties of lyotropic liquid crystals. Structural features, phase transitions and phase diagrams are discussed in detail.
The available experimental data on lyotropic mixtures is presented in the unifying context of the Landau theories.Formation of liquid crystals („lyotropic mesophases“) upon Pore structures can be seen as „cast“ of the micellar structure (Nanocasting) „The first account of a structurally Prediction of the shape of self-assembled structures in solution Common surfactants: v 0/l.