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Surfactant Interaction (surfactant + interaction)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Cyclic Enones as Substrates in the Morita,Baylis,Hillman Reaction: Surfactant Interactions, Scope and Scalability with an Emphasis on Formaldehyde

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7-8 2009
Brett
Abstract Traditionally, cyclic enones and formalin are reactants notorious for displaying problematic behaviour (i.e., poor solubility and low yields) under Morita,Baylis,Hillman (MBH) reaction conditions. The body of research presented herein focuses on the use of surfactants in water as a solvent medium that offers a resolution to many of the issues associated with the MBH reaction. Reaction scope, scalability and small angle X-ray scattering have been studied to assist with the understanding of the reaction mechanism and industrial application. A comparison against known literature methods for reaction scale-up is also discussed. [source]

Humic acid,cetyltrimethylammonium bromide interaction: a fluorimetric study

LUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 2 2009
Deepa Subbiah
Abstract Synchronous and excitation emission matrix fluorescence (EEMF) characteristics of humic acid,surfactant interaction have been studied. The variation of synchronous and EEMF spectral maxima and intensities with humic acid (HA),cetyltrimethylammonium bromide (CTAB) composition sensitively reflects the extent of flocculation of HA. It was found that the concentration range for co-precipitation of HA,CTAB was similar for all concentrations (60 p.p.m., 80 p.p.m. and 100 p.p.m.) of humic acid studied. In the concentration range 60,150 p.p.m. of humic acid, the EEMF maximum is found at 460/540 nm, indicating the presence of ligneous materials. Fluorescence intensity measurement at this contour excitation/emission wavelength (460/540 nm) is suggested as a convenient and a sensitive method for studying the physical state of humic acid in the presence of cationic surfactants. No significant interaction of HA with sodium dodecylsulphate (SDS) and TX-100 was found. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Interaction between aqueous solutions of polymer and surfactant and its effect on physicochemical properties

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2008
Mohammad Yunus Khan
Abstract Interaction between water-soluble polymers and anionic surfactants has been studied by surface tension and conductivity measurements. Sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) were used as surfactant while polyacrylamide (PAA), commercial grade partially hydrolyzed polyacrylamide (PHPA), and xanthan gum were used as water-soluble polymers for the present study. The behavior of surfactant,polymer interaction was found to be dependent on both surfactant and polymer concentrations. After the critical aggregation concentration (CAC), interaction between the water-soluble polymer and surfactants was started and above the polymer saturation point (PSP) polymer was saturated by surfactant with no further change of surface tension and conductivity of the solution. It has also been found that alkali (NaOH) and salts (Na2CO3, NaCl) have significant influence on the polymer,surfactant interaction. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

The role of surfactants in the reversal of active transport mediated by multidrug resistance proteins

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2003
Katrijn Bogman
Abstract A variety of seven nonionic, one amphoteric and, one anionic surfactant that are applied or investigated as surfactants in drug formulation, were analyzed for their capacity to modulate carrier-mediated transport by efflux pumps. Two cell lines, murine monocytic leukemia cells overexpressing P-glycoprotein (P-gp) and Madin-Darby canine kidney cells stably overexpresssing human multidrug resistance-associated protein 2 (MRP2), were used as test systems. The modulation of P-gp and of MRP2 function was studied by the reversal of rhodamine 123 and of methylfluorescein-glutathione conjugate transport, respectively. Mechanisms that were not transporter related and could lead to misinterpretations were identified, such as probe quenching, probe encapsulation by micelles, and membrane damage. P-gp-mediated rhodamine 123 transport was inhibited by five nonionic surfactants in a concentration-dependent manner and in the order TPGS,>,Pluronic PE8100,>,Cremophor EL,>,Pluronic PE6100,,,Tween 80. In contrast, none of the surfactants showed a significant inhibition of MRP2-mediated efflux in Madin-Darby canine kidney/MRP2 cells. In conclusion, the results indicate that surfactants demonstrate a transporter-specific interaction, rather than unspecific membrane permeabilization. The present analysis offers insight in the possible mechanisms of surfactant interactions with biological membranes and could help to identify specific drug formulations. © 2003 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 92:1250,1261, 2003 [source]

Lipid,nucleic acids interactions as base for organization and expression of cellular genome

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 1 2010
V. V. Kuvichkin
Abstract Although lipid,nucleic acid interactions have been studied, with certain or little progress, for more than 30 years, it is only in recent years that the problem has received particular attention. It should, however, be noted that most studies deal with DNA-cationic surfactants interactions, whereas DNA-zwitterionic interactions, which are more complex and close to nature, are poorly investigated. The long-standing studies of the triple complexes: DNA,phosphatidylcholine liposomes,divalent metal cations allow us to confirm that these complexes are responsible for the formation of not only the structures existing in DNA,cationic liposome complexes but also some other cellular structures. The author proposed hypothesis about the involvement of direct DNA,lipid interactions in the nuclear pore assembly. Only taking into account interactions between DNA and lipids of cellular membrane, one can explain the origin of such structures as nucleoid, nuclear pore, and nuclear matrix. The formation of triple complexes was accompanied by the aggregation and partial fusion of liposomes as was shown by cryo-TEM technique. The author has presented new data on the structure of triple complexes, which were obtained by phase contrast cryo-TEM. Biophysical data on the liposomes fusion during triple complex formation and perspective of their computer simulation are also presented. DNA acts as a fusogen in this process and it unwinds in the region of liposomes fusion. The nuclear envelope and pore complexes assembly is provided by membrane vesicles fusion. Author has proposed that the DNA-induced fusion of zwitterionic liposomes in vitro may suggest the involvement of direct lipids,DNA interaction in nuclear envelope assembly. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 [source]