Interfacial Dipole
Mostrando 1-12 de 13 artigos, teses e dissertações.
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1. The influence of ethoxylation degree in the behaviour of secondary alcohol ethoxylates / Influência do grau de etoxilação no comportamento de álcoois secunários etoxilados
The solubilization of non-ionic solutes via partitioning between water and the micellar pseudophase of non-ionic surfactants was evaluated for a series of secondary alcohol ethoxylates with hydrophile length varying from 7 to 40 ethylene oxide units. It was demonstrated that the micellar incorporation constant, Ks, is not dependent on the hydrophile length o
Publicado em: 2009
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2. Interfacial phenomena at the compressed co2-water interface
Compressed CO2 is considered to be a viable alternative to toxic volatile organic solvents with potential applications in areas including separation reactions, and materials formation processes. Thus an interest in CO2 stems from the fact that it is very inexpensive, has low toxicity, and is not a regulated. However, compressed CO2 has a zero dipole moment a
Brazilian Journal of Chemical Engineering. Publicado em: 2006-06
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3. Ligação e troca iônica em interfaces zwitteriônicas / Ion Binding and Exchange in zwitterionic interfaces
The effect of ionic domains of formally neutral zwitterionic interfaces, represented by micelles and vesicles obtained with dipolar headgroups amphiphiles, on the binding and exchange of ionic species were investigated. The systems studied included: aqueous micelles of 1-(N-hexadecyl-N,N-dimethylammonio) Propane Sulfonate (HPS), Hexadecyl Phosphoryl Choline
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/07/1992
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4. Magnitude of the solvation pressure depends on dipole potential.
As polar surfaces in solvent are brought together, they experience a large repulsive interaction, termed the solvation pressure. The solvation pressure between rough surfaces, such as lipid bilayers, has been shown previously to decay exponentially with distance between surfaces. In this paper, we compare measured values of the solvation pressure between bil
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5. Detection of chiral sum frequency generation vibrational spectra of proteins and peptides at interfaces in situ
In this work, we demonstrate the feasibility to collect off-electronic resonance chiral sum frequency generation (SFG) vibrational spectra from interfacial proteins and peptides at the solid/liquid interface in situ. It is difficult to directly detect a chiral SFG vibrational spectrum from interfacial fibrinogen molecules. By adopting an interference enhance
National Academy of Sciences.
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6. A helical-dipole model describes the single-channel current rectification of an uncharged peptide ion channel.
We are designing simple peptide ion channels as model systems for the study of the physical principles controlling conduction through ion-channel proteins. Here we report on an uncharged peptide, Ac-(Leu-Ser-Ser-Leu-Leu-Ser-Leu)3-CONH2, designed to form an aggregate of parallel, amphiphilic, membrane-spanning alpha-helices around a central water-filled pore.
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7. Electrostatics and electrodynamics of bacteriorhodopsin.
The stationary electric dichroism of bacteriorhodopsin is in qualitative, but not quantitative, agreement with the orientation function for disks having a permanent dipole directed perpendicular to the plane and an induced dipole in the plane. Fits of the orientation function to data measured at low field strengths demonstrate: an increase of the permanent d
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8. Internal and interfacial dielectric properties of cytochrome c from molecular dynamics in aqueous solution.
The dielectric properties of proteins are central to their stability and activity. We use the Fröhlich-Kirkwood theory of dielectrics to analyze two 1-ns molecular dynamics simulations of ferro- and ferricytochrome c in spherical droplets of 1400 water molecules. Protein and solvent are idealized as a series of concentric, spherical, dielectric media. Analy
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9. Properties of water along the liquid-vapor coexistence curve via molecular dynamics simulations using the polarizable TIP4P-QDP-LJ water model
We present an extension of the TIP4P-QDP model, TIP4P-QDP-LJ, that is designed to couple changes in repulsive and dispersive nonbond interactions to changes in polarizability. Polarizability is intimately related to the dispersion component of classical force field models of interactions, and we explore the effect of incorporating this connection explicitly
American Institute of Physics.
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10. The redox properties of cytochromes b imposed by the membrane electrostatic environment.
The effect of the dipole potential field of extended membrane spanning alpha-helices on the redox potentials of b cytochromes in energy transducing membranes has been calculated in the context of a three phase model for the membrane. In this model, the membrane contains three dielectric layers; (i) a 40-A hydrophobic membrane bilayer, with dielectric constan
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11. Preferential partitioning of melittin into the air/water interface: structural and thermodynamic implications.
The membrane active agent melittin has been investigated with regard to the formation of a Langmuir monolayer and the accordingly induced surface activities. We show that in spite of its considerable solubility in an aqueous medium, this peptide nevertheless largely accumulates in the air/water interface unless the lateral pressure is raised beyond a certain
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12. Incorporation of surface tension into molecular dynamics simulation of an interface: a fluid phase lipid bilayer membrane.
In this paper we report on the molecular dynamics simulation of a fluid phase hydrated dimyristoylphosphatidylcholine bilayer. The initial configuration of the lipid was the x-ray crystal structure. A distinctive feature of this simulation is that, upon heating the system, the fluid phase emerged from parameters, initial conditions, and boundary conditions d