scholarly journals On the Emergence of Electric Fields at the Water-C12E6 Surfactant Interface

2021 ◽  
Author(s):  
Rahul Gera ◽  
Huib Bakker ◽  
Ricardo Franklin ◽  
Uriel N. Morzan ◽  
Gabriele Falciani ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Md Simulations ◽  
Mutual Orientation ◽  
Kelvin Probe ◽  
Sum Frequency ◽  
Hydrogen Bond Strength ◽  
Air Interface ◽  
Harvesting Systems ◽  
Probe Measurements

We study the properties of the interface of water and the surfactant Hexaethylene Glycol Monododecyl Ether (C12E6)<br>with a combination of Heterodyne-Detected Vibrational Sum Frequency Generation (HD-VSFG), Kelvin-Probe measurements, and Molecular Dynamics (MD) simulations. We observe that the addition of C12E6 close to the critical micelle concentration (CMC), induces a drastic hydrogen bond strength enhancement of the water molecules close to the interface, as well as a flip in their net orientation. The mutual orientation of the water and C12E6 molecules, leads to the emergence of a broad (~ 3 nm) interface with a large electric field of ~ 1V/nm, as evidenced by the Kelvin-Probe measurements and MD simulations. Our findings may open the door for the design of novel electric-field tuned catalytic and light harvesting systems anchored at water-surfactant air interface. <br>

scholarly journals On the Emergence of Electric Fields at the Water-C12E6 Surfactant Interface

2021 ◽  
Author(s):  
Rahul Gera ◽  
Huib Bakker ◽  
Ricardo Franklin ◽  
Uriel N. Morzan ◽  
Gabriele Falciani ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Md Simulations ◽  
Mutual Orientation ◽  
Kelvin Probe ◽  
Sum Frequency ◽  
Hydrogen Bond Strength ◽  
Air Interface ◽  
Harvesting Systems ◽  
Probe Measurements

We study the properties of the interface of water and the surfactant Hexaethylene Glycol Monododecyl Ether (C12E6)<br>with a combination of Heterodyne-Detected Vibrational Sum Frequency Generation (HD-VSFG), Kelvin-Probe measurements, and Molecular Dynamics (MD) simulations. We observe that the addition of C12E6 close to the critical micelle concentration (CMC), induces a drastic hydrogen bond strength enhancement of the water molecules close to the interface, as well as a flip in their net orientation. The mutual orientation of the water and C12E6 molecules, leads to the emergence of a broad (~ 3 nm) interface with a large electric field of ~ 1V/nm, as evidenced by the Kelvin-Probe measurements and MD simulations. Our findings may open the door for the design of novel electric-field tuned catalytic and light harvesting systems anchored at water-surfactant air interface. <br>

scholarly journals Polyelectrolytes polarization in nonuniform electric fields

2014 ◽  
Vol 25 (12) ◽  
pp. 1441010 ◽  
Author(s):  
Farnoush Farahpour ◽  
Mohammad Reza Ejtehadi ◽  
Fathollah Varnik
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
External Electric Field ◽  
Electric Fields ◽  
Lattice Boltzmann ◽  
Driving Force ◽  
Equilibrium Configuration ◽  
Md Simulations ◽  
Extended Chain ◽  
Entropic Traps

Stretching dynamics of polymers in microfluidics is of particular interest for polymer scientists. As a charged polymer, a polyelectrolyte (PE) can be deformed from its coiled equilibrium configuration to an extended chain by applying uniform or nonuniform electric fields. By means of hybrid lattice Boltzmann (LB)-molecular dynamics (MD) simulations, we investigate how the condensed counterions (CIs) around the PE contribute to the polymer stretching in inhomogeneous fields. As an application, we discuss the translocation phenomena and entropic traps, when the driving force is an applied external electric field.

Formulas for the Analysis of the Surface SFG Spectrum and Transformation Coefficients of Cartesian SFG Tensor Components

1992 ◽  
Vol 46 (6) ◽  
pp. 1051-1072 ◽  
Author(s):  
Chiaki Hirose ◽  
Naotoshi Akamatsu ◽  
Kazunari Domen
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Molecular Orientation ◽  
Experimental Setup ◽  
Euler Angles ◽  
Surface Species ◽  
Nonlinear Source ◽  
Sum Frequency ◽  
Fixed Axis ◽  
Fresnel Coefficients

Comprehensive expressions have been presented to facilitate the analysis of the surface sum-frequency generation (SFG) spectrum. The electric field components of the SFG beam for a given experimental setup have been related via appropriately defined Fresnel coefficients to the nonlinear source polarization, which in turn has been related to the electric fields of exciting visible and infrared beams through the macroscopic SFG susceptibility tensor. The coefficients of transformation have been given to relate the laboratory-fixed Cartesian components of the SFG tensor to the components described in a surface-fixed axis system. The tensor components have been further related to the components of the microscopic hyperpolarizability tensor of surface species, and the explicit expressions (in terms of the Euler angles defining molecular orientation) of the transformation coefficients are presented to describe the Cartesian tensor components described in a surface-fixed axis system by the molecule-fixed components.

UNDERSTANDING ELECTRIC INTERACTIONS IN SUSPENSIONS IN GRADIENT AC ELECTRIC FIELDS II: SIMULATIONS AND APPLICATION EXPLORATION

2011 ◽  
Vol 25 (07) ◽  
pp. 927-933
Author(s):  
SHIGERU TADA ◽  
YAN SHEN ◽  
DAVID JACQMIN ◽  
BINGMEI FU ◽  
ZHIYONG QIU
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Particle Concentration ◽  
Corn Oil ◽  
Critical Concentration ◽  
Md Simulations ◽  
Continuous Model ◽  
Dynamics Model ◽  
Ac Electric Fields ◽  
Ac Electric Field

We used numerical simulations of a continuous model and the molecular dynamics model to understand the particle instability, formation of island-like structures and existence of one critical particle concentration of 1% (v/v) for formation of island-like structures in the suspension in a gradient AC electric field reported in Paper I. The simulations of the continuous model show that the critical concentration of 1% (v/v) is the concentration of which the particles of a suspension are just fully filling the lower field region finally. According to the MD simulations, the particles instability does exist in the corn oil in a gradient AC electric field, anisotropic polarization interactions among the particles are responsible for the particle instability and have memory, and the memory is still kept even when the particles are transported by a dielectrophoresis force. The island-like structures can be regarded as signature of the memory. We explored possibilities to apply our findings in biomedical fields.

Temperature Dependence of the Air/Water Interface Revealed by Polarization Sensitive Sum-Frequency Generation Spectroscopy

2018 ◽  
Author(s):  
Daniel R. Moberg ◽  
Shelby C. Straight ◽  
Francesco Paesani
Keyword(s):  
Temperature Dependence ◽  
Low Frequency ◽  
Potential Energy Function ◽  
Md Simulations ◽  
Sum Frequency Generation ◽  
Water Molecules ◽  
Water Interface ◽  
Sum Frequency ◽  
Air Water Interface ◽  
Frequency Generation

<div> <div> <div> <p>The temperature dependence of the vibrational sum-frequency generation (vSFG) spectra of the the air/water interface is investigated using many-body molecular dynamics (MB-MD) simulations performed with the MB-pol potential energy function. The total vSFG spectra calculated for different polarization combinations are then analyzed in terms of molecular auto-correlation and cross-correlation contributions. To provide molecular-level insights into interfacial hydrogen-bonding topologies, which give rise to specific spectroscopic features, the vSFG spectra are further investigated by separating contributions associated with water molecules donating 0, 1, or 2 hydrogen bonds to neighboring water molecules. This analysis suggests that the low frequency shoulder of the free OH peak which appears at ∼3600 cm−1 is primarily due to intermolecular couplings between both singly and doubly hydrogen-bonded molecules. </p> </div> </div> </div>

Tuning the Electric Field Response of MOFs by Rotatable Dipolar Linkers

2019 ◽  
Author(s):  
Johannes P. Dürholt ◽  
Babak Farhadi Jahromi ◽  
Rochus Schmid
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Structural Changes ◽  
Dielectric Behavior ◽  
Two Dimensions ◽  
Dielectric Constants ◽  
Electric Response ◽  
Dipole Strength ◽  
Metal Organic ◽  
Dynamics Simulations

Recently the possibility of using electric fields as a further stimulus to trigger structural changes in metal-organic frameworks (MOFs) has been investigated. In general, rotatable groups or other types of mechanical motion can be driven by electric fields. In this study we demonstrate how the electric response of MOFs can be tuned by adding rotatable dipolar linkers, generating a material that exhibits paralectric behavior in two dimensions and dielectric behavior in one dimension. The suitability of four different methods to compute the relative permittivity κ by means of molecular dynamics simulations was validated. The dependency of the permittivity on temperature T and dipole strength μ was determined. It was found that the herein investigated systems exhibit a high degree of tunability and substantially larger dielectric constants as expected for MOFs in general. The temperature dependency of κ obeys the Curie-Weiss law. In addition, the influence of dipolar linkers on the electric field induced breathing behavior was investigated. With increasing dipole moment, lower field strength are required to trigger the contraction. These investigations set the stage for an application of such systems as dielectric sensors, order-disorder ferroelectrics or any scenario where movable dipolar fragments respond to external electric fields.

scholarly journals Meta-Deflectors Made of Dielectric Nanohole Arrays with Anti-Damage Potential

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 107
Author(s):  
Haichao Yu ◽  
Feng Tang ◽  
Jingjun Wu ◽  
Zao Yi ◽  
Xin Ye ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Laser Cutting ◽  
High Complexity ◽  
Damage Potential ◽  
Optical Components ◽  
Nanohole Arrays ◽  
Intense Light ◽  
Polarization Of Light ◽  
Air Hole

In intense-light systems, the traditional discrete optical components lead to high complexity and high cost. Metasurfaces, which have received increasing attention due to the ability to locally manipulate the amplitude, phase, and polarization of light, are promising for addressing this issue. In the study, a metasurface-based reflective deflector is investigated which is composed of silicon nanohole arrays that confine the strongest electric field in the air zone. Subsequently, the in-air electric field does not interact with the silicon material directly, attenuating the optothermal effect that causes laser damage. The highest reflectance of nanoholes can be above 99% while the strongest electric fields are tuned into the air zone. One presentative deflector is designed based on these nanoholes with in-air-hole field confinement and anti-damage potential. The 1st order of the meta-deflector has the highest reflectance of 55.74%, and the reflectance sum of all the orders of the meta-deflector is 92.38%. The optothermal simulations show that the meta-deflector can theoretically handle a maximum laser density of 0.24 W/µm2. The study provides an approach to improving the anti-damage property of the reflective phase-control metasurfaces for intense-light systems, which can be exploited in many applications, such as laser scalpels, laser cutting devices, etc.

scholarly journals Integrating flexible electronics for pulsed electric field delivery in a vascularized 3D glioblastoma model

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Marie C. Lefevre ◽  
Gerwin Dijk ◽  
Attila Kaszas ◽  
Martin Baca ◽  
David Moreau ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Flexible Electronics ◽  
Soft Tissues ◽  
Multiphoton Microscopy ◽  
Membrane Integrity ◽  
Tumor Model ◽  
Pulsed Electric Fields ◽  
In Ovo ◽  
Cell Membrane Integrity

AbstractGlioblastoma is a highly aggressive brain tumor, very invasive and thus difficult to eradicate with standard oncology therapies. Bioelectric treatments based on pulsed electric fields have proven to be a successful method to treat cancerous tissues. However, they rely on stiff electrodes, which cause acute and chronic injuries, especially in soft tissues like the brain. Here we demonstrate the feasibility of delivering pulsed electric fields with flexible electronics using an in ovo vascularized tumor model. We show with fluorescence widefield and multiphoton microscopy that pulsed electric fields induce vasoconstriction of blood vessels and evoke calcium signals in vascularized glioblastoma spheroids stably expressing a genetically encoded fluorescence reporter. Simulations of the electric field delivery are compared with the measured influence of electric field effects on cell membrane integrity in exposed tumor cells. Our results confirm the feasibility of flexible electronics as a means of delivering intense pulsed electric fields to tumors in an intravital 3D vascularized model of human glioblastoma.

scholarly journals Electro-Optic Control of Lithium Niobate Bulk Whispering Gallery Resonators: Analysis of the Distribution of Externally Applied Electric Fields

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 298
Author(s):  
Yannick Minet ◽  
Hans Zappe ◽  
Ingo Breunig ◽  
Karsten Buse
Keyword(s):  
Lithium Niobate ◽  
Electric Field ◽  
Electric Fields ◽  
Frequency Comb ◽  
Parametric Oscillation ◽  
Pockels Effect ◽  
Optical Mode ◽  
Cylindrical Resonator ◽  
Whispering Gallery ◽  
Electro Optic

Whispering gallery resonators made out of lithium niobate allow for optical parametric oscillation and frequency comb generation employing the outstanding second-order nonlinear-optical properties of this material. An important knob to tune and control these processes is, e.g., the linear electro-optic effect, the Pockels effect via externally applied electric fields. Due to the shape of the resonators a precise prediction of the electric field strength that affects the optical mode is non-trivial. Here, we study the average strength of the electric field in z-direction in the region of the optical mode for different configurations and geometries of lithium niobate whispering gallery resonators with the help of the finite element method. We find that in some configurations almost 100% is present in the cavity compared to the ideal case of a cylindrical resonator. Even in the case of a few-mode resonator with a very thin rim we find a strength of 90%. Our results give useful design considerations for future arrangements that may benefit from the strong electro-optic effect in bulk whispering gallery resonators made out of lithium niobate.

Sign in / Sign up

Export Citation Format

Share Document