scholarly journals The Electrostatic Screening Length in Concentrated Electrolytes Increases with Concentration

2016 ◽  
Vol 7 (12) ◽  
pp. 2157-2163 ◽  
Author(s):  
Alexander M. Smith ◽  
Alpha A. Lee ◽  
Susan Perkin
Keyword(s):  
Screening Length ◽  
Concentrated Electrolytes

scholarly journals Screening length for finite-size ions in concentrated electrolytes

2019 ◽  
Vol 100 (4) ◽  
Author(s):  
Ram M. Adar ◽  
Samuel A. Safran ◽  
Haim Diamant ◽  
David Andelman
Keyword(s):  
Finite Size ◽  
Screening Length ◽  
Concentrated Electrolytes

scholarly journals Underscreening in concentrated electrolytes

2017 ◽  
Vol 199 ◽  
pp. 239-259 ◽  
Author(s):  
Alpha A. Lee ◽  
Carla S. Perez-Martinez ◽  
Alexander M. Smith ◽  
Susan Perkin
Keyword(s):  
Interaction Energy ◽  
Surface Force ◽  
Differential Capacitance ◽  
Conventional Wisdom ◽  
Ion Concentration ◽  
Decay Length ◽  
Force Measurements ◽  
Screening Length ◽  
Concentrated Electrolytes ◽  
Bjerrum Length

Screening of a surface charge by an electrolyte and the resulting interaction energy between charged objects is of fundamental importance in scenarios from bio-molecular interactions to energy storage. The conventional wisdom is that the interaction energy decays exponentially with object separation and the decay length is a decreasing function of ion concentration; the interaction is thus negligible in a concentrated electrolyte. Contrary to this conventional wisdom, we have shown by surface force measurements that the decay length is an increasing function of ion concentration and Bjerrum length for concentrated electrolytes. In this paper we report surface force measurements to test directly the scaling of the screening length with Bjerrum length. Furthermore, we identify a relationship between the concentration dependence of this screening length and empirical measurements of activity coefficient and differential capacitance. The dependence of the screening length on the ion concentration and the Bjerrum length can be explained by a simple scaling conjecture based on the physical intuition that solvent molecules, rather than ions, are charge carriers in a concentrated electrolyte.

scholarly journals Scaling Analysis of the Screening Length in Concentrated Electrolytes

2017 ◽  
Vol 119 (2) ◽  
Author(s):  
Alpha A. Lee ◽  
Carla S. Perez-Martinez ◽  
Alexander M. Smith ◽  
Susan Perkin
Keyword(s):  
Scaling Analysis ◽  
Screening Length ◽  
Concentrated Electrolytes

Information and Dose in the Scanning Transmission Ion Microscope

1980 ◽  
Vol 38 ◽  
pp. 232-233
Author(s):  
Fox T. R. ◽  
R. Levi-Setti
Keyword(s):  
Information Retrieval ◽  
Electron Microscope ◽  
Elastic Scattering ◽  
Energy Loss ◽  
Cross Sections ◽  
Previous Analysis ◽  
Single Scattering ◽  
Screening Length ◽  
Relative Damage ◽  
Scanning Transmission

At an earlier meeting [1], we discussed information retrieval in the scanning transmission ion microscope (STIM) compared with the electron microscope at the same energy. We treated elastic scattering contrast, using total elastic cross sections; relative damage was estimated from energy loss data. This treatment is valid for “thin” specimens, where the incident particles suffer only single scattering. Since proton cross sections exceed electron cross sections, a given specimen (e.g., 1 μg/cm2 of carbon at 25 keV) may be thin for electrons but “thick” for protons. Therefore, we now extend our previous analysis to include multiple scattering. Our proton results are based on the calculations of Sigmund and Winterbon [2], for 25 keV protons on carbon, using a Thomas-Fermi screened potential with a screening length of 0.0226 nm. The electron results are from Crewe and Groves [3] at 30 keV.

Solid Polymer Electrolytes from Crosslinked PEG and Dilithium N,N'-Bis(trifluoromethanesulfonyl)perfluoroalkane-1,ω-disulfonamide and Lithium Bis(trifluoromethanesulfonyl)imide Salts

2008 ◽  
Vol 73 (12) ◽  
pp. 1777-1798 ◽  
Author(s):  
Olt E. Geiculescu ◽  
Rama V. Rajagopal ◽  
Emilia C. Mladin ◽  
Stephen E. Creager ◽  
Darryl D. Desmarteau
Keyword(s):  
Ionic Conductivity ◽  
Polymer Electrolytes ◽  
Minimum Energy ◽  
Ionic Conductivities ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer ◽  
Segmental Motion ◽  
Concentrated Electrolytes ◽  
Two Factors ◽  
Poly Ethylene

The present work consists of a series of studies with regard to the structure and charge transport in solid polymer electrolytes (SPE) prepared using various new bis(trifluoromethanesulfonyl)imide (TFSI)-based dianionic dilithium salts in crosslinked low-molecular-weight poly(ethylene glycol). Some of the thermal properties (glass transition temperature, differential molar heat capacity) and ionic conductivities were determined for both diluted (EO/Li = 30:1) and concentrated (EO/Li = 10:1) SPEs. Trends in ionic conductivity of the new SPEs with respect to anion structure revealed that while for the dilute electrolytes ionic conductivity is generally rising with increased length of the perfluoroalkylene linking group in the dianions, for the concentrated electrolytes the trend is reversed with respect to dianion length. This behavior could be the result of a combination of two factors: on one hand a decrease in dianion basicity that results in diminished ion pairing and an enhancement in the number of charge carriers with increasing fluorine anion content, thereby increasing ionic conductivity while on the other hand the increasing anion size and concentration produce an increase in the friction/entanglements of the polymeric segments which lowers even more the reduced segmental motion of the crosslinked polymer and decrease the dianion contribution to the overall ionic conductivity. DFT modeling of the same TFSI-based dianionic dilithium salts reveals that the reason for the trend observed is due to the variation in ion dissociation enthalpy, derived from minimum-energy structures, with respect to perfluoroalkylene chain length.

Deep Impurities with Collision Delay

2018 ◽  
Author(s):  
Klaus Morawetz
Keyword(s):  
Wave Function ◽  
Kinetic Equation ◽  
Elastic Scattering ◽  
Response Function ◽  
Plasma Oscillation ◽  
Impurity Scattering ◽  
Fermi Momentum ◽  
Screening Length ◽  
Plasma Mode ◽  
Dissipative Mechanism

The linearised nonlocal kinetic equation is solved analytically for impurity scattering. The resulting response function provides the conductivity, plasma oscillation and Fermi momentum. It is found that virial corrections nearly compensate the wave-function renormalizations rendering the conductivity and plasma mode unchanged. Due to the appearance of the correlated density, the Luttinger theorem does not hold and the screening length is influenced. Explicit results are given for a typical semiconductor. Elastic scattering of electrons by impurities is the simplest but still very interesting dissipative mechanism in semiconductors. Its simplicity follows from the absence of the impurity dynamics, so that individual collisions are described by the motion of an electron in a fixed potential.

scholarly journals On the Appearance of a Cooper Minimum in the Photoionization Cross Sections of the Plasma-Embedded Li Atom

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Satyabrata Sahoo ◽  
Y. K. Ho
Keyword(s):  
Cross Sections ◽  
Ground State ◽  
Debye Screening Length ◽  
Debye Screening ◽  
Screening Length ◽  
Screening Effect ◽  
Plasma Environment ◽  
Plasma Screening ◽  
Debye Plasma

The plasma screening effect is found to uncover a Cooper minimum in the photoionization cross sections from the ground state of the Li atom embedded in Debye plasma environment. The variation of the location of this minimum with Debye screening length is discussed and analyzed in terms of the instability of the ground state.

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