An experimental study of ion permeation in multicomponent ion systems as a function of membrane charge density

1991 ◽  
Vol 64 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Mitsuru Higa ◽  
Akihiko Tanioka ◽  
Keizo Miyasaka
Keyword(s):  
Experimental Study ◽  
Charge Density ◽  
Ion Permeation ◽  
Membrane Charge

Dynamics of charge density wave phase-slips in mesoscopic samples

2002 ◽  
Vol 12 (9) ◽  
pp. 165-168
Author(s):  
S. N. Artemenko
Keyword(s):  
Experimental Study ◽  
Theoretical Model ◽  
Charge Density ◽  
Qualitative Agreement ◽  
Charge Density Wave ◽  
Temporal Evolution ◽  
Density Wave ◽  
Thermal Fluctuations ◽  
Charge Density Wave Phase ◽  
Phase Slips

Theoretical model of current conversion from normal to collective current in mesoscopic samples of CDW conductors is presented. The current conversion is described in terms of phase slips (PS) induced by strain of the CDW and stimulated by thermal fluctuations. Kernels of PS situated near contacts are surrounded by long-range perturbations of the CDW phase. If spacing between contacts is shorter than decaying length of these perturbations then temporal evolution of PS at different contacts becomes correlated, and PS voltage decreases with spacing between the contacts decreasing. The results are in qualitative agreement with experimental study of current conversion in submicron NbSe3 wires.

scholarly journals Anomalous Thermo-osmotic Conversion Performance of Ionic Covalent-Organic-Framework Membranes in Response to Charge Variations

2022 ◽  
Author(s):  
Qi Sun ◽  
Weipeng Xian ◽  
Xiuhui Zuo ◽  
Changjia Zhu ◽  
Qing Guo ◽  
...  
Keyword(s):  
Charge Density ◽  
Energy Conversion ◽  
Energy Demand ◽  
High Performance ◽  
Critical Factor ◽  
Energy Conversion Efficiency ◽  
Nanoporous Membranes ◽  
Power Extraction ◽  
Membrane Charge ◽  
Salinity Difference

Abstract The development of efficient thermo-osmotic energy conversion devices has fascinated scientists and engineers for several decades in terms of satisfying the growing energy demand. The fabrication of ionic membranes with a high charge population is known to be a critical factor in the design of high-performance power generators for achieving high permselectivity and, consequently, high power extraction efficiency. Herein, we experimentally demonstrated that the thermo-osmotic energy conversion efficiency was improved by increasing the membrane charge density; however, this enhancement occurred only within a narrow window and subsequently exhibited a plateau over a threshold density. The complex interplay between pore−pore interactions and fluid structuration for ion transport across the upscaled nanoporous membranes helped explain the obtained results with the aid of numerical simulations. Consequently, the power generation efficiency of the multipore membrane deteriorated, deviating considerably from the case of simple linear extrapolation of the behavior of the single-pore counterparts. A plateau in the output electric power was observed at a moderate charge density, affording a value of 210 W m−2 at a 50-fold salinity difference with a temperature gradient of 40 K. This study has far-reaching implications for discerning an optimal range of membrane charge populations for augmenting the energy extraction, rather than intuitively focusing on achieving high densities.

Experimental study of X-ray charge density and the selection of reference points for a source function in η6-(2-methyl-1,4-dihydro-2H-3,1-benzoxazine)tricarbonylchromium(0)

2019 ◽  
Vol 29 (3) ◽  
pp. 346-348 ◽  
Author(s):  
Georgy K. Fukin ◽  
Anton V. Cherkasov ◽  
Roman V. Rumyantcev ◽  
Natalia Yu. Grishina ◽  
Elena V. Sazonova ◽  
...  
Keyword(s):  
Experimental Study ◽  
Charge Density ◽  
Source Function ◽  
Reference Points ◽  
X Ray ◽  
Selection Of

Enhanced Transfection Efficiency of Multicomponent Lipoplexes in the Regime of Optimal Membrane Charge Density

2008 ◽  
Vol 112 (36) ◽  
pp. 11298-11304 ◽  
Author(s):  
Giulio Caracciolo ◽  
Daniela Pozzi ◽  
Ruggero Caminiti ◽  
Cristina Marchini ◽  
Maura Montani ◽  
...  
Keyword(s):  
Charge Density ◽  
Transfection Efficiency ◽  
Membrane Charge

scholarly journals Zeta Potential, Effective Membrane Charge and Donnan Potential for TiO2 NF Ceramic Membrane

2018 ◽  
Vol 24 (9) ◽  
pp. 21 ◽  
Author(s):  
Ahmed Faiq Hassan Al-Alawy ◽  
Amer Naji Ahmed Al-Naemi ◽  
Mudhaffar Yacoub Hussein
Keyword(s):  
Zeta Potential ◽  
Charge Density ◽  
Surface Charge ◽  
Isoelectric Point ◽  
Pore Radius ◽  
Ceramic Membrane ◽  
Effective Thickness ◽  
Donnan Potential ◽  
Membrane Charge ◽  
Effective Pore Radius

Nanofiltration (NF) ceramic membrane have found increasing applications particularly in wastewater and water treatment. In order to estimate and optimize the performance of NF membranes, the membrane should be characterized correctly in terms of their basic parameters such as effective pore radius (rp) and equivalent effective thickness as well as effective surface charge ( ), the effective charge density ( ) and Donnan potential ( ). The impact of electrokinetic (zeta) potential on the membrane surface charge density, effective membrane charge density and Donnan potential at two different concentrations of the reference solutions 0.001, 0.01 M sodium chloride at various pH values from 3 to 9, and effective pore radius (rp) for nominal 0.9 nm  ceramic TiO2 NF membrane were evaluated. Experiments were conducted at cross flow (1.0 m/s) using Microelectrophoresis technique for measuring membrane zeta potential, effective pore radius, and Donnan steric pore model (DSPM). The TiO2 membrane isoelectric point (net membrane charge equals zero) was found at pH of 3.7, 3.5 for 0.001 and 0.01 M NaCl respectively. The results showed that the NF membrane zeta potential changes its sign from positive to negative after the isoelectric point. The evaluated effective pore radius was found to be equal to 0.56 nm by using (DSPM) and the membrane equivalent effective thickness equals to (2×10-6 m).  

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