scholarly journals Preparation of Surfactant-free Polystyrene Latices with High Surface Charge and Electrical Double Layer on Their Surfaces

1982 ◽  
Vol 55 (1) ◽  
pp. 48-51 ◽  
Author(s):  
Kunio Furusawa
Keyword(s):  
Surface Charge ◽  
Double Layer ◽  
Electrical Double Layer ◽  
High Surface

A laboratory investigation of the thermoelectric effect

Geophysics ◽  
2016 ◽  
Vol 81 (4) ◽  
pp. E243-E257 ◽  
Author(s):  
A. Revil ◽  
C. D. Meyer ◽  
Q. Niu
Keyword(s):  
Seebeck Coefficient ◽  
Double Layer ◽  
Electrical Double Layer ◽  
High Surface ◽  
Surface Conductivity ◽  
Berea Sandstone ◽  
Mobile Ions ◽  
Intermediate Surface ◽  
Self Potential ◽  
Layer Coating

One contribution to self-potential signals is the thermoelectric coupling associated with a temperature gradient in a porous material, which causes mobile ions to diffuse from hot to cold regions. We have developed 35 laboratory experiments to measure the value of the Seebeck coefficient in two clean (silica) sands and two clayey sandstones fully saturated by NaCl solutions to explore the influence of salinity upon the Seebeck coefficient over four orders of magnitude in salinity. The two sands are characterized by two distinct grain sizes (coarse and medium) and therefore two low values of surface conductivity. Portland sandstone, rich in illite and kaolinite, is characterized by a high surface conductivity, and the Berea sandstone is characterized by an intermediate surface conductivity. The Seebeck coefficient of the sands ranges from [Formula: see text] (at intermediate salinities) to [Formula: see text] at very low salinities, for which surface conductivity, associated with electromigration and electrodiffusion in the electrical double layer, dominates. For the Portland sandstone, the Seebeck coefficient is positive in the range [Formula: see text] to [Formula: see text] and decreases with the increase of the salinity. A similar trend is observed for the Berea sandstone with the Seebeck coefficient going from positive to negative values at high salinity. Our experimental data can be fairly reproduced by a simple model accounting for the effect of surface conductivity due to the electrical double layer coating the surface of the grains and the dependence on salinity of the partial entropies of the ions in the pore water.

on the relationship between the electric double layer and actuation in ionomeric polymer transducers

2004 ◽  
Vol 855 ◽  
Author(s):  
Barbar J. Akle ◽  
Donald J. Leo
Keyword(s):  
Surface Charge ◽  
Double Layer ◽  
Electric Double Layer ◽  
High Surface ◽  
High Surface Area ◽  
Strongly Correlated ◽  
Charge Accumulation ◽  
Ionic Polymer ◽  
Positive Ions ◽  
Soft Actuators

ABSTRACTIonic polymer transducers are soft actuators that perform large bending deflections when voltages on the order of 1–5 V are applied across their thickness. Previous work showed that actuation performance of ionic polymer transducers is strongly correlated with the capacitance due to surface charge accumulation. Increasing the capacitance of the actuator increases the motion of the charges and increases the strain produced under the application of an electric field. Ionomeric transducers consist of an ionomer, such as Nafion (a product of DuPont), sandwiched between two high surface area electrodes. An electric double layer is formed on the interface between the cathode and the adsorbed positive ions. A novel plating technique which was previously developed is used to vary the morphology of the polymer-electrode interface to investigate the parameters of importance to the formation of the electric double layer. Electromechanical transducer tests are performed as a function of electrode morphology to correlate surface charge accumulation with the deflection generated by the transducer.

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