Papers by Keyword: Electric Double Layer

Abstract: The improved oil recovery (IOR) is a way of enhancing the reservoir properties with the use of nanomaterials to detach the oil molecule from the trapped zone. The polarization effect on reservoir sandstone under an electric double layer is one of the major research interests. The nanoparticles agglomeration such as graphene nanofluid due to poor dispersion in reservoir zone can be a major challenge that can lead to low reservoir permeability are well elucidated. This study investigated the influence of graphene nanofluid on the ionic polarization under an electric double layer in reservoir sandstone. Saturated Berea sandstone was used to investigate the interaction of ionic species on reservoir sandstone with the aid of Field-emission microscopy (FESEM), Energy dispersive X-ray mapping (EDX), Fourier Transform Infrared Spectroscopy (FTIR), Raman spectral analysis, and Core flooding experiment. This research gives information on the adsorption of ions within an electric double layer and its polarization mechanisms. It was revealed from the experimental result that ionic polarization occurs at 9.97 GHz with a 5.8nm wavelength shift which improves the mobility of the reservoir and in turn increases oil recovery factors. Graphene nanoparticles show a positive effect on both reservoir oil viscosity and stabilization characteristics of drilling fluids, wettability alteration, interfacial tension, and improving the emulsion Keywords: Nanomaterials, Sandstone, Electric double layer, Graphene

Abstract: The analysis of literature and own research have showed that there are several important processes in metal pieces coated with plastic cover, which have significant influence on the strength of fatigue. Those processes are caused by generation of electricity in double layer (EDL), affecting the electrode potential shift in positive direction. The increased adhesion forces on the metal substrate is the another factor, which translates into increased strength of fatigue. An equally important issue that could have a significant impact on the growth of strength of fatigue is the penetration of hydrogen into the metal. This phenomenon has been known for a long time, but the mechanism associated with this issue still represents an unexplored area. The aim of this paper is to introduce this mechanism basing mainly on a theoretical analysis of this phenomenon and some selected own research.

Abstract: The microminiaturization of semiconductor devices has made it necessary to control the wet etching process on the nanometer order. It is therefore extremely important to understand wet etching reactions in the nanoscale region of solid-liquid interfaces, in order to assist in optimizing process conditions to satisfy the severe demand for semiconductor devices. Simulations performed to analyze the behavior of liquid molecules in the nanoscale region have been reported ^[1], but there have been few reports of detailed experimental results. We here report detailed experimental results on the wet etching behavior of SiO₂ film in the nanoscale region between Si materials.

Abstract: This paper presents a total nitrogen (TN) detection system based on electrochemical measurement. This system integrates a three-electrode system and a specially designed detection circuit. The dynamic response characteristic of the three-electrode system during TN electrochemical determination process was studied. The equivalent circuit of the three-electrode system was used to analyze factors of interference and signal instability. Through theoretical derivations and experimental proof, a time-domain model of signal response was established and two main factors, electric double layer capacitor and holding time, were put forward. Smooth and steady signal was achieved by optimizing these two main factors. Water sample of Taihu Lake was detected by this developed TN detection system with acceptable accuracy.

Abstract: In this study, strontium titanate (SrTiO₃, ST) nanocube particles were successfully prepared, with a size of 12 nm, normal size distribution with standard deviation of 10 %, and sharp edge corner, by solvothermal method using complex titanium raw materials of TiO₂ and titanium isoproxide. Moreover, the well-dispersed ST nanocube slurry was also prepared using electric double layer with hydrochloric acid. Finally, using the ST nanocube slurry, ST nanocube accumulation was prepared by two kinds of forces of capillary force and absorption force by plaster. The obtained ST nanocube accumulation was not 3-dimentional aliened ST nanocube structure, but randomly piled structure.

Abstract: An analytical solution for pressure-driven electrokinetic flows in a narrow capillary is presented based on the Poisson–Boltzmann equation for electrical double layer and the Navier–Stokes equations for incompressible viscous fluid. The analytical solutions indicate that pressure-driven flow of an electrolyte solution in microchannel with charged solid wall induces a streaming potential, which is proportional to the flowrate and induces an electroviscous effect on flow. A device for measuring the electrokinetic flow rate and streaming potential is proposed.

Abstract: The electrical model of a capacitive soil moisture sensor is considered in this paper. In the new model established, the contact resistor and contact capacitance are taken into account. It is pointed out that the electric double layer causes the formation of the contact resistor and contact capacitance. The electrical properties of the electric double layer are the effect of both physical electricity and electrochemistry, so the relationship between the contact capacitance and the soil relative permittivity does not follow the formula of the parallel plate capacitor. Based upon the diffuse electric double layer model, this paper successfully derives the formula of the contact capacitor , whose coefficients are determined by MATLAB simulation based on experimental data, and the soil relative permittivity. Besides, this paper has established the sensor-output-voltage-Vo -soil-moisture-θ curve and compared it to that derived from the model without considering the electric double layer. It is demonstrated that the correlation coefficient between the curve derived from the model this paper established and the experimental data is 0.9997, more accurately describing the relation between the sensor output voltage Vo and soil moisture θ.

Abstract: In order to reduce the conductivity of power-station’s circulating cooling water and reduce sewage discharge, this essay does research on using electro sorption technology to replace traditional water treatment technology. Through exploring the voltage and flow of the working module from experiment, it determined the optimum working conditions for electro sorption. The experiment includes the efficiency of reducing inlet water conductivity at different voltages, and the effect of flow rate to the treatment, proving that water conductivity will drop from 3,000 to 700 μS/cm on the condition of 1.7 V voltage and 500 L/h flow rate, which makes great sense to Electro sorption industrial applications.

Abstract: In this paper, the pure squeeze thin film elastohydrodynamic lubrication (TFEHL) motion of circular contacts with electric double layer (EDL) is explored under constant load condition. The coupled transient modified Reynolds, elasticity deformation, the load balance, and lubricant rheology equations were solved simultaneously by using the finite difference method and the Gauss-Seidel iteration method. The simulation results reveal that the effect of electric double layer produces an obvious increase in the film thickness and apparent viscosity. The greater the Zeta-potential, the greater the apparent viscosity, and the greater the film thickness.

Abstract: We have obtained relatively unambiguous evidence that validates a simple, predictive model describing the uptake of noble metal coordination complexes from aqueous solutions onto oxide surfaces. The results confirm that the metal-oxide interaction is essentially electrostatic in nature. The evidence has been obtained by applying extended x-ray absorption fine structure (EXAFS) analysis to noble metal adsorption systems in which the effect of surface-localized pH has been isolated and quantified. The model has applications ranging from catalysts preparation to heavy metal pollution abatement and precious metal recovery.