Surface charge, related

A main process of membrane fabrication is an in-situ inter cial polycondensation, which is an interfacial reaction between aqueous solution of amines and organic solution of acid chlorides. In the process, many factors, eg. diffusion rate of amines, membrane thickness, surface charge related to end groups, affect membrane perfoimance (Figure 6). 

Vaisman et al. [103] formed a uniform, multi-walled nanotubes (MWNTs) distribution in water-soluble (poly(ethylene glycol)) and water-insoluble (polypropylene) polymers. In order to understand the surface-charge-related stability of the treated nanotubes solutions, zeta-potential measurements were applied. Quantification of the state of the M WNT dispersion was derived from particle-size analysis, while visual characterization was based on optical and electron microscopy. In order to estimate the nucleating ability of the surface-modified CNTs, the temperature of crystallization and the degree of crystallinity were calculated from differential scanning thermograms. 

Nakagaki1U) has given a theoretical treatment of the electrostatic interactions by using the Gouy-Chapman equation for the relation between the surface charge density oe and surface potential /. The experimental data for (Lys)n agrees very well with the theoretical curve obtained. 

The non-zero value of e Fw-e FR in Eq. (5.35) implies that there are net surface charges on the gas exposed electrode surfaces. These charges (q+,q.) have to be opposite and equal as the cell is overall electrically neutral and all other charges are located at the metal-solid electrolyte interfaces to maintain their electroneutrality. The charges q+ = -q. are quite small in relation to the charges, Q, stored at the metal-electrolyte interface but nevertheless the... 

Two distinct linear and parallel relations are seen one (to the left) for metals for which the surface charge, is positive, and another (to the right) for metals for... 

The availability of the surface charge results in redistribution of free charge carriers in semiconductor which leads to formation of a compensating space charge and electric field E related to the value of the volume charge through the Poisson equation ... 

The calculations were subsequently extended to moderate surface charges and electrolyte concentrations.8 The compact-layer capacitance, in this approach, clearly depends on the nature of the solvent, the nature of the metal electrode, and the interaction between solvent and metal. The work8,109 describing the electrodesolvent system with the use of nonlocal dielectric functions e(x, x ) is reviewed and discussed by Vorotyntsev, Kornyshev, and coworkers.6,77 With several assumptions for e(x,x ), related to the Thomas-Fermi model, an explicit expression6 for the compact-layer capacitance could be derived ... 

Here, clayer = Ksjdlayer is the capacitance per unit area (in farads/m2) of the layer. The surface voltage Vlayer can be related to the accumulated surface charge a/ (in C/m2) by the following equation ... 

This relates the change in surface tension with the applied potential at constant electrolyte composition to the surface charge density on the metal, [Pg.44]

Since the sorbing surface holds a charge, its electrical potential differs from that of the solution. The potential difference between surface and fluid is known as the surface potential T and can be expressed in volts. The product e 4 is the work required to bring an elementary charge e from the bulk solution to the sorbing surface. According to one of the main results of double layer theory, the surface potential is related to the surface charge density by,... 

For liquid electrodes thermodynamics offers a precise way to determine the surface charge and the surface excesses of a species. This is one of the reasons why much of the early work in electrochemistry was performed on liquid electrodes, particularly on mercury - another reason is that it is easier to generate clean liquid surfaces than clean solid surfaces. With some caveats and modifications, thermodynamic relations can also be applied to solid surfaces. We will first consider the interface between a liquid electrode and an electrolyte solution, and turn to solid electrodes later. 

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