The Nature of Electric Charge

Unlike charges attract (positive attracts negative), and like charges repel (negative repels negative and positive repels positive). 

Charge may be transferred from one object to another, by contact or induction. 

The less the distance between two charges, the greater the force of attraction between unlike charges (or repulsion between identical charges). The force of attraction (F) can be expressed using the following equation  

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The next four chapters provide an introduction to the concepts and techniques needed to study and understand dispersion stability. Some approaches to the characterization of emulsions, foams and suspensions, and of their dispersed species (droplets, bubbles and particles)are described in Chapter 2. The concepts of surface tension, wettability and surface activity, which are important to the stability and properties of all types of dispersion, are described in Chapter 3. To this is added the nature of electrically charged surfaces in Chapter 4. All of these aspects are brought together in Chapter 5 in an introduction to the stability of dispersions. 

Klein made an intriguing suggestion about the nature of electric charge [88] on the basis of a five-dimensional unified-field theory. 

We can summarize the nature of electrical charge as follows < Figure 4.7)... 

The discussion focuses on two broad aspects of electrical phenomena at interfaces in the first we determine the consequences of the presence of electrical charges at an interface with an electrolyte solution, and in the second we explore the nature of the potential occurring at phase boundaries. Even within these areas, frequent reference will be made to various specialized treatises dealing with such subjects rather than attempting to cover the general literature. One important application, namely, to the treatment of long-range forces between surfaces, is developed in the next chapter. 

Charged particles Particles that have a positive or negative electrical charge. The nature of this charge effects the collection of the particles in a precipitator. 

It has become recognized during recent years that the color of dyes is associated with the resonance of electric charge from atom to atom of the dye molecule.2,3> 4 6 6 Because of the complexity of the problem, however, it has not been easy to expand this idea into a theory of color permitting the rough quantitative calculation of the frequencies and intensities of the absorption bands of dyes. I have now developed a theory of this nature the theory and some of the results of its application are described briefly in the following paragraphs. 

In the absence of solvent molecules, the intermolecular forces governing the molecular interachons are essentially of an electrostatic nature and depend on the presence of electrical charges and dipoles in the molecules [3, 4]. 

Accordingly, values obtained for model or small molecules are appropriately applied to analogous polymeric materials. This does not apply in cases where the polymeric nature of the material plays an additional role in the conductance of electric charges, as is the case for whole chain resonance electric conductance. 

The purpose of the present chapter is to introduce some of the basic concepts essential for understanding electrostatic and electrical double-layer pheneomena that are important in problems such as the protein/ion-exchange surface pictured above. The scope of the chapter is of course considerably limited, and we restrict it to concepts such as the nature of surface charges in simple systems, the structure of the resulting electrical double layer, the derivation of the Poisson-Boltzmann equation for electrostatic potential distribution in the double layer and some of its approximate solutions, and the electrostatic interaction forces for simple geometric situations. Nonetheless, these concepts lay the foundation on which the edifice needed for more complicated problems is built. 

There is still another type of internal solid state reaction which we will discuss and it is electrochemical in nature. It occurs when an electrical current flows through a mixed conductor in which the point defect disorder changes in such a way that the transference of electronic charge carriers predominates in one part of the crystal, while the transference of ionic charge carriers predominates in another part of it. Obviously, in the transition zone (junction) a (electrochemical) solid state reaction must occur. It leads to an internal decomposition of the matrix crystal if the driving force (electric field) is sufficiently high. The immobile ionic component is internally precipitated, whereas the mobile ionic component is carried away in the form of electrically charged point defects from the internal reaction zone to one of the electrodes. 

The process of electrically charging a particle involves the addition of electrons to or removal of electrons from the material or the attachment of ionized gas molecules to the particle. Almost all small particles in nature acquire some charge as a result of naturally occurring radiation,... 

For percolating microemulsions, the second and the third types of relaxation processes characterize the collective dynamics in the system and are of a cooperative nature. The dynamics of the second type may be associated with the transfer of an excitation caused by the transport of electrical charges within the clusters in the percolation region. The relaxation processes of the third type are caused by rearrangements of the clusters and are associated with various types of droplet and cluster motions, such as translations, rotations, collisions, fusion, and fission [113,143]. 

The working principle of an ISFET is essentially different, which is evident from the name of this transducer information is transferred via an electric field. As is known, the source of any static electric field is charge. The nature of this charge in our case is concealed in the first two letters of the acronym ISFET ions form the source of the charge, of which the resulting electric field controls the electronic behavior of the transistor. It is important to observe that in this case no galvanic contact exists between the solution and the conducting part of the sensor, so there is no faradaic current. 

The greatest variety of polyelectrolytes is found in nature. The role of electric charges is essential for the proper functioning of nucleic acids, the numerous enzymes, proteins and polysacchardies. The fundamental role of polyelectrolytes in all living processes is unquestionable. 

As model systems for scientific study, MR fluids are superior to ER fluids, because complications due to charging and conductivity in ER fluids have no counterpart in MR fluids, since magnetic monopoles, the analog of electric charges, are unknown in nature. Thus, a magnetic analog of the simple polarization model described in Section 8.2.1 for ER fluids should be even more appropriate for MR fluids. 

Items 2 and 3 arise from the fact that both the "counterion" and the medium itself can markedly affect the nature of the growing chain end. Thus, the growing chain end may assume various forms that depend on the extent of electrical charge separation and range all the way from a polarized covalent (sigma) bond to a completely dissociated state of free ions. This characteristic presents the greatest distinction between the mechanisms of free-radical and ionic polymerization. 

The path of discovery is often winding and unpredictable. Basic research into the nature of electricity eventually led to the discovery of electrons, negatively charged particles that are part of all atoms. Soon thereafter, other experiments revealed that the atom has a nucleus—a tiny, central core of mass and positive charge. In this section, we examine some key experiments that led to our current model of the atom. 

To explore further the significance of the electrical conductivity results, we need to discuss briefly the nature of electric currents. An electric current can travel along a metal wire because electrons are free to move through the wire the moving electrons carry the current. In ionic substances, the ions carry the current. Therefore, substances that contain ions can conduct an electric current only if the ions can move—the current travels by the movement of the charged ions. In solid NaCl, the ions are tightly held and cannot move. When the solid melts and becomes a liquid, however, the structure is disrupted and the ions can move. As a result, an electric current can travel through the melted salt. 

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