Field strength, electrostatic

Equation (18) is valid when the polarizability of the dielectric is proportional to the electrostatic field strength [4]. The operator V in the Cartesian coordinate system has the form V = dldx,dldy,dldz). 

Lux (1939) introduced the symbol pO (note it is not an exponent like pH) to quantify the acid-base balance in a glass, and various attempts have been made to obtain values for this parameter. All are based on the electronegativity of the cation or a related characteristic, such as electrostatic field strength (Volf, 1984). 

Spectra of type III are shown in Fig. 7. In all four cases these materials are metallic phases, having metallic luster and conductivity. Their spectra have an appreciable absorption coefficient at 0 ev., which may correspond to electrons being promoted to the Fermi level in the conduction band and very low amplitude of fine structure, i.e., relatively flat absorption plateaus. The low amplitude may be attributed to relatively low electrostatic field strength in the first coordination sphere, to be expected in these electronic... 

The slope of the line yields the average electrostatic field strength F of 2.7 X 10 e.s.u./cm. (at the operative distance from the rutile surface to the center of the dipole) this value is in excellent agreement with that calculated for rutile by de Boer (44) from the results for argon adsorption by Morrison, Los, and Drain (4 ). 

Average Electrostatic Field Strengths for Solid Adsorbents and Commercial Pigments from Heals of Immersion... 

The separation of compounds by ion exchange depends on the differences in electrostatic field strength around the sample ions and on the activity coefficients of the resin. However, these are not the only factors involved since many anomalies have been found. 

Since the dielectric constant of a dipole is really a measure of the freedom of the dipole to become oriented in response to changes in electrostatic field strength, it would seem reasonable that the first layer of water molecules adsorbed to the charged surface (as the result at least of Van der Waals and London... 

The strength of the electrostatic field inside the cavity of the LiA, NaA, and especially CaA zeolites varies greatly. For different directions, the electrostatic field strength vector is often reversed in sign. 

An ion entering an electrostatic field travels in a circular path of radius r such that the centrifugal force is balanced by the electrostatic field strength (E). 

It is evident that the presence of water (or perhaps of other proton donors) introduces ambiguities into the interpretation of catalytic results based on a series of cation-exchanged zeolites with different calculated (40,48) electrostatic field strengths. Although the water source could be an added promoter (49-51), it could also arise via elimination in alcohol dehydration, a reaction which is known (6,7,5i,5< ,56) to proceed smoothly over mono- and divalent cation-exchanged faujasites. 

Zettlemoyer, A.C., Chessick, J.J., and HoUabaugh, C.M. (1958). Estimation of the surface polarity of solids from heat of wetting measurements. Phys. Chem., 62, 489-90. Morimoto, T. and Suda, Y. (1985). Heat of immersion of zinc oxide in organic liquids. 1. Effect of surface hydroxyls on the electrostatic field strength. Langmuir, 1, 239—43. 

Suda, Y., Heat of immersion of I iOj in organic liquids. Effect of chemisorbed HjO on the electrostatic field strength, Langmuir, 3, 1119, 1987. 

The study of carbon monoxide adsorption by Angell and Schaffer (6) has been discussed elsewhere (7, 74, 75). An interesting observation not previously emphasized is the appearance of cation specific absorption bands in the spectra of the multivalent cation zeolites because of the CO interacting with the exchanged cation via the carbon atom. They showed that the band frequency was a function of the electrostatic field strength which polarized the CO molecules. 

Table I. Electrostatic Field Strengths, F, and Dispersion Energies, E ...

It is possible to explain this variation with particle size if one considers in more detail the nature of the interaction of an ionic lattice with a dipolar molecule. The ion-dipole contribution to the interaction energy is linearly dependent on the electrostatic field strength. Any modification of crystalline to amorphous character should reduce the electrostatic field strength at the surface because of the more random arrangement of positive and negative ions. 

A quantitative estimation once again would require an estimation of the electrostatic field strength and its variation with particle size. This has been estimated previously [15], but since the electrostatic field strength is such a sensitive function of the distance normal to the surface, the calculation has little quantitative significance. 

In the present communication, we review an FIM experimental approach that uses the negative electrostatic field strength for imaging the surface at F 0.3 V/A (Figure 7.6c). All experiments were performed with a conventional field-ion/field-electron microscope. 

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