Particles attraction between

In extensively deionized suspensions, tliere are experimental indications for effective attractions between particles, such as long-lived void stmctures [89] and attractions between particles confined between charged walls [90]. Nevertlieless, under tliese conditions tire DLVO tlieory does seem to describe interactions of isolated particles at tire pair level correctly [90]. It may be possible to explain tire experimental observations by taking into account explicitly tire degrees of freedom of botli tire colloidal particles and tire small ions [91, 92]. 

Short-Chain Organics. Adsorption of an organic dispersant can reduce polarizabiHty attraction between particles, ie, provide semisteric stabilization, if A < A.p < A or A < A.p < A (T = dispersant) and the adsorption layer is thick. Adsorption in aqueous systems generally does not foUow the simple Langmuir profile because the organic tails on adsorbed molecules at adjacent sites attract each other strongly. 

A No significant attraction between particles B Less fluid than gases C More dense than gases D Exhibits viscosity... 

In studies of steric stabilizers too little attention is generally paid to the dispersion force attractions between particles and the critical separation distance (H ) needed to keep particles from flocculating. Adsorbed steric stabilizers can provide a certain film thickness on each particle but if the separation distance between colliding particles is less than H the particles will flocculate. The calculation of H is not cr difficult and measurements to prove or disprove such calculations are not difficult either. For equal-sized spheres of substance 1 with radius or in medium 2 the Hamaker equation for the dispersion force attractive energy (Uj2i) at close approach is (7) ... 

A Casson fluid is Theologically identified by two parameters yield value and plastic viscosity. The plastic viscosity relates to the asymmetry of the flow particles and the yield value is connected with the forces of attraction between particles. The... 

Type of Crystalline Solid Particles Involved Primary Forces of Attraction Between Particles Boiling Point Electrical Conductivity in Liquid State Other Physical Properties of Crystals Conditions Necessary for Formation Examples... 

Note Bond formation or attraction between particles or network chains within a gel induces the contraction and thereby the exudation of liquid from the network. 

On the assumption of a somewhat mobile double layer, electrostatic attraction between particles may occur, due to this displacement effect, even if the total net charge be not zero, i.e. coagulation may take place before the isoelectric point is reached. The data of Zsigmondy on gold particles, and of Powis Zeit. Phys. Ohem. Lxxxix 186, 1915) on oil particles, have indeed shown that the optimum point for precipitation is not actually at the isoelectric point, although in the case of gold, practically complete discharge of the double layer had to take place before coalescence. 

Diffusion Flame The flame produced by the spontaneous mixture of fuel vapors or gases and air. Dispersants These are chemicals which reduce the surface tension between oil and water, thus facilitating he breakup and dispersal of an oil slick in the form of an oil-in-water emulsion. Dispersing Agent An adjuvant diat reduces the attraction between particles. 

In reaching this conclusion we have assumed that no time lag affects the field that establishes the attraction between the particles. We have also considered particles under vacuum so no intervening medium enters the picture. Each of these simplifying approximations has the effect of overestimating the van der Waals attraction between particles at large separations from one another and embedded in a medium. We consider presently the effect of a time lapse between the interaction of a field with two different particles the effect of the medium is discussed in Section 10.8. 

Solubilization of insoluble oxidation products and soot particles. Reverse micelles (RMs) formations manage the prevention of agglomeration and the contamination process of insoluble oxidation particles and soot particles by both steric stabilization (Fig.2.1) and electrostatic stabilization mechanisms (Fig.2.2). The steric stabilization mechanism provides a physical barrier to agglomeration of particles by adsorption on particle surfaces. Adsorbed dispersant acts as a physical barrier to attraction between particles. 

London dispersion forces are the weakest of the intermolecular forces and occur between all molecules. These are the only types of intermolecular forces that are possible between nonpolar molecules and are caused by momentary dipoles. Experimental evidence suggests that electrons are not symmetrically distributed about the nucleus at all times. On average, the electrons may be spread out evenly around the nucleus, but there are brief instants when the electron density may be greater on one side of the atom than another. During these periods of time, the atoms develop a temporary or instantaneous polarity. The temporary polarity (which is the cause of the momentary dipole) allows for attraction between particles that are normally nonpolar. London dispersion forces tend to increase as the size and mass of the molecule increase. 

Unlike Pitcairne, whose forces of attraction operate between particles and the passages in the glands, Keill spoke about the attraction between particles themselves. This means that for Keill the corpuscles themselves were in-... 

The adsorption of a strongly hydrated hydrophilic colloid thus increasing the affinity of the particle to water so that it exceeds any mutual attraction between particles... 

The effective Hamaker constant equation shows that the attraction between particles is weakest when the particles and medium are most chemically similar (Ai As). The Hamaker constants are usually not well known and must be approximated. 

A fellow student says, All substances experience London dispersion forces of attraction between particles. Is this statement true Explain your answer. 

In the solid state, molecules line up in a pattern forming a crystal lattice similar to that of an ionic solid, but with less attraction between particles. The structure of the crystal lattice depends on the shape of the molecule and the type of intermolecular force. Most information about molecules, including properties, molecular shape, bond length, and bond angle, has been determined by studying molecular solids. 

Intramolecular forces do not account for all attractions between particles. There are forces of attraction called intermolecular forces. The prefix inter-means "between" or "among." For example, an interview is a conversation between two people. Intermolecular forces can hold together identical particles, such as water molecules in a drop of water, or two different types of particles, such as carbon atoms in graphite and the cellulose particles in paper. The three intermolecular forces that will be discussed in this section are dispersion forces, dipole-dipole forces, and hydrogen bonds. Although some intermolecular forces are stronger than others, all intermolecular forces are weaker than intramolecular, or bonding, forces. 

Although the kinetic-molecular theory was developed to explain the behavior of gases, the model can be applied to liquids and solids. When applying the kinetic-molecular theory to these states of matter, you must consider the forces of attraction between particles as well as their energy of motion. 

In general, the stronger the attractions between particles, the greater the surface tension. Water has a high surface tension because its molecules can form multiple hydrogen bonds. Drops of water are shaped hke spheres because the surface area of a sphere is smaller than the surface area of any other shape of similar volume. Water s high surface tension is what allows the spider in Figure 13-14b to walk on the surface of a pond. 

This is not to say that molecular compounds have no forces of attraction between particles they do. These forces are called intermolecularforces. They vary from substance to substance and are responsible for some of the varying properties between molecular compounds. For example, when a molecular compound is liquid at standard temperature and pressure, it is likely that it has stronger intermolecular forces than a molecular compound that is a gas at standard temperature and pressure. 

A. He]—Of the choices shown, helium will have the smallest particles and the least intermolecular attraction between particles, making it the most like an ideal gas. 

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