Colloidal particle interaction

We need to understand under which conditions a colloidal system will remain dispersed (and under which it will become unstable). Knowing how colloidal particles interact with one another makes possible an appreciation of the experimental results for phase transitions in such systems as found in various industrial processes. It is also necessary to know under which conditions a given dispersion will become unstable (coagulation). For example, one needs to apply coagulation in wastewater treatment so that most of the solid particles in suspension can be removed. Any two particles coming close to each other, will produce different forces. 

The above theory is needed in the interpretation of electrokinetic phenomena and the dynamics of colloid particle interaction. When particles move with... 

Electrokinetics is of direct relevance for the interpretation of the dynamics of colloid particle interaction, that is interaction, considering the rates of transient charge fluxes during the brief encounters of pairs. Charge has to flow away and to a large extent this takes place laterally, so that obviously K° and become Important variables. 

We turn now to the other side of the colloidal particle interaction problem idealised to the case of two half spaces separated by salt water [3-10, 22-24]. Typically such particles will contain ionisable groups at their surfaces, so that the surfaces are charged. Imagine that the water, as before, retains its bulk properties up to the surface of the half spaces. The charged surfaces create an inhomogeneous profile of cationic and anionic density. For an isolated surface at the simplest level of approximation and schematically only, this distribution follows from the equation ... 

When the colloidal particles interact with the SdFFF channel wall, the total potential energy, of a spherical particle is given by... 

Colloidal particles interact strongly with the fluid, but the individual particles have some structural integrity, so they cannot be said to dissolve homogeneously. The colloidal mixture behaves so distinctively because of the latge surface area of interaction between the particles and water or air. The ions at the boundary interact with the ions and molecules of both phases. This is true at any surface or phase boundary, but the interaction of colloidal phases is large because their surface areas are so large. A 1-mm sand particle has a surface area/mass ratio of about 0.002 m2g-1 a -fixa clay particle, 2 m2g 1 and a 1-nm particle, 2000 m2g 1. 

In colloid science we have to consider not only the nature of a single double layer (a subject of importance in surface electrochemistry) but also the way in which the double layers surrounding two colloid particles interact with one another when they come together. 

When the colloidal particles interact with the SdFFF channel wall, the potential energy given by Eq. 3 must be corrected, so as to include the potential energy of interaction, forces, and the total potential energy, of a spherical particle in PBSdFFF is given by the relation... 

In the case when surface phenomena are present in SdFFF, which means that the colloidal particles interact with the chaimel wall, the potential energy given by Eq. 1 must be corrected so as to include the potential energy of... 

Dukhin, S.S. and Lyklema, J. 1987. Dynamics of colloid particle interaction. Langmuir 3 94-98. 

The structure factor Ss r(q) mirrors repulsive interaction between the stars in good and 6 solvents. Star polymers in dilute solution can be assimilated to soft colloidal particles. Interaction between star polymers in dilute solutions has a character of soft repulsion that arises at separation d 2Rs,ar between the star centers. The binary repulsive potential between the stars was evaluated by Witten and... 

The cluster morphology may depend on details of colloidal particle interactions, mechanism of particle attachment to the cluster, and dimensionality of the problem. The existing models for cluster morphology simulation account for the trajectory of... 

The validity of Eq. (197) is confirmed by the results plotted in Fig. 34. As can be seen, the linear dependence given by Eq. (197) reflects well the exact numerical results derived from the RSA simulation for spheres and spheroids. The proportionality constant was found to be equal to 2.3 (for < )o = 200, which is a typical value for the colloid particle interactions). This indicates... 

Tirado-Miranda, M., A. Schmitt, J. Callejas-Femandez, and A. Femandez-Barbero. 2003. Aggregation of protein-coated colloidal particles Interaction energy, cluster morphology, and aggregation kinetics. Journal of Chemical Physics 119 (17) 9251-9259. 

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