Force depletion

As the large colloids approach each other with a separation of about 2r (where r is the radius of the smaller particles), it becomes increasingly 

This net force is known as a depletion force, and by tuning the size of the smaller particles in the solution, it is possible to control the aggregation of the larger particles. Note that the depletion attraction does not necessarily result in permanently aggregated particles (as we would expect for van der Waals attraction), and by changing the solution conditions it may be 

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Once a loop is formed, contact will be maintained by depletive forces hence the loop will preferentially relax through local gliding of the two contact points (Fig. 20). This is where local defects come into play When they meet from this gliding process, they act as local geometrical wells and stick together. This defect-induced stabilization is important since it prevents further depletive... 

Figure 2.6. Schematic representation of the depletion mechanism. Because micelles are excluded from the gap, a depletion force takes place and is calculated by integrating the uncompensated osmotic pressure over the accessible surface.

Attempts to measure the depletion force in nonadsorbing polymer medium with an SEA have failed essentially because measurements are hindered by the slow exclusion of the polymer from the narrow gap due to the large viscosity of the polymer solutions. However, depletion forces have been measured in solutions of living polymers in a semi-dilute regime by Kdkicheff et al. [50]. The... 

O. Mondain-Monval, F. Leal-Calderon, J. PhUlip, and J. Bibette Depletion Forces in the Presence of Electrostatic Double-Layer Repulsion. Phys. Rev. lett. 75, 3364 (1995). 

A. Milling and S. Biggs Direct Measurement of the Depletion Force Using an Atomic Force Microscope. J. Colloid Interface Sci. 170, 604 (1995). 

J. Bibette, D. Roux, andB. Pouligny Creaming of Emulsions The Role of Depletion Forces Induced by Surfactant. J. Phys. II France 2, 401 (1992). 

S. Sanyal, N. Easwear, S. Ramaswamy, and A.K. Sood Phase Separation in Binary Nearly-Hard-Sphere Colloids Evidence for the Depletion Force. Europhys. Lett. 18, 107 (1993). 

Trokhymchuk A, Henderson D, Nikolov A, Wasan DT (2001) A simple calculation of structural and depletion forces for fluids/suspensions confined in a film. Langmuir 17 4940-4947... 

The intermicellar exchange process, governed by the attractive interactions between droplets, can be modified by changing the bulk solvent used to form reverse micellar solution (26). This is due to the discrete nature of solvent molecules and is attributed to the appearance of depletion forces between two micelles (the solvent is driven off between the two droplets) (26). When the droplets are in contact forming... 

In the case of biopolymer molecules residing in the space between colloidal particles or droplets, the force associated with the deep energy minimum at contact is often referred to as the depletion force because the intervening biopolymer species are depleted from the narrow gap between the pair of neighbouring particles. This attractive interparticle interaction underlies the phenomenon of reversible depletion flocculation in oil-in-water emulsions (see equation (3.41) in chapter 3). 

What is the depletion force What is the bridging force ... 

The flocculation of dispersed species induced by nonadsorbing polymer molecules due to depletion forces. When solutes such as polymer molecules do not, for some reason, enter the gap between adjacent surfaces an attractive force is created between the surfaces. This depletion force arises out of the solute s ability to influence osmotic pressure in bulk but not in the gap between the surfaces. 

Non-DLVO colloidal interactions excluded volumes, undulation interactions, depletion forces and many-body effects... 

H. Huang, E. Ruckenstein Interaction Force between Two Charged Plates Immersed in a Solution of Charged Particles. Coupling between Double Layer and Depletion Forces, LANGMUIR 20 (2004) 5412-5417. 

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