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| Particle Adhesion | |
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| Van der Waals Force | JKR and Other Adhesion Models | Particle Adhesion & Removal | Effects of Charge | Effect of Humidity | Ultrasonic and Megasonic Cleaning | |
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London-van der Waals Force van der Waals Force Near a Surface The van der Waals for a sphere near a surface as shown in Figure 1 is given by
 is the Hamaker
constant for substances 1 and 2 in presence of medium 3,
and  is separation
distance. For a particle attached to a wall,
is
about 4 to 10  .
Typically  is used.
Figure 1. Schematics of a particle near a wall.
For cylinder-planar surface contacts shown in Figure 2,
Figure 2. Schematics of a cylindrical particle near a wall.
For two planar surfaces shown in Figure 3,
Figure 3. Schematics of a two planar surface at a separation distance of z0. |
,
,
,
z0
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