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London-van der Waals Force
Hamaker Constants for Dissimilar Materials
For two dissimilar materials, the Hamaker constant may be
estimated in term of Haymaker constant of each material. That is
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(7) |
or alternatively
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(8) |
For contact of two dissimilar materials in the presence of a third media,
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(9) |
From Equation (8) it follows that
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(10) |
or
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(11) |
Lifshitz developed the macroscopic theory relating the Hamaker
constant to dielectric constants of the materials. Accordingly,
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(12) |
Values of  are
given in Tables 3 and 4 for a number of materials. (Note that
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