ABSTRACT
Inmost studies of electrostatic interactions between charged bodies,
a number of simplifying assumptions are made. Beyond the purely
geometric simplifications, the charge distribution is often taken to
be uniform. This assumption is clearly always an idealization, as
charge distributions in many systems will be inherently complex
and/or disordered [1, 3, 5, 7, 21]. Examples of charge disorder are
common in colloidal and soft matter systems [9, 12, 13], specific
examples include surfactant-coated surfaces [10, 16] and random
polyelectrolytes and polyampholytes [2]. Metallic and dielectric
surfaces with local dielectric constant variation can also exhibit
charge disorder, as local variations of the crystallographic axes of
an exposed surface lead to a random surface potential, the patch effect [3, 5, 7, 20, 21]. Finally, the chemical preparation of samples is never perfect and charged impurities abound. The presence of
charge disorder, even if the system is overall net neutral, can be
shown to have strong effects on the interactions between bodies.
Notably, charge disorder can lead to interactions that can mask the
Casimir effect and may play an important role in the Casimir effect
experiments, possibly making their interpretation rather delicate
[3, 5, 7].
