  We have studied the adsorption of neutral polyampholytes on model charged
surfaces that have been characterized by contact angle and streaming current
measurements. The loop size distributions of adsorbed polymer chains have been
obtained using atomic force microscopy (AFM) and compared to recent theoretical
predictions. We find a qualitative agreement with theory; the higher the
surface charge, the smaller the number of monomers in the adsorbed layer, in
agreement with theory. We propose an original scenario for the adsorption of
polyampholytes on surfaces covered with both neutral long-chain and charged
short-chain thiols.
