Hydrophobic Polyelectrolytes do not like solvent (water) and would like to collapse into globules and precipitate from solution. Repulsion between charges on these chains prevents this collapse (see the necklace-like structure of a polyelectrolyte chain below).

We have predicted that the interplay between hydrophobic surface energy and electrostatic repulsion between charges leads to a necklace-like structure of beads connected by narrow strings.

Our model of the necklace conformation of hydrophobic polyelectrolytes has been verified analytically, through computer simulations, and experimentally. We recently predicted that this necklace-like structure would manifest itself in a number of unique properties that are currently under experimental and numerical investigation.

"Cascade of Transitions of Polyelectrolytes in Poor Solvents" Andrey V. Dobrynin, Michael Rubinstein*, Sergei P. Obukhov Macromolecules 1996, 29, 2974-2979

Polymers containing both positively and negatively charged groups are called polyampholytes. Examples of polyampholytes include proteins and some synthetic polymers. Polyampholytes can polarize and adsorb at charged surfaces even if their own charge is of the same sign as that of the surface (see the polarization of a polyampholyte chain near charged surface below). Another unique feature of polyampholytes is that not all adsorbed chains need to touch the surface. We call this long-range adsorption.

"Adsorption of a Polyampholyte Chain on a Charged Surface." Andrey V. Dobrynin, Michael Rubinstein*, and Jean-François Joanny Macromolecules 1997, 30, 4332-4341

http://online.itp.ucsb.edu/online/bio_c98/rubinstein/

We have recently demonstrated that, depending on the charge density of the surface and along the polyelectrolyte chain, there are two qualitatively different types of adsorbed polyelectrolyte layers: two-dimensional and three-dimensional ones. Addition of salt increases the coverage of two-dimensional layers, but decreases it for three-dimensional ones.