Adsorption of block polyampholyte micelles in monolayers at the silicon water interface

The adsorption of the diblock polyampholyte poly (methacrylic acid)-block-p oly((di-methylamino)ethyl methacrylate) from aqueous solution on silicon su bstrates was investigated as a function of polymer concentration and pH. Dy namic light scattering and electrokinetic measurements were used to charact erize the polyampholyte in solution. The amount of polymer adsorbed was det ermined by ellipsometry and lateral structures of the polymer layer were in vestigated by scanning force microscopy. The amount of polymer adsorbed was found to be strongly influenced by the pH of the polymer solution, while t he size of the polyampholyte micelles adsorbed on the surface was hardly af fected by pH during adsorption. From investigations by scanning force micro scopy well-seperated micelles were seen in the dried monolayers adsorbed di rectly from solution. The structures at the surface are correlated to struc tures in solution, and the adsorbed amount depends on the relative charge o f the micelles and the surface.