Macromolecules, Vol.46, No.9, 3603-3610, 2013
Interactions between Individual Charged Dendronized Polymers and Surfaces
Polymethacrylate-based amino-terminated dendronized polymers up to generation 5 were adsorbed on mica, hydrophobized mica, and gold and studied with the atomic force microscope (AFM). These studies were carried out in a mildly acidic electrolyte solution where these polymers are fully ionized. The polymers were imaged in intermitted contact mode in solution, and desorption forces of individual polymer chains were investigated by single molecule force spectroscopy. The adsorbed chains have a uniform envelope up to generation 4, but the generation 5 polymer has a pronounced pearl-necklace structure. Force spectroscopy clearly reflects this difference. While lower generation polymers show peeling events with a single force plateau or pulling event with a single spike, those of generation 5 are characterized by two different force plateaus as well as multiple pulling events. These features are probably related to the unwrapping of pearls in the polymer backbone. We suspect that the pearls result from the high hydrophobicity of the polymer backbone.