Addressable Macromolecular Architectures: Towards stimuli promoted motion at the nanoscale

Addressable polymer structures play an increasingly important role in a variety of areas, such as surface engineering, drug delivery, and micro/nanofluidics. In these structures, addressability results from the sensitivity of incorporated polymer chains to variations in temperature, electric or magnetic field strength, pH, ionic strength, etc. Macromolecules responsive to multiple types of stimuli are attracting increasing interest. Such molecules are often constructed from several building blocks where each constituent responds to a different stijulus. Although redox responsive polymers have received relatively little attention, redox is one of the very few stimuli that allows one to directly address single molecules. To utilize stimulus responsive behavior and construct 'functioning' molecular nanosystems such as molecular crawlers or motors, an external stimulus should be applied as a signal directly to a specific polymer chain, and be used for controlling its chain conformation and thus physical properties. In order to lay the foundation of such systems, in this Thesis several stimulus responsive macromolecules were studied based on two main polymer classes: (a) temperature responsive poly(N-isopropylacrylamides) (PNIPAM), and (b) redox-responsive poly(ferrocenylsilanes) (PFS). To address single chains and their assemblies and to characterize their responsive behavior, Atomic Force Microscopy, dynamic light scattering and electrochemical measurements were used.