A rapidly growing area of materials research involves the surface grafting of tethered layers that respond to external stimuli, such as pH. When stimuli-responsive polymers are tethered to solid surfaces, they may be used in a variety of fields such as membrane technology, separation, micro-sensors and micro-fluidic devices. The attractiveness of pH-responsive polymer layers is the ability to change conformation of the grafted chains according to variation in ambient pH, which relates to the degree of charge of associating groups and polymer and pendant group architecture. In this project, a well-defined series of polyamine brushes has been synthesized via surface-confined controlled/living radical polymerizations on silicon (Si) wafers. These polyamine brushes were polymerized from initiator reacted onto the terminal groups of self-assembled monolayers (SAMs). The effect of solvent, monomer concentration, ligand, and initiator on the polymerization success was examined. Chemical composition at each reaction step was characterized with FTIR, contact angle goniometry, and x-ray photoelectron spectroscopy while the thickness of the SAM and polymer layers was measured with ellipsometry. The pH-responsive behavior of polymer brush thickness was measured using in-situ ellipsometry and neutron reflectivity. This work demonstrates successful grafting of the polyamine brushes from the Si-SAM substrates and distinctive pH transition behaviors. Synthesis and characterization of a series of polyamines with varying tertiary amine functionality allowed for the systematic investigation of structure-responsiveness models; this is significant for molecular design in emerging areas of technology where responsiveness is important, such as “smart surfaces” and nanoactuators.