Volume fraction profiles of Polyelectrolyte Brushes with tunable Macromolecular Architecture

Polyelectrolyte polymer brushes (PEBs) are densely end-tethered polymer chains that contain charged units. Depending on the pH and ionic strength these responsive layer can be swollen or collapsed. Though it's essential for their function the strong swelling inside brushes (due to coulombic stress and steric effects) generates a huge tension along the polymer backbone, causing instability and consequently de-grafting of PEBs from the substrate surface. In this proposal we will depth profile brush volume fraction, which is distinctly non-trivial when swollen and can take many possible functional forms (e.g error function, tanh). Importantly we will do this for a new class of stable charged polymer brushes and characterise the volume fraction profile of the main chain and pendant charged groups. We will gain insight into switchable polymer brushes and the physics of their interactions.