Equilibrium Structure of Polymer Brushes with Multiple Tethers by Self Assembly of Stars Block Copolymers at the Solid-Fluid Interface

摘要

Because of their ability to modify interfacial properties, polymer brushes have been the focus of much research efforts, both theoretical and experimental, for the past three decades. The majority of the studies have focused on understanding the formation and structure of brushes made by attaching linear polymers by one end. Much less effort has been devoted to study the effect of polymer architecture in the formation and structure of polymer brushes. While chain architecture may be another parameter that can tuned to tailor interfacial structure and properties, the literature on this area is scarce. In this contribution we present our latest results in the study of polymer brushes made by copolymers that attach by multiple points. Neutron reflectivity (NR), atomic force microscopy (AFM) and the surface forces apparatus (SFA) have been used to study the equilibrium structure of a series of polystyrene-block-(2-vinylpyridine) star block copolymers (PS-b-PVP stars) adsorbed from toluene onto mica and silicon substrates. With a corona of PVP and a core consisting of PS, it is expected that the stars will attach by their corona, forming an octopus-like polymer brush with multiple tethering points.