Homework #5 Problem #4 A polymer brush consists of a layer of polymers attached at one end to a surface, which extends outward from the surface [wikipedia]. The polymers can be attached to the surface of the substrate in many different ways. Essentially, the polymers act as a barrier between the two components and even under significant loading can provide beneficial lubrication properties. The Bielecki paper discusses grafted-form structures that are covalently attached to the substrate. The paper goes on to discuss that when the polymer brushes are immersed in a good solvent they can achieve a low coefficient of friction. However, when immersed in a poor solvent, the polymer brushes do not provide good lubrication properties. Essentially, the polymers act as a barrier between the two components and even under significant loading can provide