Polymer brush is a layer of polymer

Polymer

A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

s attached with one end to a surface. The brushes may be either in a solvent state, when the dangling chains are submerged into a solvent, or in a melt state, when the dangling chains completely fill up the space available. Additionally, there is a separate class of polyelectrolyte brushes, when the polymer chains themselves carry an electrostatic charge.

The brushes are often characterized by the high density of grafted chains. The limited space then leads to a strong extension of the chains, and unusual properties of the system. Brushes can be used to stabilize colloid

Colloid

A colloid is a substance microscopically dispersed evenly throughout another substance.A colloidal system consists of two separate phases: a dispersed phase and a continuous phase . A colloidal system may be solid, liquid, or gaseous.Many familiar substances are colloids, as shown in the chart below...

s, reduce friction between surfaces, and to provide lubrication in artificial joint

Joint

A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...

s.

Polymer brushes have been modeled with Monte Carlo methods, Brownian dynamics simulations and molecular theories