Recent Trends in Self-Healing Polymer Brushes and Their Tribological Applications

Abstract

Polymer brushes, which are dense polymer arrays whose ends are tethered to substrate or particles, can provide various properties on materials' surface based on their chemical structure, topology, or combined swelling agent, which have been utilized in various research fields like dispersion of particles, separation of biomolecules and antifouling. While tribological applications are also expected due to their super-lubricity based on high osmotic pressure, surface contamination and wear over time remain practical issues. On the other hand, self-healing polymers can repair damaged areas either intrinsically or extrinsically, which are expected to be utilized to suppress the functional deterioration of polymer brushes over time. This paper first describes the basic strategies of self-healing polymers utilizing microencapsulation, dynamic covalent bonding, or non-covalent bonding to perform intrinsic or extrinsic self-healing. Then, the formation and characterization of self-healing polymer brushes utilizing thermal treatment or phase separation to perform self-healing to maintain the surface properties are discussed. Finally, recent examples of tribological application of these self-healing polymer brushes are described.