Interplay of symmetries of block polymers and confining geometries

The morphologies that block polymers exhibit under various types of confinement are reviewed with emphasis on experimental results and theoretical predictions. Confining geometries in all three dimensions are considered and special attention is paid to cylindrical and spherical boundary conditions. Past experimental techniques and theoretical understanding are discussed and an outlook for future advances due to the possibility for novel, well ordered and aligned morphologies to occur when polymers are confined between surfaces of varying distance, curvature, and surface chemistry is provided. Confinement creates new morphologies which are not present in the bulk, indicating that the confined thermodynamic boundary conditions result in phase behavior that is distinct from the bulk and that there is the possibility for new phases and order-order transitions to be discovered as future researchers impose new types of confinement and explore a greater range of block polymer architecture, composition and molecular weights. The article concludes with a brief introduction of interference lithography, which can be used to form arbitrary and novel boundary conditions, and a perspective on the future outlook of the phase behavior of confined block polymers.