| Diblock copolymer melts, dubbed ``designer materials'', have the remarkable ability for self-assembly into various ordered structures. In this talk, I will first review two mean field theories used to predict the phase separation: the self-consistent mean field theory and the density functional theory. Focusing on the latter, I will discuss some analytical techniques which provide insight on the scales of the minimizing structures (phases). These techniques have the advantage that they are not based upon any preassigned bias for the domain geometry. |