Patrone, Paul NathanIn this dissertation, I give an overview of my work on multiscale modeling of interfaces in crystalline and block-copolymer systems. I focus on two distinct interface systems: steps on vicinal surfaces and microdomain interfaces in block- copolymers melts. For each system, I consider how to (i) define the interface, (ii) derive a coarse-grained model of the interface, and (iii) use the model to study morphological features of the interface. For vicinal surfaces, we define a step by means of ensemble averages, which leads to a Burton-Cabrera-Frank (BCF) -type model of surface evolution. Using the BCF model, we study the combined effects of step interactions and fluctuations. For block-copolymers, we define the microdomain interfaces in terms of the relative density of monomers and use the Leibler-Ohta- Kawasaki phase-field Hamiltonian to study the line-edge roughness.DissertationPhysicsAsymptotic MethodsMultiscale ModelingPolymer PhysicsStatistical MechanicsSurface Physics