Lifshitz points in blends of AB and BC diblock copolymers

We consider micro- and macro- phase separation in blends of AB and BC diblock copolymers. We show that, depending on architecture, a number of phase diagram topologies are possible. Microphase separation or macrophase separation can occur, and there are a variety of possible Lifshitz points. Because of the rich parameter space, Lifshitz points of multiple order are possible. We demonstrate Lifshitz points of first and second order, and argue that, in principle, up to 5th order Lifshitz points are possible.