Controlling polymorphism by crystallization on self-assembled multilayers

In this paper, we present a new approach based on crystallization onto self-assembled multilayers (SAMs) for the control of polymorphism. To demonstrate our approach, we studied the crystallization of L-glutamic acid on a self-assembled multilayer of a phenyalanine derivative. It is shown that crystallization of L-glutamic acid on SAMs resulted in stabilization of the metastable α-form of L-glutamic acid. Additionally, crystallization onto SAMs led to crystal growth with preferential orientation along the 〈111〉 crystal direction. The possibility of using SAM surfaces to stabilize thermodynamically metastable structures as demonstrated in this work offers a powerful tool in the development of processes in polymorphic systems.