Hyperpolarized NMR to investigate nucleation and crystallization in confinement – MICRONMR

Crystallization underpins essential processes in our everyday life, creating exceptional materials. Control of crystallization outcome is paramount for polymorphic solids because each polymorph is potentially a “new” material with unique properties. Crystallization in confinement has emerged as a promising strategy for polymorph selection. Yet, controlling crystallization is out of reach today because fundamental understanding of the mechanisms underlying crystallization processes is still lacking. The missing link is an analytical route to access the atomic-level structural details of the sequence of events leading to the formation of a specific polymorph from a confined solution with sufficient time resolution (ms-s).
Capitalizing on the chemical specificity of Nuclear Magnetic Resonance (NMR) spectroscopy and sensitivity enhancement of Dynamic Nuclear Polarization (MAS DNP), MICRONMR will enable the detection and atomic-level characterization of short-lived crystallization phases that are undetectable by conventional NMR by developing an experimental toolkit to achieve time-resolved mechanistic comprehension of crystallization in confinement. MICRONMR will combine NMR, microfluidics and polymer chemistry to:
1) capture time-resolved snapshots of crystallization processes occurring into two types of suitably developed nano/micro confined hyperpolarizing reactors compatible with MAS DNP; 2) identify key structural and morphological details of transient species in each snapshot (from the Å- to the um-scale) via MAS DNP; 3) explore the effect of the application of external fields on confined crystallization in challenging polymorphic systems, such as molecular pharmaceutical solids.
By disclosing mechanistic aspects of crystallization that are currently inaccessible, MICRONMR will pave the way to a paradigm shift in materials development by rationalizing the outcome of crystallization, opening new avenues to targeted polymorphism in materials science.