Nanoconfinement Effects on the Glass Transition and Crystallization of Polymorphic Molecules

Nanoconfinement has been shown to significantly impact the glass transition temperature (Tg) and viscosity of molecular and polymeric glasses as the degree of confinement is decreased^1,2. In this work, we investigate the effects of nanoconfinement on phase changes in polymorphic molecules, D-mannitol and Acetaminophen. Using the Capillary Rise Infiltration (CaRI) method, these m were confined within the pores of self-assembled films of silica or alumina nanoparticle with various diameters to form highly loaded nanocomposites with varying degrees of confinement. Flash Differential Scanning Calorimetry was utilized to examine the thermal transitions, including the glass transition temperature (Tg), crystallization, and melting behavior as a function of nanoparticle size. Our results show that confinement raises Tg and suppresses melting point and crystallization rate of the polymorphic molecules. These findings suggest that nanoconfinement can modulate molecular mobility, stabilizing amorphous phases and enhancing control over crystallization, which is crucial for the development of amorphous drug formulations. Ongoing work focuses on optimizing film preparation to enhance signal strength and explore other polyamorphic systems.