Crystallization of Small Organic Molecules in a Polymer Matrix: Multistep Mechanism Enables Structural Control. Issue 38 (5th August 2019)

• Record Type: Journal Article
• Authors: Bronshtein, Ilya; Weissman, Haim; Kaplan‐Ashiri, Ifat; Rybtchinski, Boris
• Is Part Of: Small. Volume 15:Issue 38(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-05
• Subjects: hybrid materials -- organic crystals -- perylene diimides -- polymer matrices; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201902936
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: The widely employed crystallization of organic molecules in solution is not well understood and is difficult to control. Employing polymers as crystallization media may allow enhanced control via temperature‐induced regulation of polymer dynamics. Crystallization of a small organic molecule (perylene diimide) is investigated in polymer matrices (polystyrene) that enable the mechanistic study and control over order evolution. The crystallization is induced by heating above the glass transition temperature of the polymer, and quenched by cooling, leading to stabilization of crystallization intermediates. The mechanistic studies include direct imaging by electron microscopy, revealing a complex self‐assembly process starting from amorphous aggregates that densify and transform into an unstable crystalline phase of N, N ′‐bis(2, 6‐dimethylphenyl)perylene‐3, 4, 9, 10‐tetracarboxylic diimide (DMP‐PDI), followed by a conversion into a more stable crystalline form. Stabilization of crystallization intermediates at room temperature provides diverse structures based on a single molecular component. These findings have implications for the rational design of organic crystalline materials. Abstract : Crystallization of an organic dye in a polymer matrix starts from the amorphous phase and proceeds via a sequence of structural transformations. These can be induced by heating above the glass transition temperature of the polymer, and quenched by cooling, enabling investigation and utilization of otherwise elusive crystallization intermediates.