You are cordially invited to attend this seminar to be held on
Tuesday, July 28th, 15:00
Zoom Departmental M.Sc. seminars
Structural Characterization and Crystallization Kinetics of a Supramolecular
System in a Microfluidic Platform
by Dana Cohen Gerassi
Under the supervision of Prof. Yosi Shacham-Diamand and Dr. Lihi Adler-Abramovich
Abstract
Supramolecular self-assembly is a key process in natural systems, allowing for the formation of structures across all length-scales with a wide range of functionalities. Notable progress has been made in the bottom-up design and generation of natural and artificial peptides, which through self-assembly provide diverse nano- and micro-scale architectures for a variety of applications. These systems possess advantageous properties including facile synthesis and biocompatibility. However, their self-assembly mechanisms, particularly in relation to the underlying kinetics and dynamics, remain challenging to determine.
This work provides an experimental and theoretical framework into the kinetics and dynamics of the supramolecular self-assembly processes of amino-acid-based building blocks, leading to the design of tailor-made materials for biomedical and material science applications. Here, we present a study of the self-assembly of Fmoc-pentafluoro-phenylalanine (Fmoc-F5-Phe), a modified amino-acid, shedding light on those key processes. We show that Fmoc-F5-Phe forms diverse architectures, including fibrils, ribbons, and crystals, modulated by the solution conditions in which self-assembly takes place. We further elucidate the specific molecular interactions which play a role in crystal structure formation using powder X-ray diffraction. Finally, by probing the self-assembly of Fmoc-F5-Phe using a microfluidic platform, we reveal the formation of transient spherical assemblies, followed by a gel composed of fibrils and finally crystals, and monitor these structural transitions in real-time. Furthermore, we show that the kinetic behavior of the crystallization process adheres to the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model of phase transformation rate.
