2022 – 2023 Soft Matter Graduate Fellowship Recipients
Posted in News Story
The ISM is excited to introduce the 2022-2023 Soft Matter Graduate Fellowship recipients: Davina Adderley and Victor Francis!
Advisor: Professor Steven Metallo
Biomolecular condensates, also termed ‘membraneless compartments’, emerge from a phase condensation reaction of biomolecules. These biomolecules can establish stable and distinct boundaries despite the lack of membrane encapsulation. Examples of biomolecular condensates include nuclear stress bodies that regulate gene expression and stress granules found in the cytoplasm that store translation machinery. The condensates manifest as liquid droplets and are an example of the general phenomenon known as liquid-liquid phase separation (LLPS). LLPS is a reversible process that involves the equilibration of a uniform fluid into two distinct liquid phases: a dense phase and a dilute phase. The dense phase appears as liquid droplets in coexistence with a dilute phase.
Although LLPS is an essential process in cells, the energetics of the weak, intermolecular interactions that drive most biomolecular condensates is not fully understood. To address this gap, we employ systematically varied small-molecule probes to elucidate the strength of specific chemical interactions within the dense phase of LLPS protein systems. A common feature of proteins that undergo LLPS is the presence of intrinsically disordered regions: stretches of sequence that exist as an ensemble of rapidly fluctuating conformations that lack a stable secondary or tertiary structure. My research uses the disordered Laf-1 RGG protein as a model physiological LLPS system and the partitioning of small molecule probes between the dense and dilute phases to determine the free energy of interactions. Specifically, we assess the ability of C-H/π interactions to contribute to phase separation and the ability of an aromatic system’s electron density and substitution pattern to modulate the interaction strength with a phase-separated protein. Additionally, we investigate the energetic contributions of the phosphate backbone of nucleic acids involved in complex phase condensate assembly using sequence-matched polymers with synthetic, uncharged linkages in order to isolate the energetic contributions to LLPS formation that are combined in the native systems.
Advisor: Professor Nag Gavvalapalli
My research focuses on developing design rules for n-type thermoelectric (TE) polymeric materials. Polymer TE materials are advantageous due to their solution processability, light weight, flexibility, and low thermal conductivity, which paves the way for large area, low cost, and low power TE applications. TE performance of n-type polymers is inferior to that of p-type polymers and impedes the development of practical polymer TE devices. Towards this, I am developing azaacene-based n-type polymers containing larger acenes with varying numbers and positions of azo groups. Depending on the number of rings, azo groups and their position, azaacene polymers are expected to show deeper LUMOs (<-4.6 eV), higher conductivity, and even become air stable after n-doping. More importantly, the azaacenes can undergo multiple reductions and therefore are expected to show higher conductivity. These characteristics will take azaacene polymers to the forefront of n-type TE polymers.