Materials science, chemistry, medicine
— I am passionate about using scientific knowledge and tools to address important problems.
Ferroelectricity is considered the electronic analogue of ferromagnets: an electronic polarization can be manipulated with an external electric field. This property has been studied in organic charge-transfer complexes for more than four decades, however, only manifests at < 81 K. In collaboration with Sir Fraser Stoddart, we developed a new supramolecular design for organic charge-transfer complexes that are capable of spontaneously forming hydrogen bonded networks. These structures demonstrate ferroelectricity at room temperature and above . (Tayi et al. Nature 2012)
(w/ Alex Shveyd, Andrew Sue, and Dennis Cao)
As we studied the versatility of our supramolecular design, we stumbled upon a new architecture for charge-transfer complexes. Historically, CT complexes form two architectures in a one-to-one ratio: a mixed stack lattice (alternating donors and acceptors) or segregated stacks (a stack of donors neighboring a stack of acceptors). By incorporating supramolecular recognition sites, we developed a class of CT complexes that assembles into a two-dimensional architecture with bidirectional charge-transfer ferroelectricity in two dimensions. (Tayi et al. submitted ).
(w/ Alex Shveyd, Andrew Sue, Dennis Cao, and Ashwin Narayanan)
Nanofiber, nanoparticle fabrication
Another type of hydrogen-bonded network is a peptide amphiphile (PA). PAs are molecules with three specific segments: a biepitope, β-sheet-forming segment, and a hydrophobic tail. When solubilized in water, these molecules self-assemble into filamentous, one-dimensional nanostructures that are bioactive. Using techniques like electrospinning and electrospray, we can create large-area thin films of peptide amphiphile microfibers with control over the bioactivity and mesostructure. (Tayi et al. submitted )
(w/ Tommy Pashuck)
My interest in composites came from examining the shortcomings of conventional composites, like rebar-reinforced concrete and fiber-reinforced composites. For example, once cast, these materials are difficult to change; once broken, they are expensive to repair. We have developed a new concept for composite materials: systems that are adapt to their environment and are reconfigurable in shape and strength. Such properties were realized by exploiting dynamic non-covalent interactions.
(w/ Ju-Hee So, George Whitesides)
The earth is getting warmer - grappling with the extensive production of carbon dioxide is an important scientific problem. Conventional approaches to dealing with carbon dioxide involve carbon sequestration: compress the gas and bury it in the ground. To date, this approach is not cost competitive. Instead of taking a physical approach, we intend to take a chemical one. Our approach converts carbon dioxide into a more reactive form that is highly reactive; by mixing this form of carbon dioxide with another compound, we can hope to produce a new chemical that has economic value. Therefore, capturing carbon dioxide and selling the chemical product could make such a "carbon conversion" process more cost effective.
(w/ Mostafa Baghbanzadeh, George Whitesides)