Title: Revealing morphological insights on organic semiconductors using charge transport measurements

Speaker: Prof.Nikos Hadjichristidis

Time: 10:00 AM, April 20,2026 

Venue: 346 Meeting Room, Weimei Building (North Campus)

Abstract:

This lecture presents three recent breakthroughs from our laboratory, illustrating how precision synthesis enables unprecedented control over polymer structure and properties. The first study addresses the long-standing challenge of achieving living/controlled ring-opening polymerization of glycolide. By employing fluoroalcohols as cosolvents, we simultaneously enhance monomer solubility and activate both the monomer and the propagating chain end, as supported by DFT and NMR studies. This approach provides access to well-defined polyglycolide and advanced macromolecular architectures, while enabling selective chemical recycling back to the monomer, offering a sustainable alternative. The second study revisits the synthesis of linear polyethylene via C1 polymerization. Using a novel initiator, 1,5-(bis-borinane)pentane, in combination with highly purified monomers, branching is reduced below 0.02%, yielding α,ω-hydroxy polymethylenes with crystallinity approaching theoretical limits (~99%), as confirmed by advanced NMR and X-ray analyses. The third study tackles the long-standing challenge of introducing functionality at every backbone carbon. Through two controlled C1 polymerization pathways, carbenium-initiated and Ni(acac)₂-mediated, we achieve fully aromatic-substituted polymethylenes with programmable iso- and syndiotacticity, establishing a new paradigm beyond conventional polyolefins. Together, these advances demonstrate how solving fundamental synthetic challenges through molecular precision leads to transformative materials, capturing the essence and beauty of polymer chemistry.