Electrospinning Polyelectrolytes from Complex Coacervates

Electrospun fibers are canvases that can be tailored towards a wide variety of applications. However, traditional electrospinning often involves organic solvents that can cause cytotoxicity concerns. Here, I will highlight our revolutionary fibers that form using only water and salt. Polyelectrolyte complexes (PECs) form due to the electrostatic complexation between oppositely-charged polymers. We have recently demonstrated that by exploiting the salt-driven plasticization of PECs, we can enable the electrospinning of ultra-stable solid fibers from an aqueous solution containing a pair of strong polyelectrolytes and salt. Electrospun PEC fiber mats are stable over a wide range of pH values, ionic strength conditions, and many organic solvents. To address the challenge of delivery, we encapsulated a library of dyes into the coacervate phase and subsequently, achieved highly-loaded electrospun fibers. Finally, I will propose a mechanistic understanding of the design rules for electrospinnable coacervates by correlating polymer chain length, with coacervate phase behavior, and as-spun fiber morphology. The overall goal of the talk is to illustrate our recent findings and how these results can guide the green engineering of multifunctional fiber mats.