Electrospinning Nanofiber Mats from Aqueous Polyelectrolyte Solutions

University Of Massachusetts Amherst, Amherst MA

Investigators

Abstract

Electrospinning is a well-established technique used to manufacture non-woven fiber mats comprised of nano- and micro-scale diameter fibers. Due to their high porosity and surface area, the fiber mats are promising materials for medical, environmental, and energy applications. While mats have been electrospun from over 100 different polymers, nearly all reports on the electrospinning of charged polymers have utilized toxic solvents in the precursor electrospinning solution and/or poisonous molecules post-production to make the mats chemically robust. This award supports fundamental research into the development of chemically robust nanofiber mats electrospun from aqueous polyelectrolyte solutions. The new aqueous precursor solutions will use salt to enable the preparation of thermally and chemically robust fibers without the use of toxic solvents, crosslinkers, or post-processing. Using green chemistry to manufacture polyelectrolyte nanofiber mats that can encapsulate cargo such as small molecule compounds, will broadly impact the design of multifunctional fiber scaffolds for a broad range of applications, including, wound healing and active food packaging. The U.S. economy and society will benefit from the production of safer materials that is enabled by this research. In addition to the technical achievements, this research will educate, provide research experiences, and mentor a diverse workforce at the emerging interface of chemical engineering, fiber science, and polymer physics. This research will result in numerous new research experiences and an enhanced engineering education for women and underrepresented groups. The full application potential of electrospun non-woven polyelectrolyte fiber mats cannot be realized due to the dependence of the manufacturing process on toxic solvents and/or cytotoxic crosslinking agents. This research will provide a critical translation between the processing, structure, and properties of aqueous polyelectrolyte solutions electrospun into chemically robust fiber mats. Electrospinning precursor solutions will be comprised of complex coacervates, which are dense, polyelectrolyte-rich liquids that result from the electrostatic complexation of oppositely-charged polymers in water. The research team will establish parametric design rules for the electrospinning of polyelectrolyte fibers by correlating electrospinning with thermodynamic phase behavior and the rheological properties of a model coacervate system. Additionally, the partitioning and loading of hydrophilic and hydrophobic cargo into the precursor solutions and electrospun fibers will be established as a function of the hydrophobicity of the polyelectrolytes and the cargo. Chemically and thermally robust cargo-carrying fiber mats hold tremendous potential in applications where green materials are imperative, such as, wound healing, water remediation, catalysis, and food packaging.