The development of synthetic fibers that mimic the complex, hierarchical nano-to-microscale structures found in nature, like cellulose and silk, can potentially revolutionize various fields, from smart active textiles to environmental science an sustainability. These fibers, which contain internal features spanning from the nano- to the microscale, can exhibit superior properties compared to conventional fibers, opening doors for innovations in filtration, separation, catalysis, energy, and more.

Unmet Need
While significant progress has been made in controlling the external properties of synthetic fibers, achieving intricate internal structures has remained a challenge. Existing methods for creating such hierarchical structures within fibers are often complex, costly, and lack the versatility to produce a diverse range of morphologies, with tailored hierarchical architectures for diverse applications.

Our Technology
Our method allows the fabrication of hierarchically structured polymeric fibers using a simple yet elegant approach: polymerization-induced spontaneous phase separation coupled with chemical fixation. This method utilizes a core-sheath fiber structure produced through coaxial electrospinning, where the core comprises a polyamine, polyethylene glycol, and a solvent. The sheath consists of a biodegradable polymer, poly lactic-co-glycolic acid (PLGA), dissolved in a solvent mixture.

The fabrication process involves three steps:
• Coaxial Electrospinning: the core and sheath solutions are simultaneously electrospun through a coaxial needle, resulting in the formation of core-sheath fibers.
• Collection into a Reactive Gel Matrix: The fibers are collected on a rotating drum coated with a gel containing a crosslinking agent.
• Spontaneous Phase Separation and Fixation: Upon contact, the crosslinker diffuses into the core, initiating spontaneous phase separation of the polyamine solution and rapidly crosslinking the formed structures. This process results in the creation of diverse porous architectures within the fiber’s core.

Potential Markets
This technology holds immense potential in various sectors:
Filtration and Separation: The highly porous structure of these fibers, characterized by interconnected voids within the core, decorated with “sticky” nitrogen moieties, makes them ideal for applications in filtration and separation.
Catalysis: The nitrogen-rich chemistry of the polyamine core allows for the chemisorption of metal ions and the physisorption of enzymes, enabling the development of efficient and selective catalytic systems. This has implications for industries reliant on catalytic processes, offering improved efficiency and sustainability.
Sensing: The ability to selectively adsorb specific molecules, like heavy metals, opens up possibilities in sensor development. The fibers could be integrated into sensors designed to detect environmental pollutants or monitor water quality.
Biomedical Applications: The biodegradable nature of the PLGA sheath, combined with the tunable porosity and potential for biomolecule immobilization, makes these fibers promising for drug delivery and tissue engineering applications.