In the heart of San Sebastian, Spain, at the University of the Basque Country’s POLYMAT Applied Chemistry Department, a team of researchers led by Mario Andres Martinez has been tackling a significant challenge in the field of nanofiber production. Their work, recently published in *Macromolecular Materials and Engineering* (or *Macromolecular Materials and Engineering* in English), focuses on improving the water resistance of nanofibers created through a process called suspension electrospinning.
Electrospinning is a technique that uses electric force to draw charged threads of polymer solutions into nanofibers. Suspension electrospinning, a variant of this method, uses a water-soluble template polymer to enable the spinning of hydrophobic polymers in water, eliminating the need for toxic organic solvents. This is a significant advantage, as it makes the process more environmentally friendly and safer for workers.
However, the use of a template polymer presents a dilemma. While it is necessary to form continuous fibers, increasing its amount reduces the fibers’ water resistance. “We needed to find a balance,” Martinez explains. “We wanted to use just enough template polymer to form uniform fibers, but not so much that it would compromise their water resistance.”
The team’s research identified the minimum template concentration needed to produce uniform, water-resistant nanofibers from a monomodal acrylic latex. But they didn’t stop there. They also successfully spun a high solids content bimodal acrylic latex for the first time, enhancing process productivity and allowing a 50% reduction in the template polymer compared to the monomodal system.
The implications for the energy sector are substantial. Water-resistant nanofibers have potential applications in various energy-related fields, such as in the production of advanced membranes for water filtration and desalination, or in the development of more efficient batteries and supercapacitors. “The energy sector is always looking for more efficient, sustainable materials,” Martinez says. “Our research could contribute to the development of such materials.”
The team also explored two additional strategies to increase the water resistance of the nanofibers. One involved thermal cross-linking of a carboxylic acid functionalized latex with polyvinyl alcohol (PVA), while the other involved spinning a high glass transition temperature latex followed by its coalescence before the template removal. They also compared the effectiveness of PVA and polyethylene oxide (PEO) as template polymers.
This research could shape future developments in the field by providing a more sustainable and efficient method for producing water-resistant nanofibers. It opens up new possibilities for the use of nanofibers in various applications, particularly in the energy sector. As the world grapples with climate change and the need for sustainable energy solutions, such advancements are not just welcome, but necessary.
The full study is available in the journal *Macromolecular Materials and Engineering*, offering a deep dive into the methods and findings of this promising research.