Report method of fabricating larger amounts of nanofibers in liquid
Creating large amounts of polymer nanofibers dispersed in liquid is a challenge that has vexed researchers for years. But engineers and researchers at North Carolina State University and one of its start-up companies have now reported a method that can produce unprecedented amounts of polymer nanofibers, which have potential applications in filtration, batteries and cell scaffolding.
In a paper published online in Advanced Materials, the NC State researchers and colleagues from industry, including NC State start-up company Xanofi, describe the method that allows them to fabricate polymer nanofibers on a massive scale.
The method - fine-tuned after nearly a decade of increasing success in producing micro- and nanoparticles of different shapes - works as simply as dropping liquid solution of a polymer in a beaker containing a spinning cylinder. Glycerin - a common and safe liquid that has many uses - is used to shear the polymer solution inside the beaker along with an antisolvent like water. When you take out the rotating cylinder, says Dr. Orlin Velev, Invista Professor of Chemical and Biomolecular Engineering at NC State and the corresponding author of the paper describing the research, you find a mat of nanofibers wrapped around it.
When they first started investigating the liquid shearing process, the researchers created polymer microrods, which could have various useful applications in foams and consumer products. "However, while investigating the shear process we came up with something strange. We discovered that these rods were really just pieces of 'broken' fibers," Velev said. "We didn't quite have the conditions set perfectly at that time. If you get the conditions right, the fibers don't break."
NC State patented the liquid shear process in 2006 and in a series of subsequent patents while Velev and his colleagues continued to work to perfect the process and its outcome. First, they created microfibers and nanoribbons as they investigated the process. "Microfibers, nanorods and nanoribbons are interesting and potentially useful, but you really want nanofibers," Velev said. "We achieved this during the scaling up and commercialization of the technology."
Velev engaged with NC State's Office of Technology Transfer and the university's TEC (The Entrepreneurship Collaborative) program to commercialize the discoveries. They worked with the experienced entrepreneur Miles Wright to start a company called Xanofi to advance the quest for nanofibers and the most efficient way to make mass quantities of them.
"We can now create kilograms of nanofibers per hour using this simple continuous flow process, which when scaled up becomes a 'nanofiber gusher,'" Velev said. "Depending on the concentrations of liquids, polymers and antisolvents, you can create multiple types of nanomaterials of different shapes and sizes."
"Large quantities are paramount in nanomanufacturing, so anything scalable is important," said Wright, the CEO of Xanofi and a co-author on the paper. "When we produce the nanofibers via continuous flow, we get exactly the same nanofibers you would get if you were producing small quantities of them. The fabrication of these materials in liquid is advantageous because you can create truly three-dimensional nanofiber substrates with very, very high overall surface area. This leads to many enhanced products ranging from filters to cell scaffolds, printable bioinks, battery separators, plus many more."
The research was funded by the National Science Foundation's Accelerating Innovation Research program. NC State's researchers Stoyan Smoukov, Tian Tian and Eunkyoung Shim co-authored the paper, as did Narendiran Vitchuli, Sumit Gangwal, Miles Wright and Pete Geisen from Xanofi Inc.; Manuel Marquez from Ynano Llc.; and Jeffrey Fowler from Syngenta Co.
Note to editors: An abstract of the paper follows.
"Scalable Liquid Shear-Driven Fabrication of Polymer Nanofibers"
Authors: Stoyan Smoukov, Tian Tian, Eunkyoung Shim and Orlin Velev, North Carolina State University; Narendiran Vitchuli, Sumit Gangwal, Miles Wright and Pete Geisen, Xanofi Inc.; Manuel Marquez, Ynano Llc.; and Jeffrey Fowler, Syngenta Co.
Published: March 18, 2015, online in Advanced Materials
Abstract: A simple process for batch or continuous formation of polymer nanofibers and other nanomaterials in the bulk of a sheared fluid medium is introduced. The process could be of high value to commercial nanotechnology as it can be easily scaled up to the fabrication of staple nanofibers at rates that could exceed tens of kilograms per hour.
Dr. Orlin Velev | EurekAlert!
Let the good tubes roll
19.01.2018 | DOE/Pacific Northwest National Laboratory
Method uses DNA, nanoparticles and lithography to make optically active structures
19.01.2018 | Northwestern University
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy