Ceramic nanofiber sponges offer large-scale insulation, water purifica-tion possibilities
In a collaboration between Brown University and Tsinghua University in China, researchers have created small sponges out of ceramic nanofibers that are heat-resistant and highly deformable.
The researchers wanted to come up with a material that was highly deformable but resistant to high temperatures, Huajian Gao, Brown University School of Engineering professor and one of the researchers, says in a Brown news release.
Through their research, Gao’s lab, along with Hui Wu and Xiaoyan Li’s lab at Tsinghua, discovered that ceramic materials behave differently on a nanoscale. They do not crack or break – which is that typically happens to ceramics on a larger scale. In addition, Gao explained that the ceramic nanofibers they created have a tendency to creep – in other words, enabling the material to deform without breaking, he says.
The challenge the scientists initially faced lies within the creation of nanofibers. Wu’s previous method of electrospinning did not work well with ceramic materials, and 3D laser printing was too costly. So he developed a method called blow-spinning – which uses air pressure to blow ceramic liquid through a tiny syringe. The liquid hardens into nanofibers and is then heated and collected in a small spongy ball.
After creating sponges from various oxide ceramic materials-including titanium dioxide, zirconium oxide, yttria stabilized zirconium dioxide, and barium titanate- the research team subjected them to compression tests. All sponges rebounded from being compressed up to 50%. See the sponges compress and spring back in a short video available at youtu.be/gpwpLieVtmY.
In addition, the team wanted to compare the insulating effects of the nanofiber sponges with various other materials, including glass, iron, and aluminum oxide. When flower petals were placed on top of each material, which was then heated to 400º, only he nanofiber sponges were able to keep the flower petals from burning up.
The work could have a significant impact in industries that make insulated materials requiring flexibility, Gao notes in the release.
Most important, Gao says, the method can be manufactured at a large scale. The method we use for doing it is inexpensive and scalable to make these in large quantities.
The researchers provide an example of another use of their ceramic sponges-water purification. When titanium dioxide sponge was placed in water containing a dye, it absorbed 50 times its weight and degraded the dye. Plus, they were able to recuse the sponge.
The open-access paper, published in Science Advances, is Ultralight, scalable, and high-temperature-resilient ceramic nanofiber sponges.
Brown University and Tsinghua University researchers have created ceramic nanofiber sponges that bend without breaking.