Aerogel materials play a vital role as shielding materials required for several fields, including electromagnetic interference protecting material for 5G technology, which thermally insulates material in high-rise structures, and infrared stealth material for applications in the military.
Present protective materials, though, frequently lose their protective roles under drastic conditions like extreme temperatures that render them ineffective, a Phys.org report specified.
New #aerogel maintains functionality, superelasticity at #extremetemperatures https://t.co/Aw1NsUCbmR https://t.co/JoFcjFC8Tv
— PhysOrg Physics News (@physorg_physics) July 19, 2022
Other shielding materials are losing their elasticity, resulting in similar problems with performance. A research team from Sichuan University has developed new aerogel materials that can retain their usefulness and superelasticity under very high temperatures.
SEM images in a and b show that the aerogels have nanotube structures coated by the nanosheets.
Polymer-Based Foam Materials
The corresponding author of the study published in the Nano Research journal, Hai-Bo Zhao, a professor in the College of Chemistry, explained they aimed to address the issue that the conventional protective aerogel materials' performance deteriorates severely under harsh working conditions.
Before the developments of Zhao's team, polymer-based foam materials were typically used as shielding or protective materials.
Such materials showed the positive characteristics of superelasticity and high compressibility, although they were able to retain the properties following the melting temperatures of the polymers.
Another commonly applied material was ceramic and metallic foams, which were stable through temperature ranges in a manner their polymer-based foam counterparts were not, yet did not have the elasticity required to be practical.
Carbon Aerogels
A method that came closer to a scalable solution involved using carbon aerogels, which have traits that lend themselves well to thermal insulation and electromagnetic interference, like high specific surface area, good electrical conductivity, chemical and thermal stability, and low density.
Nonetheless, carbon aerogels have limitations because of certain inherent properties. Moreover, carbon nanotubes turned out to be a popular way to build superelastic carbon aerogels since they could retain the needed properties at high temperatures, although since the preparation required numerous steps, the techniques were not scalable.
By focusing on the microstructure design, Zhao and his team wear able to produce a polymer aerogel with superelasticity that worked in a temperature range of -196 to 500 degrees Celsius with a process that was salable, not to mention practical.
The corresponding author also said that unlike most carbon aerogels reported in the past that usually own poor mechanical properties, the prepared aerogel materials show temperature-invariant superelasticity while retaining multifunctional shielding performance.
Carbon Aerogel Composite Multi-Walled Carbon Nanotubes
Zhao is affiliated with the National Engineering Laboratory for Eco-Friendly Polymeric Materials in Sichuan and the Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials.
Zhao uses bidirectionally oriented carbon or carbon aerogel composite multi-walled carbon nanotubes in this approach.
Combining the positive characteristics of carbon aerogels with the positive characteristics of carbon nanotubes with a highly ordered carbon skeleton is one of the key differentiators between the said new approach and the past methods.
Such a scalable approach to attaining the desired microstructures, a similar Nano Magazine report specified, particularly highly oriented arch structures, engages a bidirectional freezing and carbonization process for developing the carbon or carbon aerogels.
Related information about aerogels is shown on Active Aerogel's YouTube video below:
RELATED ARTICLE: Freezing Electrons as Temperature Rises: Discovered Graphene System Does That!
Check out news and information on Nanotechnology in Science Times.
