Recently, Beihang’s micro-nano physics and application research group led by Professor Chen Ziyu and Associate Professor Xie Yong, in collaboration with Prof. Ivan Smalyukh from University of Colorado Boulder, published a research article entitled “Programmable Ultralight Magnets via Orientational Arrangement of Ferromagnetic Nanoparticles within Aerogel Hosts” in ACS Nano.
Aerogel, as the lightest solid material which has a density of 0.16 kg m–3 in a vacuum, is preferred for developing the ultralight composite materials. With advantages of low thermal conductivity and high shock resistance, aerogel is also a promising candidate in the field of aerospace. However, due to stable physical and chemical properties of the material, its application in intelligent control unit fails to gain smooth progress.
To solve the problem, the research group embedded orientationally ordered, ferromagnetic nanoparticles into aerogels to achieve ultralight programmable aero-magnets. Combining the advantages of noncontact and remote control of magnetic stimulation and the ultra low density of aerogels, the aero-magnets are expected to be widely applied in the fields of aerospace components.
In the aero-magnets preparation procedures, the ferromagnetic nanoparticles were first dispersed in the aerogel precursor solution. Then the particles were oriented by imposing localized, uniform fields utilizing a sandwich structure with reversed magnetic poles during the solution state. The magnetic field was removed when the sol–gel process was completed with entrapment of the magnetic nanoparticles within the gel. The gel was then aged for a specified time and followed by solvent exchange with isopropanol. At last, aero-magnets were obtained by critical point drying. Using the approach, samples with a large areaand well-defined shape can be obtained by a homemade casting mold.
Procedures for Fabricating Aero-Magnets
Measurement and adjustment of properties of single-domain aero-magnet
Design and measurement of magnetic properties of double domain aero-magnet
The ultralight programmable aero-magnets can be applied in the fields of aerospace and intelligent devices like lightweight tiny satellites, aircraft and spacecraft components, space station devices and so on. The use of aero-magnets can greatly reduce the cost of aerospace devices and boost the development of aviation and space industry.
Li Yuanyuan, a PhD student under the supervision of Prof. Chen Ziyu is the first author of the article. Associate Professor Xie Yong and Prof. Ivan Smalyukh are corresponding authors of this work. The research work is supported by the National Natural Science Foundation of China, Key Program of Beijing Municipal Level (Condensed Matter Physics Program) and Beihang’s Outstanding Young Scholar Program. Chemical & Engineering News (C&EN), published by the American Chemical Society, and China’s media platform “Polymer-science” have reported on the research work.
The research article is available at：https://pubs.acs.org/doi/10.1021/acsnano.9b04818
C&EN’s report on the research work：https://cen.acs.org/materials/Featherweight-magnets-made-aerogels-embedded/97/web/2019/12
Reported by Liu Rui
Edited by Jia Aiping
Reviewed by Li Guangchao
Translated by Xiong Ting