Researchers use multiphase composition and electrospinning to produce SiOC nanofibers
Rapid advances in the electronics industry have brought great convenience to civilian applications, but they also contribute to electromagnetic pollution and pose risks to human safety. To meet the diverse requirements of consumer applications, such as equipment with different curved surfaces and clothing for different work environments, electromagnetic wave absorbers not only provide effective absorption, but also are lightweight and easy to process. and must be sufficiently flexible.
Additionally, electromagnetic wave-absorbing materials face challenges under extreme conditions commonly encountered in the construction and transportation industries, such as high temperatures, frequent vibrations, and pressure shocks.
Therefore, the search for materials with good thermal insulation, good flexibility and elasticity, good processability, and ultralight properties represents a trend in the development of advanced microwave absorbers. Polymer-derived ceramic (PDC) SiOC exhibits robust mechanical and high-temperature performance in extreme environments, coupled with low density, high strength, and low raw material cost, offering potential applications in both thermal and electromagnetic wave (EMW) protection. emphasize. .
However, SiOC ceramics obtained from a single precursor polymer have poor dielectric properties, which limits their further applications. To improve the EMW damping performance, it is common to introduce a second phase into the SiOC matrix to take advantage of different components to enhance EMW absorption.
On the other hand, the inherent brittleness of SiOC ceramics significantly hinders their use in complex environments. In this case, electrospinning is a versatile method to produce one-dimensional micro-nanofiber materials with uniform size distribution and consistent morphology. Aiming to improve both flexibility and electromagnetic wave absorption performance, the research team applied a multiphase composition and electrospinning strategy to fabricate SiOC nanofibers.
The research team published their findings in the Journal of Advanced Ceramics on September 9, 2024.
Co and TiO2 modified SiOC nanofibers (CTS) were successfully prepared using a simple and controllable electrospinning technique. Thanks to the excellent three-dimensional continuous network structure and uniform distribution of the composite material within the fibers brought about by electrospinning, CTS composites have excellent thermal insulation properties (thermal conductivity <0.0404 Wm-1K-1), remarkable flexibility (resistance less than 4%). (change after 1,500 cycles of 180° bending), excellent compression resistance (<12% residual strain after 500 cycles at 60% strain).
The CTS-800 sample (silicone resin) with filler content of only 5 wt% achieves an effective absorption bandwidth (EAB) of 8.64 GHz (9.36 to 18.00 GHz) with a thickness of 3.25 mm and an RLmin value of -66.00 dB . At 17.11GHz. The successful preparation of such multifunctional CTS nanofiber materials holds promise for applications in thermal and microwave protection.
SiOC nanofiber samples exhibit comprehensive multifunctional properties due to their high porosity and multilayered structure in the thickness direction. External electromagnetic waves or thermal shock waves are significantly attenuated. Moreover, with great flexibility, these findings ensure that the required deformations in various high-demand scenarios can be fully addressed, improving work efficiency.
Further information: Linghao Pan et al, Electrospun flexible and elastic Co/TiO 2/SiOC nanofibers: Towards thermal and electromagnetic protection, Journal of Advanced Ceramics (2024). DOI: 10.26599/JAC.2024.9220968
Provided by Tsinghua University Press
Citation: Researchers use multiphase composition and electrospinning to make SiOC nanofibers (October 21, 2024) https://phys.org/news/2024-10-multi-phase-composition-electrospinning Retrieved October 21, 2024 from -fabricate.html
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