Research on flame-retardant aramid nanofiber aerogel-eutectic phase change solvent host-guest composite film has made progress
Flame-retardant aramid nanofiber aerogel – Research progress in deep eutectic phase change solvent host-guest composite film
With the miniaturization, integration and high power of electronic products, how to control the heat generated by electronic products has become a scientific issue that has attracted much attention. Phase change materials have the advantages of high latent heat of phase change and good stability, and have application potential in the fields of thermal energy storage and thermal management. However, how to prepare flame-retardant phase change films that can work in low temperature environments still faces challenges. To this end, the team of Zhang Xuetong, a researcher at the Suzhou Institute of Nanotechnology and Nanobionics, Chinese Academy of Sciences, and the team of Professor Liao Jianhe of Hainan University collaborated to obtain aramid nanofibers (ANF) by dissolving aramid, and then through scraping, sol-gel, and dopamine In-situ polymerization and other processes obtain polydopamine/aramid nanofiber (PANF) airgel films with excellent flame retardant properties; using this airgel film as a porous host to load a eutectic (DES) phase change guest, a flame retardant The preparation process of PANF-DES host-guest phase change film with combustion and low-temperature thermal management functions is shown in Figure 1.
PANF films can be controlled in thickness, density, shape, and continuously prepared in large sizes by changing process parameters. They are bendable, foldable, and have good mechanical flexibility. The in-situ polymerization of dopamine does not change the high specific surface area of the aramid aerogel film. It can also shorten the self-extinguishing time on the alcohol lamp flame and basically maintain the integrity of the matrix, laying a material foundation for the subsequent structural support of the host-guest composite film. .
In this study, the ternary eutectic phase change material was filled into the PANF airgel film. The resulting PANF-DES host-guest film has a phase transition temperature of -21°C, a phase change enthalpy of up to 225J/g, and has excellent flame retardancy. property, its heat release and gas release are one order of magnitude lower than commercial flame-retardant phase change films. There is no open flame when exposed to the flame of an alcohol lamp in a vertical, curved or parallel state, and is only partially carbonized. It releases less heat and has a small flame propagation ability. The excellent flame retardant properties ensure the safety of practical applications. In addition, the researchers explored the thermal management performance of PANF-DES host-guest films on low-temperature electronic devices by building a simple device. The PANF-DES host-guest film can absorb or release a large amount of heat energy through the melting or crystallization process, slowing down the heating or cooling rate; during the cycle of temperature rise and cooling, the PANF-DES host-guest film can reduce temperature fluctuations and maintain the temperature of electronic devices relatively stable. Therefore, this PANF-DES host-guest film can be applied to the temperature management of electronic components in low-temperature environments.
The relevant research results were published in Advanced Functional Materials under the title Flame-Retardant Host–Guest Films for Efficient Thermal Management of Cryogenic Devices. The research work was funded by the National Key Research and Development Program and the Royal Society-Newton Senior Scholars Fund.
Figure 1. Schematic diagram of the preparation and flame retardant and thermal management functions of PANF-DES host-guest composite film.
Figure 2. PANF airgel film: (a-b) optical photos; (c) effect of different concentrations of dopamine solutions on the weight gain rate of aramid airgel film; (d) ANF; (e) polydopamine; (f) PANF microscopic morphology.
Figure 3. Phase change behavior and flame retardant properties of PANF-DES host-guest composite film
Figure 4. Thermal management performance of PANF-DES host-guest composite film
