Fabrication and radiative cooling properties of polyoxymethylene fiber⁃based composite aerogels

doi:10.19491/j.issn.1001-9278.2025.09.005

Abstract

Abstract:

In this study， polyoxymethylene （POM）/cellulose nanofiber （CNF） composite aerogels were fabricated via vacuum freeze⁃drying， and the influence of fiber length on their structure and properties was systematically investigated. Nano⁃silica （SiO₂） was incorporated at varying mass percentages to produce POM/CNF/SiO₂ composite aerogels， and their radiative cooling performance was evaluated. Temperature variations of the aerogels were monitored under direct sunlight and shaded conditions on a clear day. Results indicated that the POM/CNF aerogel prepared with 1 mm fibers achieved a maximum sub⁃ambient cooling of 8.7 ℃ under direct sunlight. With the addition of nano⁃SiO₂， the composite aerogel exhibited enhanced cooling performance， reaching a maximum temperature reduction of 12.2 ℃. Under shaded conditions， the temperature drops were 2.5 and 1.6 ℃ for the POM/CNF and POM/CNF/SiO₂ composite aerogels， respectively. Notably， the optimal incorporation of nano⁃SiO₂ significantly improved solar reflectance （up to 92.44 %） and compressive strength while maintaining high infrared emissivity （82.56 %） and low thermal conductivity ［0.048 W/（m·K）］. These findings indicate that POM⁃based composite aerogels exhibit exceptional radiative cooling performance and favorable mechanical properties， offering a viable strategy for energy⁃efficient cooling applications and the development of high⁃performance radiative cooling textiles.

Key words: polyoxymethylene fibers, aerogel, radiative cooling, thermal management

CLC Number:

TQ320

CHEN Xi, DONG Jinming, WANG Yatao, BAI Ruyi, SHI Tao, LIU Huan, MA Xiaofeng, WANG Xiaodong. Fabrication and radiative cooling properties of polyoxymethylene fiber⁃based composite aerogels[J]. China Plastics, 2025, 39(9): 26-37.

Figures/Tables 22

Fig.1. Outdoor radiative cooling performance testing device

Fig.2. Photographic image of the samples

Fig.3. Density and porosity of the samples

Fig.4. SEM images of the samples

Fig.5. SEM images of POM/CNF/SiO2 aerogels with different mass percentage contents of nano⁃SiO2

Fig.6. （a） Stress⁃strain curves and （b） maximum compressive stress and compressive modulus of POM/CNF aerogels with different POM fiber lengths

Fig.7. （a） Stress⁃strain curves and （b） maximum compressive stress and compressive modulus of POM/CNF/SiO₂ aerogels with different nano⁃SiO₂ contents

Fig.8. Stress⁃strain curves of aerogels under different strains：（a） POM/CNF1 aerogel and （b） POM/CNF/SiO₂ 4.0 wt% aerogel

Fig.9. （a） Stress–strain cyclic curves of POM/CNF1 aerogel and （b） POM/CNF/SiO₂ 4.0 wt.% aerogel under 25% strain

Fig.10. FTIR of POM/CNF aerogel and POM/CNF/SiO2 aerogel

Fig.11. X⁃ray diffraction pattern of the samples

Fig.12. Emissivity curves of POM fibers and POM/CNF/SiO₂ aerogels

Fig.13. Reflectance of POM fibers， POM/CNF aerogels and POM/CNF/SiO2 aerogels with different nano⁃SiO2 contents

Fig.14. （a） Outdoor solar radiative cooling testing device；（b） Testing device for POM/CNF aerogels with different POM fiber length；（c） Testing device for different kinds of materials；

POM长度/mm	1.0	2.0	3.0	5.0
阳光直射下温差/℃	8.8	7.4	7.2	5.8
阴影下温差/℃	2.0	2.1	1.7	1.0

Tab.1. Maximum delta temperature of POM/CNF aerogels with different POM fiber length

Fig.15. （a） Wind speed and air temperature changes；（b） Curve of solar irradiance；（c） Measurement temperature changes and （d） delta temperature changes with ambience of POM/CNF aerogels with different POM fiber length

纳米SiO₂含量/wt%	0	2.0	4.0	6.0	8.0	10.0
阳光直射下温差/℃	9.4	10.6	12.2	9.2	7.6	6.1
阴影下温差/℃	1.6	1.8	1.4	0.9	0.7	0.4

Tab. 2. Maximum delta temperature of POM/CNF/SiO2 aerogels with different mass percentage contents of nano⁃SiO2

样品名称	POM/CNF₁aerogel	Cotton	PI aerogel
阳光直射下温差/℃	7.5	5.8	1.5

Tab.3. Maximum delta temperature of different materials

Fig.16. （a） Wind speed and air temperature changes；（b） Curve of solar irradiance；（c） Measurement temperature changes and （d） delta temperature changes with ambience of POM/CNF/SiO2 aerogels with different SiO2 content

Fig.17. （a） Measurement temperature changes and （b） delta temperature changes with ambience of different kinds of materials

Fig.18. Thermal conductivity of POM/CNF/SiO2 aerogels with different SiO2 content

Fig.19. Thermal conductivity of POM/CNF/SiO2 aerogels with different mass percentage contents of nano⁃SiO2

References 12

[1]	WANG Y， CHEN L， CHENG H， et al. Mechanically flexible， waterproof， breathable cellulose/polypyrrole/polyurethane composite aerogels as wearable heaters for personal thermal management［J］. Chemical Engineering Journal， 2020， 402： 126222.
[2]	LI Z， CHEN Q， SONG Y， et al. Fundamentals， Materials， and Applications for Daytime Radiative Cooling［J］. Advanced Materials Technologies， 2020， 5（5）： 1901007.
[3]	杨京南. 昼间辐射制冷用气凝胶厚膜的可控制备与光学性能研究［D］. 中国科学院大学（中国科学院上海硅酸盐研究所）， 2021.
[4]	ZHAO B， HU M， AO X， et al. Radiative cooling： A review of fundamentals， materials， applications， and prospects［J］. Applied Energy， 2019， 236： 489⁃513.
[5]	GRIGGS M. Measured and Calculated Earth⁃Atmosphere Radiance in the 8⁃14⁃mu Window as a Function of Altitude［J］. Applied Optics， 1969， 8（1）： 171.
[6]	BERDAHL P. Radiative cooling with MgO and/or LiF layers［J］. Applied Optics， 1984， 23（3）： 370.
[7]	RAMAN A P， ANOMA M A， ZHU L， et al. Passive radiative cooling below ambient air temperature under direct sunlight［J］. Nature， 2014， 515（7528）： 540⁃544.
[8]	KECEBAS M A， MENGUC M P， KOSAR A， et al. Passive radiative cooling design with broadband optical thin⁃film filters［J］. Journal of Quantitative Spectroscopy and Radiative Transfer， 2017， 198： 179⁃186.
[9]	YU X， CHAN J， CHEN C. Review of radiative cooling materials： Performance evaluation and design approaches［J］. Nano Energy， 2021， 88： 106259.
[10]	陈曦. 被动昼间辐射制冷薄膜的制备及冷却性能的研究［D］. 东南大学， 2024.
[11]	WU X， LI J， JIANG Q， et al. An all⁃weather radiative human body cooling textile［J］. Nature Sustainability， 2023， 6（11）： 1446⁃1454.
[12]	任泽钰. 纤维素纳米纤维复合气凝胶的制备及其昼间辐射制冷性能研究［D］. 东华大学， 2024.