The cold energy of the Universe can be harnessed through radiative cooling (RC) to achieve thermal comfort and energy conservation, representing a promising green thermal management strategy. However, most studies have focused on maximizing cooling power. The limitations of dynamic environmental changes in the RC performance have been overlooked. In this study, a Janus-structured polyimide composite nanofiber membrane was developed using electrospinning for efficient thermal management in various environments. The concept of mismatched charge transfer complexes was utilized to prepare fluorinated polyimides, which exhibit excellent RC performance and effectively address the issue of high solar absorption (average solar reflectance (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\overline{R}_{{{\text{solar}}}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mover> <mi>R</mi> <mo>¯</mo> </mover> <mtext>solar</mtext> </msub> </math></EquationSource> </InlineEquation>) = 96.2%; average mid-infrared emissivity (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\overline{\varepsilon }_{{{\text{MIR}}}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mover> <mi>ε</mi> <mo>¯</mo> </mover> <mtext>MIR</mtext> </msub> </math></EquationSource> </InlineEquation>) = 89.7%). Moreover, lauric acid@fluorinated polyimide composite nanofibers with a core–shell structure were continuously deposited onto hollow polyimide nanofibers to construct a Janus-structured membrane that integrates RC, thermal shock resistance (melting enthalpy (ΔHm) = 107.6 J g−1 and crystallization enthalpy (ΔHc) = 111.9 J g−1), and thermal insulation. This structure exhibits excellent RC power (105.9 W m−2), temperature regulation ability (cooling of approximately 12.8 °C in summer and maintaining temperature for 2400 s without sunlight), and thermal insulation performance under complex weather changes. The thermal management mechanism and energy-saving principle of this structure in different environments were systematically summarized. Considering these advantages, this study provides design inspiration and theoretical support for the development of multifunctional integrated RC materials. Graphic Abstract

Janus-Structured Polyimide Composite Nanofiber Membrane Enabling Integrated Radiative Cooling, Thermal-Shock Resistance, and Thermal Insulation for Efficient Thermal Management in Complex Environments

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发表日期：

2025年10月8日

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Renhao Li,
Yan Bao,
Ruyue Guo,
Lu Gao,
Wenbo Zhang,
Chao Liu,
Jianzhong Ma

摘要

The cold energy of the Universe can be harnessed through radiative cooling (RC) to achieve thermal comfort and energy conservation, representing a promising green thermal management strategy. However, most studies have focused on maximizing cooling power. The limitations of dynamic environmental changes in the RC performance have been overlooked. In this study, a Janus-structured polyimide composite nanofiber membrane was developed using electrospinning for efficient thermal management in various environments. The concept of mismatched charge transfer complexes was utilized to prepare fluorinated polyimides, which exhibit excellent RC performance and effectively address the issue of high solar absorption (average solar reflectance ( $\overline{R}_{{{\text{solar}}}}$ ${\bar{R}}_{solar}$ ) = 96.2%; average mid-infrared emissivity ( $\overline{\varepsilon }_{{{\text{MIR}}}}$ ${\bar{ε}}_{MIR}$ ) = 89.7%). Moreover, lauric acid@fluorinated polyimide composite nanofibers with a core–shell structure were continuously deposited onto hollow polyimide nanofibers to construct a Janus-structured membrane that integrates RC, thermal shock resistance (melting enthalpy (ΔH_m) = 107.6 J g⁻¹ and crystallization enthalpy (ΔH_c) = 111.9 J g⁻¹), and thermal insulation. This structure exhibits excellent RC power (105.9 W m⁻²), temperature regulation ability (cooling of approximately 12.8 °C in summer and maintaining temperature for 2400 s without sunlight), and thermal insulation performance under complex weather changes. The thermal management mechanism and energy-saving principle of this structure in different environments were systematically summarized. Considering these advantages, this study provides design inspiration and theoretical support for the development of multifunctional integrated RC materials.

Graphic Abstract