关键词: 辐射调温织物, 辐射制冷, 辐射制热, 热管理纺织品, 双模态调温织物, 共轭静电纺丝, 包覆纱

Abstract:

Objective To address the poor mechanical properties and unidirectional functionality of conventional radiative thermoregulatory textiles, this study developed a dual-mode fabric capable of dynamically switching between cooling and heating. This was achieved by preparing thermoregulatory nanofiber-coated yarns via conjugate electrospinning and subsequent weaving. Based on the understanding that over 50% of human body heat exchange occurs via radiation, this mechanism was strategically utilized as the main pathway for thermal regulation. The core goal was to create a scalable and user-friendly textile that enables on-demand thermal comfort through a simple physical action - flipping the fabric, aiming to provide a practical zero-energy solution for personal microclimate control.

Methods Core-sheath structured coated yarns were fabricated using conjugate electrospinning. Cotton fibers served as the core for mechanical strength and comfort. Two functional polymer solutions were used to form the sheath membrane. A polyvinylidene fluoride (PVDF) solution with silicon dioxide (SiO₂) nanoparticles was used for radiative cooling, and a polyacrylonitrile (PAN) solution blended with MXene nanosheets was employed for radiative heating. The concentrations of SiO₂ and MXene in the corresponding solutions were varied from 1 to 5 wt% to optimize performance. These core/sheath functional yarns were woven into a double-faced fabric with a cooling side and a heating side. The morphology was examined by scanning electron microscopy (SEM). Optical properties (solar reflectance and absorptance, 250-2 500 nm) were measured via UV-Vis-NIR spectroscopy. Uniform dispersion of particles was verified using energy-dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FT-IR). Thermal performance was evaluated under indoor simulated solar irradiation (1 000 W/m²) using an infrared camera and in outdoor field tests under natural sunlight (500-1 000 W/m²), with plain cotton fabric as the baseline.

Results Morphological analysis showed that the radiative cooling nanofiber-coated yarns (10% PVDF-3% SiO₂) exhibited a distinct nanoparticle-structured surface, significantly enhancing light scattering. This structure achieved an average solar reflectance more than 83% via Mie scattering, effectively reducing heat gain. In contrast, the radiative heating yarns (10% PAN-2% MXene) maintained a smooth surface, with MXene providing a high solar absorptance of 0.78 for efficient light and heat absorption.Thermal performance was found obvious. In indoor tests conducted using a xenon lamp, compared to cotton fabric (47.3 ℃), the cooling side of the material achieved a temperature reduction of 3.0 ℃ (reaching 44.3 ℃), while the heating side increased the temperature by 18.6 ℃ (reaching 65.9 ℃). Outdoor tests under ambient conditions of 22-33 ℃ exhibited enhanced temperature regulation performance: the cooling side achieved a temperature reduction (ΔT) of 6.3 ℃ relative to cotton, and the heating side attained a temperature increase (ΔT) of 28.4 ℃. The core mechanism lies in the synergistic effect—SiO₂ nanoparticles provide cooling via Mie scattering of sunlight, while MXene enables strong and broadband (200-2 500 nm) photothermal absorption for heating.

Conclusion In summary, a reversible dual-mode radiative thermoregulatory fabric was successfully demonstrated, fabricated via conjugate electrospinning and weaving. The fabric enables efficient, switchable cooling/heating through simple inversion, outperforming conventional textiles with substantial temperature differentials (ΔT up to 28.4 ℃). The optimized formulations, i.e. 10% PVDF-3% SiO₂ nanofiber-coated yarn for cooling and 10% PAN-2% MXene nanofiber-coated yarn for heating, effectively balance processability with excellent optical and thermal performance. This technology offers a highly adaptable, scalable, and energy-free solution for advanced personal thermal management, suitable for outdoor environments.

Key words: radiation modulating fabric, radiative cooling, radiative heating, personal thermal management textiles, dual-mode temperature-regulating fabric, conjugated electrospinning, covered yarn