In the fields of smart wearables and personal thermal management, phase-change materials (PCMs) are regarded as a revolutionary solution. They can absorb or release large amounts of heat at specific temperatures, effectively providing fabrics with a “thermal buffering” capability. However, their practical application has long been constrained by a fundamental trade-off: pursuing high energy-storage density often results in poor mechanical properties, leakage, and low thermal conductivity, while improving structural stability usually comes at the expense of heat-storage capacity. Conventional phase-change fibers either suffer from leakage, low strength, and difficult processing, or sacrifice thermal-storage capacity in exchange for mechanical stability. These challenges have severely limited their large-scale application in wearable devices. Therefore, achieving synergistic optimization of these key properties through fundamental structural innovation has become a critical scientific challenge in the field.
Addressing this challenge, the research team led by Professor Zou Ruqiang at Peking University reported a breakthrough in Nature Communications. The team proposed an innovative nanostructure-confined encapsulation–oriented assembly strategy.
Fig. 1 Illustration of the procedure for fabricating C22/CNT@HDPE-SEBS, C22/CNT fibers and PCM-based fabric: (a) The preparation flowchart of C22/CNT@HDPE-SEBS composite, (b) the production of C22/CNT fibers through bi-component melt-spinning, phase-change fabric and garments, (c) the influence of CNT on the orientation of phase change fibers, (d) a photograph of spooled CNT-reinforced PCFs produced by continuous spinning (e) crystallization enthalpy values and melting enthalpy values for the cooling and heating process curves of C22/CNT2 fibers, respectively. Similarly, crystallization enthalpy values and melting enthalpy values corresponding to the cooling and heating process curves of CNT-reinforced phase-change fabric, respectively, (f) a photograph of the CNT-reinforced phase change fabric with scale bar of 20 cm, and (g) a photograph of thermoregulated phase-change garments.
In this work, trace amounts of carbon nanotubes (CNTs) were introduced as both a “nano-skeleton” and heterogeneous nucleation agent, and were integratively designed with three-dimensional interpenetrating polymer networks (3D-IPNs) to construct a multifunctional microstructure for the phase-change material n-docosane. This microstructure simultaneously provides rigid support, rapid thermal transport pathways, and elastic confinement spaces. CNTs act as directional reinforcing units. During melt spinning and drawing processes, they induce highly oriented alignment of both polymer chains and phase-change molecules (n-docosane). This significantly enhances the mechanical strength and axial thermal conductivity of the fibers while also promoting more complete crystallization, thereby improving the heat-storage density. Meanwhile, the 3D-IPNs function as nano-confinement frameworks, forming robust yet elastic cage-like structures at the nanoscale that firmly confine the phase-change molecules. This design fundamentally eliminates leakage during the solid–liquid phase transition and ensures long-term morphological and functional stability during repeated thermal cycling.
Through this precise structural regulation—achieving substantial performance improvements with minimal material addition—the team successfully developed a new generation of high-performance phase-change fibers (PCFs) with multiple performance breakthroughs. The fibers exhibit a melting enthalpy of up to 139.0 J g⁻¹ and a crystallization enthalpy of 138.0 J g⁻¹, corresponding to a heat-storage efficiency exceeding 99%. After 125 intense thermal cycles, the heat-storage capacity shows almost no degradation, while the thermal decomposition temperature is significantly improved. The fibers also demonstrate exceptional toughness and strength, with an elongation at break of 1530% and a tensile strength of 6.32 MPa. These properties allow them to withstand cutting and high-speed sewing on commercial textile equipment, achieving a processing fidelity of over 98%. Importantly, the entire fabrication process is based on mature bicomponent melt-spinning technology, which is highly compatible with existing synthetic fiber industrial production lines. This effectively addresses the key bottleneck preventing high-performance phase-change fibers from transitioning from laboratory research to industrial manufacturing. To evaluate real-world performance, the team fabricated phase-change thermoregulating garments and conducted multi-scenario human-wear tests. In summer outdoor environments, while the surface temperature of a conventional polyester vest reached approximately 50 °C, the phase-change thermoregulating vest maintained a surface temperature of about 42 °C, providing significantly improved thermal comfort for the wearer. In high-temperature indoor working environments, the garments also demonstrated excellent heat-absorption buffering and thermal protection, maintaining a cooler and safer microclimate for users.
The significance of this work goes far beyond the development of a new fiber. It demonstrates a general design paradigm for synergistically optimizing the core properties of phase-change materials through precise multiscale nanostructure engineering. The study elegantly resolves the long-standing “performance trade-off” dilemma in phase-change fibers, achieving simultaneous improvements in energy-storage density, mechanical robustness, cycling stability, and functional performance (such as photothermal conversion).This breakthrough not only paves the way for the large-scale application of intelligent thermal management technologies, but also shows strong potential in fields such as special protective clothing, wearable medical devices, smart sportswear, aerospace cabin garments, and energy-saving building textiles. By providing a powerful material foundation for efficient, personalized, and adaptive thermal management, this work holds significant strategic value for energy conservation, emission reduction, and improving human comfort in extreme environments, demonstrating Peking University’s systematic innovation capabilities in advanced materials research.
The study was published in Nature Communications under the title “Ultralow CNT-reinforced phase-change fibers for scalable wearable thermoregulation.”
Author Information
Professor Zou Ruqiang and Professor Wang Qining from Peking University are the corresponding authors of the paper. The School of Materials Science and Engineering at Peking University is the primary affiliation. The first author is Geng Xiaoye, a postdoctoral fellow in Professor Ruqiang Zou's group at the School of Materials Science and Engineering, Peking University.
This research was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, and the Strategic Cooperation Program between Peking University and China National Petroleum Corporation (CNPC). Molecular dynamics simulations were conducted with valuable guidance from Professor Wang Qian of the School of Materials Science and Engineering. Materials characterization was supported by the Materials Processing and Analysis Center of Peking University and other research platforms.
Paper link:
https://doi.org/10.1038/s41467-026-68951-x
