Biomimetic nanofibres for sustainable thermal insulation

With a commitment to environmental protection, sustainable practices and ethical standards, there is compelling motivation to replace animal feathers and wool with synthetic materials that mimic the natural curl structure of animal fibres. However, the fabrication of these curved structures remains challenging due to inherent limitations in fibre spinning technologies. Here we develop a grid-induced homogeneous turbulence spinning system to efficiently spray the spinning solution, resulting in the mass production of highly curved nanofibres (HCNFs). A garment made with HCNFs offers excellent overall performance in terms of wearability, comfort, porosity (~99.60%), weight, thermal conductivity, moisture permeability and breathability. Furthermore, the garment exhibits a superior clothing insulation value (measured in CLO) of 0.31 CLO mm−1 at 0 °C, which is twice that of an 850-fill-power goose-down garment (0.15 CLO mm−1). Moreover, the results of a life cycle impact assessment demonstrate that HCNFs made of polyvinyl butyral show notable sustainability advantages over 850-fill-power down across 14 indicators, including mineral resource scarcity, land use, ecotoxicity, water consumption and human toxicity (eight indicators are less than 5% of those for down). Our findings not only underscore the advantages of nanofibres with highly curved structures but also introduce sustainable materials that outperform traditional down, making them suitable and sustainable for mass-market production.