Dope‐Dyed Polyacrylonitrile Nanofibers for Outdoor Protective Textiles With Tailored Spectral Properties to Mimic Natural Leaf Reflection

ABSTRACT Outdoor protective textiles with good simulation of plant optical reflectance and robust waterproof‐breathable performance are highly desirable in jungle environments to both reduce the exposure risks and elevate the human body comfort, contributing to better camouflage survival ability. However, current waterproof‐breathable nanofibers fail to mimic natural leaf reflectance. Herein, we propose high‐performance waterproof‐breathable protective nanofiber nonwovens with good simulation of optical reflection spectra of natural leaves by a straightforward and efficient direct one‐step electrospinning technique, eliminating the need for any subsequent finishing or coating steps. The electrospun polyacrylonitrile nanofibers are dope‐dyed to simulate the spectral reflectance of the natural leaf by the in situ adjustment of the proportions of trichromatic cationic dyes in the spinning solution. Moreover, the colored polyacrylonitrile nanofibers are endowed with good waterproofness and breathability via the in situ introduction of fluorinated chemicals into the electrospinning solution while maintaining the fidelity of the pristine leaf‐like spectrum. Benefiting from the synergistic effects of cationic dyes and fluorinated dopants, the spectral reflectance and surface wettability of electrospun nanofibers can be precisely tailored as needed for high‐performance camouflage textiles. The resultant dope‐dyed polyacrylonitrile nanofibrous nonwovens effectively mimic the spectral reflectance of natural leaves, as evidenced by a high correlation coefficient (0.95), small spectral distance (0.448), low spectral angle (0.24 rad), and superior spectral channel proportion (72.5%). Simultaneously, these leaf‐like colored nanofibers exhibit excellent waterproofness (712 mmH 2 O) while maintaining a good water vapor transmission rate (3847.6 g m −2 day −1 ). This combination of spectral simulation ability and waterproof‐breathable performance demonstrates the strong potential for jungle camouflage applications. This strategy of tailoring the spectrum reflection of nanofibers can open up new pathways to next‐generation outdoor protective textiles.