Polyurethane-Coated Polyaniline/SiO2 Nanoparticle Electrospun Nanofiber Membranes for Waterproof and Moisture-Permeable Materials

In this paper, hydrophobic PAN/SiO2–PU composite nanofiber membranes were prepared by coaxial electrospinning combined with a hydrothermal method. The effects of the feeding rate ratio of the shell (PAN/SiO2) solution and the core (PU) solution, the content of SiO2 in the shell solution, and the hydrothermal time on the composite nanofiber membrane were analyzed. The results showed that when the feeding rate ratio of the shell–core solution was 5:1 and the SiO2 content in the shell solution was 60 mg·mL–1, the PAN/SiO2–PU nanofiber presented a uniform diameter and an obvious shell–core structure, and the Si element was uniformly distributed on the fiber surface. After hydrothermal treatment, the surface water contact angle of the PAN/SiO2–PU composite nanofiber membrane reached 152°, and the water vapor transmission rate was 8.48 kg·m2·d–1. In addition, the average solar reflectance of the composite nanofiber membrane was as high as 60.29%, and the temperature difference between the PAN/SiO2–PU and PAN–PU composite nanofiber membranes was 4.5 °C, indicating an obvious radiative cooling effect.