Nanofabrics made from abundant natural protein that possesses enormous amounts of functional groups may have important applications such as air filtration. However, protein nanofabrics with randomly distributed nanofibers have very low mechanical properties and high airflow resistance, both of which seriously reduce the breathability. Here, a super-breathable zein (corn protein) fabric having a unique "woven-like" nanofibrous structure (w-PNF) via the accumulation effect between the charged nanofibers and the collector during electrospinning is reported. The resulting w-PNF exhibits remarkable tensile strength and modulus, which are 3 and 9 times, respectively, higher than the random protein nanofibrous materials. The filtration tests indicate that w-PNF presents super-breathable performance, including ultralow airflow resistance (1/12 of that of the nonwoven nanofabric) and high filtration efficiency for capturing PM2.5. As compared with the reported nanofabrics, w-PNF maintains the same airflow resistance at up to 4 times higher airflow rate. In addition, w-PNF presents visible-light transparency (80%) and high resolution even in microareas. This work provides a significant strategy for designing and fabricating nanofabrics for boosting the development of biological nanomaterials.
Keywords: air filtration; nanofabric; protein; super-breathable; woven-like.