There are two main concepts of nanofibers. The first is strictly defined as nanofibers. The diameter of ultrafine fibers is less than 100 nm, but the length can be more than 100 nm. Secondly, fibers that modified by filling nanoparticles are also called nanofibers and this type nanofiber is common in industry field. The nanofibers filling with nanoparticles of different properties can be used to develop various functional fibers, which have the properties of antibiosis, inflaming retarding, ultraviolet-proof, electromagnetic shielding and the others. Nanofibers https://nanomaterials.alfa-chemistry.com/products/nanofibers.html