nanofiber 3d icon - textile fibers for face mask

pcl peva pla pu air alginate appreciable arrangement cellulose chain chitosan coating collagen counterparts electrospinning engineering fiber fibroin filtration flexibility functionalization gelatin industrial keratin material mechanical method microfiber nanofiber nanometer natural physical polycaprolactone polymers polysaccharide polyurethane porosity potential production properties science silk strength surface synthesis synthetic technological thin ultrathin unique