Electrospinning PVP/Urushiol/Ag nanofilms: Use as wrapper of stainless steel yarns

In this study, ethanol rotary steaming is used to extract urushiol from raw lacquer. Polyvinylpyrrolidone (PVP) and urushiol are mixed at different ratios, after which the blends are made into PVP/Urushiol nanofilms by means of the electrospinning process. The test results show that PVP/Urushiol nanofilms are insoluble in water, improving the water contact angle. In addition, with a PVP/Urushiol rate being 4/5, the resulting nanofilms retain an impact structure when being immersed in an H2SO4 solution with a concentration being 60%, 80%, or 100%. This result indicates that the combination of urushiol helps improving the downsides of PVP films (i.e., the water-soluble feature and low acid resistance). Furthermore, PVP/Urushiol nanofilms are tested for antibacterial efficacy, which is proven that the antibacterial efficacy is only 15% regardless of whether it is Staphylococcus aureus (S. aureus) or Escherichia coli (E. coli). In order to improve the antibacterial efficacy, a PVP/Urushiol ratio being 4/5 and a nano Ag antibacterial agent are formulated to form the electrospinning mixture that is subsequently electrospun into nanofilms that wrap 0.08 mm-diameter stainless steel yarns, thereby produces acid resistant, antibacterial PVP/Urushiol/Ag-cladded stainless steel yarns. The urushiol is acid resistant, instead of alkali resistant, which enables the application of the PVP/Urushiol/Ag-cladded stainless steel yarns in detecting the pH value of the surroundings, or serving as conduction lines or flexible smart wearable devices in an acid environment.