Poly(3-hydroxybutyrate)/Poly(lactic acid) Composite Nanofibrous Membrane with Outstanding Photochromic and Antibacterial Performances for Multifunctional Applications

Photochromic and antibacterial fibrous materials are of interest due to the growing demand for fashion and the potential threat of bacterial infections in daily life. The preference for multifunctional biobased fibrous materials has also grown, driven by severe environmental pollution problems and the need to meet individual public needs. In this study, the effect of the preparation method and the ratio of poly(3-hydroxybutyrate) (PHB) to poly(lactic acid) (PLA) on solution spinnability was first analyzed. Subsequently, organic photochromic dye (OPD) and silver nanowires (AgNWs) were added to the PHB/PLA mixed solution. An exceptional photochromic and antibacterial PHB/PLA composite nanofibrous membrane (OA-PHB/PLA NFM) was created via electrospinning. The results indicated that the OA-PHB/PLA NFM produced under the optimal electrospinning parameters exhibited an average diameter of 240 nm with concentrated diameter distribution. The OA-PHB/PLA NFM also demonstrated good mechanical properties, including a breaking stress of 1.61 MPa and a breaking strain of 42.53%, as well as excellent photochromic and antibacterial properties (>98%). The 143 μm thick OA-PHB/PLA NFM@PLA composite exhibited notable advancements in ultraviolet (UV) protection and filtration efficiency (99.9%) with a minimal pressure drop (73.4 Pa), ensuring its suitability for sun-protective and photochromic masks. Furthermore, the OA-PHB/PLA NFM also demonstrated great potential in the field of anticounterfeiting. Overall, this study presents an approach to develop a biobased PHB/PLA NFM with excellent photochromic and antibacterial characteristics, showcasing great potential for applications in smart clothing, healthcare, anticounterfeiting, etc.