Affiliation: | 1. College of Intelligent Textiles and Materials, Changzhou Vocational Institute of Textile and Garment, Changzhou, 213164 China College of Textile and Clothing Engineering, Soochow University, Suzhou, 215123 China;2. College of Textile and Clothing Engineering, Soochow University, Suzhou, 215123 China;3. Innovation Center for Textile Science and Technology, Donghua University, Shanghai, 201620 China;4. Innovation Center for Textile Science and Technology, Donghua University, Shanghai, 201620 China Department of Textile, Garment and Design, Changshu Institute of Technology, Suzhou, 215500 China;5. Jiangsu Province Engineering Research Center of Special Functional Textile Materials, Changzhou Vocational Institute of Textile and Garment, Changzhou, 213164 China |
Abstract: | The air filtration materials with high efficiency, low resistance, and extra antibacterial property are crucial for personal health protection. Herein, a tree-like polyvinylidene fluoride (PVDF) nanofibrous membrane with hierarchical structure (trunk fiber of 447 nm, branched fiber of 24.7 nm) and high filtration capacity is demonstrated. Specifically, 2-hydroxypropyl trimethyl ammonium chloride terminated hyperbranched polymer (HBP-HTC) with near-spherical three-dimensional molecular structure and adjustable terminal positive groups is synthesized as an additive for PVDF electrospinning to enhance the jet splitting and promote the formation of branched ultrafine nanofibers, achieving a coverage rate of branched nanofibers over 90% that is superior than small molecular quaternary ammonium salts. The branched nanofibers network enhances mechanical properties and filtration efficiency (99.995% for 0.26 µm sodium chloride particles) of the PVDF/HBP-HTC membrane, which demonstrates reduced pressure drop (122.4 Pa) and a quality factor up to 0.083 Pa−1 on a 40 µm-thick sample. More importantly, the numerous quaternary ammonium salt groups of HBP-HTC deliver excellent antibacterial properties to the PVDF membranes. Bacterial inhibitive rate of 99.9% against both S. aureus and E. coli is demonstrated in a membrane with 3.0 wt% HBP-HTC. This work provides a new strategy for development of high-efficiency and antibacterial protection products. |