Liu Ya,Wang Xueming,Li Nana,Wang Xiaoyin,Shi Lei,Wu Enjie,Wang Rui,Shan Mingjing,Zhuang Xupin
Nanofiber mats have received considerable attention from researchers in the field of particulate protection. In this study, polyvinylidene fluoride (PVDF) nanofiber mats were prepared on a large scale by a solution blowing process, and then crosslinked by ultraviolet (UV)-radiation using trimethylolpropane tri-acrylate (TMPTA) as a crosslinker. The structure, morphology, mechanical and thermal properties, and protective performance of the nanofiber mats were evaluated. Results show that the addition of TMPTA and UV treatment decreased the diameter of the nanofibers and enhanced the mechanical properties, air permeability, and moisture permeability. Nanofiber mats show higher filtration and lower filtration resistance compared with a commercial product. Furthermore, the nanofiber mats were bonded with Nylon 6 fabric, which showed good performance as a novel functional layer in protective clothing.
A multi-use fibrous filter medium composed of an electrospun polyimide (PI) nanofiber layer and a functional zeolitic imidazolate framework-8 (ZIF8) nanofilm layer was successfully fabricated to cope with the complex environmental pollution issues. The nanofilm layer consists of the anti-microbial ZIF8 converted from non-toxic zinc oxide (ZnO) nanocoating on PI fibers. One-step magnetron sputtering is utilized to deposit the ZnO nanocoating for the sake of desired functionality conformally onto the PI nanofibrous membrane without sacrificing its bulk structure and mechanical performance. The as-prepared PI/ZIF8 nanofibrous filter medium showed conspicuous biocidal efficacy and excellent interception ratio against gram-negative Escherichia coli (>99.9%) and gram-positive Staphylococcus aureus (>99.9%) within 20 min contact. Besides, compared with commercial media, the bilayer PI/ZIF8 fibrous medium showed exceptional thermal-wet comfortability due to the high porosity that could realize effective heat and humidity conduction. Moreover, the PI/ZIF8 30 NFM still present a high filtration efficiency of 99.6% towards PM 0.3 even after treated at 300 °C for 1 h. Furthermore, the PI/ZIF8 30 NFM with a fiber basis weight of 1.8 g/m 2 was endowed with a permeate flux of 17,279.2 L/m 2 /h and a high oil/water separation efficiency of > 99.6% because of the hydrophobicity and superoleophilicity. We envision that the antimicrobial, thermal-wet comfort, multi-use fibrous membrane will serve as a core-medium of environmentally-friendly platform for bioprotective equipment against future pathogen threats or oily wastewater treatment .
The recent outbreak of a coronavirus disease (COVID-19) has posed a great threat to public health and financial system. Most current masks used to prevent the spread of COVID-19 are typically absence of biocidal properties. We designed a novel polymer, polystyrene grafted by 5, 5-dimethylhydantoin and trimethylamine (PSDT), which possesses halamine site and cationic quaternary ammonia salt site. Furthermore, PSDT/PU [email protected] membranes (PSDT/PU NNMs) were obtained by electrospinning technology. Our strategy enables inherent N-halamine and quaternary ammonia salt (QAS) group to be covalently integrated into membranes, realizing the efficient and stable biocidal properties. Meanwhile, the introduction of nanonets endows electrospun membranes with prominent air filtration performance. The resulting membranes exhibit integrated properties of high interception of fine particles (96.7%) and low pressure drop (95.4 Pa). Besides, chlorinated PSDT/PU [email protected] membranes (with active chlorine content of 0.60 wt% and quaternary ammonia salt content of 2.20 wt%) exhibited superior bactericidal (>99.9999%) and virucidal (>99.999%) efficiency in a short time (2 min), which enables chlorinated PSDT/PU NNMs to be served as the filtration material by providing bacterial interception (99.77%) and contact killing against pathogens. The successful synthesis of PSDT/PU NNMs provide innovative insights for exploring filtration materials in a nanonet and biocidal form.
危险品化学品经营许可证（带存储）