SF-AgNPs/PVDF-HFP亲疏水双层电纺纤维膜的制备及其过滤抗菌性能

Preparation of SF-AgNPs/PVDF-HFP hydrophilic-hydrophobic bilayer electrospun fibermembranes and their filtration and antibacterial properties

为了减少空气污染及病毒传播给人们造成的危害,优秀的可穿戴个人防护材料的开发具有重要意义。本文利用静电纺丝技术制备了具有亲疏水复合结构的过滤抗菌性丝素蛋白纳米银/聚偏氟乙烯六氟丙烯(SF-AgNPs/PVDF-HFP)双层电纺纤维膜。本文通过扫描电镜、透射电镜、傅里叶红外光谱、X-射线衍射光谱对纤维膜形貌、纳米银还原情况及结构特性进行了表征,并对双层复合纤维膜的过滤性能、水蒸气透过率、抗菌性能等进行了测试。结果表明:当SF质量分数为16.5%,AgNO_(3)质量分数为0.7%,PVDF-HFP质量分数为20%时,通过调整SF-AgNPs亲水层的厚度和固定PVDF-HFP疏水层的厚度,电纺纤维膜可以实现对PM 2.5的过滤效率达99.00%,对金黄色葡萄球菌抑菌率最高达99.76%,水蒸气透过率达7.80 mg/(cm^(2)·h),且具有单向导湿性。

With the prevalence of the COVID-19 and the improvement of personal health protection awareness,the development of excellent wearable personal protective materials is of great practical significance.The traditional mask filter element is made of micron polypropylene melt-blown nonwoven fabric,which has the disadvantages of low filtering efficiency for small particles in the air and poor protection against bacteria and viruses.In recent years,the research of electrospun nanofiber membranes in the field of air filtration and personal protection has attracted great attention due to the characteristics of large surface area,high porosity,interconnected pore structure and controllable diameter.However,most of the filter element membranes developed at present have undiversified functions,and do not have antibacterial and comfortable properties,so they cannot meet people’s requirements for the versatility and skin-friendly comfort of filter materials.To improve the antibacterial property,wearing comfort and protection ability against small inhalable particulate matter(PM 2.5)of the filter element membrane,a bilayer hydrophilic-hydrophobic antibacterial nanofiber filtration membrane was constructed by electrospinning technology through silk protein(SF)with biocompatibility,oxygen and air permeability and polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)with excellent mechanical properties as raw materials.Firstly,PVDF-HFP nanofiber hydrophobic membranes were prepared by electrospinning with the concentration of PVDF-HFP solution in the range of 18%and 24%,and the suitable concentration of spinning solution was selected.Secondly,AgNO_(3) solution with different contents was mixed with SF solution,and the SF nanofiber membrane loaded with silver ion was prepared by electrospinning.After UV reduction,SF-AgNPs nanofiber hydrophilic membranes loaded with silver nanoparticles(AgNPs)were obtained.Finally,a series of hydrophilic-hydrophobic bilayer composite nanofiber membranes with a certain thickness ratio were obtained by electrospinning SF nanofiber membranes with different thicknesses on the surface of PVDF-HFP electrospun fiber membranes with fixed thickness,the hydrophobic base layer.The effects of spinning solution concentration on surface morphology,fiber diameter distribution and hydrophilicity-hydrophobicity of nanofiber membranes were characterized by SEM and water contact angle tests.The reduction of silver nanoparticles was successfully demonstrated by TEM,EDS and XRD.The effect of silver nanoparticles on the structure of silk fibroin nanofibers was characterized by FTIR and XRD.In addition,we tested the water vapor transmission rare,filtration properties and antibacterial properties of the hydrophilic and hydrophobic bilayer composite nanofiber membranes prepared with different thickness ratios and different contents of AgNO_(3) in spinning solution.The results show that when the membrane thickness is in the range of 120μm and 145μm(the hydrophobic layer thickness of PVDF-HFP is 35±5μm),the filtration efficiency of PM 2.5 reaches 99.00%,the bacteriostatic rate of Staphylococcus aureus reaches 99.76%,and the water vapor transmission rare reaches 7.80 mg/(cm^(2)·h),which is higher than the transmission value of YY0469-2011 common medical masks.The SF-AgNPs/PVDF-HFP bilayer nanofiber membranes prepared by electrospinning technology have improved the filtration performance of small particulate matter(PM 2.5).By UV reduction,silver nanoparticles were loaded on SF nanofibers in situ,which endowed the composite fiber membranes with excellent antibacterial properties.Based on the hydrophobicity of PVDF-HFP nanofiber membranes and the hydrophilicity of SF-AgNPs nanofiber membranes,the hydrophilic-hydrophobic bilayer composite membranes have one-way water vapor transmission function,which improves the comfort of the filter membranes.This study extends the application of silk protein in medical filtration membranes and directional moisture removal fabrics,paving the way for the preparation of fiber materials with high efficiency air filtration,high antibacterial activity and high water vapor transmission rare.The prepared composite membranes are expected to be applied in the field of masks and wearable personal protection.