Autoclavable,breathable,and Waterproof Membranes Tailored By Ternary Nanofibers For Reusable Medical Protective Applications

In recent years,biosafety problems emerge in an endless stream.In particular,thebiological protection issues caused by the Corona Virus Disease 2019(Covid-19)have caused socio-economic harm worldwide.Furthermore,it poses a huge challenge to the resources of hospitals and health systems worldwide.In order to safeguard the safety of medical staff and patients,and maintain the stable operation of social order,there is an urgent need to solve the problems,such as the lack of supply of protective materials and the non-standard performance of protective materials under recycling.The protection mechanism of protective materials is generally passive physical interception,so the premise of reusable medical protective materials is to find a fast and reliable method to disinfect the pathogens,which are intercepted on the surface.However,the long analysis time of ethylene oxide fumigation sterilization has become the bottleneck of rapid circulation supply of protective clothing;The influence of absorbed dose of irradiation sterilization increases the uncertainty of the performance of protective materials after sterilization;Autoclave sterilization can kill all colonies and can be operated in most traditional medical institutions.However,the common core layers of protective clothing are prone to deformation or damage after sterilization,resulting in the loss of original protective performance and comfort performance of protective clothing.Thus,to solve the problem of the lack of supply of medical protective materials under biosafety problems,the development of a high-performance medical protective material capable of withstanding autoclaving operations is imperative.In order to prepare reusable medical protective materials with excellent waterproof andmoisture permeability,the experiment was mainly designed according to the following three standards:(1)The whole composite fabric,including core fiber membrane and composite materials,could withstand autoclave sterilization operation,and the preparation procedure requires to guarantee environmental protection;(2)The composite fabrics had excellent waterproof,moisture permeability and mechanical properties;(3)The composite fabrics had good particle filtration efficiency and bacterial aerosol interception rate before and after cyclic autoclave sterilization operations.Based on this,this subject has carried out the following research:(1)A novel recyclable autoclavable ternary electrospun nanofiber membranes(TENMs)were prepared by one-step electrospinning process,in which Polyether Sulfone(PES)was used as thermostable matrix,Polyurethane(PU)provided flexibility,and Fluorinated Polyurethane(FPU)gives rise to the hydrophobic performance.The spunbonded non-woven fabrics with excellent mechanical properties and high thermostability were selected as composites.The composite fabric was obtained by hot-processing and ultrasonic pressing processes.(2)The preparation of recyclable high temperature and high-pressure nanofibermembrane was realized by adjusting the mass ratio of PU/PES.Combined with the scanning electron microscope,the capillary flow porometer,and other characterization means,the influence of the introduction proportion of PES on the performance changes of fiber membrane before and after sterilization was analyzed,and the optimum blending radio was gained.The membranes prepared under the experimental parameters(the total concentration of polymer PU and PES is 18wt%,the blending ratio of PU/PES is 4/6)had the best performance,can maintain a good microstructure after autoclave sterilization operation,and had excellent mechanical properties.(3)The waterproof and moisture permeability of nanofiber membrane was optimized byadjusting the blending concentration of FPU.The final spinning parameters of membranes were determined by X-ray photoelectron spectroscopy,hydrostatic pressure and moisture permeability.Meanwhile,to ensure the autoclave sterilization stability of membrane after FPU blending,the comprehensive reusable performance of nanofiber membrane after cyclic autoclave sterilization operation was explored.When the concentration of FPU was controlled to 3 wt%,the obtained TENMs had excellent properties(the hydrostatic pressure of the membrane was up to 102.71 k Pa,the water vapor permeability of the membrane was as high as 11.56 kg m^-2 d^-1),and still showed good micro morphology,waterproof and moisture permeability under 10 times of autoclave sterilization operation.(4)The composite fabric was prepared by hot-pressing and ultrasonic-pressing.Thetensile strength of the composite fabric increased to 9.78 MPa;Before sterilization,the fabric showed a hydrostatic pressure of 113.78 k Pa and a water vapor permeability of 10.83 kg m^-2 y^-1.After 10 times of autoclave sterilization operation,the hydrostatic pressure decreased slightly to100.87 k Pa and the water vapor permeability was at 8.98 kg m^-2 d^-1.At the same time,before and after the cycle of sterilization,the composite fabric showed extremely high particle interception efficiency(99.99%)and bacterial filtration efficiency(99.99%),which could be well applied to the field of medical protective clothing.The preparation of TENMs provides a basis for the development of high-performancemedical protective clothing materials with recyclable autoclave sterilization resistance.