In-suit Growth Of Nano-ZnO Array On The Surface Of Polymer Fiber Filter And Physical Sterilizing Performance

Microbial safety has always received widespread attention,and a variety of treatment methods have been developed,such as the use of antibacterial chemical reagents and metal ions.But this may cause bacteria to produce mutations or drug resistance;it may also cause secondary pollution and cause harm to the human body.Therefore,it is very important to control microorganisms more safely.In recent years,researchers have discovered a new type of sterilization method on the surfaces of animals and plants,which can kill bacteria only through physical and mechanical action.This discovery is of great significance to the safe handling of bacteria.In this regard,the researchers designed a series of surfaces with physical bactericidal properties and achieved good results.However,the current research results have not yet been applied in practice,and this problem needs to be solved urgently.This thesis takes the high-efficiency particulate air filter membrane as the research object.First,it studies the growth process of nano-ZnO arrays on the surface of two fiber filter membranes,explores the growth mechanism of ZnO,and studies its physical sterilization performance.Then,by optimizing the experimental parameters,the large-area preparation of the nano-ZnO array was realized on the surface of the industrial product HEPA film.At the same time,design and build an air microorganism detection device,integrate the modified membrane into the air purifier,and explore the application of the modified membrane in the air environment.The specific work and main research results of this paper include:1.When a nano-array imitating a dragonfly wing structure is grown on the surface of the PET fiber membrane,nanorods,nanotubes and nanoblade structures are obtained.Through the study of the growth mechanism of nanotubes and nanoblade,it is found that their formation is only related to the concentration of the growth solution and standing at room temperature,and it is proved through experiments that the formation of nanotubes and nanoblade is not etched,but obtained by secondary growth.The physical bactericidal properties of three different nano-ZnO structures were studied,and the results showed that under the same conditions,the bactericidal effect of the nano-blade was the best,the effect of the nanotube was the second,and the effect of the nanorod was the worst.In addition,this result proves that physical sterilization has species differences.The same sample has better killing effects on E.coli than S.aureus under the same conditions.2.Aiming at the hydrophobicity of PP fiber,polydopamine is used to modify its surface to increase its adhesion to the nano-ZnO array.The experimental results show that the optimal treatment conditions for polydopamine are that the concentration of the dopamine solution is 2.0 mg/m L and the treatment time is 24 h.Then the nano arrays imitating the dragonfly wing structure were grown on the surface by the hydrothermal method,and three structures of nanowire arrays,nanorod arrays and nanotubes were obtained.The physical sterilization performance of nano ZnO of the three structures was tested.It shows that the physical sterilization performance of nanowires is the best,the effect of nanotubes is second,and the effect of nanorods is the worst.And under the same conditions,the same sample has better killing effect on E.coli than S.aureus.This result also further proves that physical sterilization has species differences.3.In order to realize the large-area preparation of nano-ZnO arrays on the HEPA membrane,the preparation process of the seed layer and the experimental conditions of the hydrothermal growth process were optimized.The area of the HEPA membrane was changed from 5 cm×5 cm to 5 cm×25 cm.From the preparation process of the seed layer to the experimental conditions of the hydrothermal growth process are optimized.The preparation method of the seed layer was improved from the dipping method to the spray method,and the placement of the sample and the use of the growth solution during the hydrothermal growth process were optimized.After realizing the large-area preparation of biomimetic nano-ZnO on the surface of the HEPA membrane,the HEPA membrane was matched with a small air purifier,and an air microbial detection device was built to test the application robustness and sterilization performance of the nano-ZnO array.The results showed that after 32 days of testing,the nano-ZnO array did not fall off or other changes,indicating its excellent robustness.The interception rate of E.coli and S.aureus is very high,respectively99.10% and 98.71%;the killing effect is also very good,respectively 99.16% and 95.39%.