| Bacteria can adhere to the surface of various materials through their own characteristics and physical and chemical properties of the material surface,and the adhesion and breeding of bacteria on the surface of the material are easy to form irreversible biofilms.Therefore,how to achieve anti-bacterial adhesion on the surface of materials,prevent the breeding of microorganisms and the formation of biofilm,has attracted extensive attention of scientists.In order to inhibit and reduce the adhesion of bacteria at the initial stage and eliminate and cut off the breeding of bacteria on the substrate surface,scientists at home and abroad modified the material with hydrophilic substances to form a superhydrophilic surface.Through the hydration layer to block bacteria and material surface direct contact to achieve the purpose of biofilm resistance.However,the superhydrophilic surface has the problems of poor durability and unknown mechanism of antimicrobial membrane.Therefore,in order to solve this problem,this project proposed to use Coulomb force generated by triboelectric nanogenerator,to drive charged microfluid on superhydrophobic surface to drive the directional movement of bacterial droplets to achieve the purpose of antibacterial and anti-adhesion.The details of this study are as follows:(1)Construction of triboelectric nanogenerator:Taking acrylic plastic plate as the base,rectangular aluminum foil was arranged on the surface of acrylic plastic plate and combined with Kapton film to form an independent layer triboelectric nanogenerator.The driving platform of triboelectric nanogenerator power generation system was constructed by pasting PTFE film,copper electrode and PTFE film successively on the glass slide.The hydrophobic silica was sprayed on the surface of the driving platform by heating spraying method to make it superhydrophobic.(2)Selection and characterization of hydrophobic silica content on the surface of driving platform and output performance test of triboelectric nanogenerator:The results show that with the increase of spraying amount of hydrophobic silica,the droplet contact angle increases,the rolling angle decreases,and the adhesion decreases.When the spraying amount of hydrophobic silica increases to 0.055 mg/cm~2,the contact angle of droplets on the surface of the driving platform reaches 151.276°,the rolling angle decreases to 6°,and the adhesion force reaches 0.048 m N.The contents of target elements were analyzed by SEM-EDS and X-ray photoelectron spectroscopy,and the hydrophobic silica was successfully loaded onto the surface of PTFE film.In the output performance test of the triboelectric nanogenerator,the peak value of the open-circuit voltage is 465.2 V and the peak value of the short-circuit current is 1.07?A.(3)Study on the critical volume and driving mechanism of water droplets driven by triboelectric nanogenerator:When two or more copper electrodes are arranged on the substrate,the minimum and maximum droplet volumes that can be driven increase with the increase of electrode spacing and electrode width.The mechanism of droplet directional motion is explained by the force analysis of droplet on the driving platform surface.The moving water droplets on the surface of the substrate are filmed by a high-speed camera to observe the moving path and morphological changes of water droplets.(4)Study on the synthesis and antibacterial properties of triangular silver nanoprisms:The silver nanoparticles were prepared by chemical reduction synthesis and characterized by ultraviolet-visible spectrophotometer and TEM.The antibacterial activity of triangular silver nanoprisms with different concentrations was tested.The results showed that the antibacterial activity of triangular silver nanoprisms became stronger and stronger with the increase of the concentration of triangular silver nanoprisms.The antibacterial rate of triangular silver nanoprisms against S.aureus reached 48.21%,58.34%,70.58%,97.65%and 99.01%,respectively.The antibacterial rates against E.coli were 69.81%,79.36%,86.21%,99.42%and 99.61%,respectively.The bactericidal mechanism of releasing silver ions from silver nanoparticle to destroy bacterial cell membrane was further explained.The optimal concentration of triangular silver nanoprisms solution was selected as the target fungicide solution,and the test results showed that the bacteria on the surface of the base had been completely killed after being mixed with tiny bacterial droplets and stationary for 15h under the drive of triboelectric nanogenerator.(5)Study on anti-bacterial adhesion of triboelectric nanogenerator driven platform surface:The anti-bacterial adhesion rate of the hydrophobic platform to S.aureus and E.coli reached 96.53%and 90.02%respectively by the method of bacterial droplet stationary on the driving platform,indicating that the surface of the hydrophobic platform has a good anti-bacterial adhesion.The mechanism of anti-bacterial adhesion of hydrophobic substrate was explained by establishing a model. |
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