Study On Air Flow Dispersion Device Of Nano-particles And Its Application In Plastic Microtubule Coating

Medical microtubules often cause infection in the process of indwelling human body.To this end,members of the research group proposed to prepare antibacterial functional coatings on the surface of medical microtubules,and proposed a method to prepare antibacterial coatings.This method combined with the gas-assisted extrusion technology of plastic microtubules,formed an air cushion film between the plastic microtubule melt and the extrusion exit mold wall,and used the air stream to carry antibacterial nanoparticles and make them adhere to the surface of plastic microtubules,thus forming antibacterial functional coatings.Nanoparticles have large surface area and high surface energy,which makes the nanoparticles easy to agglomerate together.When the antibacterial coating of plastic microtubules is formed by gas-assisted extrusion technology,the quality of the antibacterial coating on the surface will be seriously affected,so it is necessary to disperse the nanoparticles.Therefore,this thesis selected the topic of nanoparticle air dispersion as the research object.The numerical simulation technique is used to simulate the flow field of the dispersing system,and the particle flow with the gas auxiliary layer in the process of gas-assisted extrusion is simulated.The air dispersion system of nanoparticles was established,and the experiment of gas-assisted extrusion of nanoparticles and plastic microtubules was carried out by using the system,and the dispersion effect of the nanoparticle dispersion system and the adhesion of nanoparticles on the surface of plastic microtubules were analyzed.The main research contents of the thesis are as follows:(1)The nanoparticle aggregates were dispersed by the force generated by the velocity change of the high-pressure air flow released from the microporous nozzle,and the nanoparticle air dispersion system was built to disperse the nanoparticle continuously and stably.(2)Fluent software was used to conduct numerical simulation analysis on the flow field at the nozzle outlet of the established nanoparticle air dispersion system,and to explore the dispersion mechanism of nanoparticle and the influence of different process parameters on the flow field.(3)Fluent was used to analyze the flow path of nanoparticles in the gas-assisted extrusion process outside the mouth mold,so as to understand the adhesion of particles on the surface of plastic microtubules and the influence of different process parameters on the adhesion rate of nanoparticles.(4)The preparation experiment of nanoparticles on the surface coating of plastic microtubules was carried out with the nanoparticle air dispersion system combined with the plastic microtubules gas co-extrusion.The functional coating on the surface of plastic microtubules was analyzed by scanning electron microscopy to study the distribution of nanoparticles on the surface of microtubules and the influence of process parameters on the adhesion and dispersion of nanoparticles.