Preparation Of Super-hydrophobic Nano-aluminum Film And Its Application In Oil-water Separation

Water and oil are valuable resources for human beings and play a crucial role in the survival of humankind and the development of civilization.With the continuous development of modern society,various types of waste oil pollution have been produced in large numbers.The direct discharge of oil-containing waste water without treatment has not only severely damaged the ecological environment,but also caused numerous harms to human production activities,causing various safety issues.In this paper,a superhydrophobic oil-water separation material containing nano-aluminum film was prepared by electrophoretic deposition method.Through experiments and numerical simulation techniques,we studied the extreme wettability of different morphologies substrates and the oil-water separation performance of nano-films.And Based on the theory of capillary mechanics,the separation mechanism of superhydrophobic oil-water separation materials was discussed.The main innovations achieved in the thesis are:(1)The electrophoretic deposition method was used to deposit the nano-aluminum particles onto the titanium substrate and the stainless steel mesh,respectively,thereby obtaining a rough film with a nano-structure.The measured contact angle and roll angle to water were 164.3° and 3.5°,respectively.(2)The oil/water droplet impact test and numerical simulation were performed to study the impact dynamics of oil/water on the superhydrophobic surface.We have found that water droplets form air cushions during impact on rough surfaces with nanostructures.It causes the friction coefficient between the water droplet and the surface to decrease,the energy dissipation of the water droplet in the impact process decreases,and multiple rebound shocks are formed.(3)We have invented a dynamic,continuous and efficient oil-water separation device.Oil-water separation efficiency can reach more than 90%.After 20 cycles of oil-water separation,the separation efficiency did not decrease significantly,indicating that the superhydrophobic oil-water separation material is stable in the separation process.At the same time,the influence of the flow rate and effective separation length of oil-water mixture on the separation efficiency of oil-water was studied.(4)Through experiments and numerical simulation calculations,the separation of oil-water mixtures during the passage of superhydrophobic networks was explored.And based on the theory of capillary mechanics to discuss the separation mechanism,which mainly depends on the oil and water in the wettability of the material and capillary pressure produced by the differential pressure.