Research On Fog Collection And Oil/Water Separation Technology Based On Micropore Structure

With the increase of the world population and the increase of industrial waste water caused by the rapid development of industrial civilization and the occurrence of water pollution problems frequently,the fresh water resources has become a hot global research topic.This paper has carried out two research works on this topic.First,a kind of Janus film is prepared by femtosecond laser processing to realize fog collection and water transportation.A regular array of tapered micro-holes is prepared on the surface of the aluminum foil by femtosecond laser,and fog is collected by the hydrophobic surface and the liquid transportation is realized by the driving force formed by the micro structure of the Janus foil.The liquid driving force allows the collected fog to be transferred to the hydrophilic surface quickly,improving the fog collection efficiency greatly.Second,the unmodified nylon-mesh is used to remove oil from domestic sewage and absorb oil floating on the sea.The oil/water separation function of the nylon-mesh is achieved by making use of the natural wettability of nylon-mesh,eliminating the complicated processing of fabric materials in previous studies.Besides,the nylon-mesh is just cheap commercial material,which makes it possible to be used in practical application.The detail content of the two research aspects is as follows:(1)A conical micro-pore array is prepared by femtosecond laser cutting technology on the basis of aluminum foil,and a Janus aluminum foil was prepared by subsequent fluorosilane immersion and single-sided laser scanning to remove fluorosilane.The mechanism of Janus aluminum foil collecting fog and transporting water is revealed by study of the microstructure and surface wettability of the Janus aluminum foil.(2)By comparing the differences in wettability,microstructure and liquid transport capacity of different aluminum foils with different parameters,the necessary conditions for Janus foil transporting water are obtained.The fog collection ability and liquid transport ability of the Janus aluminum foil are further improved by optimizing the period and the pore diameter of the micro-pores in the micro-pore array.Finally,a set of conceptual devices floating on the sea for seawater desalination is designed,which could realize seawater desalination without additional energy input,which has certain reference significance for the design of seawater desalination device.(3)The second part of the research starts with the special wettability of nylon-mesh,and proposes the possibility of achieving oil/water separation by using untreated nylon-mesh.The separation of vegetable oil and water is realized by studying the separation effect of different micro-pore density and layer number of nylon-mesh.Besides,the removal of oil stain in domestic sewage and the absorption of sea surface oil are further realized by adjusting the parameters of nylon-mesh.Finally,the separation of multi-layer liquid by the nylon-mesh is realized.