Research On The Preparation Of Honeycomb Pattern Film By Dipping And Pulling Method

Surface patterning of materials is an emerging field with broad prospects,of which porous patterned membranes have important applications in hydrophobic materials,microfluidic chips,and cell culture.However,traditional film surface patterning methods such as photolithography,soft etching,and breathing patterning generally have the disadvantages of high cost,complicated procedures,and high requirements on the preparation environment.For this reason,from the perspective of solvent volatilization,this study proposes a simple and effective strategy for constructing a three-dimensional topological pattern on the surface of a polymer film,that is,a method of preparing a patterned film by using dip-coating method.The formation mechanism and key factors of the ordered structure on the film surface were systematically studied.Through the adjustment and optimization of the process conditions,the controllable preparation of the micropattern structure on the film surface was realized.The related research is of great significance for enriching the method of pattern film construction.In this thesis,using ethyl cellulose(EC)as a membrane material,a patterned membrane with a honeycomb porous structure was successfully prepared through solvent blending and phase separation strategies.It was found that the formation of a honeycomb structure on the surface of the membrane and the polymer concentration,relative humidity,non-solvent type,and the ratio of solvent to non-solvent are closely related,the surface structure of the film is adjusted around factors such as the concentration of the casting film solution,relative humidity,non-solvent type,and the ratio of solvent to non-solvent.The film surface pattern was characterized,and the evolution of the film surface pattern structure was discussed.The results show that the order of the surface pattern of the film is the best when the mass fraction of ethyl cellulose is 7%.As the concentration of the casting film solution increases,the pore size of the film surface gradually decreases.There are certain requirements,and the pore size of the film surface gradually increases with increasing humidity.When the relative humidity is 65%,the order of the film pore shape and distribution is the best.The ratio of toluene / methanol to the pattern film has a certain effect.The pattern and distribution of the membrane pores of the pattern film with a volume ratio of 2:1 of toluene / methanol is the best,and the membrane pore size increases with the increase of the methanol content.Has good thermal stability and excellent acid and alkali resistance.Meanwhile,in this paper,using EC as a membrane material,to a mixed solvent of toluene and methanol to form a microemulsion by adding a small amount of water,were successfully prepared in a three-dimensional topology with low humidity conditions(RH =40%)the pattern film,and in terms of the water content,humidity,etc.of the substrate forming the surface of the pore structure of the regulation,proved the film structure evolution,the results showed that: a low humidity,the water content of the membrane surface is ordered porous structure the key factor is formed,the water content of the film to the surface pore structure having a significant impact,the surface pore size of the membrane increases with increasing water content,when the water content was 3.4%,the film surface to give a more regular honeycomb porous film,to film substrate having a film surface topography for some impact,between the substrate and the better the wettability of the casting solution is prepared in a high tacticity the pattern film facilitates,when the film forming substrate is a nonwoven fabric,having successfully prepared three-dimensional network structure of the pattern film,enables efficient yeast suspension was filtered.