Preparation Of Ordered Porous Films By Non-Solvent Induced Phase Separation And Its Application Of Structural Replica

Due to the unique microstructures thin films with structured pore structure have wide applications in optical devices,sensing systems,solar cells and biological tissue frames.Traditional methods for preparing porous structures can be divided into top-down and bottomup methods.Common methods include laser direct writing technology,3D printing technology,reactive ion etching technology and respiration diagram,etc.However,these traditional manufacturing methods usually have higher requirements on the precision degree of equipment and experimental environment,which increases the difficulty and cost of the experiment virtually.With the help of the traditional non-solvent induced phase separation,this paper has realized the low cost,fast and large area of highly homogeneous porous structure of micron scale,and has prepared the microconvex array with different functions by using the porous array as the complex template.Polymethylmethacrylate(PMMA)with good film-forming properties was selected and treated with a certain proportion of polymer good solvent chloroform and a mixture of nonsolvent methanol,and a highly orderly polymer porous membrane was prepared with the help of phase separation induced by non-solvent.By adjusting the concentration of polymer solution,the ratio of mixed solvent,the stirring time of mixed solvent,the environmental humidity when the solvent volatilized,and the type of substrate,the factors affecting the formation of porous structure were investigated,and the process of non-solvent induced phase separation was analyzed in detail by computer simulation.The ordered porous film is used as a good template,and the microlens array with certain optical properties can be obtained to enhance the fluorescence detection signal.PMMA porous membrane was also used as template to obtain PDMS-Ag wrinkle composite structure through Polydimethylsiloxane(PDMS)retype and electrodeposition of silver film on the surface of microlens array.The wrinkle morphology was controlled by adjusting the precipitation time of silver and the swelling degree of PDMS.The wrinkle structure can be used to construct pressure sensors,the resulting device has a sensitivity of 32.5at 1780 Pa and can be used to detect small forces generated by vocal cord vibration,which can realize the preparation of pressure sensors with high sensitivity,low detection limit and cyclic stability.