Study On The Construction Of Three-dimensional Multilayer Microporous Membrane And Its CO₂ Adsorption Performance

Carbon dioxide capture and storage(CCS)technology is gradually used to reduce the impact of carbon dioxide on global warming by reducing carbon dioxide emissions from industrial production.Because of its advantages of low energy consumption,environmental sustainability and continuous operation,the capture technology based on porous membrane is a very promising one.The preparation of porous nanofilms from organic,inorganic or organic-inorganic hybrid materials with different pore sizes has been widely reported.Hypercrosslinked polymers(HCPs)have been widely concerned in the field of gas capture.Because of the extensive crosslinking reaction to prevent polymer chain collapse,they have permanent porosity.The colloidal microspheres self-assembly(LBL)technology based on template technology has the advantages of low cost,mass production and high efficiency.Therefore,high efficient covalent Lb L self-assembly combined with hypercrosslinking can obtain ordered porous materials.First,the size homogeneous composite microspheres(400nm)were synthesized by soap free emulsion polymerization.The surface of the microspheres was rich in amino groups by ammoniation.The films were prepared by covalent self-assembly with multi aldehyde PAD and ammoniacal microspheres P(St-BA)-NH₂ as the assembly materials.After the super crosslinking,the adsorption curves of the films were I,microporous and mesoporous,and mesoporous.Through the amount of chemical adsorption and physical adsorption,it is found that after the pore making,the film is mainly physical adsorption.It is further proved that the pore performance of the film increases greatly after the hypercrosslinking reaction.These porous nanofilms have a high BET specific surface area,reaching 605.7m²/g.At 273k/1bar,the amino rich microporous membrane also has a good CO₂ capture effect,reaching 53.6wt%(12.2mmol/g)And has good circulation ability.In order to consider the factors that affect the CO₂ adsorption energy of the film,after controlling the film thickness and pore forming,the CO₂ adsorption capacity of the film is the best when the number of assembled layers is 20,and the CO₂ adsorption capacity decreases with the increase of the number of layers.Then the porous films with excellent mechanical properties were prepared by self-assembly of hybrid PMMA microspheres and P(St-BA)microspheres.The mechanical properties of the hybrid films were characterized by a tensile machine,and the(P(St-BA)₂/PMMA₃)100 hybrid nanoporous film was selected as the synthesis scheme of the excellent mechanical properties porous film.The results show that the hybrid microsphere film has excellent mechanical properties and considerable CO₂ adsorption properties.Finally,the mechanical properties and CO₂ adsorption properties of the porous microspheres with different thickness and different hybrid conditions were characterized.The results showed that the mechanical properties increased with the increase of film thickness,and the CO₂ adsorption performance decreased.The results show that the microspheres in the assembled film can not be arranged tightly,and it is easy to fall off,and its mechanical properties can not be measured.