Preparation Of Porous Polymers Templating From Emulsions Stabilized By Ionic Liquid-based Janus Particles

Janus particles can be used to construct highly stable Pickering emulsions due to own different surface wettability of their two opposite sides,and the introduction of ionic liquidfunctional groups to one side of Janus particles can endow anionic exchangeable properties so as to tuning their amphiphilicity.In this paper,the factors influencing phase inversion of Pickering emulsion were discussed,the high internal phase emulsions(HIPEs)was fabricated by the Janus emulsifier,and the pore structures of the emulsion templating macroporous polymers was studied.The main research contents are as follows:(1)Janus hollow spheres with the exteriorsurface and the interior surface terminated byimidazolin groupsand phenyl group,n-octyl group or octadecyl group,respectively,were prepared by the self-assembly of various silane agent with different functional groups at the emulsion interface.The IL based Janus sheets obtained bycrushing and ionizing of the hollow spheres,one side terminated byCl-based ionic liquid groups,while the opposite side terminated by hydrophobic groups.The Janus sheets with different counter anions were obtained by the anion exchanging of ionic liquids.The phase inversion of Pickering was discussed by using these ionic liquid-based Janus sheets to emulsify toluene-water system,through studying on the effects of Janus sheets sides,different hydrophobic groups,and different anionic groups.The results showed that the particle size of Janus has obvious influence on the emulsion droplets size,and the wettability of the Janus sheetscan becontrolled by the difference of hydrophobic group and the counter anions,which leads to different droplet size and type of the emulsion.(2)The ionic liquid functional groups were introduced to the snowman-like Janus particles to stabilize water-in-oil HIPEs.Porous polymers were obtained after polymerizing styrene-divinylbenzene in continuous phase.Afterwards,the effects of emulsifier concentration,surface hydrophobicity and initiatortypes on the pore structure of macroporous polymer were discussed.It was found that the ratio of open-cells was increased by increasing amount of emulsifier.The hydrophobicity of snowman-like Janus particles was increased with the length of alkyl chain of bromoalkanesfor ionizing,consequently reduced minimum amount of the emulsifierfor obtaining porous polymers with open-cell structure.The oil-soluble initiator can give the interconnectivity pore structure,while the water-soluble initiator lead the collapsedpore structure.