Adsorbent Modified With Poly(Ionic Liquids) With Functional Side-Chain For The Use In Adsorption And Separation

Poly(ionic liquids)are a new class of polyelectrolytes which combine the unique properties of ionic liquids and polymers.In recent years,poly(ionic liquids)have received great concern in separation science field.The reported poly(ionic liquids)generally have only one kind of functional group in the cationic portion,causing the selectivity to be barely adjustable.To resolve the problem,different functional groups were introduced into the cationic portion to achieve adjustable selectivity.In this paper,two kinds of adsorption and separation materials modified with poly(ionic liquids)with multi-functional groups were prepared by surface initiated-atomic transfer radical polymerization.The main contents are as follows:1.A new poly(ionic liquids)-functionalized magnetic mesoporous nanoparticle was designed and used as an adsorbent in magnetic solid-phase extraction for the enrichment of eight pyrethroids.In contrast to the reported poly(ionic liquids)with only one kind of functional group in the cationic part,the new poly(ionic liquids)with mixed cyano and phenyl groups in cationic part matched the chemical structure of the analytes to improve extraction efficiency.Under the optimum conditions,an effective method was established for the determination of eight pyrethroids in apples.Adsorption equilibrium can quickly be reached in 1 min,greatly decreasing the extraction time.The linearity range was found to be 10-200 ng/g,and the detection limits ranged from 0.24 to 1.98 ng/g.Recoveries of analytes in apple samples ranged from 87.3 to 119%,with relative standard deviations varying in the range of 3.0-21%(intra-day)and 0.3-15%(inter-day).The results indicate that the proposed method is a good candidate for the determination of pyrethroid residues in apple samples.2.Three different types of poly(ionic liquids)modified stationary phase were synthesized by introducing different functional groups on imidazolium,i.e.carboxyl group,cyano group and tetrazolyl group.The obtained stationary phase was characterizied by fourier transform infrared spectrometry,thermogravimetric analysis(TGA)and elemental analysis,suggesting the stationary phase has been synthesized successfully.Then,the retention behavior was studied using a wide range of compounds by changing acetonitrile volume fraction and pH of the mobile phase.Under the reverse phase/ion exchange mixed-mode,the prepared column shows good separation performance towards different types of solute.Compared to cyano-functionalized stationary phases,carboxyl and tetrazolyl functionalized stationary phases could offer enchanced cation exchange and ?-?interactions with solutes,resulting in different separation performance.In summary,the proposed design strategy provide a new way to develop imidazolium based poly(ionic liquids)stationary phases.