Study on Seperation Performance of a Novel Microporous Metal-Organic Framework

KeyWord:metal-organic framework  gas chromatography(GC)  separation  phenolic isomers

Abstract:

      More attention has been given to developing a microporous material,metal-organic frameworks(MOF) with large surface area as an advanced separation media in the field of separation science.In this work,a novel metal-organic framework,{£ÛSm(L)(DMF)£Ý?2(DMF)?5(H2O) }(MOF-Sm-L),with a one dimensional channel and active amido groups was chosen as stationary phase to prepare a capillary gas chromatographic column via a verified dynamic coating procedure to study the separation performance of linear alkanes,linear alcohols and substituted aromatics.The column could offer good separations for linear alkanes,linear alcohols,as well as aromatic positional isomers(e.g.cresol,hydroquinone,bromobenzonitrile,chloronitrobenzene and nitrotoluene).The separation behaviors of the column upon different organic substances may be related to the 1D pore structure of MOF-Sm-L,in which the van der waals forces between the compounds without hydroxyl and the hydrophobic inner surfaces might have great effect on separation of the compounds without hydroxyl,whereas the separation of the hydroxyl compounds was affected by(OH¡­O or OH¡­N) hydrogen bonds formed between the analytes and the active amido groups on the pore wall except for the van der waals forces.The effect of temperature on separation of aromatic positional isomers was investigated to elucidate entropy and enthalpy controlling of the separation process.