Seyed Abdollatif Hashemifard

The objectiveofthisstudyistoproposeanovelapproachforpredictingthestructuralparametersof integrallyskinnedporousmembranesusinggaspermeationdata.Itisintendedtoovercomethe limitation oftheconventionalgaspermeationtesting(GPT)method,sincethelattermethodseemsto suffer fromseveralconceptualdrawbacks.Inparticular,acomparisonismadebetweenthetheoretical calculation andtheexperimentaldatatoshowthesuperiorityofthenewlyproposedmodel.Thenew model isamodification ofWakaoetal.0s model,inwhich,unliketheconventionalGPTmethod,the contribution oftheslip flow isconsidered.AlthoughWakaoetal.0s modelwasfoundsuperiortothe conventionalGPTmethod,themodel fitting totheexperimentaldatawasnotcompletelysatisfactory.It waslikelythattheslip flow,althoughitseffectcannotbeneglected,isnotfullydeveloped.Therefore,a factor ? is introducedtoshowtheextentofthecontributionoftheslip flowmechanismtothetotalgas permeation rate.Asaresult,thenewmethodcanovercometheshortcomingsoftheconventionalGPT method bymanifestingthefollowingadvantages:(i)itcancovertheentirerangeof J versus P diagram, (ii) itcanspecifythecontributionoftheindividualmechanismsinvolvedinthetotalgaspermeationand (iii) unliketheconventionalGPTmethod,itisnotlimitedbyanyconstraintsorconditionsofdata acquisition.Insummary,themodelcanpredictporesizeandeffectiveporosity,andalsosimulatethe experimental J versus P trends withsufficient accuracy(within 2% overthepressurerangestudied)for all typesofmembranes,i.e.NF,UF,MF,MDandmembranecontactors.Inviewofthisfact,theproposed model issimplertoapplythanRangarajanetal.0s modelandmoreaccuratethantheconventionalGPT method.