Asymptotic variation of radius of a viscous polymer jet in the electrospinning process

Abstract.Thispaperpresentsresultsofanalyticalmodelingofasteadystatejetflowin theelectrospinningprocess.Amodelofaweaklyconductiveviscouspolymerjetdriven byanexternalelectrostaticfieldisdeveloped.Aclassofpolymerfluidsdescribedby nonlinearpower-lawrheologicconstitutiveequationisconsidered.Asymptoticdecayof radiusatlargedistancesfromthebeginningofthejetisstudied.Themodelcanbeused fortheprocessoptimizationanddesignofbetterelectrospinningapparatus.·

1.Introduction Motionofaliquidmassdeformedandacceleratedbyanexternalelectricfieldconstitutea problemofelectrohydrodynamicsthathasattractedconsiderableattentionofinvestigators[l4].Whenliquidmassisattachedtoasolidobject,themassshapeiscalledameniscus.The meniscusdeformsintheelectricfield.Inweakfields,themeniscusisheldonthesurfaceofa solidobjectbysurfacetension.Whenthefieldincreases,themeniscuselongatesuntil,at somecriticalvalueofthefield,surfacetensioncannolongerbalanceelectricforcesandthe liquidmassemitsajet[5-6].Dependingonprocessparameters,anintermittentorcontinuous jetflowcanbeobserved.Thecontinuousflowmodecanbeusedtodisperseliquids(atomization)[6]ortofabricatepolymerfibers(electrospinning)[7-8].