Due to tiny diameter

big specific surface area

and ability to achieve surface functionalization easily

nanofibers are attracting great attentions world widely .Electropinning is an effective method to produce continuous nanofibers

whereas more advanced coxial-electrospinning technique can be used to fabricate core-shell composite nanofibers.In this review article

the fundamental issues with electrospinning based on electrohydrodynamics are addressed .Special attention is paid to recent studies on mechanism of coaxial electrospinning .Disucssions are made on Taylor cone

two-phase flow patterns

flow instabilities

non-Newtonian properties of polymer liquids

and stratified non-Newtonian fluid flows .Several untouched matters are mentioned as well.