Stretching of an Electrically Charged Viscoelastic
Jet
Feng, J. J.
J. Non-Newtonian Fluid Mech. 116,
55-70 (2003).
Abstract - A charged polymer jet may be
accelerated
and stretched by an external electric field in a process known as
electrospinning.
The process is governed by the interplay among electrostatics, fluid
mechanics
and rheology, and the role of viscoelasticity has not been fully
explored
before. This paper presents a slender-body theory for the stretching of
a charged jet of Giesekus fluid. Results show strain-hardening as the
most
influential rheological property. It causes the tensile force to rise
at
the start, which enhances stretching of the jet. Further downstream,
however,
the higher elongational viscosity tends to suppress jet stretching. In
the end, strain-hardening leads to thicker fibers.