TY - JOUR
T1 - Buckling of jets in electrospinning
AU - Han, Tao
AU - Reneker, Darrell H.
AU - Yarin, Alexander L.
N1 - Funding Information:
We acknowledge financial support from the National Science Foundation, DMI-0403835-2 (NIRT), NSF subcontract 25-1110-0038-002 (Nebraska DMI-0600733), and a subcontract through Ohio State University, NSF EEC-0425626 (RF 60002999). The Coalescence Filtration Nanomaterials Consortium of the University of Akron provided financial support and an industrial point of view. The authors thank Dr. Daniel Galehouse for the design and construction of a laser velocimeter, and Mr. Steven Roberts for technician support. DHR and TH thank Apogee Technology Inc. for financial support. ALY also acknowledges partial support of this work by the National Science Foundation under Grant NIRT CTS-0609062.
PY - 2007/9/21
Y1 - 2007/9/21
N2 - Various buckling instabilities of electrospinning jets were observed and compared with the buckling instabilities of uncharged fluid jets. Buckling instability arises due to jet compression at impingement on a collector surface and occurs independently of the electrical bending instability. The velocity, diameter, density and viscosity of the electrospinning jets are the key factors that determine the buckling frequency. The electrically charged jets impinging onto grounded, horizontal or inclined (wedge-like) electrodes moving laterally at a constant velocity are studied experimentally. Straight and bending (electrospinning) jets emerge at short and sufficiently long inter-electrode distances, respectively. The experiments show that both straight segment and bending jets, when impinging onto a counter-electrode, buckled and produced patterns of meandering deposits. In the case of bending electrospun jets these short-length buckling patterns were superimposed on the bending loops found in the deposits. Buckling-related and bending-related morphologies are easily distinguishable. The buckling patterns have frequencies of the order of 105-106 Hz, whereas the bending loops are formed at the frequencies of the order of 103 Hz. The deposited buckling patterns include sinuous, zigzag-like, figures-of-eight, recurring curves, coiled and other structures that resembled many patterns created by uncharged jets of highly viscous fluids impinging a hard flat surface. In addition, several new morphologies which were not observed before with uncharged jets were found. The experimentally measured frequencies of the buckling patterns were compared to the theoretical predictions and a reasonable agreement was found.
AB - Various buckling instabilities of electrospinning jets were observed and compared with the buckling instabilities of uncharged fluid jets. Buckling instability arises due to jet compression at impingement on a collector surface and occurs independently of the electrical bending instability. The velocity, diameter, density and viscosity of the electrospinning jets are the key factors that determine the buckling frequency. The electrically charged jets impinging onto grounded, horizontal or inclined (wedge-like) electrodes moving laterally at a constant velocity are studied experimentally. Straight and bending (electrospinning) jets emerge at short and sufficiently long inter-electrode distances, respectively. The experiments show that both straight segment and bending jets, when impinging onto a counter-electrode, buckled and produced patterns of meandering deposits. In the case of bending electrospun jets these short-length buckling patterns were superimposed on the bending loops found in the deposits. Buckling-related and bending-related morphologies are easily distinguishable. The buckling patterns have frequencies of the order of 105-106 Hz, whereas the bending loops are formed at the frequencies of the order of 103 Hz. The deposited buckling patterns include sinuous, zigzag-like, figures-of-eight, recurring curves, coiled and other structures that resembled many patterns created by uncharged jets of highly viscous fluids impinging a hard flat surface. In addition, several new morphologies which were not observed before with uncharged jets were found. The experimentally measured frequencies of the buckling patterns were compared to the theoretical predictions and a reasonable agreement was found.
KW - Buckling instability
KW - Electrospinning
KW - Nanofibers
UR - http://www.scopus.com/inward/record.url?scp=34548488216&partnerID=8YFLogxK
U2 - 10.1016/j.polymer.2007.08.002
DO - 10.1016/j.polymer.2007.08.002
M3 - Article
AN - SCOPUS:34548488216
SN - 0032-3861
VL - 48
SP - 6064
EP - 6076
JO - Polymer (United Kingdom)
JF - Polymer (United Kingdom)
IS - 20
ER -