Applications of Polymer Nanofibers. Группа авторов

Applications of Polymer Nanofibers - Группа авторов


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jetting from a planar surface typically requires high electric field strength which results in corona discharge in the air impeding the process. To overcome this challenge, perturbations are often introduced to the liquid surface. When an electric field is applied, each bump concentrates charge accumulation on the surface of the polymer solution and becomes the origin of an electrospun jet. Throughput using various needleless setups has been on the order of ~5 g/h. This approach has been commercialized by El Marco. The production rate of the Nanospider™ (El Marco) is at least ~100 g/h (Persano et al. 2013; Niu et al. 2011; Guo et al. 2010).

      (1.12)equation

      where γ is surface tension, ε 0 is the permittivity of free space, E 0 is the electric field at the edge of the fluid, and images is the electric field gradient. The shorter the wavelength, the higher the maximum number of jets. Therefore, the maximum number of jets increases with decreasing surface tension and increasing electric field strength. Additionally, the same relationship for current in needleless electrospinning has been reported (Yener et al. 2013). Counting the number of jets, Yener et al. surmised that the value of current is approximately the same in all the jets occurring simultaneously.

      1.7.3 Alternative Fiber Production Methods

Method Fiber size Scale Production rate (g/h)
Needle electrospinning 40 nm–2 μm Bench 0.3
Melt electrospinning 800 nm–500 μm Bench 300
Needleless electrospinning 40 nm–2 μm Industrial 100
Solution blowing 40 nm–several μm Bench 1.2
Centrifugal spinning 25 nm–several μm Bench 50

      In closing, electrospinning is a widely used technique for producing nonwoven nanofibers on a laboratory scale. Significant effort has been spent on understanding how process parameters, e.g. flow rate, applied voltage, tip‐to‐collector distance, affect the final fiber size using theoretical and experimental approaches. However, the experimental data is conflicting and the changes in fiber diameter relatively minor. The solution properties play a significant role in the ability to produce uniform fibers. The polymer concentration and elastic properties generally dictate electrospinnability. Factors in the electrospinning setup, e.g. auxiliary electrodes, collector geometry, provide some tunability in terms of nanoparticle size and nanofiber patterning. Ability to make hierarchical fiber structures and complex cross sections have advanced significantly and provide opportunities in advanced functional properties. Production of nanofibers on a larger scale is a growing area of interest.

      1 Abbasipour, M. and Khajavi, R. (2013). Nanofiber bundles and yarns production by electrospinning: a review. Advances in Polymer Technology 32 (3): 1–9.

      2 Agarwal, S., Wendorff, J.H., and Greiner, A. (2008). Use of electrospinning technique for biomedical applications. Polymer (Guildf) 49 (26): 5603–5621.

      3 Agarwal, S., Wendorff,


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