Bubble electrospinning is a relatively new development in fiber production using electrospinning. Ejection of electrospinning jet from bubble electrospinning is similar to conventional droplet electrospinning in which accumulation of sufficient charge to break free from the surface tension is necessary for jet initiation. This form of single bubble electrospinning differs from surface disruption by bubbles where bursting of bubbles are used to initiate electrospinning (Temporary Surface Disruptions). In single bubble electrospinning, the concept is based on maintenance of the bubble during electrospinning.
Fig 1. Multiple electrospinning jets emerging from a single bubble.
In single bubble electrospinning, larger surface area of the spinning bubble encourages multiple jet initiation from its surface. In the study by Pringle C (2011) , comparing the parameters affecting polyvinyl alcohol (PVA) solution and polyacrylonitrile (PAN) solution, it was found that more jets erupted from PAN bubble surface (4 to 5 jets) compared to PVA bubble solution (1 to 2 jets). This was attributed to lower surface tension of PAN which favours jet eruptions. A high concentration of solution was also found to reduce the lifespan of the bubble, presumably, due to higher viscosity slowing replenishment of the solution on the bubble. Similar to conventional droplet electrospinning, an increase in concentration also increases the fiber diameter [Pringle 2011, Ren 2010].
A comprehensive study by Varabhas et al (2009) on the influence of bubble size on the applied voltage using polyvinyl pyrrolidone solution showed higher voltage is necessary to initiate spinning for smaller bubble. It is hypothesized that for smaller bubble, more energy is required for it to deform and create an apex for the jet to initiate.
In an extension of the single bubble electrospinning concept, a hexagonal mesh has been used for coating with a film of the polymer solution. Air is blown from under the mesh so that a bubble forms on each mesh opening [Chase G G et al 2011]. Since there are numerous mesh openings, the electrospinning production rate can be increased significantly.
Bubble electrospinning relies on the large spherical surface of the bubble to facilitate ejection of more electrospinning jets. Currently there are few detailed studies on the process although there are some short reports on mathematical models to describe the parameters [Dong et al 2010, Liu et al 2013] and development in the setup [Dou et al 2012, Kong et al 2013]. With more established needleless mass production electrospinning process, it remains to be seen whether bubble electrospinning have something different to offer.
Chase G G, Varabhas J S, Reneker D H. New Methods to Electrospin Nanofibers. Journal of Engineered Fibers and Fabrics 2011; 6: 32.
Open Access
Dong L, Liu Y, Wang R, Kang W M, Cheng B W. Mathematical Model of Electric Field Distribution at a Critical State in Bubble Electrospinning. Journal of Fiber Bioengineering and Informatics 2010; 3: 117.
Open Access
Dou H, Zuo B Q, He J H. Blown Bubble-spinning for Fabrication of Superfine Fibers. Thermal Science 2012; 16: 1465.
Open Access
Kong H Y, He J H, Chen R X. Polymer Liquid Membrane for Nanofiber Fabrication. Thermal Science 2013; 17: 1479.
Open Access
Liu F J, Dou H. A Modified Young-Laplace Equation for the Bubble Electrospinning Considering the Effect of Humidity. Thermal Science 2013; 17: 629.
Pringle C. Single Bubble-Electrospinning of Polyvinyl Alcohol and Polyacrylonitrile Solutions. University of Stellenbosch MSc Thesis 2011.
Open Access
Ren Z F, He J H. Single Polymeric Bubble for the Preparation of Multiple Micro/Nano Fibers. J Appl Polym Sci 2011; 119: 1161.
Varabhas J S, Tripatanasuwan S, Chase G G, Reneker D H. Electrospun jets launched from polymeric bubbles. Journal of Engineered Fibers and Fabrics. 2009; 4: 46.
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