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CURATOR

PhD student, University of Malaya

PINBOARD SUMMARY

Electrospinning is a method of drawing very thin fibres down to the nanoscale range by means of electric forces. It is a simple and versatile method for the fabrication of nanofibres, used in many applications including biomedicine, tissue engineering, filtration, and energy. Although the setup is simple, the process is complex and time-consuming, yielding very small amount of materials through hours of production. Multiple-nozzle electrospinning is a straightforward approach in increasing the production rate of nanofibres. However, the addition of nozzles usually causes processing problems and lower fibre quality due to electric field interference between nozzles and non-uniformity of the process, limiting the possibility of mass production. The current research aims to investigate the parameters affecting the process, and find ways to improve the method. Ultimately, the goal is to develop a multiple-nozzle electrospinning setup to maximise the production rate, whilst maintaining the quality of nanofibres and minimising cost.

8 ITEMS PINNED

Nanoporous nanocomposite membranes via hybrid twin-screw extrusion-multijet electrospinning.

Abstract: Non-woven nanoporous membranes of poly(caprolactone), PCL, incorporated with multi-walled carbon nanotubes, CNTs, could be fabricated via an industrially-scalable hybrid twin screw extrusion and electrospinning process. The utilization of a spinneret with multiple nozzles allowed the increase of the flow rate beyond what is possible with conventional electrospinning using a single nozzle, albeit at the expense of difficulties in the control of the thickness distributions of the nanofibrous membranes. The thickness and orientation distributions and the resulting mechanical properties of the membranes could be modified via changes in voltage, angular velocity of the collector mandrel and separation distance of the collector from the spinneret. The increases in crystallinity due to the presence of the CNTs and the preferential alignment of the nanofibers via rotation of the collecting mandrel led to increases in the tensile properties of the nanoporous membranes. The use of poly(ethylene oxide), PEO, together with PCL, followed by the dissolution of the PEO, rendered the nanofibers themselves nanoporous with typical surface porosity values of around 50% and pore sizes of about 220 nm. The demonstrated versatility of the hybrid twin screw extrusion and electrospinning process and the manipulation of mesh dimensions and properties are indicative of the applicability of the hybrid process for fabrication of nanoporous membranes for myriad diverse industrial applications ranging from water treatment to tissue engineering applications.

Pub.: 03 Dec '16, Pinned: 18 Aug '17

Syringeless Electrospinning toward Versatile Fabrication of Nanofiber Web.

Abstract: Although electrospinning is considered a powerful and generic tool for the preparation of nanofiber webs, several issues still need to be overcome for real-world applications. Most of these issues stem from the use of a syringe-based system, where the key factor influencing successful electrospinning is the maintenance of several subtle balances such as those of between the mass and the electrical state. It is extremely difficult to maintain these balances throughout the spinning process until all the polymeric solution in the syringe has been consumed. To overcome these limitations, we have developed a syringeless electrospinning technique as an alternative and efficient means of preparing a nanofiber web. This new technique uses a helically probed rotating cylinder. This technique can not only cover conventional methods, but also provides several advantages over syringe-based and needless electrospinning in terms of productivity (6 times higher) and processibility. For example, we can produce nanofibers with highly crystalline polymers and nanofiber-webs comprising networks of several different polymers, which is sometimes difficult in conventional electrospinning. In addition, this method provides several benefits for colloidal electrospinning as well. This method should help expand the range of applications for electrospun nanofiber webs in the near future.

Pub.: 26 Jan '17, Pinned: 18 Aug '17