VIT-FIT syringe pump for electrospinning and electrospraying
VIT-FIT high pressure and high force laboratory syringe pumps for electrospinning and electrospraying applications, driven by a microprocessor controlled brushless long life BLDC motor, provides a high resolution control of the flow rate.
The flow rate of the syringe pump ranges from the minimum of 0.4 nl/min to a maximum of 110 ml/min using 0.5 µl and 150 ml syringes respectively. The users are free to choose the syringe type, e.g.: glass, plastic, single use or metal syringes with the syringe pump.
A. Electrospinning process setup
In most of the electrospinning laboratory set-up, the syringe pump is used to feed the sample solution through an insulating Teflon tubing to the steel spraying capillary where the polymer solution is extruded towards the collector and the capillary is charged using a high voltage power supply (DC).
When the polymer solution is charged to a suitably high level (about 5 to 50 kV), the surface of the liquid elongates and a cone (known as a Taylor cone) is formed. From the tip of the cone, a narrow jet of liquid is emitted and attracted to an earthed collector (planar, rotating drum, rotating disc, etc.).
The collector is placed at a distance between 7 to 20 cm from the syringe nozzle and it is grounded (sometimes connected to negative voltage show interesting results).
It is necessary check that the polymer solution feed is stable and constant, since the variation would result in varying thickness of the spun nanofibers or microfibers.
B. Electrospraying technique set-up
Electrospinning and electrospraying are two similar technologies with the same devices and arrangements, which differ mainly in the structure of produced nano or micro materials. The electrospinning process results in spun nanofibers or microfibers whereas the electrospraying process results in microparticles, nanobeads or nanoparticles.
Electrospraying can be used for the production of small, nearly monodisperse particles when a colloidal suspension of solid nanoparticles or a solution of a material is sprayed. Usually, electrospraying of colloidal suspension after electrospinning of polymer solution is done consecutively.
The size of droplets formed can be controlled by the feed solution flow rate and the droplet charge by adjusting the voltage applied to the syringe nozzle.
C. Electrospinning + electrospraying
It is also possible to use both the techniques at a same time i.e. simultaneous electrospinning of polymer solution and electrospraying of colloidal suspension from two separate capillary nozzles. It can be used, for example to produce a non-woven nanocomposite fabric from a polymer material with nanoparticles deposited on a fibre surface.