Week 3 Cont. - Spinning Process *Detailed*

A major component that was not taken into account was the constants was the needle gauge. We chose a 21 gauge that had an inner diameter of 14.5 mm. The higher the gauge, the smaller the diameter becomes. It is important to keep the gauge constant because different sized gauges will change the diameter of respective nanofibers. This will cause innaccurate comparisons between the different spun fibers [11]. This was an important constant to add to the list because it is an important part of the apparatus. The rotational mixer used to mix the solutions was made by Elmeco Engineering Inc and the specific model was the Arma-Rotator A-1. When the spinning began some measurements were taken: the temperature was 24.3 degrees Celsius and the humidity was 26%.

Figure 3. Our Electrospinning Apparatus

Evan and Tristan began to spin the mixed solution that they created on the previous day. They started off by changing the distance variable and completed the first 6 deliverables. They spun at 4 cm, 6 cm, 8 cm, 10 cm, 12 cm, and 16 cm. These distances represented the distance of the syringe's needle tip to the collecting plate. The purpose of changing the distance was to see the effect on the fiber's diameter, abundance, and pattern that formed. In Figure 3 (to the left), the final apparatus can be seen. The syringe contains the PEO solution and the needle slowly releases the solution at a rate of 1 mL/hr. The red wire is the voltage that hits the solution and begins the fiber forming process. The silver square sheet is actually aluminum foil that is wrapped around a brown metallic sheet. This will keep the charged PEO fiber to stick onto the collecting plate and it will allow for a sample to form. The other wire (on the right) keeps the collecting plate charged for this exact reason. In the back, the holder allows the plate to be held at a certain elevation. The holder is wrapped so no current is able to pass through it.

Figure 4. 5% PEO solution used during spinning process

Evan and Tristan used the solution they made the day before. The solution was 5% PEO in water and the figure on the right shows the color of the solution as well as the solution itself. The solution was clear and is perfectly mixed because it was placed in the rotational mixer. This solution was then put into the syringe to be hit by high voltage as mentioned above.