Page 24 - Tailoring Electrospinning Techniques for Regenerative Medicine - Marc Simonet

CHAPTER 1
Table 1.2 Overview of electrospinning parameters and their main influence on the process.
Parameter
Polymer chain entanglements Surface tension
Solution conductivity Solution dielectric constant Flow rate
Voltage
High voltage type Nozzle design Target design Distance
Ambient parameters
1.5 Electrospinning parameters
In general, the choice of the electrospinning setup assembly and process parameters define the overall structure of the final product, whereas the interplay of solution-, process- and ambient parameters influences the fiber morphology. For reproducible and successful electrospinning, a set of parameters has to be found, which build up on each other, while keeping in mind that changing only one parameter might a ect the final outcome of the electrospinning test. Table 1.2 gives an overview of the di erent parameters and their main impact on the electrospinning process. More details on theses parameters can be found in the following paragraphs.
Main electrospinning impact
Defines if drops, beads or fiber are obtained34–37 Causes the formation of beads38,39
Fiber diameter40–44
Fiber diameter40–44
Fiber diameter25,45, deposition rate
Fiber diameter36,46,47
E ects polymers polar group arrangement48–50 Fiber morphology, productivity51–59
Sca old design and morphology24,30,31,60–63 Fiber diameter, fiber fusion64,65
Fiber morphology36,48,66–75
1.5.1 Solution parameters
The solution properties have the largest influence on the electrospinning process and resulting fiber morphology.
For a stable electrospinning process, a minimum amount of polymer chain entanglements is crucial to counteract the forces during the stretching of the jet. The number of entanglements defines whether the electrospinning jet breaks up in droplets, spins smooth fibers or a mix of both.34–37 The degree of the solution chain entanglements correlates with polymer concentration and molecular weight. Increasing either of them will increase the
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Process Solution