1. Electrospinning Nanofiber Filtration Tubes using Quadrupole Design
Katie Wittibschlager 10
Abstract
Design
Objectives
Electrospinning is often used as a technique to produce nanofibers. One concern involving this method is the low production rate. The main objective of the study is to increase the production rate of small filtration tubes made of polymer nanofibers using for vertical rods in a quadrupole structure.
This study focuses on optimizing both production rate and concentration of fibers by location. Characterization of fiber morphology via scanning electron microscopy will determine the quality of the fabricated fiber mats.
Use quadrupole design to improve production rate of nanofibers via electrospinning.
Add secondary electric field to increase fiber concentration in desired areas (collection rod).
Compare nanofiber production rate to syringe method and previous vertical rod studies.
Optimize production rate by varying:
Distance from secondary electric field to threaded rods.
Distance from threaded rods to the collection rod
Applied voltage
Polymer concentration in solution
Background
The following methods were used in the design of the experiment.
Vertical Rod
The use of vertical rods in the quadrupole is to improve the fiber production rate. This mimics the use of multiple syringes or nozzles without a significant increase in cost. The polymer solution flows along the threads and launches many fiber jets. This has been shown to increase fiber production rate by up to 26.5%1.
Secondary Electric Field
Another method to improve the production rate is with a secondary electric field. By preventing fiber buildup in undesirable locations, fiber concentration can be maximized on the collection rod. The fiber jets will follow the voltage gradient. Thus the fibers jets can be predicated using the electric field current density lines to the secondary electrodes2.
Future Application
Figure 1. Conceptual quadrupole design for electrospinning small nanofiber tubes with secondary electrodes.
The desired application for this methodology is in nanoparticle separation, specifically diesel and water. The hydrophobic properties of the fiber mat prevent water from moving through the filter. Water molecules build up on the tube. When a large enough droplet forms, it will sink down to bottom on the tubing.
Key Design Aspects
Vertical threaded rods are used to launch multiple fiber jets from each rod.
PVC piping allows polymer solution to contact all four rods while also holding the 4 rods in a quadrupole configuration.
A secondary electric field with an applied voltage that is 80% of the primary voltage.
References
[1] Viswanadam, Goutham, and George G. Chase. "Modified Electric Fields to Control the Direction of Electrospinning Jets." Polymer 54.4 (2013): Web.
[2] Shin, Hyeon Ung, Yalong Li, Ariel Paynter, Kitchaporn Nartetamrongsutt, and George G. Chase. "Vertical Rod Method for Electrospinning Polymer Fibers." Polymer 65 (2015): Web.