1. Electrospinning functionalized nanofibre membrane for anti-bacterial nanofiltration systems
Conor Keevey (AOS)
Garrett Nekic (AOS)
Darryl Chai (HCI)
Sit Han Zhe (HCI)

2. Background
Electrospinning is a simple and versatile process that is used to create nanofibre membranes for a variety of applications.
Scientists have implemented various chemicals into the polymer solution to create modified mesh.

3. Background
Copper nanoparticles have shown to possess antimicrobial properties against bacteria such as Escherichia Coli and Bacillus subtilis (Faheem et al, 2011).
Past research has also shown that chlorhexidine digluconate could kill both gram positive and gram negative bacteria (Chen et al., 2008).

4. Rationale Lack of access to drinking water
Current conventional methods have their disadvantages:
Non-controllable pore size
Lack of ability to control nanofiber composition/ functionalising agents for desired functions
Great demand for a more efficient and cheaper method of water purification.

5. Objectives
Confirm the effectiveness of chlorhexidine digluconate and copper nanoparticles electrospun for the log removal of bacteria while integrated in separate nanofibre membranes
Determine the effectiveness of a combination of chlorhexidine digluconate and copper nanoparticles electrospun into the same membrane for water purification

6. Hypothesis
A combination of copper nanoparticles and chlorhexidine digluconate is more effective than the individual functionalising agents or no functionalising agents when electrospun into nanofibres.

7. Variables Controlled Variables:
Ambient measurements, type and amount of bacteria and water, spinning parameters, size of mesh, methods used for filtration and measurements
Independent Variable:
Type(s) of anti-bacterial agent electrospun with polymer
Dependent Variable:
The total log removal of colony forming units (CFUs)

8. Materials Acetic acid (18 M glacial) Formic acid (98% concentration)
Nylon 6 ([-NH(CH2)5CO-], Sigma Aldrich)
Nutrient agar broth
Escherichia coli k-12 (ATTC)
Bacillus megaterium (ATTC)
Sterilised water
Bleach

9. Apparatus Electrospinning apparatus Petri dishes Sterile Spreaders
Micropipettes
AA Spectrophotometer
Autoclave
Beakers
Buchner Funnel
Flask

10. Preparation of Copper nanoparticles
Mix copper(II) sulfate with ethylene glycol
Centrifuge mixture to obtain copper nanoparticles
Rinse with distilled water and pat dry with filter paper

11. Preparation of Nanofibres
Dissolve nylon 6 in acetic and formic acid
Mix in antibacterial agent (copper nanoparticles/chlorhexidine digluconate)
Spin an anti-bacterial mesh
(Daels et al., 2011)

12. Testing with Bacteria
Grow the Escherichia coli, and Bacillus megaterium using nutrient broth in separate test tubes
Measure and adjust optical density
Mix bacteria with sterilised water
Deposit 100 µL diluted culture into the agar plates (10 plates)

13. Testing with Bacteria
Place mesh on circular plate and fasten to cylinder. Place in funnel
Pour the 500 mL of water through it
Deposit 100 µL of diluted culture onto the agar plates (10 plates)
Place the plates in the incubator

15. Thank You

16. Bibliography
Agarwal, S., Greiner, A., & Wendorff, J. H. (2008). Use of electrospinning technique for biomedical applications. Polymer, 49, doi: /j.polymer
Bhardwaj, N. & Kundu, S. C. (2010). Electrospinning: A fascinating fiber fabrication technique. Biotechnology Advances, 28, doi: /j.biotechadv
Bjorge, D., Daels, N., Devrieze, S. Dejans, P., Camp, T.V., Audenaer, W,... Van Hulle, S. W. H. (2009). Performance assessment of electrospun nanofibers for filter applications. Desalination, 249, doi: /.j.desal
Chen, L., Bromberg, L., Hatton, T. A., & Rutledge, G. C. (2008). Electrospun cellulose acetate. Fibers containing chlorhexidine as a bacteriacide. Polymer, 49, doi: /j.polymer
Daels, N., De Vrieze, S., Sampers, I., Decostere, B., Westbroek, P., Dumoulin, A.,...Van Hulle, S. W. H. (2011). Potential of a functionalised nanofibre microfiltration membrane as an antibacterial water filter. Desalination, 275, doi: /j.desal
Faheem, A.S. , Muzafar, A.K. , Saurabah, S, Chung, W.J. & Kim, H (2011). Polyurethane nanofibers containing copper nanoparticles as future materials. Applied Surface Science, 257,

17. Bibliography
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Hem, R.P. , Dipendra, R.P. , Ki, T.N. , Baek, W.I. , Seong, T.H. & Kim, H.Y. (2011). Photocatalytic and antibacterial properties of a TiO2/nylon-6 electrospun nanocomposite mat containing silver nanoparticles. Journal of Hazardous Materials, 189,
Lok, C.N. et al. (2006). Proteomic analysis of the mode of antibacterial action of silver nanoparticles. J Proteomic Research, 5(4):
Rutledge, G. C. & Fridrikh, S. V. (2007). Formation of fibers by electrospinning. Advanced Drug Delivery Review, 59, doi: /j.addr
Sondi, I., Salopek-Sondi, B. (2004). Silver nanoparticles as antimicrobial agent: a case study on E. coli as a model for Gram-negative bacteria. Journal of Colloid and Interface Science, 275,
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Zussman, E., Theron, A. & Yarin, A. L. (2003). Formation of nanofiber crossbars in electrospinning. Appl Phys Let, 82,