1. Supervisor: Prof N. Manyala
Production of nanofibers by electrospinning of polymer-graphene solutions
By Isaac Manabile
PhD Student
DST Chair in carbon materials and technology, IAM, University of Pretoria, Lynnwood road, Pretoria , 0002
Supervisor: Prof N. Manyala

2. Outline Introduction Aims and objectives Experimental Results
Conclusions

3. Introduction
Electrospinning or ‘‘electrostatic spinning’’ is a process in which nanofibers are generated by the application of electrostatic forces to a jetting polymer solution
Graphene is a two dimentional sheet of SP2-hybridised carbon
Polymer is a large molecule composed of repeating subunits called monomers
Properties of polymer nanofiber have been improved and enhanced using various nanofillers
Graphene is a multifunctional nanofiller that can enhance polymer fiber properties at a very small loading (Das, S et al., 2012)

4. Introduction cont
Schematic illustration of basic electrospinning setup (Li, D and Xia, Y. 2004)

5. Objectives Mass produce graphene with good properties
To investigate the influence of graphene on properties of polymer fibers
To produce graphene/polymer fibers that could used in various application including solar cells and supercapacitors

6. Experimental
Materials: Expandable graphite, synthetic graphite and exfoliating and dispersing solvents/polymers
Two method have been employed to produce graphene through microwave irradiation
1. Commercial synthetic graphite suspension was irradiated with microwave to yield graphene.
2. Commercial expandable graphite was irradiated with microwave and dispersed
The resultant products were successfully incorporated in polymer fibers

7. Results
SEM of raw expandable graphite (left) and irradiated expandable graphite (right)

8. Results cont
Raman spectra of raw expandable graphite and irradiated expandable graphite
Malard, et. al., (2009), Physics Reports (473) 5187

9. SEM of PVA fibers incorporated with graphene
Results cont
SEM of PVA fibers incorporated with graphene

10. Results cont
SEM of synthetic graphite and synthetic graphite derived graphene powders

11. Results cont
SEM of synthetic graphite derived graphene and some nanoparticles

12. Results cont
Raman spectra of synthetic graphite and synthetic graphite derived graphene

13. SEM of PVA fibers incorporated with graphene
Results cont
SEM of PVA fibers incorporated with graphene

14. Conclusions
Graphene could be mass produced using established method and a relatively new method all involving microwave irradiation
Graphene produced by both method could be incorporated in to the polymer matrix during electro-spinning

15. Acknowledgements
The South African Research Chairs Initiative of the Department of Science and Technology
The National Research Foundation.
University of Pretoria
My supervisor and colleagues

16. Reference
1]. Kuilla, T., Bhadra S., Yao, D., Kim, N.H., Bose, S. Recent advances in graphene based polymer composites Progress in Polymer Science 35 (2010) 1350–1375
[2]. Malard L.M., Pimenta, M.A., Dresselhaus, G., Dresselhaus, M.S. Raman spectroscopy in graphene, Physics Reports 473 (2009) 5187
[3]. Chung D. D. L. Review Exfoliation of graphite, Journal of materials science 22 (1987)
[4]. Das, S., Wajid, A.S., Bhattacharia, S.K., Wilting, M D., Rivero, I V. and Green, M.J. (2012). Electrospinning of Polymer Nanofibers Loaded with Noncovalently Functionalized Graphene Journal of applied polymer science

17. Thanks