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

Outline

Introduction Aims and objectives Experimental Results Conclusions

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)

Introduction cont

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

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

Results

SEM of raw expandable graphite (left) and irradiated expandable graphite (right)

Results cont

SEM of PVA fibers incorporated with graphene

Results cont

SEM of synthetic graphite and synthetic graphite derived graphene powders

SEM of synthetic graphite derived graphene and some nanoparticles

Results cont

Results cont

1200 1400 1600 1800 2000 2200 2400 2600 2800 3000

0

500

1000

1500

2000 Syngraph-Graphene synthetic graphite

Inte

nsity (a.u

)

Raman shift cm-1

Raman spectra of synthetic graphite and synthetic graphite derived graphene

Results cont

SEM of PVA fibers incorporated with graphene

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

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

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) 4190 4198

[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

Thanks