Preparation and characterization of graphene/polymer nanocomposites

Graphene has been garnering great interest because of its distinctive band structure and impressive physical properties. The challenges to produce graphene in large scale for research and application purposes as well as the drawbacks of various synthesising methods are addressed. A new approach is p...

Full description

Saved in:
Bibliographic Details
Main Author: Soah, Jie Miin
Other Authors: Lu Xuehong
Format: Final Year Project
Language:English
Published: 2015
Subjects:
Online Access:http://hdl.handle.net/10356/64692
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Nanyang Technological University
Language: English
Description
Summary:Graphene has been garnering great interest because of its distinctive band structure and impressive physical properties. The challenges to produce graphene in large scale for research and application purposes as well as the drawbacks of various synthesising methods are addressed. A new approach is proposed to prepare high concentration of high quality graphene by direct exfoliation of graphite in aqueous media using alkali lignin (AL) as surfactant. The newly introduced method is simple, effective yet inexpensive and environmental friendly. Monolayer and multi-layer graphene are being successfully exfoliated, clearly displayed by the SEM and TEM images. With optimal dispersing parameters, an aqueous graphene dispersion concentration of 0.65 ± 0.03 mg mL−1 can be reached. Electrostatic repulsion due to adhesion of negatively charged AL on graphene and formation of π–π interaction between them are the underlying principles of nanosheets stabilization mechanism. Finally, mechanical property enhancement due to the inclusion of 0.1wt% graphene filler in epoxy resin is reported, improving the tensile strength, critical stress intensity factor and critical strain energy release rate by 15%, 49%, and 97% respectively.