Preparation and evaluation of graphene-based nanocomposite conductive hydrogels

Author: Nyi Nyi Tun

Tun, Nyi Nyi, 2021 Preparation and evaluation of graphene-based nanocomposite conductive hydrogels, Flinders University, College of Science and Engineering

Terms of Use: This electronic version is (or will be) made publicly available by Flinders University in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. You may use this material for uses permitted under the Copyright Act 1968. If you are the owner of any included third party copyright material and/or you believe that any material has been made available without permission of the copyright owner please contact copyright@flinders.edu.au with the details.

Abstract

Owing to various unique properties, there have been a keen interest in the hydrogels to use in the biomedical field due to their rich water content, and biocompatibility. However, due to insufficient mechanical properties, low electrical conductivity, and short lifetime of conventional hydrogels, they were disrupted to use in large variety of applications. Thus, in this project, the conducting nanocomposite hydrogels were fabricated using mussel-inspired chemistry with a simple step procedure to improve various properties of conventional hydrogels, including mechanical and electrical properties by introducing graphene nanoparticles into polyacrylamide monomer (PAM). Remarkably, these hydrogels could be extended to 11 times of original length (higher than 1100%) and has tensile strength of 95 kPa and thus, these hydrogels integrate with high stretchability and strong mechanical strength. These hydrogels also showed high electrical conductivity of 0.0418 S/m at the water content of 89% and they demonstrated high sensing abilities by sensing small and large deformation. The self-healing properties of these hydrogels was received from their double-crosslinked polymer networks, which are physically and chemically crosslinked networks. The physically crosslinked networks helped to form the reversible self-treatment properties of hydrogels by interacting the ions between the ferric ions and carboxylic groups of acrylamide monomer and covalent bonds also helped to become stable and strong chemical network for these hydrogels. As graphene-based nanoparticles provided effective electric pathways, strain sensitivity can be achieved in these hydrogels and can detect the various deformation. In this project, the fabrication method is uncomplicated, simply scaled up, which will reduce the expense of preparation of hydrogels, and they can be used in wider applications including electronic skin and strain sensors due to higher electrical and mechanical properties.

Keywords: Conductive hydrogels, Self-healing, Graphene, Adhesive hydrogels

Subject: Engineering thesis

Thesis type: Masters
Completed: 2021
School: College of Science and Engineering
Supervisor: Professor Youhong Tang