In some countries or institutions, the convention is for thesis defences to be public events where you will give a lecture explaining your research, followed by a discussion with a panel of examiners (opponents).
Both your examiners and the audience are able to ask questions.
Take the preparation for your viva seriously and devote a substantial amount of time to it.
The viva preparation checklist may be useful to help you prepare.
Your institution may offer courses on viva preparation and there may be opportunities to organise a practice viva.
Take advantage of these opportunities: they can be extremely valuable experiences.
The process is based on hydrodynamic tube-shearing and can produce both multilayer graphene and nanometer-thick and micrometer-wide flakes of nanographite.
I also describe the production of highly conductive and robust carbon composites based on the addition of nanocellulose during production; these are suitable as electrodes in applications ranging from supercapacitors and batteries to printed electronics and solar cells.
Furthermore I demonstrate a scalable route for roll-to-roll coating of the nanographite-nanocellulose electrode material and propose a novel aqueous, low-cost, and metal-free supercapacitor concept with graphite foil functioning as the current collector.
The supercapacitors possessed more than half the specific capacitance of commercial units but achieved a material cost reduction of more than 90 %, demonstrating an environment-friendly, low-cost alternative to conventional supercapacitors.