Morphing and Healing Composite Materials
Thursday 22 February 16:00 until 17:00
Pev3 4C10
Speaker: Dr Matthieu Gresil (University of Manchester)
Part of the series: Materials Physics seminars
This talk will be divided into two parts. The first part will be on the design and application of synthetic morphing composite materials. On the basis of large thermal expansion differences, bi-layered graphene-reinforced chitosan/polydimethylsiloxane (PDMS) composites are able to achieve rapid, reversible and repeatable morphing in response to both direct and indirect thermal triggers, for example near IR (NIR). Elastomers such as PDMS typically has relatively high coefficients of thermal expansion compared to chitosan and reduced graphene oxide (rGO), which enables morphing in such bi-layer composites. The presence of rGO allows remote photo-thermal triggered morphing via NIR irradiation. This work addresses the challenge to form printed and patterned bi-layered morphing composites, with suitable interfaces, to allow hinge-like and complex morphing.
The second part is to introduce the unique healing capacity of a shape morphing polymer. To date broadly two strategies have been adopted for self-healing materials: (i) extrinsic self-healing, where a component is added to the polymer formulation (e.g., nano/micro capsule), and (ii) intrinsic self- healing, using the dynamism and reactivity of the polymer molecular chains. A covalent adaptive network using epoxy-based molecules will be introduced. Using a diol or anhydride as the hardener, the simple addition of a transesterification catalyst to the network led to a thermoset polymer with glass- like behaviour at higher temperatures. This new class of polymers was named vitrimers. Our preliminary work on healing and shape morphing will be presented and discussed. Further challenges on multi-functional composite materials for various application will conclude this talk.
By: Sean Paul Ogilvie
Last updated: Monday, 8 January 2018