Cactus Based Solids

Abstract

Biological materials have always been on the forefront of the development of novel materials either through the use of the biological material itself or via the development of bioinspired materials that mimic the structures observed in nature. Plant fibres specifically have demonstrated significant application potential in the automotive industry through their use as composite reinforcements while their interesting structures have prompted the development of
superior bioinspired materials. The focus of this thesis is to further investigate the
morphological properties and application potential of the fibres obtained from the biological material of cactus species Opuntia ficus indica. Initially, in Chapter 4, the morphology of these cactus fibres is investigated in order to gain a better understanding of the mechanical properties they demonstrate. A fractal geometry characterisation methodology is developed in an attempt

to explain the hierarchical structure characteristics present while the morphology is compared to other commonly used natural fibres. The morphological information obtained is then utilized in Chapter 5 for the development of cactus bioinspired materials via 3D printing. The developed materials are mechanically characterized, and their mechanical properties are compared to those of the original cactus fibres to determine whether the morphology present
is directly related to the mechanical behaviour. Moreover, the application potential of these 3D printed analogues is assessed via mechanical comparison with other 3D printed structure as well as dynamic mechanical testing. In Chapter 6, the last results chapter, the cactus fibres are used as a biological material for the development of novel thermoplastic and hydrogel composite materials. The materials developed are compared with other natural fibres in terms
of mechanical properties to determine the mechanical benefits obtained via the use of the cactus fibres. Additionally, a bone tissue engineering application route is followed utilizing the cactus fibres as a natural reinforcement for a hydrogel bioink for tissue engineering application providing a novel approach to mechanically reinforce scaffolds for biomedical applications.

Date of Award	23 Mar 2021
Original language	English
Awarding Institution	University of Bristol
Supervisor	Fabrizio Scarpa (Supervisor) & Adam W Perriman (Supervisor)