Fabrication and mechanical testing of bioinspired composites

• Main Author: Adam Haziq Bin Kamsani
• Other Authors: Hortense Le Ferrand
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/166017
• Institution: Nanyang Technological University

The field of materials science has witnessed a surge in interest in bioinspired composites owing to their exceptional properties and potential for diverse applications. A novel approach for fabricating bioinspired composites involves the application of a magnetically assisted slip casting process (MASC). Anisotropic particle alignment is precisely controlled by this unique process, which combines slip casting with the application of an external magnetic field. The magnetized particles can be made to align in specific directions using the magnetic field, and this allows for the creation of composite materials that are inspired by biological systems with desired properties. However, the method is still relatively new and can be greatly improved on. Currently, a continuing investigation is underway, which aims to integrate the infiltration phase of polymers with MASC, into a singular step method for the production of bioinspired composites. The research attempts to utilize interpenetrative polymer networks (IPN), which can be incorporated into the MASC process, to achieve physical interfacial bonding of polymers to the alumina platelets simultaneously. Nonetheless, the findings of the study are inconclusive due to speculation of inadequate adhesion between the polymers and the alumina platelets used in MASC. Consequently, the focus of this study will be directed towards exploring the chemical bonding of polymer and ceramic particles by employing the use of surface modification techniques. First, alumina platelets will be roughened with colloidal silica and functionalized with vinyltrimethoxysilane (VTMS), followed by observation under field emission scanning electron microscope (FESEM) and Fourier Transform infrared (FTIR). The platelets will then be used to fabricate composites and their effects will be examined through compression tests. The results shows that surface roughened alumina platelets have better toughness compared to unmodified ones, and the addition of IPN to roughened alumina platelets further improves their ultimate tensile strength and toughness. Furthermore, the highest value of ultimate tensile strength and toughness were obtained from samples with VTMS-functionalized roughened alumina and presence of IPN. However, due to considerably high error bars, the results may be affected. As a suggestion for future work, more samples types can be created, approximately five for each sample type, to obtain a more accurate result. At the same time, more exploration on optimizing the surface roughening and functionalization is recommended. Other characterization methods can also be implemented such as Brunauer-Emmett-Teller (BET) analysis and X-ray photoelectron spectroscopy (XPS) to facilitate the optimization.