Fabrication and Characterization of Electrospun Alumina Nanofibre Reinforced Polycarbonate Composites
Year: 2017
Type: dissertation
Abstract: Fibres with ultra-high tensile strength have attracted unprecedented attention due to the rapidly increasing demand for strong fibre reinforced composites in various fields.However, despite a theoretical strength as high as around 46 GPa, current commercial alumina fibres only reach strength value of around 3.3 GPa because of the defects between the grains.Electrospinning provides a method to produce ceramic nanofibres with diameters reduced to nano-scale with effectively enhanced strength.Different calcination procedures were applied to study the morphology and crystal structure growth of alumina.Tested with a custom-built AFM-SEM system, the tensile strength of single crystal αalumina nanofibres were found to have little dependence on diameter variations, with an average value of 11.4±1.1 GPa.While the strength of polycrystalline γ-alumina nanofibres were controlled by defects, showing a diameter dependent mechanism.Apart from the intrinsic properties of the fibre and matrix, the interface between them also plays an important role in determining composite mechanical properties.Collected by a rotating drum during electrospinning, aligned fibres were used to reinforce polycarbonate matrix for fabricating composite.The composite mechanical properties were successfully improved after surface modification with silane coupling agent.With a fibre volume fraction of around 7.5%, the composite strength doubled and the Young's modulus increased by a factor of 4 when compared with the pure polycarbonate.Apart from surface modification, the fibre/matrix interface can also be affected by transcrystallinity.Other methods .......
Author: Wenjun Sun
Language: English
Subfield: Ceramics and Composites
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2773764502