ISBN 9783843931663

978-3-8439-3166-3, Reihe Ingenieurwissenschaften

Jefferson Jean do Rosário
On the photonic and mechanical properties of ordered and disordered arrays of pores

185 Seiten, Dissertation Technische Universität Hamburg-Harburg (2017), Softcover, A5

Zusammenfassung / Abstract

This thesis aims to investigate the fabrication of porous films with inverse photonic crystal (PhC) and inverse photonic glass (PhG) structures for broadband reflection of wavelengths from 1 to 5 µm. Yttrium-stabilized zirconia (YSZ) is the material of choice for classical thermal barrier coatings (TBCs), and it was chosen as the primary material in this study due to its phase stability and low thermal conductivity. Tools from colloidal science, such as electrostatic attraction and repulsion, are used to achieve the desired structure. PhG films explored here could reflect radiation in the 1-5 µm wavelength range and withstand longer times (up to 120 h) at high temperatures (1200 °C). Additionally, a silica inverse PhC (often called inverse opal, IO) is investigated as a model material to explore the mechanical behavior of this ordered design. Here, the effect of reinforcement with a titania coating on the base IO design and the effect of loading mode on the characterization (indentation versus compression) were vastly explored. The IO design presented high specific strength and modulus, outperforming many state-of-the-art microfabricated metamaterials and populating an interesting region of the property charts. The multifunctionality of these highly porous materials – the combination of photonic properties and temperature stability with insights on the mechanical behavior of model materials – is the core of this work.