Date of Award
Doctor of Philosophy (PhD)
School of Materials Science and Engineering
Rajendra K Bordia
Polymer derived ceramics is an attractive route to make Si-based ceramics with high temperature stability in a broad range of physical forms. Partial thermal decomposition of hybrid Si- and C-based polymers allows for the creation of unique materials with attractive properties, such as high surface area, high electrical conductivity, and pores in nanometer range. However, investigations of these materials have been limited and are the focus of this research. The unique aspect of this work is the pyrolysis temperature which is at a low/intermediate temperature range of below 1000 °C. Several systems have been investigated to explore a broad range of compositional space. Specifically, system composed of polysiloxane and polycarbosilane polymers as Si-based polymers and divinylbenzene (DVB) as C-based polymer have been studied. In some cases, boron and boron nitride were incorporated as well to influence the microstructure and chemical stability of the material. Overall, the processing, characterization, and specific application-relevant properties of these materials were investigated. In addition to the composition, the focus was on varying the pyrolysis temperature. The characterization of the material was conducted using a variety of chemical and microstructural characterization methods, including Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), solid state nuclear magnetic resonance (NMR), thermogravimetric analysis coupled with mass spectrometry (TGA-MS), and electrochemical impedance spectroscopy (EIS). The research has provided insights on the chemical, structural, and microstructural evolution, as a function of precursor composition and thermal treatment, for this new class of materials. Materials with a unique combination of properties – high electrical conductivity and high microporosity, are being developed for potential applications as gas separation membranes and/or battery electrodes.
Greenough, Michelle, "Carbon Rich Polymer-Derived Ceramics: Processing, Characterization, and Properties" (2021). All Dissertations. 2882.