Preceramic Polymers; Synthesis, Processing, Modeling, and Derived Ceramics: On-Demand Poster Presentations
Sponsored by: ACerS Engineering Ceramics Division
Program Organizers: Matthew Dickerson, Air Force Research Laboratory; Gurpreet Singh, Kansas State University; Paolo Colombo, University of Padova; Günter Motz, Universität Bayreuth
Friday 8:00 AM
October 22, 2021
Room: On-Demand Poster Hall
Location: MS&T On Demand
Session Chair: Joe Bowen, Air Force Research Laboratory
Fabrication of SiOC Fibermats via Electrospinning and their Applications in Energy Storage Systems: Shakir Bin Mujib1; Gurpreet Singh1; 1Kansas State University
Electrospinning has attracted widespread attention for application in energy storage, as researchers have been able to greatly control the size, dimensionality, and microstructural development of fibers. Polymer-derived-ceramics (PDCs) and PDC-based fibers are being studied as potential high capacity electrode materials for electrochemical energy storage applications. Among these, silicon oxycarbide (SiOC) has shown most promise, especially as electrodes in lithium ion batteries (LIB). Herein we report fabrication of molecular precursor-derived SiOC fibermats via electrospinning and pyrolysis of cyclic polysiloxanes-based precursors at significantly lower weight loadings of organic co-spin agent. Ceramic fibermats were prepared by a one-step spinning (in air) and post heat-treatment for crosslinking and pyrolysis. The pyrolyzed fiber mats were revealed to be amorphous and a few microns in diameter. This work investigates the fabrication of SiOC-based PDC fiber mats via electrospinning and pyrolysis of pre-ceramic polymers of varying composition, and their use as supercapacitor and LIB electrodes.
Investigation of Polymer Derived SiOC/Carbon Nanotube Electrodes for Na-ion Batteries: Mabel Anstine1; Shakir Bin Mujib1; Gurpreet Singh1; 1Kansas State University
Herein we present a study on polymer-derived silicon oxycarbide (SiOC)/CNT composites for a potential application as an electrode in energy storage devices. Free-standing SiOC/CNT fibermats were prepared using electrospinning process, which were then used as binder-free anodes in Sodium-ion Batteries (SIBs). Electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy was performed to study the effect of precursor chemical composition, polymer to ceramic transformation and free carbon content of the composite electrodes. The electrochemical measurements revealed enhanced capacity and cyclic stability for SiOC/CNT composite compared to the pure components.
Porous SiOC/SiC Ceramics via an Active-filler Catalyzed Polymer-derived Method: Advaith Rau1; Kathy Lu1; 1Virginia Polytechnic Institute and State University
Bulk and porous SiOC materials were synthesized via a polymer-derived ceramic (PDC) method from a polysiloxane (PSO) precursor and an iron catalyst under inert pyrolytic conditions. Fe catalyzes not only the formation and nucleation of β-SiC at lower temperatures but also promotes phase segregation of the amorphous SiOxCy phase. Samples with Fe pyrolyzed at 1100°C have an appreciable β-SiC content compared to minimal β-SiC content in the corresponding Fe-less samples. Selective etching of the SiO2 phase shows that Fe also induces segregation of the amorphous SiOxCy phase, yielding larger specific surface areas and gas sorption capability below 1300°C. At 1500°C, the pore structure changes to form interconnected networks due to the highly phase separated SiO2 and β-SiC microstructure. A Gibbs free energy minimization method was used to determine the relative phase content of the pyrolyzed samples, with the effect of Fe quantified with simplified vapor-liquid-solid and classical nucleation theories.
Synthesis of Precursor Derived Si(B)CN Ceramic Coating for High-temperature Applications: Lanie Mannebach1; Shakir Bin Mujib1; Gurpreet Singh1; 1Kansas State University
Polymer derived ceramics (PDC) have shown promise as coatings due to their thermal stability, chemical and oxidation resistance, as well as tunable microstructure. This present work focuses on boron modified silicon carbonitride, Si(B)CN thin coating film preparation and characterization. The coatings are prepared from a polysilazane precursor by a single-step dip-coating technique. The films were transparent and dense in microstructure. Investigations on the structural and compositional development of the prepared coatings are conducted via Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy to determine the cross-linking and pyrolysis behavior, uniformity, and crack-free preparation of the coating films. The molecular structure of the preceramic polymers as well as the thermomechanical properties of the resulting Si(B)CN significantly influenced the quality of the coatings. Further thermal characterization suggested the potential of ceramic coatings in high temperature applications.