Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials: Heterostructures & Polymer-Derived Ceramics
Sponsored by: ACerS Basic Science Division, ACerS Electronics Division, ACerS Engineering Ceramics Division
Program Organizers: Haitao Zhang, University of North Carolina at Charlotte; Gurpreet Singh, Kansas State University; Kathy Lu, University of Alabama Birmingham; Edward Gorzkowski, Naval Research Laboratory; Jian Shi, Rensselear Polytechnich University; Michael Naguib, Tulane University; Sanjay Mathur, University of Cologne
Wednesday 2:00 PM
October 12, 2022
Room: 320
Location: David L. Lawrence Convention Center
Session Chair: Kathy Lu, Virginia Tech; Gurpreet Singh, Kansas State University
2:00 PM Invited
The Many Faces of “Free” Carbon in Polymer-Derived Ceramics: Peter Kroll1; 1University of Texas at Arlington
We explore the structure formation of carbon during thermal processing of hybrid organic-inorganic polymers by various computational methods at different length scales. Focusing on polymer-derived SiCO and SiCN ceramics, we follow excess carbon through distinct stages. Initially, isolated carbon units of a molecular precursor are well dispersed throughout the polymer precursor. Upon annealing, those units combine and form a “free” carbon phase embedded in and surrounded by the polymer and glass network. Whether the “free” carbon forms distinct carbon flakes or extended graphene-like sheets depends on composition and temperature. In many instances, carbon segregations attain tubular structures. We will show that the mechanical properties of PDCs with identical compositions depend on the carbon morphology present in those ceramics. We will also highlight 2D-materials based on SiCO that await their realization.
2:30 PM Invited
Bioceramic Cellular Solids: Structure, Mechanics, and Formation: Ling Li1; 1Virginia Polytechnic Institute
While many engineering cellular solids or foams are based on metallic and polymeric materials, ceramic foams are often used for non-structural applications. The main limitation of using ceramic foams as structural components are their brittleness and flaw sensitivity. In this talk, I will present our recent works in elucidating the structural design principles of natural ceramic or biomineralized cellular solids from a variety of model systems, such as echinoderm stereom, cuttlefish bone, and sponges. These structures are characterized by their highly mineralized porous morphology, yet exhibiting remarkable damage tolerance, in stark contrast to synthetic ceramic foams. We utilize a combinatorial approach by integrating quantitative 3D structural analysis, 4D mechanical analysis, theoretical and mechanical modeling to establish the structure-property relationship for these biological materials. The structural design strategies to overcome the intrinsic brittleness of porous ceramics learned from these biological material systems could inspire novel lightweight ceramic cellular solids.
3:00 PM
Inquiry of SiOC Structural Evolution via Synchrotron X-ray and Reactive Force Field Simulation: Kathy Lu1; Yue Zhou1; Harrison Chaney1; Ni Yang1; 1Virginia Polytechnic Institute and State University
Silicon oxycarbide (SiOC) is a unique system that can generate various compositions and microstructures via different polymeric precursors and pyrolysis conditions. However, understanding of the resulting atomic structural domains and characteristics, such as atomic coordination, cluster distribution, and phase genesis, is lacking. In this study, the structural cluster size, atomic packing, nanodomains of different carbon-containing SiOC ceramics synthesized at 1200°C and 1500°C, were investigated by synchrotron small-angle X-ray scattering and high energy X-ray method. The high energy X-ray pair distribution function (PDF) was processed and analyzed. Also, a new ReaxFF molecular dynamics modeling approach was developed and compared with the experimental data to uncover the relationship between compositions and pyrolysis temperatures on the evolution of atomic packing and nanodomains of different SiOCs.
3:20 PM Break
3:40 PM
Building Better Lithium-ion Battery Anodes with Enhanced Capability and Cycling Efficiency Using MoSe2/SiOC Freestanding Structure: Sonjoy Dey1; Gurpreet Singh1; 1Kansas State University
Transition metal dichalcogenides (TMDs) are potential candidates for Li-ion (Li+) battery electrodes as they possess properties such as weak force between layers-of interest for ion-intercalation, and conversion chemistry with lithium-ions. But disadvantages such as capacity decay, and degradation reaction with electrolytes at low discharge potential make them vulnerable. As polymer-derived ceramics (PDCs) and PDC-based fibers specially silicon oxycarbide (SiOC) exhibit practicable energy storage capabilities towards Li+, SiOC functionalized TMDs can be beneficial in overcoming the disadvantages stated above. Herein, we report fabrication of SiOC functionalized TMD (MoSe2) in fibermat form which can be used as a freestanding electrode in Li-ion cells. Characterization of the structure of SiOC functionalized TMD fiber mats was carried out via electron microscopy and spectroscopic techniques (such as SEM, TEM, XPS, Raman Spectroscopy and FTIR). The electrochemical analysis of the electrodes showed improved cycle stability which are the signs of a promising Li-ion battery electrode.
4:00 PM
Using a Reactive Hydrogen Atmosphere to attain Polymer-Derived SiCN ceramics: Akshada Hande1; Peter Kroll1; 1University of Texas Arlington
We compare the impact of hydrogen and nitrogen atmosphere during the processing of Durazane 1800(PSZ20). Visual differences appear in bulk and powdered samples. FTIR spectroscopy performed on H2-pyrolyzed samples indicates the persistence of carbidic carbon integrated into the SiCN host structure. Complementary Raman analysis supports the presence of graphitic segregations in N2-pyrolyzed samples but does not indicate similar constituents in H2-pyrolyzed samples. Subsequent additional annealing at 1300 °C and 1500 °C under Ar converts the amorphous SiCN into poly-crystalline ceramics. Phase analysis by XRD shows that N2-pyrolyzed samples further annealed under Ar, completes the carbothermal reduction and yields silicon carbide(SiC). In contrast, H2-pyrolyzed sample further annealed in Ar results in a SiC and silicon nitride (Si3N4), with a carbothermal reduction being significantly delayed even at 1500°C. We show that the amount of excess carbon present in the chosen SiCN-polymer can be tailored using hydrogen atmosphere during pyrolysis.
4:20 PM
Non-hydrolytic Sol-gel Chemistry to Functional Hybrid Materials: Nicola Pinna1; 1Humboldt-Universitaet Zu Berlin
The current trend in various energy applications,ranging from lighting to batteries and electrolizers,lays in the control of structural,physicochemical and morphological properties of materials and their interfaces. During this presentation, recent strategies for nanostructured materials synthesis, targeting energy and environmental applications will be discussed. Especially, we will focus on one-pot strategies for the fabrication of hybrid and complex nanomaterials focusing on the importance of the organic-inorganic and inorganic-inorganic interfaces. Among the examples presented, we will discuss the synthesis of complex nanostructures and the stabilization of metastable phases for applications in energy storage and conversion. We will see that nowadays the available strategies allow a control in terms of composition,crystalline structure,morphology and nanostructuration that would have been unimaginable just few years ago.Finally, the open challenges the field is currently facing and possible further developments which are needed to meet the always growing demand for high performing materials will be also discussed.
4:40 PM
Novel Carbyne Based Materials for Gas Sensing: Fabrication and Characterization: Mohamad-Anas Hejazi1; Osman Eksik2; Çiğdem Taşdelen-Yücedağ2; Caner Ünlü1; Andrey Brigadin3; Alexander Lukin4; Levent Trabzon1; 1Istanbul Teknik University; 2Gebze Teknik University; 3Swissimpianti Sagl; 4Western-Caucasus Research Center
Carbyne-enriched nanostructures with their unique aspects could open a new era in materials science and technology. The use of such carbon metamaterials for practical applications is almost a virgin field, and their properties have not been well discovered yet. In this study, the synthesis via ion-assisted carbon pulse-plasma deposition technique has been reported to provide carbyne-enriched thin films. Samples with film thicknesses between 25 and 120 nm have been obtained by varying the deposition parameters. The characterization of film structure by micro Raman spectroscopy at two wavelengths of 532 and 785 nm showed the formation of sp-sp2-sp3 carbon nanostructured hybrids. Elemental analysis using x-ray photoelectron spectroscopy (XPS) revealed minimal oxidation even after 30 days after deposition. This new class of carbon nanostructures has the potential to be employed in many fields. The optimization of these nanostructures will be considered in the near future for exploring their gas sensing capabilities.