Advances in Powder and Ceramic Materials Science: Ceramic Particles and Powder
Sponsored by: TMS Extraction and Processing Division, TMS Materials Processing and Manufacturing Division, TMS: Materials Characterization Committee, TMS: Powder Materials Committee
Program Organizers: Bowen Li, Michigan Technological University; Shefford Baker, Cornell; Huazhang Zhai, Beijing Institute of Technology; Kathy Lu, University of Alabama Birmingham; Rajiv Soman, Eurofins EAG Materials Science LLC; Faqin Dong, Southwest University of Science and Technology; Jinhong Li, China University of Geosciences (Beijing); Ruigang Wang, Michigan State University; Eugene Olevsky, San Diego State University
Tuesday 8:30 AM
March 16, 2021
Room: RM 37
Location: TMS2021 Virtual
Session Chair: Bowen Li, Michigan Tech; Rajiv Soman, Eurofins EAG Materials Science LLC
8:30 AM Invited
Understanding the Role of Electric Field in the Manipulation of Particles in Aqueous Media and Fabrication of Ice-templated Ceramics: Dipankar Ghosh1; Sashanka Akurati1; Shizhi Qian1; Diego Terrones1; Bharath Gundrati1; 1Old Dominion University
Ice-templating technique enables the fabrication of directionally porous ceramic materials. In recent years, extrinsic manipulation of ice-templated structure using energized fields has received significant attention. However, the potential of electric fields is yet to be fully explored for the ice-templating technique. A significant advantage is that ceramic particles can directly respond to the applied electric field without the need for the second phase material, making the electric fields preferable for particle manipulation. Also, electric fields can be applied to different concentration of aqueous ceramic suspensions. In this presentation we will discuss our ongoing efforts in using electric fields in the manipulation of ceramic particles in aqueous media and fabrication of ice-templated ceramics. We will discuss the role of various parameters of electric field in the manipulation of ceramic particles and ice-templated microstructure. Preliminary results on computational modeling of the interactions between ceramic particles and electric field will be also presented.
8:50 AM
Chemical Etch/Modification Effect on CO Oxidation Performance of Ceria Supported Catalysts: Ruigang Wang1; Yifan Wang1; 1The University of Alabama
To satisfy the expanding demand about the exhaust gases treatment and more stringent EPA regulations, it is pressing to design and synthesize catalysts with economic viability of process and excellent catalytic activity/selectivity for better low temperature performance. Ceria (CeO2) has been widely adopted as an active carrier material in supported catalysts due to its unique redox property, which is highly correlated to the surface chemistry of CeO2. In this work, we used NaBH4, a strong reducing etching agent, to modify and transform the surface structure and chemistry of CeO2 nanorods (CeO2NR) support and then loaded the transition metal oxides on the surface modified CeO2NR. In a preliminary test, the 6 wt% NaBH4 etched CeO2NR supported transition metal oxide samples show clearly enhanced CO oxidation performance at lower temperature, which is mainly attributed to the created surface defects by boron doped CeO2 surface during NaBH4 chemical etching and strong metal-CeO2NR interaction.
9:10 AM
Layered Ceramic Structures In1+x(Ti1/2Zn1/2)1-xO3(ZnO)m (m = 2, 4, and 6; x = 0.5): Synthesis, Phase Stability and Dielectric Properties: Victor Emmanuel Alvarez Montano1; Subhash Sharma2; Francisco Brown1; Alejandro Durán3; 1Universidad De Sonora; 2Catedra CONACYT CNyN-UNAM; 3Universidad Nacional Autonoma de Mexico CNyN-UNAM
New ceramic materials with layered crystal structures and chemical formula In1+x(Ti1/2Zn1/2)1-xO3(ZnO)m (x = 0.5; m = 2, 4 and 6), here named ITZO-II, ITZO-IV, and ITZO-VI, have been synthesized by solid state reaction method. The phase characterization, phase stability with temperature and their microstructure has been studied by X-ray Powder Diffractometry (XRD) and Scanning Electron Microscopy (SEM). The XRD showed a hexagonal single phase at 1200 °C whereas at higher temperatures (1300 and 1400 °C) they decompose in secondary phases such as the In2Zn7O10 solid solution and starting material traces. SEM micrographs showed an increase in grain size as the temperature of sintering increases, reducing the porosity and increasing the bulk density. Here, the dielectric spectra in a wide range of temperatures and frequencies are reported. The permitivity results seems to indicate a classical paraelectric behavior in this class of layered-structural ceramic compounds.
9:30 AM
Mineralogical Characteristics of Sepiolite under Thermal Treatment: Huaguang Wang1; Bowen Li1; 1Michigan Technological University
Despite sepiolite from the United States is superior in terms of quantity and quality, there is little research on it, especially for the changes of structure and morphology during heat treatment. In this paper, sepiolite from Nevada was investigated by heat treatment from 200- 1000°C. The results were characterized by XRD, SEM, FTIR, and TGA/DTG. It was found that the sorption, zeolitic and coordinated water are removed successively at 104°C, 115°C and 296°C, with the sepiolite transferred into sepiolite tetrahydrate, sepiolite dihydrate and sepiolite dehydrate. The dehydration of the hydroxyls happened at 684°C, with the complete collapse of the sepiolite structure. Calcite and dolomite are completely decomposed into CaO at around 700°C. Finally, MgSiO3 was formed. The average diameter of sepiolite bundles decreases with the heating temperature increasing to 800°C but the shapes remain the same. After 800°C, the sepiolite bundles partly melt forming a porous structure after calcination.
9:50 AM
Dielectrophoretic Control of Ceramic Particles for Fabrication of Ice-templated Structures: Bharath Gundrati1; Sashanka Akurati1; Shizhi Qian1; Dipankar Ghosh1; 1Old Dominion University
Under AC electric field, mutual dielectrophoretic (DEP) forces between particles create particle chaining. Dielectrophoresis (DEP) is adopted for the first time to control ceramic particles in the ice-templating process, which can benefit from employing DEP forces to externally control the fabrication of ceramic materials with directional porosity and hierarchical structure. To this end, it is crucial to understand the interactions between ceramic particles in aqueous media and AC electric field. The dynamic interactions of ceramic particles under AC electric field are modelled using the iterative dipole moment (IDM) method, which was first validated by the Maxwell stress tensor (MST) method. The IDM method has the capability to simulate the field-particle interactions and formation of particle chains for large number of ceramic particles in aqueous media. The DEP assembly of ceramic particles is investigated as functions of the frequency of the applied electric field, size and electric properties of ceramic particles.