Functional Nanomaterials 2020: Translating Innovation into Pioneering Technologies: Translating Innovation into Pioneering Technologies VI
Sponsored by: TMS Functional Materials Division, TMS: Nanomaterials Committee
Program Organizers: Simona Hunyadi Murph, Savannah River National Laboratory; Huanyu Cheng, Pennsylvania State University; Yong Lin Kong, University of Utah; Min-Kyu Song, Washington State University; Ning Zhang, Baylor University
Wednesday 2:00 PM
February 26, 2020
Room: Point Loma
Location: Marriott Marquis Hotel
Session Chair: Ning Zhang, University of Alabama; Jaeyun Moon, University of Nevada - Las Vegas
2:00 PM Invited
Metastable Phase Transformation and Deformation Twinning Induced Hardening-stiffening Mechanism in Silicon Nanoparticles: Yu Hong1; Ning Zhang2; Mohsen Asle Zaeem1; 1Colorado School of Mines; 2University of Alabama
The compressive mechanical responses of silicon nanoparticles with respect to crystallographic orientations are investigated by atomistic simulations. Superelastic and abrupt hardening-stiffening behaviors are revealed in [110]-, [111]- and [112]-oriented nanoparticles. The obtained hardness values of these particles are in good agreement with the experimental results. In particular, [111]-oriented particle is extremely hard since its hardness (∼33.7 GPa) is almost three times greater than that of the bulk silicon (∼12 GPa). To understand the underlying deformation mechanisms, metastable phase transformation is detected in these particles. Deformation twinning of the metastable phase are observed to account for the early hardening-stiffening behavior in [110]-oriented particles. The twin phase then coalescences and undergoes compression to resist further deformation, and leads to the subsequent re-hardening and re-stiffening events. The same metastable phase is also detected in [111]- and [112]-oriented particles. A size effect on hardness of silicon nanoparticles, i.e., “smaller is harder”, is revealed.
2:20 PM
Synthesis of Micro-encapsulated Phase Change Materials using Chain Transfer Agent via Emulsion Polymerization and its Chemical, Optical and Thermal Characterization: Sun Choi1; 1KIST
Microencapsulated phase change materials (MPCMs) are thermal energy storage materials. Emulsion polymerization is the most common encapsulation method thanks to its economical and simple synthetic routes. In this work, by utilizing emulsion method, we synthesize two different MPCMs: PMMA PCMs and PMMA-DDT PCMs of which 1-Dodecanethiol (DDT) was used as a chain transfer agent. To explore the effect of chain transfer agent to the synthesis of MPCMs, each MPCM has been chemically, physically, and thermally characterized by using Fourier Transform-Infrared Spectroscopy (FT-IR), Optical Microscopy (OM), Scanning Electron Microscopy (SEM), and Differential scanning calorimetry (DSC). The analysis shows that DDT promotes uniform formation of spherical MPCMs by enhancing oil-water interfacial stability of the emulsions. Also, the DDT was not included in the structural element and did not affect the thermal properties of the MPCMs such as heat capacity and melting point, demonstrating that DDT served its role as a surfactant only
2:40 PM
The Microstructural Evolution of Nanotwinned Nickel Superalloys: Joel Bahena1; Andrea Hodge1; 1University of Southern California
Nanotwinned materials have been shown to exhibit exceptional mechanical and thermal properties due to their high density of coherent twin boundaries, while superalloys typically achieve their strengthening through second phase or precipitate formation. By developing nanotwinned superalloys, there lies potential to produce microstructures that leverage strengthening effects from both nanotwins and precipitates. In this study, nanotwinned nickel-based superalloys were synthesized via magnetron sputtering and ageing treatments were performed to investigate the microstructural evolution of these nanomaterials and the effects on mechanical properties. To examine the segregation behavior and precipitate formation in these alloys at different aging conditions, microstructural characterization techniques such as TEM and STEM/EDS were utilized. This study examines how the role of nanotwins on aging kinetics and precipitate formation can be employed to tune microstructures for optimized mechanical and thermal properties of superalloys.
3:00 PM
Synthesis of Tailored Nanostructures: Andrea Hodge1; 1University of Southern California
Nanometallic multilayers (NMMs) are of considerable interest due to their high density of interfaces which lead to unique mechanical, chemical, and thermal properties. NMM systems have been shown to undergo several microstructural transitions when annealed at elevated temperatures while still retaining nanoscale features. The microstructural evolution of these materials and the nanostructures that develop after annealing are not well understood but have been shown to provide a promising route to synthesize new nanomaterial compositions by using bimodal nanometallic multilayers with engineered interfaces. To further understand the thermal evolution of these materials, several sputtered NMMs systems including Mo-Au, Hf-Ti, W-C and Ta-Hf were annealed to critical temperatures determined and characterized using various techniques including TEM and APT.
3:20 PM Break
3:40 PM
Programmable Self-Assembly of 3D Printed Particles: David Doan1; Xun Gu1; 1Stanford University
Particle-based crystallization relies on the synthesis and self-assembly of monodisperse, nano or micron-sized particles. Currently, inorganic nanoparticles with simple geometries (e.g. spheres, cubes) can be fabricated through bottom-up synthesis. However, it is of interest to form lower symmetry particles, in which shape can be used to control interparticle forces. For instance, particles with one or more concavities can be combined with convex structures to form complex self-assembled structures. Here, we address the challenge of fabricating colloidal particles with complex geometries by using 2-photon lithography to 3D print microscale particles of arbitrary shapes. This method has been used to print hollow cones, spheres, and cubes with dimensions of ~5 um out of a fluorescent photoresist. These 3D printed particles will be combined with traditional particles (e.g polymer or silica spheres) to form controlled networks of multi-particle assemblies, with the goal of forming millimeter-sized periodic lattices.
4:00 PM
Electrically Functional Three-dimensional ZnO Nanomesh Architectures Directly Derived from Vapor-phase Infiltration of ZnO in Hierarchically Self-assembled Block Copolymer Thin Film Templates: Ashwanth Subramanian1; Gregory Doerk2; Kim Kisslinger2; Daniel Yi1; Robert Grubbs1; Chang-Yong Nam2; 1Stony Brook University; 2Brookhaven National Laboratory
Three-dimensional (3D) nanoarchitectures offer superior material properties, such as large specific surface areas critical for technological applications like catalysis and sensing. Here, we demonstrate optoelectrically functional 3D ZnO nanomesh architectures generated by combining successive self-assembly of block copolymer (BCP) thin films and the ZnO infiltration synthesis, an inorganic-organic hybridization technique derived from atomic layer deposition (ALD). The 3D ZnO nanomesh exhibited optoelectrical functionality, featuring stack-layer-number-dependent electrical conductance resembling the percolative transport originating from the intrinsic morphological network connectivity of lamellar BCP pattern. Detailed studies on infiltration protocols and foreign atom doping revealed the importance of precursor-polymer binding interaction and retarding the grain agglomeration for enabling high-fidelity generation of 3D nanoarchitectures. The results not only demonstrate the electrical functionality based on the ZnO nanoarchitecture generated by self-assembled BCP templates but also present a new, large-area scalable, metal oxide 3D nanoarchitecture fabrication method utilizing facile polymer solution coating and ALD processing.
4:20 PM
Synthesis and Growth Mechanism of Bismuth Nanoflowers and Their Application for Electrochemical Sensing: Edward Fratto1; Mary Joens1; Jirui Wang1; Zhiyong Gu1; 1University of Massachusetts Lowell
Heavy metal ion contamination is a significant, invisible threat to public health. Government agencies actively survey and maintain established regulatory limits on heavy metal contamination, but prioritized to localized hotspots in high-risk communities. The characterization techniques of heavy metal ions are typically expensive, time consuming, and requiring specialized training. In this work, a bismuth nanoflower structure has been developed as a potential nontoxic sensor material for detection of heavy metal ions. The high surface area nanostructure was synthesized via aqueous chemical reduction of bismuth chloride salt in a micellar environment, designed for high sensitivity by consideration of the crystallization mechanism in optimization of associated parameters. The nanoflower structure was deposited onto an electrode and coated with a Nafion layer, achieving a lower detection limit for lead and zinc, respectively. These results indicate the viability of bismuth-based nanoflower structures for portable, accessible detection of heavy metal ions, with enhanced sensitivity.
4:40 PM
Trade of Technological Advances in the Field of Nanomaterials: Shah Ashraf1; 1NIT Srinagar
We explored a new bio-safe and bio-compatible route for the synthesis of oxide nanomaterials using water as solvent as well as source of oxygen. The use of water as a reagent is particularly attractive because it is safe, inexpensive, environmentally benign and bestowed with many virtues especially under supercritical conditions. The simple and straightforward route is based on simple reaction of water and metal powder at relatively low temperature. Since water is regarded as a benign solvent and non toxic, the product (nanostructures) could be used safely for biomedical and other applications, including sensors. In addition, the method is simple, straightforward, economical, environmentally benign, involves green chemistry, which can make it suitable for scale large production. The prospects of the process are bright and promising. There are number of applications including energy and environment which shall be discussed during the talk.