Self-organizing Nano-architectured Materials: Synthesis: Novel Approaches
Program Organizers: Yu-chen Karen Chen-Wiegart, Stony Brook University / Brookhaven National Laboratory; Ian Mccue, Northwestern University; Erica Lilleodden, Fraunhofer Insitute for Microstructure of Materials and Systems (IMWS); Pierre-Antoine Geslin, CNRS / INSA-Lyon; Qing Chen, Hong Kong University of Science & Technology
Tuesday 8:00 AM
March 1, 2022
Room: 260C
Location: Anaheim Convention Center
Session Chair: Ian McCue, Northwestern University; Andrea Hodge, University of Southern California
8:00 AM Invited
Composite Hierarchical Structures: Andrea Hodge1; 1University of Southern California
Magnetron sputtering has emerged as a promising and versatile deposition method for coating nano- and micro-lattices to produce novel core-shell composite structures. By leveraging sputtering’s expansive material workspace and its ability to tailor coating microstructure, this work aims to achieve unrealized combinations of lattice geometry, composition, microstructure, and feature size to further functionalize these advanced hierarchical materials. Previous work has demonstrated that sputtering can effectively introduce new ceramic, metallic, and alloyed materials onto lattice structures. This research seeks to further develop core-shell composite nano- and micro-lattices by presenting a foundational understanding of sputter deposition to enable enhance designs and synthesis of novel architected core-shell composites
8:30 AM Invited
3D Printing of Biomimetic Hierarchical Architectures by Integration of Self-organized Nanoporous Materials: Juergen Biener1; 1Lawrence Livermore National Laboratory
Self-organized nanoporous materials have unique physical, chemical, and mechanical properties related to their nanoscale structure and large surface area but their performance is often limited by slow mass transport through their nanoporous architecture. Nature overcomes this limitation by intgrating functional macroscale architectures that, for example, provide organs with their unique functionality. Recent advances in 3D printing now enable fabrication of biomimetic hierarchical architectures based on self-organized nano-architectured materials. Among other processing techniques, 3D printing is unique by providing deterministic control over engineered macroscale features such as shape or macroporous flow chanels while the self-organizing „ink“ provides control over nanoscale features such as porosity or composition. This talk will provide an overview over recent work at LLNL to design, fabricate, integrate, characterize and test 3D printed hierarchical nanoporous materials based on metal or polymer self-organizing nanoporous „inks“. Examples include hierarchical nanoporous catalyst reactors, flow-through electrodes, membranes, and other functional structures.
9:00 AM Invited
Additive Manufacturing of Nanoporous Nanostructures: Wendy Gu1; Qi Li1; John Kulikowski1; David Doan1; 1Stanford University
Inorganic materials with nanoscale feature sizes, hierarchical porosity and controllable architecture are of interest as lightweight structural materials, catalysts, and for thermal and fluid transport. Here, I will present the development of novel two-photon lithography resins that contain metallic nanoclusters which serve as both photoinitiators and inorganic precursors. Using these resins, we demonstrate the additive manufacturing of structures with nano to microscale features with complex geometries and large overhangs, such as buckyballs, helices, and lattices. Through a high temperature pyrolysis step, the as-printed nanocluster-polymer composites are transformed into nanoporous materials with an average pore size of ~50 nm and relative density of ~0.5. The mechanical properties of the as-printed composites materials, and the final nanoporous structures are characterized using nanoindentation-based compression testing, and related to the heterogeneous microstructure.
9:30 AM Break
9:50 AM
Hierarchically Porous Gold via 3D Printing and Dealloying for Selective Electrochemical Reduction of CO2 to CO with Enhanced Mass Transport: Jintao Fu1; Shahryar Mooraj2; Shuai Feng2; Wen Chen2; Eric Detsi1; 1University of Pennsylvania; 2University of Massachusetts
Au is one of the best heterogenous electrocatalysts for the selective reduction of CO2 to CO. Nanoporous Au (NP-Au) in particular is very promising for this purpose because of its high specific surface area and high density of active CO2-to-CO catalytic sites such as high-index facets, steps, and kinks. Most NP-Au electrocatalysts for CO2-to-CO conversion are made of thin films with thicknesses in the sub-micrometer range, but bulk and robust NP-Au electrodes are more desirable for large scale conversion. Additionally, conventional bulk NP-Au electrodes with unimodal pore size distribution suffer from kinetics issues associated with mass transport in or out of the material. In this talk, I will show how this kinetics issue can be overcome using hierarchically bulk porous Au with various pore size distributions made from direct ink writing-based 3D printing and dealloying.
10:10 AM Invited
Programming Self-assembly of Designed Nano-architectured Materials: Oleg Gang1; 1Columbia University
The ability to organize functional nanoscale components into the targeted architectures promises to enable a broad range of nanotechnological applications, from designed biomaterials to photonic devices and to materials with desired mechanical responses. However, we are currently lacking a broadly applicable method for the 3D bottom-up formation of nanostructures with ability to prescribe their architecture and to integrate different types of nanocomponents. The talk will discuss our progress in establishing a versatile self-assembly platform for the fabrication of designed large-scale and finite-size nano-architectures from diverse nanocomponents through the DNA-programmable assembly. The recent advances in creating and characterizing periodic and hierarchical organizations from inorganic nanoparticles and biomolecules will be presented. The templating of formed architectures into robust inorganic 3D nanostructures will be shown. Finally, the use of the developed assembly approaches for generating functional nanomaterials with nano-optical, electrical, mechanical, and biochemical functions will be demonstrated.
10:40 AM
Centimeter-scale Crack-free Self-assembly for Ultra-high Tensile Strength Metallic Nanolattices: Zhimin Jiang1; James Pikul1; 1University of Pennsylvania
Nanolattices exhibit extraordinary mechanical, energy conversion, and optical properties, but manufacturing challenges prevent them from being fabricated at cm-length scales or larger while maintaining the dense regular nm features that enable their properties. This work overcomes these limitations by realizing a crack-free self-assembly approach for cm-scale nickel nanolattices with a 20,000X increase in crack-free area and 1,000X more unit cells along mechanically loaded samples than prior self-assembled and 3D-printed nanolattices. These nickel nanolattices have 30 nm grains, 100 nm features, and 260 MPa tensile strengths, which are 3X the strength of all porous metals at the same relative density, approach the theoretical strength limit for porous nickel, and are 10X the strength of prior nanolattices. The new insights into self-assembly and porous metal mechanics developed in this work will advance the fabrication and applications of high-strength multifunctional porous materials.
11:00 AM
Kinetic Monte-Carlo Simulations of Vapor Phase Dealloying: Longhai Lai1; Alain Karma1; 1Northeastern University
Dealloying techniques to produce open porous or bicontinuous structures have flourished during the past decade. Existing techniques include electrochemical dealloying (ECD), liquid metal dealloying (LMD), solid-state dealloying, and vapor phase dealloying (VPD), introduced relatively recently, which exploits the selective evaporation of one element on an alloy. Experiments have revealed that the kinetics of VPD switches from ECD-like interface-controlled kinetics at the early stage of dealloying followed by LMD-like diffusion-controlled kinetics at a later stage. Modeling VPD is made especially challenging by the fact that the mean free path of evaporating atoms in the vapor state is much larger than the pore size, which makes transport in the vapor phase pore-size dependent (Knudsen diffusion). We report the results of a simulation study of VPD structures and kinetics using a novel kinetic Monte-Carlo (KMC) algorithm that models simultaneously selective evaporation, surface diffusion, and geometrically confined vapor phase transport.