Porous Metals via Ice Templating

Project Overview

This project explored approaches to producing novel ultra-low-density metal foams through the controlled assembly of metal nanowires by freeze-casting. Metallic foams at these very low densities present unique material properties that are attractive to a broad range of technologies such as energy storage and conversion. They are particularly critical to enabling high-energy-density-physics experiments within high-power laser facilities, such as the National Ignition Facility. The project was successful in delivering the first monolithic, ultra-low density gold foams down to 6 mg/cc (milligrams/cubic centimeter) with high reproducibility, homogeneity, and controlled pore size. Further, advanced characterization tools were employed to interrogate fundamental mechanisms of foam synthesis and processing to enable improved tunability of foam properties towards application requirements.

Mission Impact

The broad impact of this project is the development of a new class of low-density metal foams of interest to both the fundamental and applied science communities. This technology is important to several inertial confinement fusion and high-energy-density experiments since no other approach has demonstrated such ultra-low-density gold foams. Within the DOE complex, the scientific outcomes of this project are enabling high-priority, laser-driven experiments that were previously beyond our target fabrication capabilities. In fact, these gold foams are actively being fielded in shots at the National Ignition Facility at Lawrence Livermore National Laboratory. Our research is forecast to benefit radiation transport, advanced sensor, and energy conversion and storage research-and-development programs that support NNSA energy and nuclear security goals. Further, this research expands the Laboratory's core competencies in advanced materials and manufacturing by developing new capabilities to make materials that were previously unattainable.

Publications, Presentations, and Patents

Fears, T. M., et al., 2018. "Ultra-Low-Density Silver Aerogels Via Freeze-Substitution." APL Materials 6, no. 9 (2018): 091103. LLNL-JRNL-745061.

Fears, T. M., et al., 2018. "Metal Nanowire Aerogels." LLNL Postdoc Poster Symposium, Livermore, CA, June 8, 2018. LLNL-POST-752815.

Fears, T. M., et al., 2018 "Ultra-Low-Density Metal Nanowire Aerogels." International Seminar on Aerogels, Hamburg, Germany, Sept. 25, 2018. LLNL-PRES-758554.

Fears, T. M., et al., 2018. "In Situ Characterization of Freeze-Cast Metal Nanowire Aerogels." AVS National Meeting, Long Beach, CA, Oct. 21-26, 2018. LLNL-POST-760070.

Fears, T. M., et al., 2018 "Ultra-Low-Density Metal Nanowire Foams." MRS Spring Meeting, Phoenix, AZ, April 2-6, 2018. LLNL-POST-748361.

Fears, T. M., et al., 2019. "Ultra-Low-Density Metal Aerogels for Laser Targets." Target Fabrication Meeting, April 25, 2019. LLNL-PRES-771902.

Fears, T. M., et al., 2019. "Geometric and Morphological Control in Ultra-Low-Density Freeze-Cast Materials." Conference on Aerogel Inspired Materials, Newcastle upon Tyne, UK, Sept. 20, 2019. LLNL-PRES-790579.

Qian, F., et al., 2018. "Ultralight Gold Nanowire Aerogels." MRS Fall Meeting& Exhibit, Boston, MA, Nov 27, 2018. LLNL-PRES-753113.

Qian, F., et al., 2020. "Gold Aerogel Monoliths with Tunable Ultralow Densities." Nano Letters 20, no. 1 (2020/01/08 2020): 131-35. LLNL-JRNL-762478.

Ringuette, A., et al., 2018. "Ultralight Gold Nanowire Aerogels: Ligand Exchange toward High Quality Gold Foams." Summer Intern Symposium, Livermore, CA, Aug. 8, 2018. LLNL-POST-755759.

Troksa, A. L., et al., 2018. "Fabricating Ultra-Low Density Nanoporous Metals by Freeze-Casting Nw Suspensions." MRS Fall Meeting & Exhibit:, Boston, MA, November 25-30, 2018. LLNL-PRES-762644.

Troksa, A. L., et al., 2018. "Silver and Gold Nanowires for Ultralight Metal Foam Fabrication." MRS Spring Meeting & Exhibit, Phoenix, Az, April 2-6, 2018. LLNL-POST-748525.