Dr. William Rice
The Charles Stark Draper Laboratory
University of Wyoming
Over the past decade, substantial progress has been made in the chemical control (chiral enrichment, length sorting, handedness selectivity, and filling substance) of single-wall carbon nanotubes (SWCNTs). Recently, it was shown that large, horizontally aligned films can be created out of post-processed SWCNT solutions. In this work [1], we use machine-vision automation and parallelization to simultaneously produce globally aligned SWCNT films using pressure-driven filtration. Feedback control enables filtration to occur with a constant flow rate that not only improves the nematic ordering of the SWCNT films, but also provides the ability to align a wide range of SWCNT types and on a variety of nanoporous membranes using the same filtration parameters. Using polarized optical spectroscopic techniques, we show that under standard implementation meniscus combing produces a two-dimensional radial SWCNT alignment on one side of the film. After we flatten the meniscus through silanization, spatially resolved nematicity maps on both sides of the SWCNT film reveal global alignment across the entire structure. From experiments changing ionic strength and membrane charging, we provide evidence that the SWCNT alignment mechanism stems from the interplay of intertube interactions and ordered membrane charging. Our work opens up the possibility of creating globally aligned SWCNT film structures for a new-generation of nanotube electronics and optical control elements.
[1] J. Walker et al. Nano Letters. 19, 7256 (2019).
Dr. William Rice received his Sc. B. (with Honors) in Physics from Brown University in 2005. He studied spin behavior in carbon nanotubes and strong-field terahertz behavior in quantum wells at Rice University, including a short stint at the free-electron laser at the Helmholtz Institute in Rossendorf, Germany. After receiving his Ph. D. in Applied Physics from Rice in 2012, he spent three years as a post-doctoral fellow at the National High Magnetic Field Laboratory in Los Alamos, NM, where was a Director’s fellow from 2013—2015. There, he worked on optically induced magnetization in complex oxides and ultrafast spin phenomena in magnetically doped nanocrystals. In the fall of 2015, he joined the Physics and Astronomy department at the University of Wyoming as an assistant professor with a focus on magneto-optical spectroscopy of nanomaterials and spintronics. In the summer of 2020, Dr. Rice left the University of Wyoming to join the Charles Stark Draper Laboratory in Boston as a Principal Member of the Technical Staff.