January 30
@
1:00 PM
–
2:00 PM
UW-Madison Department of Materials Science and Engineering welcomes Dr. Joseph Jakes. Their seminar on “Multimodal Study Reveals Diffusion Mechanism through Wood Cell Walls” will be on Thursday, Jan. 30 in MS&E 265 from 1 p.m. to 2 p.m.
Abstract
The diffusion of chemicals and inorganic ions through wood cell walls is a critical process in nearly all woody biomass applications, including biorefineries, wood-based building materials, green electronics, and even as bioinspiration for new multifunctional smart materials. Wood cell walls are hygroscopic polymeric materials consisting of nanoscale cellulose fibrils embedded in a matrix of hemicelluloses and lignin. Despite the near ubiquitous importance of intra-cell wall diffusion, the diffusion mechanisms and the effects of moisture sorption were poorly understood. In this work, we employ a multimodal approach to study intra-cell wall diffusion. Experimental techniques developed and employed include synchrotron-based micro-X-ray fluorescence microscopy to study moisture-dependent diffusion at sub micrometer length scales in wood cell walls, nanoindentation-based dynamic mechanical analysis to quantify the moisture dependence of molecular-scale relaxations in wood cell walls, and small angle neutron scattering to study nanoscale swelling in wood cell walls. The study revealed that intra-cell wall diffusion of larger diffusants like inorganic ions occurs via interconnecting pathways of rubbery amorphous polysaccharides, which supplants the nearly century-old assumption of intra-cell wall transport occurring through interconnecting water pathways. With these new insights, researchers can now utilize polymer science approaches to engineer the molecular architecture of lignocellulosic biomass to optimize properties for specific end uses.
Bio
Since 2010, Joseph Jakes has been a Research Materials Engineer in the Forest Biopolymer Science and Engineering group at the USDA Forest Service, Forest Products Laboratory in Madison, WI, USA. He received a BS in Chemical and Biological Engineering from the University of Wisconsin-Madison in 2005 and a PhD from the Materials Science Program at the University of Wisconsin-Madison in 2010. His current research interests include developing fundamental wood cell wall processing-structure-property-performance relationships with an emphasis on mechanical behavior, moisture sorption, and diffusion. This research has required the development of advanced material characterization techniques to probe structures and properties at micrometer length scales and below in wood and forest products, which has led to the development of innovative nanoindentation, X-ray, and neutron characterization techniques. Joseph has authored over 105 research papers and his work has been recognized through numerous invited talks, an invitation to spend two years as a visiting scientist at the Advanced Photon Source at Argonne National Laboratory (2013-2015), and several awards including the 2012 Presidential Award for Early Career Award for Scientists and Engineers (PECASE), 2018 TMS Young Leaders Award, and 2024 Forest Products Society Fred W. Gottschalk Memorial Award.