IMX Seminar Series - Nanocellulose

In the first half of this talk, I will introduce cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs), how they are typically produced, their main defining features, and some popular applications of these materials. CNCs and CNFs are crystalline nanomaterials that are isolated from natural sources of cellulose in the form of water-based suspensions. The properties of CNCs and CNFs depend on the specifics of how they are isolated, as this determines their size distribution, nano-fraction, and surface charge density. In turn, these features dictate the colloidal stability, percolation, and viscosity of CNC/CNF suspensions, as well as the optical, mechanical, and barrier properties of films cast from these suspensions.
Next, I will focus on CNCs produced from cotton and from softwood kraft pulps (fully bleached vs. residual lignin). Within a given cellulose source, varying the conditions of isolation influences fundamental CNC properties, with milder conditions yielding lower surface charges, larger and more polydisperse particles, and lower crystallinity. In addition, differences in the cellulose source itself can also influence downstream nanoparticle properties, for instance cotton CNCs have larger lateral dimensions, higher crystallinity, and lower surface charge, compared to similarly isolated CNCs from softwood kraft pulps. From a sustainability perspective, yield and water usage are also affected, with low-to-intermediate charged CNCs produced using less reagent and at higher yield and solid content. Furthermore, CNC suspensions produced from wood pulps with residual lignin additionally contain lignin nanoparticles, which can further modify material properties.
Papers:
1. Kaschuk, J. J., Al, Y., Rojas, O. J., Miettunen, K., Abitbol, T., Vapaavuori, J., Plant-Based Structures as an Opportunity to Engineer Optical Functions in Next-Generation Light Management. Adv. Mater. 2022, 34, 2104473. https://doi.org/10.1002/adma.202104473
2. Tiffany Abitbol, Doron Kam, Yael Levi-Kalisman, Derek G. Gray, and Oded Shoseyov, Langmuir 2018 34 (13), 3925-3933 DOI: 10.1021/acs.langmuir.7b04127
Bio: In 2011, I obtained my PhD in Chemistry from McGill University in Prof. Derek Gray’s group, where my work focused on cellulosic nanocomposite films, fibers, hydrogels, and colloids. After two postdocs, one at McMaster University, where I focused on cellulose nanocrystal (CNC) characterization, self-assembly, and surface modification, and a second at the Hebrew University of Jerusalem, where I further studied CNCs, here branching to protein-CNC complexes and a deeper look at CNC self-assembly, I moved to Stockholm, Sweden. In Sweden, I worked as a senior researcher from 2017-2022 at RISE Research Institutes of Sweden, where I participated in and led cross-disciplinary commercially sponsored projects, including in packaging, wound care, food, and personal care. At the same time, I continued to engage in fundamental nanocellulose research, supported by public funding and by industry consortia interested in building up a knowledge base to address key challenges related to nanocellulose implementation. Not that long ago, in June 2022, I started a professor position at EPFL in the Institute of Materials. My group (Sustainable Materials Laboratory – SML) continues to focus on cellulose and other bio-based materials, with an overarching aim of connecting composition and colloidal properties to the performance of engineered materials derived from renewable resources.