Amir Ameli

Mechanical and Physical Properties of Carbonized Foams Derived from Cellulose

Abstract: This work is an effort to develop cellulose-based ultralight materials with characteristics similar to polymeric insulators as well as carbonaceous foams. In this approach, nanocrystalline cellulose (NCC) was cross-linked with polyvinyl alcohol (PVA) using 1,2,3,4–butane tetracarboxylic acid (BTCA) as crosslinking agent with the aid of dipotassium phosphate (DP) catalyst. Both pure NCC and NCC-based foams were prepared and characterized. The fabrication process was freeze drying utilizing only water as the solvent. Carbonization was then conducted on PVA/BTCA/NCC foams using a two-step heating process up to 800 °C under nitrogen. The density, microstructure, mechanical properties, thermal and electrical conductivities, and fire retardancy of the foams were characterized. PVA/BTCA/NCC foams revealed low thermal conductivity, high compression strength, and high fire retardancy, suggesting them as a potential plant-based alternative for insulator foams. The results also revealed that the cellular structure was kept intact during the carbonization process and the carbonized foam showed linear elastic behavior at low strain levels, reaching 50 kPa of strength at 50% strain. Both the strength and density reduced by ~30% after carbonization. Carbonized foams showed a relatively high electrical conductivity (~55 sm-1) at a very low density level (0.018 gcm-3), which makes them suitable for conductivity-driven functional applications. These results can open a new window for a plan-based and sustainable material to play a key role in numerous applications.

Biography: Amir Ameli is an Assistant Professor of Plastics Engineering at UMass Lowell. His research interests encompass material design, process development, and characterization of multi-functional nanocomposites and bio-based polymeric systems. He received his PhD from the University of Toronto in 2011. He was the NSERC and MITACS postdoctoral fellow in Canada 2011-2014. Prior to joining UMass Lowell, he served as an Assistant Professor of Mechanical and Materials Engineering at Washington State University from 2015-2019. He has published 60+ journal articles and 110+ conference papers.