LNNano - Brazilian Nanotechnology National Laboratory

Mold heat conductance as drive force for tuning freeze-casted nanocellulose foams microarchitecture

Marcos Mariano, Juliana da Silva Bernardes, Mathias Strauss

Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Zip Code 13083-970, Campinas, São Paulo, Brazil.

Institute of Chemistry, University of Campinas (Unicamp), 13083-970 Campinas, Brazil.

Abstract
The influence of ice-crystals growing direction over the organization of cellulose nanofibers as freeze-casted foams is reported. This tuning was achieved by changing the metallic (copper) area of the sample molds which altered the freezing-front behavior, causing an oriented foam structure in certain directions. This orientation imparted different microarchitectures to the foams, leading to different pores sizes and wall thicknesses which could be characterized by advanced image techniques based on microtomography. As consequence, mechanical properties, such as compression modulus, have changed. In this study, a statistical approach is used to validate all the results obtained.

Materials Letters
Link: https://doi.org/10.1016/j.matlet.2018.05.013