Flexible Nanocellulose/Lignosulfonates Ion-Conducting Separators for Polymer Electrolyte Fuel Cells
authors Vilela, C; Morais, JD; Silva, ACQ; Munoz-Gil, D; Figueiredo, FML; Silvestre, AJD; Freire, CSR
nationality International
journal NANOMATERIALS
author keywords bacterial nanocellulose; lignosulfonates; mechanical performance; thermal-oxidative stability; ion-exchange membranes; biobased separators; ionic conductivity
keywords NANOCOMPOSITE MEMBRANES; PROTONIC CONDUCTIVITY; COMPOSITE MEMBRANES; NANOCELLULOSE; LIGNIN; MECHANISMS; TRANSPORT; NAFION(R)
abstract The utilization of biobased materials for the fabrication of naturally derived ion-exchange membranes is breezing a path to sustainable separators for polymer electrolyte fuel cells (PEFCs). In this investigation, bacterial nanocellulose (BNC, a bacterial polysaccharide) and lignosulfonates (LS, a by-product of the sulfite pulping process), were blended by diffusion of an aqueous solution of the lignin derivative and of the natural-based cross-linker tannic acid into the wet BNC nanofibrous three-dimensional structure, to produce fully biobased ion-exchange membranes. These freestanding separators exhibited good thermal-oxidative stability of up to about 200 degrees C, in both inert and oxidative atmospheres (N(2)and O-2, respectively), high mechanical properties with a maximum Young's modulus of around 8.2 GPa, as well as good moisture-uptake capacity with a maximum value of ca. 78% after 48 h for the membrane with the higher LS content. Moreover, the combination of the conducting LS with the mechanically robust BNC conveyed ionic conductivity to the membranes, namely a maximum of 23 mS cm(-1)at 94 degrees C and 98% relative humidity (RH) (in-plane configuration), that increased with increasing RH. Hence, these robust water-mediated ion conductors represent an environmentally friendly alternative to the conventional ion-exchange membranes for application in PEFCs.
publisher MDPI
isbn 2079-4991
year published 2020
volume 10
issue 9
digital object identifier (doi) 10.3390/nano10091713
web of science category Nanoscience & Nanotechnology; Materials Science, Multidisciplinary
subject category Science & Technology - Other Topics; Materials Science
unique article identifier WOS:000580779000001

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