Protonic conductivity and fuel cell tests of nanocomposite membranes based on bacterial cellulose

Poly(bis[2-(methacryloyloxy)ethyl] phosphate)/Bacterial Cellulose Nanocomposites: Preparation, Characterization and Application as Polymer Electrolyte Membranes

“…So, these membranes present a highly anisotropic microstructure because of the alternating nanofibril layers of BC and the P(bisMEP) phase. This morphological anisotropy was recently demonstrated to originate differences in the protonic conductivity in the through-and in-plane configurations; nevertheless, the impact of this anisotropy in the fuel cell performance is lessened near RH saturated conditions, i.e., 98% RH [23].…”

“…The capacitance associated to the high frequency relaxation is mostly the stray capacitance (C stray , ca. 20-30 pF) due to the platinum wires of the sample holder (see Reference [20], including electronic supplementary data, and Reference [23] for further details on the analysis of impedance data). In fact, the capacitance of the sample in the in-plane direction is much lower due to the small cross-sectional area determined essentially by the thickness of the membrane (C in-plane = ε 0 ε r wδL 0 −1 , where ε 0 and ε r are the vacuum and relative permittivities, respectively, of the membrane material, and w, δ and L 0 are the width, thickness and length of the membrane).…”

Highly proton conductive membranes based on carboxylated cellulose nanofibres and their performance in proton exchange membrane fuel cells

“…[25][26][27] Several different types of nanocelluloses 16 have been investigated in PEMFCs: bacterial cellulose (BC) membranes have shown a low conductivity z 0.008 mS cm À1 at 40 C and 98% RH. 28 Bayer et al studied carboxylated cellulose nanobers (CNF) and cellulose nanocrystals (CNC) membranes as PEM for high temperature application and obtained a slightly higher performance characterized by a maximum conductivity value at 100% RH of 0.05 mS cm À1 (100 C) and 0.01 mS cm À1 (30 C) using an ex situ measurement replicating the fuel cell environment. 23 Jankowska et al 24 compared the performance of several nano-and microcelluloses and observed a maximum proton conductivity of z0.001 mS cm À1 at 90 C under non-controlled RH conditions.…”

Enhanced Proton Conductivity and Methanol Permeability Reduction via Sodium Alginate Electrolyte-Sulfonated Graphene Oxide Bio-membrane

“…For instance, the mechanical strength of alginate has been successfully enhanced by introducing carbon nanotube and graphene oxide into the alginate polymer matrix [ 3 , 10 , 11 ]. Previous studies on the development of biopolymer-based membranes have shown good potential when combined with other materials such as inorganic or synthetic polymers, e.g., double layer-chitosan (1.67 × 10 −6 cm 2 s −1 ) [ 12 ], chitosan-PVA/Nafion (2.2 × 10 −6 cm 2 s −1 ) [ 13 ], chitosan-SHNT (0.76 × 10 −2 Scm −1 ) [ 14 ], chitosan-zeolite (2.58 × 10 −2 S cm −1 ) [ 15 ], chitosan-PMA (1.5 × 10 −2 S cm −1 ) [ 16 ], chitosan-sodium alginate (4.2 × 10 −2 S cm −1 ) [ 17 ], alginate-carrageenan (3.16 × 10 −2 S cm −1 ) [ 18 ], sulfonated chitosan-SGO (72 × 10 −2 S cm −1 ) [ 19 ], PVA-sodium alginate (9.1 × 10 −2 S cm −1 ) [ 20 ], biocellulose-Nafion (7.1 × 10 −2 S cm −1 ) [ 21 ], chitosan-SPSF (4.6 × 10 −2 S cm −1 ) [ 22 ], chitosan-silica/carbon nanotube (CNT) (2.5 × 10 −2 S cm −1 ), chitosan-PVP (2.4 × 10 −2 S cm −1 ) [ 23 ], nanocellulose/polypyrrole (1.6 mW cm −2 ) for enzymatic fuel cell [ 24 ], cellulose nanofibres (CNFs) (0.05 × 10 −3 S cm −1 ) and cellulose nanocrystals (CNCs) (4.6 × 10 −3 S cm −1 ) [ 25 ], bacterial cellulose (BC)/poly (4-styrene sulfonic acid) (PSSA) (0.2 S cm −1 ) [ 26 ], and imidazole-doped nanocrystalline cellulose (2.79 × 10 −2 S cm −1 ) [ 27 ]. However, the number of biopolymer-based membranes developed is too small compared to the studies involving synthetic polymers in many areas including fuel cells.…”