abstract
Recent studies have demonstrated the potential of bacterial cellulose (BC) as a substrate for the design of bio-based ion exchange membranes with an excellent combination of conductive and mechanical properties for application in devices entailing functional ion conducting elements. In this context, the present study aims at fabricating polyelectrolyte nanocomposite membranes based on poly(bis[2-(methacryloyloxy)ethyl]phosphate) [P(bisMEP)] and BC via the in-situ free radical polymerization of bis[2-(methacryloyloxy)ethyl]phosphate (bisMEP) inside the BC three-dimensional network under eco-friendly reaction conditions. The resulting polyelectrolyte nanocomposites exhibit thermal stability up to 200 degrees C, good mechanical performance (Young's modulus > 2 GPa), water-uptake ability (79-155%) and ion exchange capacity ([H+] = 1.1-3.0 mmol g(-1)). Furthermore, a maximum protonic conductivity of ca. 0.03 S cm(-1) was observed for the membrane with P(bisMEP)/BC of 1: 1 in weight, at 80 degrees C and 98% relative humidity. The use of a bifunctional monomer that obviates the need of using a cross-linker to retain the polyelectrolyte inside the BC network is the main contribution of this study, thus opening alternative routes for the development of bio-based polyelectrolyte membranes for application in e.g., fuel cells and other devices based on proton separators.
keywords
PROTONIC CONDUCTIVITY; COMPOSITE MEMBRANES; EXCHANGE MEMBRANE; BACTERIAL; NANOCELLULOSE; ACID; TEMPERATURE; NAFION(R); MODULUS; FIBER
subject category
Chemistry; Materials Science; Physics
authors
Vilela, C; Martins, APC; Sousa, N; Silvestre, AJD; Figueiredo, FML; Freire, CSR
our authors
Ana Patrícia Martins
MSc Student
Armando Jorge Domingues Silvestre
Full professor
Carla Vilela
Assistant Professor
Carmen Sofia da Rocha Freire Barros
Coordinating Researcher
Filipe Miguel H Lebre R Figueiredo
Principal Researcher
Nuno André Carvalho Sousa
PhD StudentGroups
G3 - Electrochemical Materials, Interfaces and Coatings
G4 - Renewable Materials and Circular Economy
acknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), and UniRCell POCI-01-0145-FEDER-016422 (Ref. SAICTPAC/0032/2015), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. The Portuguese Foundation for Science and Technology (FCT) is also acknowledged for the post-doctoral grant to C. Vilela (SFRH/BPD/84168/2012), doctoral grant to N. Sousa (SFRH/BD/89670/2012), and research contracts under Investigador FCT to C.S.R. Freire (IF/01407/2012) and F.M.L. Figueiredo (IF/01174/2013).