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Di Virgilio M, Basso Peressut A, Pontoglio A, Latorrata S, Dotelli G. Study of Innovative GO/PBI Composites as Possible Proton Conducting Membranes for Electrochemical Devices. MEMBRANES 2023; 13:428. [PMID: 37103855 PMCID: PMC10143660 DOI: 10.3390/membranes13040428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/23/2023] [Accepted: 04/11/2023] [Indexed: 06/19/2023]
Abstract
The appeal of combining polybenzimidazole (PBI) and graphene oxide (GO) for the manufacturing of membranes is increasingly growing, due to their versatility. Nevertheless, GO has always been used only as a filler in the PBI matrix. In such context, this work proposes the design of a simple, safe, and reproducible procedure to prepare self-assembling GO/PBI composite membranes characterized by GO-to-PBI (X:Y) mass ratios of 1:3, 1:2, 1:1, 2:1, and 3:1. SEM and XRD suggested a homogenous reciprocal dispersion of GO and PBI, which established an alternated stacked structure by mutual π-π interactions among the benzimidazole rings of PBI and the aromatic domains of GO. TGA indicated a remarkable thermal stability of the composites. From mechanical tests, improved tensile strengths but worsened maximum strains were observed with respect to pure PBI. The preliminary evaluation of the suitability of the GO/PBI X:Y composites as proton exchange membranes was executed via IEC determination and EIS. GO/PBI 2:1 (IEC: 0.42 meq g-1; proton conductivity at 100 °C: 0.0464 S cm-1) and GO/PBI 3:1 (IEC: 0.80 meq g-1; proton conductivity at 100 °C: 0.0451 S cm-1) provided equivalent or superior performances with respect to similar PBI-based state-of-the-art materials.
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Affiliation(s)
| | | | | | - Saverio Latorrata
- Correspondence: (A.B.P.); (S.L.); Tel.: +39-02-2399-3190 (A.B.P. & S.L.)
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Basso Peressut A, Cristiani C, Dotelli G, Dotti A, Latorrata S, Bahamonde A, Gascó A, Hermosilla D, Balzarotti R. Reduced Graphene Oxide/Waste-Derived TiO 2 Composite Membranes: Preliminary Study of a New Material for Hybrid Wastewater Treatment. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13061043. [PMID: 36985937 PMCID: PMC10055702 DOI: 10.3390/nano13061043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/07/2023] [Accepted: 03/11/2023] [Indexed: 06/01/2023]
Abstract
This work reports the preliminary results of the development of composite self-assembling membranes obtained by the combination of reduced graphene oxide (rGO) with commercial Degussa P25 titanium dioxide (TiO2). The purpose is to demonstrate the possibility of combining, in the same self-standing material, the capability to treat wastewater containing both inorganic and organic pollutants by exploiting the established ability of rGO to capture metal ions together with that of TiO2 to degrade organic substances. Moreover, this study also investigates the potential photocatalytic properties of tionite (TIO), to demonstrate the feasibility of replacing commercial TiO2 with such waste-derived TiO2-containing material, fulfilling a circular economy approach. Thus, rGO-TiO2 and rGO-TIO composite membranes, 1:1 by weight, were prepared and characterized by SEM-EDX, XRD, thermogravimetry, as well as by Raman and UV-Vis spectroscopies to verify the effective and homogeneous integration of the two components. Then, they were tested towards 3-mg L-1 aqueous synthetic solutions of Fe3+ and Cu2+ ions to evaluate their metal adsorption ability, with values of the order of 0.1-0.2 mmol gmembrane-1, comparable or even slightly higher than those of pristine rGO. Finally, the ability of the composites to degrade a common organic pesticide, i.e., Imidacloprid®, was assessed in preliminary photocatalysis experiments, in which maximum degradation efficiencies of 25% (after 3 h) for rGO-TiO2 and of 21% (after 1 h) for rGO-TIO were found. The result of tionite-containing membranes is particularly promising and worthy of further investigation, given that the anatase content of tionite is roughly 1/6 of the one in commercial TiO2.
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Affiliation(s)
- Andrea Basso Peressut
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milan, Italy
| | - Cinzia Cristiani
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milan, Italy
| | - Giovanni Dotelli
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milan, Italy
| | - Anna Dotti
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milan, Italy
| | - Saverio Latorrata
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milan, Italy
| | - Ana Bahamonde
- Instituto de Catálisis y Petroleoquímica, Consejo Superior de Investigaciones Científicas, Calle de Marie Curie 2, 28049 Madrid, Spain
| | - Antonio Gascó
- Departamento de Ingeniería y Gestión Forestal y Ambiental, Universidad Politécnica de Madrid, Calle de José Antonio Novais 10, 28040 Madrid, Spain
| | - Daphne Hermosilla
- Departamento de Ingeniería y Gestión Forestal y Ambiental, Universidad Politécnica de Madrid, Calle de José Antonio Novais 10, 28040 Madrid, Spain
| | - Riccardo Balzarotti
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Via la Santa 1, 6962 Lugano, Switzerland
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A Novel Approach to Water Softening Based on Graphene Oxide-Activated Open Cell Foams. Mol Vis 2023. [DOI: 10.3390/c9010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
This work focuses on exploring a new configuration for the reduction of water hardness based on the surface modification of polyurethane (PU) open cell foams by the deposition of thin graphene oxide (GO) washcoat layers. GO was deposited by the dip–squeeze coating procedure and consolidated by thermal treatment. The final washcoat load was controlled by performing consecutive depositions, after three of which, a GO inventory up to 27 wt% was obtained onto PU foams of 60 pores per inch (PPI). The GO-coated PU foams were assembled into a filter, and the performance of the system was tested by continuously feeding water with hardness in the 190–270 mgCa2+,eq·L−1 range. Remarkable results were demonstrated in terms of total adsorbing capacity, which was evaluated by measuring the outlet total hardness by titration and exhibited values up to 63 mgCa2+,eq·gGO−1 at a specific filtered water volume of 650 mLH2O·gGO−1, outperforming the actual state-of-the-art adsorbing capacity of similar GO-based materials.
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Basso Peressut A, Di Virgilio M, Bombino A, Latorrata S, Muurinen E, Keiski RL, Dotelli G. Investigation of Sulfonated Graphene Oxide as the Base Material for Novel Proton Exchange Membranes. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27051507. [PMID: 35268613 PMCID: PMC8912047 DOI: 10.3390/molecules27051507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/20/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022]
Abstract
This work deals with the development of graphene oxide (GO)-based self-assembling membranes as possible innovative proton conductors to be used in polymer electrolyte membrane fuel cells (PEMFCs). Nowadays, the most adopted electrolyte is Chemours’ Nafion; however, it reveals significant deficiencies such as strong dehydration at high temperature and low humidity, which drastically reduces its proton conductivity. The presence of oxygenated moieties in the GO framework makes it suitable for functionalization, which is required to enhance the promising, but insufficient, proton-carrying features of GO. In this study, sulfonic acid groups (–SO3H) that should favor proton transport were introduced in the membrane structure via a reaction between GO and concentrated sulfuric acid. Six acid-to-GO molar ratios were adopted in the synthesis procedure, giving rise to final products with different sulfonation degrees. All the prepared samples were characterized by means of TGA, ATR-FTIR and Raman spectroscopy, temperature-dependent XRD, SEM and EDX, which pointed out morphological and microstructural changes resulting from the functionalization stage, confirming its effectiveness. Regarding functional features, electrochemical impedance spectroscopy (EIS) as well as measurements of ion exchange capacity (IEC) were carried out to describe the behavior of the various samples, with pristine GO and commercial Nafion® 212 used as reference. EIS tests were performed at five different temperatures (20, 40, 60, 80 and 100 °C) under high (95%) and medium (42%) relative humidity conditions. Compared to both GO and Nafion® 212, the sulfonated specimens demonstrate an increase in the number of ion-carrying groups, as proved by both IEC and EIS tests, which reveal the enhanced proton conductivity of these novel membranes. Specifically, an acid-to-GO molar ratio of 10 produces a six-fold improvement of IEC (4.23 meq g−1) with respect to pure GO (0.76 meq g−1), while a maximum eight-fold improvement (5.72 meq g−1) is achieved in SGO-15.
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Affiliation(s)
- Andrea Basso Peressut
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy; (A.B.P.); (A.B.); (S.L.)
| | - Matteo Di Virgilio
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy; (A.B.P.); (A.B.); (S.L.)
- Correspondence: (M.D.V.); (G.D.)
| | - Antonella Bombino
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy; (A.B.P.); (A.B.); (S.L.)
| | - Saverio Latorrata
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy; (A.B.P.); (A.B.); (S.L.)
| | - Esa Muurinen
- Environmental and Chemical Engineering Research Unit, Faculty of Technology, University of Oulu, Pentti Kaiteran katu 1, FI-90014 Oulu, Finland; (E.M.); (R.L.K.)
| | - Riitta L. Keiski
- Environmental and Chemical Engineering Research Unit, Faculty of Technology, University of Oulu, Pentti Kaiteran katu 1, FI-90014 Oulu, Finland; (E.M.); (R.L.K.)
| | - Giovanni Dotelli
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy; (A.B.P.); (A.B.); (S.L.)
- Correspondence: (M.D.V.); (G.D.)
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