Hren Maša, Makuc Damjan, Plavec Janez, Roschger Michaela, Hacker Viktor, Genorio Boštjan, Božič Mojca, Gorgieva Selestina
Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, 2000 Maribor, Slovenia.
Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
Polymers (Basel). 2023 Feb 24;15(5):1146. doi: 10.3390/polym15051146.
In this work, fully polysaccharide based membranes were presented as self-standing, solid polyelectrolytes for application in anion exchange membrane fuel cells (AEMFCs). For this purpose, cellulose nanofibrils (CNFs) were modified successfully with an organosilane reagent, resulting in quaternized CNFs (CNF (D)), as shown by Fourier Transform Infrared Spectroscopy (FTIR), Carbon-13 (C13) nuclear magnetic resonance (C NMR), Thermogravimetric Analysis (TGA)/Differential Scanning Calorimetry (DSC), and ζ-potential measurements. Both the neat (CNF) and CNF(D) particles were incorporated in situ into the chitosan (CS) membrane during the solvent casting process, resulting in composite membranes that were studied extensively for morphology, potassium hydroxide (KOH) uptake and swelling ratio, ethanol (EtOH) permeability, mechanical properties, ionic conductivity, and cell performance. The results showed higher Young's modulus (119%), tensile strength (91%), ion exchange capacity (177%), and ionic conductivity (33%) of the CS-based membranes compared to the commercial Fumatech membrane. The addition of CNF filler improved the thermal stability of the CS membranes and reduced the overall mass loss. The CNF (D) filler provided the lowest (4.23 × 10 cm s) EtOH permeability of the respective membrane, which is in the same range as that of the commercial membrane (3.47 × 10 cms). The most significant improvement (~78%) in power density at 80 °C was observed for the CS membrane with neat CNF compared to the commercial Fumatech membrane (62.4 mW cm vs. 35.1 mW cm). Fuel cell tests showed that all CS-based anion exchange membranes (AEMs) exhibited higher maximum power densities than the commercial AEMs at 25 °C and 60 °C with humidified or non-humidified oxygen, demonstrating their potential for low-temperature direct ethanol fuel cell (DEFC) applications.
在这项工作中，提出了完全基于多糖的膜作为自支撑固体聚电解质，用于阴离子交换膜燃料电池（AEMFC）。为此，用有机硅烷试剂成功修饰了纤维素纳米原纤维（CNF），得到了季铵化的CNF（CNF（D）），傅里叶变换红外光谱（FTIR）、碳-13（C13）核磁共振（C NMR）、热重分析（TGA）/差示扫描量热法（DSC）和ζ电位测量结果均证明了这一点。在溶剂浇铸过程中，将纯（CNF）颗粒和CNF（D）颗粒原位掺入壳聚糖（CS）膜中，得到了复合膜，并对其形态、氢氧化钾（KOH）吸收和溶胀率、乙醇（EtOH）渗透率、机械性能、离子电导率和电池性能进行了广泛研究。结果表明，与商用Fumatech膜相比，基于CS的膜具有更高的杨氏模量（119%）、拉伸强度（91%）、离子交换容量（177%）和离子电导率（33%）。添加CNF填料提高了CS膜的热稳定性，并减少了总体质量损失。CNF（D）填料使相应膜的EtOH渗透率最低（4.23×10 cm s），与商用膜（3.47×10 cms）处于同一范围。与商用Fumatech膜（62.4 mW cm对35.1 mW cm）相比，含纯CNF的CS膜在80°C时的功率密度提高最为显著（约78%）。燃料电池测试表明，在25°C和60°C下，使用加湿或未加湿氧气时，所有基于CS的阴离子交换膜（AEM）的最大功率密度均高于商用AEM，证明了它们在低温直接乙醇燃料电池（DEFC）应用中的潜力。
