Ceballos-Alvarez Carlos, Jafari Maziar, Siaj Mohamed, Shahgaldi Samaneh, Izquierdo Ricardo
Département de Génie Électrique, École de Technologie Supérieure, 1100 Notre-Dame Street West, Montreal, QC H3C 1K3, Canada.
Département de Chimie, Université du Québec à Montréal, 2101 Rue Jeanne-Mance, Montreal, QC H2X 2J6, Canada.
Nanomaterials (Basel). 2025 Jan 3;15(1):68. doi: 10.3390/nano15010068.
This study explored the influence of graphene oxide (GO) on morphological and mechanical properties of Nafion 115 membranes with the objective of enhancing the mechanical properties of the most widely employed membrane in Proton Exchange Membrane Water Electrolyzers (PEMWE) applications. The membrane surface was modified by ultrasonically spraying a GO solution and different annealing temperatures were tested. Scanning Electron Microscopy (SEM) cross-sectional images revealed that annealing the composite membranes was sufficient to favor an interaction between the graphene oxide and the surface of the Nafion membranes. The GO covering only 35% of the membrane surface increased the composite's wettability from hydrophobic (105.2°) to a highly hydrophilic angle (84.4°) while slightly reducing membrane swelling. Tensile tests depicted an increase in both the strain levels and tensile loads before breaking. The samples with GO presented remarkable mechanical properties when the annealing time and temperature increased; while the Nafion control samples failed at elongations of 95% and 98%, their counterparts with GO on the surface achieved elongations of 248% and 191% when annealed at 80 °C and 110 °C respectively, demonstrating that the presence of GO mechanically stabilizes the membranes under tension. In exchange, the presence of GO altered the smoothness of the membrane surface going from an average 1.4 nm before the printing to values ranging from 8.4 to 10.2 nm depending on the annealing conditions which could affect the quality of the subsequent catalyst layer printing. Overall, the polymer's electrical insulation was unaffected, making the Nafion-GO blend a more robust material than those traditionally used.
本研究探讨了氧化石墨烯（GO）对Nafion 115膜形态和力学性能的影响，目的是增强质子交换膜水电解槽（PEMWE）应用中使用最广泛的膜的力学性能。通过超声喷涂GO溶液对膜表面进行改性，并测试了不同的退火温度。扫描电子显微镜（SEM）横截面图像显示，对复合膜进行退火足以促进氧化石墨烯与Nafion膜表面之间的相互作用。仅覆盖35%膜表面的GO将复合材料的润湿性从疏水性（105.2°）提高到高亲水性角度（84.4°），同时略微降低了膜的溶胀。拉伸试验表明，断裂前应变水平和拉伸载荷均有所增加。当退火时间和温度增加时，含GO的样品呈现出显著的力学性能；Nafion对照样品在伸长率为95%和98%时失效，而表面含GO的对应样品在80℃和110℃退火时分别达到了248%和191%的伸长率，表明GO的存在使膜在张力下具有机械稳定性。作为交换，GO的存在改变了膜表面的光滑度，从印刷前的平均1.4nm变为取决于退火条件的8.4至10.2nm的值，这可能会影响后续催化剂层印刷的质量。总体而言，聚合物的电绝缘性未受影响，使得Nafion-GO共混物成为比传统使用的材料更坚固的材料。
