Mechanical milling and a gas-selective polymer were used to protect MgH₂ from oxidation and improve its dehydrogenation properties. MgH₂ and poly(methyl methacrylate) (PMMA) were simultaneously ball-milled for 5 and 20 h, respectively, to prepare an air-resistant nanostructured composite. The properties of the nanostructured composite were studied by XRD, SEM, and FTIR methods. The dehydrogenation performance of all samples was investigated by TGA analysis. The hydrogen desorption performance of ball-milled samples was also evaluated after exposure to air for 4 weeks. Results showed that MgH₂ desorbed about 0.79 wt.% of hydrogen after heating up to 300 ˚C and holding for 15 min at this temperature. The ball-milling of MgH₂ and PMMA for 5 and 20 h led to hydrogen desorption of 6.21 and 6.10 wt.% after heating up to 300 ˚C and holding for 15 min at this temperature, respectively, which proved the surface protection of MgH₂ from oxidation by PMMA. After 4 weeks of exposing the ball-milled MgH₂–PMMA samples to air, their hydrogen desorption percentage at the same condition changed to 5.80 and 5.72 wt.% for 5 and 20 h milled samples, respectively. A slight reduction in the dehydrogenation percentage of air-exposed samples proved that the air stability of MgH₂ had been significantly enhanced by its confinement with PMMA.

中文翻译：

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直接高能球磨制备的MgH 2 -PMMA纳米复合材料的脱氢性能和空气稳定性的研究

机械研磨和气体选择性聚合物用于保护MgH ₂免受氧化并改善其脱氢性能。同时分别将MgH ₂和聚甲基丙烯酸甲酯（PMMA）球磨5个小时和20个小时，以制备一种耐空气的纳米结构复合材料。通过XRD，SEM和FTIR方法研究了纳米结构复合材料的性能。通过TGA分析研究了所有样品的脱氢性能。暴露于空气中4周后，还对球磨样品的氢气脱附性能进行了评估。结果表明，加热到300°C并在此温度下保持15分钟后，MgH ₂解吸了约0.79 wt。％的氢。MgH ₂的球磨分别加热至300°C和在此温度下保持15分钟后，PMMA和PMMA分别在5 h和20 h导致氢气脱附分别为6.21和6.10 wt。％，这证明了MgH ₂的表面保护免受PMMA氧化。将球磨过的MgH ₂ -PMMA样品暴露在空气中4周后，在5和20 h磨碎的样品下，在相同条件下其氢气脱附百分比分别变为5.80和5.72 wt。％。暴露于空气中的样品的脱氢百分率略有降低，这表明MgH ₂的空气稳定性由于其与PMMA的限制而显着提高。