Department of Physics, De La Salle University, Manila, Philippines.
Sci Rep. 2023 Jan 31;13(1):1787. doi: 10.1038/s41598-023-27623-2.
Gold mine tailings, fly ash, and bagasse ash has been repurposed to produce geopolymer (GP) with enhanced electromagnetic interference shielding efficiency (EMI-SE) and high thermal property. GP has low shielding efficiency compared to concrete. Due to this, an appropriate filler must be incorporated into its matrix to enhance its EMI-SE. For this study, bismuth oxide nanomaterial (BiNP) was utilized as the additive filler. The percent content of BiNP was varied to evaluate its influence on the EMI-SE of GP. Morphology shows that BiO was embedded in the matrix of GP, and no new aluminu-phyllosilicate minerals were formed. This indicates that some minerals acted only as internal fillers in the matrix. Compressive strength shows synthesized GP composites were more than 20 MPa, with neat GP reaching the maximum strength. Moreover, the EMI-SE of neat GP was 21.2 dB for 20-4500 MHz range. This indicates that GP alone has sufficient characteristics to attenuate EMI radiation. Addition of 5%, 10% and 15% weight of BiNP improves EMI-SE by 4-10%, with 5% BiNP shown to be the optimum ratio. Lastly, the addition of BiNP improves the thermal stability of GP. This study shows that GP incorporated with BiO can be recommended for small-scale construction and small residential building.
金矿尾矿、粉煤灰和甘蔗渣灰已被重新用于生产具有增强电磁干扰屏蔽效率（EMI-SE）和高热性能的地质聚合物（GP）。与混凝土相比，GP 的屏蔽效率较低。因此，必须在其基质中加入适当的填料来提高其 EMI-SE。在这项研究中，使用氧化铋纳米材料（BiNP）作为添加剂填料。改变 BiNP 的百分含量以评估其对 GP 的 EMI-SE 的影响。形貌表明 BiO 嵌入在 GP 的基质中，并且没有形成新的铝硅酸盐矿物。这表明某些矿物仅在基质中充当内部填料。抗压强度表明合成的 GP 复合材料的强度超过 20 MPa，纯 GP 达到最大强度。此外，纯 GP 在 20-4500 MHz 范围内的 EMI-SE 为 21.2 dB。这表明 GP 本身具有足够的特性来衰减 EMI 辐射。添加 5%、10%和 15%重量的 BiNP 可将 EMI-SE 提高 4-10%，其中 5%的 BiNP 显示出最佳比例。最后，添加 BiNP 可提高 GP 的热稳定性。这项研究表明，掺入 BiO 的 GP 可推荐用于小型建筑和小型住宅建筑。
