Abstract The sensing of ammonia leakage at room temperature has potential applications in many areas such as industry. A sensitive etched-tapered fiber Bragg grating (FBG) based ammonia sensor is developed and investigated towards different concentrations of ammonia. The investigations are performed at room temperature. FBGs are etched with 50 µm diameter and tapered with 15 and 30 µm waist diameters. These FBGs are coated with polyaniline/graphite nanofibers (PANI/GNF) nanostructures as a sensing layer using spray method. The developed FBG sensors are based on Bragg wavelength shift on exposure to different ammonia concentrations due to change in refractive index of the sensing layers as interact with ammonia molecules. FBG sensors proved a linear Bragg wavelength shift with ammonia concentrations. The developed sensors exhibited linear, stable response, high sensitivity and good repeatability. Furthermore, FBGs sensors proved strong response towards NH3 by exhibiting high Bragg wavelength shift. This is because of porous structures of PANI\GNF nanostructures which improves the capability to adsorb additional NH3 molecules. This is in turn eventually enhances the interaction between NH3 and PANI\GNF nanocomposites. PANI\GNF coated FBG sensor with 15 µm waist diameter shows the highest sensitivity and good selectivity towards NH3.

中文翻译：

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一种新型的基于光纤布拉格光栅 (FBG) 的氨传感器涂覆有聚苯胺/石墨纳米纤维纳米复合材料

摘要 室温下氨泄漏的传感在工业等许多领域都有潜在的应用。开发了一种基于敏感蚀刻锥形光纤布拉格光栅 (FBG) 的氨传感器，并针对不同浓度的氨进行了研究。研究在室温下进行。FBG 蚀刻的直径为 50 µm，锥形腰部直径为 15 和 30 µm。这些FBG使用喷涂方法涂有聚苯胺/石墨纳米纤维（PANI/GNF）纳米结构作为传感层。由于与氨分子相互作用时传感层的折射率发生变化，因此开发的 FBG 传感器基于暴露于不同氨浓度时的布拉格波长偏移。FBG 传感器证明了与氨浓度的线性布拉格波长偏移。开发的传感器表现出线性，响应稳定，灵敏度高，重复性好。此外，FBG 传感器通过表现出高布拉格波长偏移证明了对 NH3 的强烈响应。这是因为 PANI\GNF 纳米结构的多孔结构提高了吸附额外 NH3 分子的能力。这反过来最终增强了 NH3 和 PANI\GNF 纳米复合材料之间的相互作用。腰部直径为 15 µm 的 PANI\GNF 涂层 FBG 传感器显示出最高的灵敏度和对 NH3 的良好选择性。这反过来最终增强了 NH3 和 PANI\GNF 纳米复合材料之间的相互作用。腰部直径为 15 µm 的 PANI\GNF 涂层 FBG 传感器显示出最高的灵敏度和对 NH3 的良好选择性。这反过来最终增强了 NH3 和 PANI\GNF 纳米复合材料之间的相互作用。腰部直径为 15 µm 的 PANI\GNF 涂层 FBG 传感器显示出最高的灵敏度和对 NH3 的良好选择性。