Acid gas, as a kind of polluting gas, poses a great threat to human health. Therefore, there is a need for a material that can detect it, and it is of great significance to find and deal with acid gas leakage in time. In this paper, the fluorescent micromolecule NAP-OH, a naphthalimide derivative modified by morpholine, was introduced into polyurethane as an end-capping agent, and the prepared nanometer fluorescent sensing material E-NAP_0.5/PU by electrospinning technology exhibited a sensitive ratiometric fluorescence response behavior to acid gas. The E-NAP_0.5/PU's specific surface area was 9.142 m²/g and its diameter was 200–400 nm. In 6 ppm HCl gas, TFA and FA gases, the response time of E-NAP_0.5/PU (deep orange red) films were 2, 20, and 40 s, and the colors were green, light green and light orange-red, respectively. This showed that the membrane has great potential application in distinguishing acid gases. In addition, the E-NAP_0.5/PU changed from orange-red to colorless within 30 s in SO₂ gas with a concentration of 360 ppm. The detection limits of E-NAP_0.5/PU for HCl, TFA, FA and SO₂ gases were 996 ppb (0–10 ppm), 660 ppb (0–8 ppm), 724 ppb (0–10 ppm) and 39 ppm (0–360 ppm), respectively. More importantly, E-NAP_0.5/PU could be reused multiple times. After five times of recovery, the E-NAP_0.5/PU film still recovered to its original fluorescence intensity, and kept a good response to acid. The ¹H NMR and fluorescence spectra results indicated that the possible mechanism for acid gas detection of NAP-OH was attributed to the protonation of morpholine group. To sum up, E-NAP_0.5/PU had a broad application prospect in acid gas detection.

中文翻译：

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可回收荧光静电纺丝薄膜的制备及其在酸性气体鉴别定量分析中的应用

酸性气体作为一种污染性气体，对人体健康构成极大威胁。因此，需要一种能够对其进行检测的材料，对及时发现和处理酸性气体泄漏具有重要意义。本文以吗啉修饰的萘酰亚胺衍生物荧光小分子NAP-OH作为封端剂引入聚氨酯中，制备纳米荧光传感材料E-NAP _{0。静电纺丝技术制备的5} /PU对酸性气体表现出灵敏的比例荧光响应行为。_E -NAP ₀。₅ /PU的比表面积为9.142 m ²/g，其直径为 200-400 nm。在 6 ppm HCl 气体、TFA 和 FA 气体中，E-NAP的响应时间_0。5 /PU（深橙红）膜分别为2、20和40 s，颜色分别为绿色、浅绿色和浅橙红色。这表明该膜在区分酸性气体方面具有巨大的应用潜力。此外，E-NAP _0。5 /PU在浓度为 360 ppm 的SO ₂气体中，在 30 s 内由橙红色变为无色。E-NAP ₀的检测限_。5 /PU用于 HCl、TFA、FA 和 SO ₂气体分别为 996 ppb (0–10 ppm)、660 ppb (0–8 ppm)、724 ppb (0–10 ppm) 和 39 ppm (0–360 ppm)。更重要的是，E-NAP _0。5 /PU可以重复使用多次。经过五次恢复，E-NAP _{0 . 5} /PU薄膜仍恢复到原来的荧光强度，对酸保持良好的响应。1 H NMR 和荧光光谱结果表明，NAP-OH^酸性气体检测的可能机制是吗啉基团的质子化。综上所述，E-NAP _0。5 /PU在酸性气体检测方面具有广阔的应用前景。