木质素磺酸钠荧光膜的制备及其在硝基爆炸物检测中的应用

以木质素磺酸钠(LS)为原料, 聚乙烯醇为黏合剂, 制备了木质素磺酸钠荧光膜。通过荧光光谱仪和激光粒度分析仪对LS的形态和光学性质进行了分析, 研究了硝基化合物和无硝基化合物对LS的荧光猝灭作用及猝灭机理, 并将木质素磺酸钠荧光膜应用于硝基爆炸物的检测。研究结果表明: LS随着制备溶剂中乙醇体积分数的增加, 其荧光发射峰强度增加, 分子之间发生缓慢聚集, 且聚集体颗粒变大, 具有聚集诱导发射(AIE)性质; 硝基苯和对硝基苯酚均对LS的荧光猝灭程度高达90%, 间二硝基苯对LS的荧光猝灭程度也有56%;苯、甲苯、苯酚、对苯二甲酸、对苯二甲醛和邻苯二甲醛等无硝基化合物对LS的荧光猝灭作用几乎没有。LS对硝基苯、间二硝基苯和对硝基苯酚等硝基化合物显示出专一、特异的高灵敏检测性能, 该现象主要由光诱导电子转移机制造成的。浸泡过硝基苯/乙醇溶液、间二硝基苯/乙醇溶液和对硝基苯酚/乙醇溶液的木质素磺酸钠荧光膜的荧光猝灭程度分别为89%、78%和100%。将硝基化合物溶液在荧光膜上涂写, 在日光下观察不到笔迹存在, 而在紫外光下能观察到笔迹部分有明显的荧光猝灭现象。

Preparation of Sodium Lignosulfonate Fluorescent Films and Their Application in the Detection of Nitro Explosives

Using sodium lignosulfonate(LS) as a raw material and polyvinyl alcohol as an adhesive, a sodium lignosulfonate fluorescence membrane was prepared. The morphology and optical properties of LS were analyzed by fluorescence spectrometer and nano-size analyzer, and the quenching effect and mechanism of LS fluorescence by nitro compounds and non-nitro compounds were studied. Additionally, sodium lignosulfonate fluorescence membrane was applied for nitro-explosive detection. The results showed that LS had the property of aggregation induced emissions. The fluorescence quenching degree of LS by nitrobenzene and p-nitrophenol was as high as 90%, and the fluorescence of LS by m-dinitrobenzene was 56%, while benzene, toluene, phenol, terephthalic acid, terephthalaldehyde, o-phthalaldehyde and other nitro-free compounds almost had no fluorescence quenching effect on LS. This indicated that LS had high sensitivity and specific detection performances for nitrobenzene, m-dinitrobenzene, p-nitrophenol and other nitro-compound, which was mainly owing to the photoinduced electron transfer mechanism. The degrees of fluorescence extinction of the sodium lignosulfonate membrane immersed in the nitrobenzene solution, the m-dinitrobenzene solution and the p-nitrophenol solution were 89%, 78% and 100%, respectively. When the nitro compound solution was used to write on the fluorescent film, the handwriting could not be observed under sunlight, while the obvious fluorescence quenching phenomenon could be observed in the handwriting part under ultraviolet light.