聚氨酯基重金属离子识别荧光化学传感器的构建及性能研究

发布时间：2018-03-04 06:19

  本文选题：重金属识别　切入点：荧光化学传感器　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：工业作为经济腾飞的重要支柱,在世界经济发展的同时,所导致的环境污染问题也日益严重。重金属污染由于其处理难度大、周期长,成为一个严重的污染问题。汞因其特殊的物理化学性质,它的环境污染特性呈现高毒性、迁移性、持久性和生物积蓄性等显著特点,不仅会威胁生物健康,还会对整个环境造成持久的污染,俨然已成为全球最关注的污染物之一。随着人们对环境问题重视程度的提高,水环境中重金属离子的检测识别及分离去除也备受关注。荧光化学传感器能依外部环境的变化而改变自身荧光性能,使其能感知环境中存在的某种特定物质的信息。BODIPY(氟硼二吡咯)为母体的荧光染料因其具有较强的荧光发射强度和良好的稳定性而受到研究者们的重视。将BODIPY小分子荧光探针与大分子结合,制备具有重金属离子识别功能的荧光高分子材料也是近几年的研究热点之一。本文制备了几种能够识别检测重金属离子汞离子(Hg~(2+))、铁离子(Fe~(3+))和铬离子(Cr~(3+))的BODIPY基小分子荧光探针,并将其中三种(B3a、B3b和B3c)小分子荧光探针接入聚氨酯制备出聚氨酯基大分子荧光传感器,通过紫外-可见光谱和荧光光谱等分析方法研究了这几种荧光探针对于重金属离子的识别性能。具体研究如下:(1)利用核磁共振氢谱(1H-NMR)、傅里叶红外光谱(FTIR)、质谱(MS)等确认了BODIPY小分子荧光探针的结构。(2)通过控制反应物的加入比例,可得到一个分子中分别含有一个和两个荧光基元的小分子OS11和OS21。小分子OS11和OS21在纯溶剂中,OS21的荧光强度是OS11荧光强度的两倍,这是因为一个OS11分子中只含有一个荧光团,而一个OS21分子中含有两个荧光团。分子中荧光基元越多,荧光强度越高。并且OS11和OS21在识别Hg~(2+)和Fe~(3+)时,表现为荧光猝灭。而B3a、B3b和B3c能够增强荧光强度识别Hg~(2+)、Fe~(3+)和Cr~(3+)。(3)实验表明,OS11能在pH为3.65-11.09的缓冲液中稳定存在,OS21能在pH为3.16-11.88的缓冲液中稳定存在。当OS11和OS21与含有Hg~(2+)或Fe~(3+)的水溶液作用时,OS11和OS21表现为荧光强度减弱,而OS21小分子溶液的荧光强度比OS11小分子溶液的荧光强度减弱的程度要大很多。同时OS11和OS21小分子溶液的颜色由玫红色变为淡黄色。工作曲线滴定实验表明,OS11和Fe~(3+)的络合比为1:2,OS11和Hg~(2+)的络合比为1:1,OS21与Fe~(3+)的络合比为1:3,OS21与Hg~(2+)的络合比为1:1。并且OS21小分子探针能够识别Hg~(2+)浓度为0.5μmol/L。(4)B3a、B3b和B3c与Hg~(2+)、Fe~(3+)和Cr~(3+)溶液作用后,表现为荧光强度增强且颜色改变。B3a、B3b和B3c的小分子溶液由红色变为黄色。同时,能识别浓度为2.5×10-6mol/mL的铁离子溶液。当将B3a、B3b和B3c引入到聚氨酯上制成聚氨酯膜(PU-B3a、PU-B3b和PU-B3c)后,小分子对金属离子的选择识别作用依然保持。小分子B3a、B3b和B3c的荧光峰出现在510nm左右,大分子聚氨酯膜的荧光峰在580nm附近出现了一个新峰。原子吸收实验表明,大分子聚氨酯膜PU-B3a单位时间内可以吸收84mg/g Hg~(2+),PU-B3b的吸收值为80mg/g Hg~(2+),PU-B3c的吸收值为76mg/g Hg~(2+)。
[Abstract]:As an important pillar industry of economic development, economic development in the world at the same time, the problem of environmental pollution caused by heavy metal pollution is increasingly serious. Because of its difficulty, long period, become a serious pollution problem. Mercury due to its special physical and chemical properties, environmental pollution characteristics that showed high toxicity, mobility obviously, persistence and biological accumulation, not only threatens the health of living will cause persistent pollution to the whole environment, has become one of the world's most concerned pollutants. As people improve the degree of attention to environmental issues, detection and identification and separation of heavy metal ions in water to remove the fluorescent chemical is also of concern. The sensor can change their fluorescence properties according to changes in the external environment, so that it can be a specific material existence in the environment of information.BODIPY (fluorboric two pyrrole) as matrix. Light dye attention of researchers because of its strong fluorescence emission intensity and good stability. The BODIPY small molecule fluorescent probes and fluorescent molecules, to prepare polymer materials with metal ion recognition function is one of the research hotspot in recent years. This paper prepared several can identify the detection of heavy metal ions mercury ion (Hg~ (2+)), iron (Fe~ (3+)) and chromium (Cr~ (3+)) BODIPY based small molecule fluorescent probe, and three of them (B3a, B3b and B3c) small molecule fluorescent probe access prepared polyurethane based polyurethane macromolecular fluorescent sensor, by UV the visible spectrum and fluorescence spectrum analysis method to study the recognition performance of fluorescent probes for metal ions. The specific studies are as follows: (1) using nuclear magnetic resonance spectroscopy (1H-NMR), Fourier transform infrared spectroscopy (FTIR), mass spectrometry (MS) confirmed BODIPY small 瀛愯崸鍏夋帰閽堢殑缁撴瀯.(2)閫氳繃鎺у埗鍙嶅簲鐗╃殑鍔犲叆姣斾緥,鍙�寰楀埌涓�涓�鍒嗗瓙涓�鍒嗗埆鍚�鏈変福�

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