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Preparation and Sensing Performaces of Nanocomposite Fluorescent Chemosensing Materials

Author: WangYingZuo
Tutor: LiBin
School: Graduate Schoo,Chinese Academy of Sciences
Course: Condensed Matter Physics
Keywords: Metal Complexes Photochemical sensing material Nanocomposites Electrospinning Covalent grafting
CLC: TB383.1
Type: PhD thesis
Year: 2011
Downloads: 109
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Abstract

With the human activities and the rapid development of the global economy, the survival of our environment has been the unprecedented destruction. Intensification of industrial pollution, not only lead to declining air quality, and various heavy metal pollutants, especially the high toxicity of mercury ions through different channels into the waters brought great harm to human production and life. Therefore, for the analysis of the field of chemistry, biochemistry, medical diagnostics, environmental monitoring and other research to measure the oxygen concentration of the main indicators of air quality and the determination of trace mercury ions has a very important significance. In recent years, the fluorescence as the detection signal of the fluorescent chemical sensor is widely applied to the detection of oxygen and the concentration of mercury ions. Of this thesis is the design from the fluorescent probe molecules and nano matrix material prepared by the two-pronged approach, the use of a simple electrospinning hydrothermal prepared a variety of nanocomposite sensing material, and a detailed study of nanocomposite sensing material structure, sensing performance, stability and reusability. The main results achieved in this paper are as follows: (1) design and synthesis of a luminous performance of copper (I) complexes, and the first time using a simple electrospinning method and its preparation to become the composite nanofibers oxygen sensing material. The material having a high sensitivity (I ₀ / I ₁₀₀ = 15.56), a short response and reduction time (T ↓ (s) = 7 and t ↑ (s) = 14), and near-linear Stern-Volmer curve. This is the best performance of the physical oxygen sensor material based on cheap metal complex reported. The material is excellent sensing performance, low price, simple preparation and environment-friendly features of its potential commercial applications. (2) design and synthesis of a novel rare earth europium (III) complexes and its preparation to become the composite nanofibers oxygen sensing material using simple electrospinning method. The material has a short response and reduction time (T ↓ (s) = 5 and t ↑ (s) = 8), good stability and reusability. The large specific surface area of ??the material, and a porous structure, and is conducive to the diffusion of oxygen and with the complexes of the collision, significantly improve the sensitivity of the material. Its sensitivity by almost no application value less than 2 raised to the practical application of 3.38 for the current international optical oxygen sensor based on rare earth complexes, the highest value. (3) the use of chemically bonded pyrene derivatives assembled mesoporous silica SBA ^{-1 5 in their preparation to become a nanocomposite sensing material (Py-SBA ^{-1 < / sup> 5). The material of the heavy metals mercury ions with good selectivity, short response time and high sensitivity, the detection limit of 1.7 × 10 ^{-7 -1 . And the fluorescence intensity showed a linear response to mercury ions, can achieve real-time detection of mercury ion concentration. In addition, the material can be repeatedly reused. For the above reasons, the material is expected to be applied to detect the concentration of mercury ions in the water. (4) The design and synthesis of a novel rhodamine derivatives, the material can be used not only to detect heavy metals mercury ion, you can also use its different fluorescence response to heavy metals like mercury and copper ions, to build molecular keypad lock . Only when the correct password is entered, the system exhibits strong fluorescence, keyboard lock is opened; password error occurs, the system of non-fluorescent and warning signal. The keypad lock not only to achieve a molecular level of information protection, but also can be applied to future molecular computer security devices for authorized users to identify the product identity and other fields. (5) by the sol - gel method of preparation of a series of organically modified organic - inorganic hybrid rare earth materials, and to study the optical properties of the material in the series. By changing the proportion of the organic modified silicate and TEOS, the fluorescent intensity rapidly increases VTES: TEOS = 4:6, the fluorescence intensity of this material is 2.4 times that of pure europium complexes, unmodified material 3.3 times. Meanwhile, the quantum efficiency of the material and the light emitting thermal stability is also significantly improved.}}}

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