| In recent years, increasing researchers begin to pay attention to novel functionalmaterials, i.e., nanocomposite materials. The studies of the preparation method andsubsequent application of nanocomposite materials have been developed drastically.Since the turn of the century, organic fluorescent material has been widely used inthe field of industrial and civil fields and other fields.Fluorescence intensity is mainlyrelated to the structure of the dye molecules. Classification from the structure, theorganic fluorescent material mainly includes coumarins, rhodamine dye (RhB),distyrylbenzene, anthraquinones, naphthalimides, porphyrinetc.Organic fluorescent nanocomposite materials are functional materials, whichcombines organic fluorescent materials and inorganic/polymeric materials into oneentity. This kind of nanocomposite materials has both the excellent properties ofnanoscale materials and the unique performance of the organic fluorescent materials.With the deepening of the research for nanocomposite materials, there are numerouskinds of method to prepare these functional materials.This thesis is composed of two main parts. In the first part, two kind of organicfluorescent nanocomposite materials were prepared by two new methods. NBA/PSnanocomposite materials were prepared by the swelling dispersion method.CSB@TiO2core-shell nanocomposite materials, which contain organic fluorescentmaterial as core and inorganic material as shell, were prepared by the self-templatingmethod. In the second part,we prepared two new fluorescent nanocompositematerialswith different morphologies (spheres and fibers) by two traditional methods,i.e., st ber method and electrospinning, with organic fluorescent nanocomposite asfluorescent recognition and sensing material, organic fluorescent probe (porphyrinfluorescent probes and rhodamine fluorescent probe) as the functional groups. Thenthe as-prepared nanocomposite materials were utilized todetect heavy metal ions inenvironment. The details are shown as follows.1. NBA as naphthalimide-type molecule is an organic fluorescent agent. NBA/PSorganic fluorescent nanocomposite materials have been prepared by swellingdispersion method. First, we prepared polystyrene (PS) microspheres byemulsifier-freeemulsion polymerization, and then effects of initiator, the dosage ofinitiator and monomer on morphology were studied, respectively. By selecting properswelling agent, the organic fluorescent materials were scattered into the swelled PSmicrospheres. After that, NBA/PS fluorescent nanocomposite materials have beenobtained by high-speed centrifugation. Organic fluorescent dyes NBA has beensuccessfully embedded PS microspheres.The as-prepared fluorescent nanocompositematerialsare spherical and monodisperse. The optimum parameters of the swellingdispersion approach have been obtained by tuning swelling agent, swelling time,NBA/PS ratio, choice of surfactant etc. The plausible mechanism of swellingdispersion method was established.2. In this thesis, TiO2colloidas the precursor of self-templatingmethodforsynthesizing core-shell nanoparticles have been prepared by sol-gel method bytetrabutyl titanate as titanium source, acetate as chelating agent, hydrochloric acid asacid medium.The preparation process was optimized and the optimal valuefor H2O/Tiand HCl dosage.CSB is a commonly used organic fluorescent agent. Herein,CSB@TiO2core-shell organic fluorescent nanocomposite materials were fabricatedby a novel technique, i.e., self-templating method. This method does not require anyother additives such as surfactant and stabilizer compared with the traditional methods.Self-templating method has greatly simplified preparation and reduced the probabilityof the pollution caused by additives. Characterization results show that CSB has beensuccessfullycoated with a layer of dense TiO2, and the as-prepared nanoparticles haveuniform spherical appearance and core-shell structure. The size is between100-200nm, and shell thickness is about12nm. More importantly, the CSB@TiO2core-shellnanoparticles have obvious fluorescence properties.3. In this thesis, SiO2microspheres in nanoscale were synthesized by the st bermethod. Then SiO2was acted as carrier to carry porphyrins(Amino-substituted tetraphenylporphyrin) with excellent fluorescent properties on their surface by thechemical bonding. The as-prepared organic fluorescent nanocomposite materialsendow excellent sensing capability, and have a specific and focused recognitionperformance for mercury ions.The immobilization of amine porphyrin on silicananospheres was inferred by several techniques. We used the test such as fluorescencespectrum analysis, selective test, and sensitive test to study the property of theporphyrin functionalized silica nanoparticles. The fluorescence intensity of theprepared functional silica nanoparticles decreasedwhenwe inducing the mercury ion.The responsing time of the materials for the sensing of mercury is1minute. From thetest results we can see that the materials have showed good selectivity and sensitivity.It can be expected that the composite microsphere has good potential applicationvalue in the field of mercury ion sensing.4. In this thesis,electrospinning technique was applied to prepare a kind of fibermaterials with nanometer scale and fluorescence probe-rhodamine. These materialshave goodcolorimetric response andrecognition performance towards copper ion. Theas-prepared products have fiber morphology, smooth surface. Thesizeis between100-200nm.The fiber materials have been tested by pH concentration test,fluorescence spectrum analysis, selective and competitive experiment, repetitiveexperiments, responceand identification experiment.The experimental results showthat the fluorescence intensity of the prepared nanocomposite fibers increased withthe increase of the introduction of copper ion concentration. The fiber materials havespecific selectivity and strong anti-jamming capability towards copper ion. Besides,they also have a good colorimetric response capability, and can be used repeatedly,which have expanded their applications and improved the practical potentials.In summary, this thesis studied and discussed two kinds of new method for thepreparation of organic fluorescent nanocomposite by swelling dispersion method andself-templating method to combine organic fluorescent dyes with polymer matrix andinorganic matrix. For another, using two traditional method, i.e., st ber method andelectrospinning method, two organic fluorescent nanocompositewith differentmorphologies and fluorescent sensing properties for heavy metal ions have been prepared,andobtained good experimental results. |
