Fluorescent Conjugating Polymer Synthesis And Analysis Application Characteristics,

Since the first fluorescent material composed of polymer as a substrate was reported, fluorescent polymers have attracted much attention because of its unique photophysical and photochemical characteristics and recently various new materials have been successfully synthesized. The water-soluble fluorescent polymers have an important theoretical research and practical application value because they can evenly dispersed in water medium, and the active group on polymer chains decided its chemical and biological technology applications. As an important type of intelligent materials, hydrogel's synthesis and application study have been keeping a quite active field, and conferring fluorescence properties onto hydrogels have been received a numerous researchers' attention.In this thesis, taking acrylamide (MBA) as monomer, azobisisobutyronitrile (ABIN) as initiator, a polyacrylamide of low molecular weight was prepared via free radical polymerization reaction (FRPR) in anhydrous alcohol and acetone mixed solvent. After Holffman degradation, polyethylene amine was obtained. Then, making the polyethylene amine reacted with 5,6-bicarboxylic fluorescein under heating condition, fluorophore was introduced in polymer's side chain. After hydrolysising, we got a water-soluble fluorescent polymer with good fluorescence properties. Similarly, using MBA as monomer, potassium sulfate (SBS) as initiator, we got a polyacrylamide of high molecular weight in polyethylene glycol (PEG) aqueous solution. After Holffman degradation, another polyethylene amine was obtained. Then, using 5,6-bicarboxylic fluorescein as crosslinking agent for the polyethylene amine, a hydrogel with good fluorescence characteristics was obtained after hydrolysising. Due to its excellent performance, the applications in analysis sensing, in biological detection and other fields are discussed. The main research contents are divided into four parts:The first chapter reviewed the fluorescence phenomenon and fluorescent produce principle, and emphatically introduced the related properties of fluorescent polymers, the type, the synthesis method and their application in fluorescent probe and analytical sensors etc, and briefly introduced the topic ideas and research content of this paper.The second chapter introduced the method and synthetic routes of water-soluble fluorescent polymers, and optimized its synthesis conditions, and related characterization technology of the polymer synthesized under the optimum experimental conditions are conducted. The influences of pH, surfactant and 18 kinds of common metal ions (including NH4+) on polymer's fluorescence properties was studied specifically. Experimental results showed that, in the examined pH range, the fluorescence intensity of this polymer present a staged strengthen feature with the pH elevated; Cationic surfactants(CTAB) can make the polymer's fluorescence intensity slacked, and cause a little red shift of the peak position; Cu2+, Co2+ and Ni2+ can make the polymer's fluorescence intensity quenched effectively(when polymer concentration is 5x10-6 g/mL, that of metal ion is 1x10-4 mol/L, their quenching efficiency are more than 70%), and the quenching ability is Cu2+> Co2+> Ni2+, but there was no significant effect on the peak position of the emission spectrum.Taking advantage of this property, new fluorescent chemosensors for the aforementioned ions detection are expected to be developed. Moreover, owing to the strong affinity between sulfur ions or sulphur compounds and copper ions, all of them can make the fluorescence of polymer-copper(â…¡) complex recovered, which is expected to used for determination the content of sulfur ion in environmental samples and mercapto compounds in medicine or food. Based on fluorescence analysis and TEM characterization results, the fluorescence quenching mechanism of the polymer in Cu2+ solution was surmised.In chapter three, we synthesized a hydrogel with fluorescence properties referenced the synthesis routes and conditions of the water-soluble fluorescent polymer. Determined the related parameters of this hydrogel which adopted fluorescence reagent as crosslinking agent, observed its morphology by SEM, tested the swelling performance and adsorption kinetics for copper(â…¡), surveyed its intelligence response characteristics of temperature, pH and Cu2+, and proposed the potential applications prospect of this fluorescent hydrogel.The last chapter summarized the full text.