Preparation Of Polypyrrole And Polyphosphazene Nanomaterials And Their Application In Adsorption Treatment Of Dyes

Because a large amount of dyes and pigments are used in many industrial fields(such as textile, leather, paper, printing and cosmetics), there will be a lot of dye wastewater. Emissions of sewage even contain a small amount of dye, it can also cause serious environmental problems. The dye waste water will harm to aquatic organisms and human, such as genetic mutations, cancer and so on. Besides, if industrial waste water containing dyes directly discharge into rivers, lakes or other water bodies without treatment, it will affect the photosynthesis of aquatic organisms. Not only that, but it can also weaken light penetration and increase chemical oxygen demand(COD). Therefore, it is necessary to treat wastewater before discharging. Due to the stable structure of benzene ring in the dye molecules, so it has the nature of the aerobic degradation of resistance and anti-biodegradation. This will increase the difficulty to treat wastewater. Many methods such as flocculation, adsorption, oxidation, membrane filtration, photocatalytic, biological and degradation are used in dye wastewater treatment. Among them, adsorption is the most promising method, because of its simple operation, high adsorption efficiency and the low cost. Adsorption behavior occurs on the surface of adsorbent generally, so the adsorbent with high specific surface will arouse people’s concern. Therefore, the nanoscale materials with high specific surface and a large number of adsorption sites has become the research focus. In this paper, we prepared a series of polymer nanomaterials using the template self-assembly methods such as oxidation polymerization and in situ template synthesis. Besides, we investiage the structure and performance of these materials by using SEM, TEM and FITR and XRD characterization methods and explore these nanomaterials’ s adsorption behavior and mechanism as adsorbent. At the same time, we investigate its selective adsorption behavior to achieve the goal of dye separation. Specific research is as follows:Polypyrrole nanospheres was synthesized using oxidation polymerization. At room time, pyrrole monomer(Py) was added into the solution of trimethyl ammonium bromide(CTAB), and then added ammonium persulfate(APS) by drop. In order to make them polymerize fully, the reaction conducted under magnetic stirring. After washing the product, we obtained PPy nanospheres. In order to increase the adsorption capacity, we changed synthesis condition to prepared network structure PPy nanofibers with high specific surface area.Polyphosphazenes(PZS) nanotubes was prepared by using in situ template polymerization. Polyphosphazenes(PZS) nanotubes was synthesized under the condition of ultrasonic(50 W), tetrahydrofuran(THF) as solvent, trimethylamine(TEA) as acid-acceptor.We studied the structure and properties of polymer we obtained by using SEM, TEM, FITR, XRD, BET, size analysis and surface charge test.As-obtained nanomaterials was studied their adsorption capacities systematicly, and results showed that they all had high adsorption capacities for dyes. The adsorption capacity of polypyrrole nanofibers for methyl orange reached 169.55 mg/g. Besides, pseudo second order kinetics model and Langmuir isotherm model could better fit the adsorption behavior of polypyrrole nanomaterials. In addition, the cyclicity of polypyrrole nanomaterials was studied, and found that the adsorption properties of adsorbent did not reduce significantly after several cycles. Therefore, polypyrrole nanomaterials is a kind of renewable adsorbents. We put forward and verified that electrostatic interaction is the prominent force in the process of adsorption. According to its adsorption mechanism, polypyrrole nanofibers was applied to the selective adsorption of mixed solution, and achieved good results.The adsorption behavior of polyphosphazenes nanotubes for dyes fit pseudo second order kinetics model and Langmuir isotherm model well. Polyphosphazenes nanotubes showed different adsorption capacities for anionic and cationic dyes, so it could be applied to selective adsorption of mixture dyes, then dyes were separated effectively. Moreover, we put forward and verified that the acid-base interaction was the prominent force in the process of adsorption.