Synthetization Of Polymer-Based Nanomaterials And Their Application In The Adsorption Treatment Of Organic Dyes

Based on the excellent properties and advantages of polymer-based nanomaterials, we have explored their synthetization, structures, the possibilities of application in adsorption treatment of organic dyes, adsorption processes, relevant mechanisms and so on. Polymer-based nanomaterials gained more and more attention owing to their unique structures, properties and potential applications. They made full use of the properties of nano materials and polymer materials, such as small scale, large specific surface area and the designability of surface groups, to expand their applications in the fields of composites, catalysis, sensors, drug carriers, batteries, capacitors, water purification and so on. To date, exploring novel and efficient adsorbents to remove dyes from industrial effluents has been goals of many researchers due to increasingly serious environmental problems caused by dye industries. Therefore, synthesizing novel polymer-based nanomaterials and exploring their dye adsorbability were of great significance. In this study, we successfully synthesized a series of different morphologies of polymer-based nanomaterials including solid and hollow polyphosphazene(PZS) nanospheres, PZS nanotubes, solid and hollow PDA microspheres by in situ template method or oxidative polymerization. And we also thoroughly studied their properties, structures and adsorption behavior for organic dyes. Main results are as follows.PZS nanospheres were facilely synthesized under the condition of ultrasound by precipitation polymerization between hexachlorocyclotriphosphazene(HCCP) and 4,4?-sulfonyldiphenol(BPS) using triethylamine(TEA) as acid-acceptor and acetonitrile as solvent. Then, we studied its adsorption ability towards cationic dye(methylene blue, MB). To improve the adsorption ability, we prepared PZS nanotubes by changing the reaction condition(ultrasonic power and solvent). PZS nanospheres and nanotubes were characterized by a series of characterization methods, such as SEM, TEM, FITR, XPS, BET, particle size analysis and zeta-potential. The synthetic mechanism was also elaborated in detail. Results showed that PZS nanotubes had superior adsorption capacity due to its numerous hydroxyl groups, aromatic rings, electron-rich atoms and high specific surface area.To improve the adsorption capacity of PZS nanospheres, we have successfully prepared hollow PCPP microspheres by precipitation polymerization between HCCP and phloroglucinol, and then organic solvent etching. Some characterization methods were used to characterize its structure and surface properties. The synthetic mechanism was elaborated.PDA microspheres were successfully synthesized by oxidative polymerization using dopamine hydrochloride as monomer in Tris(hydroxymethyl) aminomethane(Tris) solution under an aerobic atmosphere and dark environment. Then, we also prepared hollow PDA microspheres by covering polystyrene microspheres with dopamine polymer and organic solvent(THF) etching. Numerous characterization methods were used to characterize their structure and surface properties. The synthetic mechanism was also elaborated in detail.In this study, the as-synthesized PZS nanospheres, PZS nanotubes, hollow PCPP microspheres and PDA microspheres were employed as adsorbents to remove cationic dye(MB) from aqueous solution. We systematically studied various effects on MB adsorption including initial solution p H, temperature, initial concentration of MB solution and adsorbent dosage. And the adsorption isotherm, kinetics and thermodynamics of adsorption process were thoroughly studied. Based on experimental results, we proposed high-efficiency adsorption mechanism. In addition, we also studied the adsorption behavior of hollow PCPP microspheres and PDA microspheres for other seven dyes(anionic dyes: methyl orange(MO), acid chrome blue K(ACBK), eosin-Y(EY), eosin-B(EB), cationic dyes: safranine T(ST), malachite green(MG), and neutral dye: neutral red(NR)). The result of selective adsorption of mixture dyes(MB and MO(a), MB and EY(b)) by hollow PCPP microspheres and PDA microspheres showed that the cationic dye of MB was absorbed preferentially and thoroughly in the mixture solutions. It suggested that hollow PCPP microspheres could be an excellent selective adsorbent to remove cationic dyes from mixture solutions.