Preparation Of Mussel Inspired Functional Materials And Their Adsorption Performance

Accompanying with the development of human society, a mass of industrial and domestic wastewater contained various heavy metal ions and organic dyes have been emitted into the environment before untreated or treated without perfection, which caused the seriously polluted for the water system. These pollutions not only have destroyed the entironment of human survival, but also been harmful for the public health. Therefore, the exploration of advanced techniques and methods for removal these heavy metal ions and organic dyes existed in wastewater has attracted numerous attentions from scientists in the world. As one kind of treatment strategies, adsorption method has become a high-efficiency and promising method for the removal of heavy metal ions due to its high efficiency and handleability, which make it draw attentions from researchers in various fields.Carbon-based materials such as carbon nanotubes(CNTs), activated carbons(ACs)and graphene powder(GP)have widely used as adsorbents to remove these pollutants(heavy metal ions and organic dyes)due to their outstanding properties such as unique structure,large specific surface area and abundant pores on their surface. However, the original CNTs possess bad water dispersibility and limited groups on their surface, which certainly influence their adsorbability for those pollutants. Therefore, preparation of polymer-CNTs composites with remarkable advantages contained excellent adsorbability, easy separation and convenient production in large scale is urgent.In this work, we have successfully synthesized functional CNTs and graphene oxide sheets with polymers via combination of mussel inspired chemistry and Michael addition reaction. The measurements such as Transmission Electron Microscope(TEM), Fourier Transform Infrared Spectroscopy(FT-IR), Thermogravimetric Analysis(TGA)and X-ray Photoelectron Spectroscopy(XPS) are applied to characterize these polymer-CNTs and GO-polymer composites. Under the static adsorption model, we discuss the adsorption capacity of polymer modified CNTs and GO composites for copper ion and organic cationic dye methylene blue in the different experimental conditions, and confirm the optimal condition and the maximum adsorption of composites for copper ion and methylene blue. According to the analysis of the adsorption equilibrium state by adsorption isotherm model,kinetic model and thermodynamic model, we discuss the adsorption property in this procedure.The final researched results in this work could be described in follow:(1) The equilibrium adsorption capacity of CNTs-PDA-PEI for Cu2+ aqueous could arrive to 34.6 mg/g, and the adsorption capacity would increase to 47.4 mg/g accompanying with the pH value enhanced. When the solution pH exceed 10, adsorption capacity is not significant change. Therefore, the adsorption experiment in this work better conforms to the Langmuir model and the pseudo-first-order kinetic model.(2) The equilibrium adsorption capacity of CNTs-PDA-PSPSH composite for cationic dye(methylene blue) is 174 mg/g, and the adsorption model of CNTs-PDA-PSPSH for MB solution better conforms for the Langmuir monolayer adsorption model and the pseudo-first-order kinetic model.(3) The maximal adsorption capacity of GO-PDA-PSPSH for MB solution can reach 183 mg/g, and adsorption model of GO-PDA-PSPSH also conforms the Langmuir model and the pseudo-first-order kinetic model.