Preparation And Characterization Of Multi-walled Carbon Nanotube Composite Film / Polyamide

Carbon nanotubes could be provided good carrier and filter medium for composite membrane, and became the ideal inorganic additives, due to it’s properties of unique pore structure, good hydrophilic, chemical stable, high specific surface area, and good adsorption capability. In this paper, using polysulfone membrane as support membrane, piperazine and trimesoyl chloride as monomer, embedded modification multiwalled carbon nanotubes into the polyamide composite membrane through interfacial polymerization. On this basis, the composite films were characterized by the permeability and anti-fouling performance.The multi-walled carbon nanotubes were first treated by mixed acid of H2SO4/HNO3to prepare carboxylated carbon nanotubes, then anination by piperazine, for hydrophilic the multi-wall carbon nanotubes to polar; multi-walled carbon nanotubes grafted methyl methacrylate by microemulsion polymerization for lipophilic nonpolar treated, emulsifier was sodium dodecyl sulfate, coupling agent was AIBN. And two products were characterization to indicate that the desired functional group have been successfully grafted on the multiwalled carbon nanotubes, and then preserved for membrane preparation.Trimesoyl chloride as monomer in oil phase and piperazine as monomer in aqueous phase, modified multi-walled carbon was embedded into polyamide layer of composite membrane by interfacial polymerization method on the support membrane of polysulfone ultrafiltration membrane. The composite membrane structure was characterized by the Fourier infrared spectroscopy (FTIR), Raman spectroscopy (Raman), X ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and static contact angle, the results showed that a layer of poly-piperazine was preparation on the support membrane.The preparation method of how to embed carbon nanotubes grafted PMMA into polyamide composite membrane were studied, and also the conditions of microemulsion polymerization and interfacial polymerization. The concentration in the microemulsion polymerization, the reaction time, the membrane process, the organic phase concentration, reaction time polymerization, the MWNTs concentration, which would have a great effect on the separation performance of the composite nanofiltration membrane were detailed studied.Finally, the composite membrane prepared in this experiment is applied to remove the precursors of disinfection by-products in water, and also with the anti-fouling performance test, found that the color of humic acid solution was disappeared after filtration, the removal rate is up to above99%test by UV spectrophotometer, moreover after a long time operation the membrane cleaned with dilute acid, the contamination resistance recovery ability basically reached more than90%.Also the alignment experiment of carbon nanotubes in polyamide composite membrane was tried by the self-made electric field. We studied the effect of both the strength and time of electric field and found that the permeability of composite membrane have an obvious change with the increase of time or strength, which the alignment may occur under the action of the electric field.