Synthesis of PVDF Membranes with Magnetic Nanoparticles for Applications in Desalination

  • Taofeeqah A. Agbaje

Student thesis: Master's Thesis

Abstract

In a world of dwindling water resources, it has become imperative to preserve water resources judiciously by water reuse, recycle and reduction. To produce fresh, drinkable water, desalination technologies have been explored. This thesis reports on the fabrication of blend membranes by incorporating magnetite nanoparticles (NP) in polyvinylidene fluoride (PVDF) for applications in membrane distillation, an emerging desalination technology, and in heavy metal removal from wastewater streams. The incorporation of nanoparticles rendered the membrane bulk hydrophilic while maintaining a hydrophobic top surface. These blend membranes were tested in a membrane distillation (MD) setup. Hansen solubility parameters (HSP) were first calculated to assess the affinity/compatibility of NP with the polymer, dope solution and aqueous feed. Extensive characterizations were done to elucidate the structural and physiochemical properties of the blend membranes. Energy dispersive spectrometry (EDS) analyses confirmed the uniform distribution of NP within the membrane matrix. Contact angle values showed that the NP did not compromise the hydrophobicity of the membrane top layer. The blend membrane had a 92% higher water uptake value, compared to the pristine sample, indicating the high hydrophilicity of the membrane bulk. Blend membrane also showed higher (ca. 136%) DCMD (direct contact membrane distillation) flux, due to their hydrophilic sub-layer, without compromising the salt rejection. Leaching tests were conducted using both water and concentrated acid to confirm the presence of nanoparticles and to demonstrate the membrane stability in aqueous medium.
Date of AwardDec 2017
Original languageAmerican English

Keywords

  • Nanoparticles
  • water preserveration
  • water reuse
  • water recycle
  • water reduction
  • desalination technologies
  • magnetite nanoparticles
  • polyvinylidene fluoride
  • membrane distillation applications
  • wastewater streams
  • blend membranes
  • Energy dispersive spectrometry
  • hydrophilicity.

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