Preparation and characterization of disulfonated polysulfone films and polyamide thin film composite membranes for desalination

dc.contributor.advisorFreeman, B. D. (Benny D.)en
dc.contributor.committeeMemberPaul, Donald R.en
dc.contributor.committeeMemberSanchez, Isaac C.en
dc.contributor.committeeMemberBielawski, Christopher W.en
dc.contributor.committeeMemberMcGrath, James E.en
dc.creatorXie, Wei, 1982-en
dc.date.accessioned2012-01-30T22:21:59Zen
dc.date.accessioned2017-05-11T22:23:58Z
dc.date.available2012-01-30T22:21:59Zen
dc.date.available2017-05-11T22:23:58Z
dc.date.issued2011-12en
dc.date.submittedDecember 2011en
dc.date.updated2012-01-30T22:22:13Zen
dc.descriptiontexten
dc.description.abstractThe current reverse osmosis desalination membrane market is dominated by aromatic polyamide thin film composite (TFC) membranes. However, these polyamide membranes suffer from poor resistance to continual exposure to oxidizing agents such as chlorine in desalination applications. To overcome these problems, we have synthesized and characterized a new generation of materials, disulfonated poly(arylene ether sulfone) (BPS) random copolymer, for desalination membranes. A key technical feature of these new materials is their high tolerance to chlorine in feed water and their excellent reproducibility in synthesis. In this study, water and sodium chloride solubility, diffusivity and permeability in BPS copolymers were measured for both acid and salt form samples at sulfonation levels from 20 to 40 mol percent. The hydrophilicity of these materials, based on water uptake, increased significantly as sulfonation level increased. The water and salt diffusivity and permeability were correlated with water uptake, consistent with expectations from free volume theory. In addition, a tradeoff was observed between water/salt solubility, diffusivity, and permeability selectivity and water solubility, diffusivity and permeability, respectively. The influence of cation form and degree of sulfonation on free volume, as probed via positron annihilation lifetime spectroscopy (PALS), was determined in BPS random copolymers in both the dry and hydrated states. PALS-based free volume data for hydrated polymers were correlated with water and salt transport properties. The influence of processing history on transport properties of BPS films was also studied. Potassium form BPS films having a 32 mol% sulfonation level were acidified using solid state and solution routes. Additionally, several films were subjected to various thermal treatments in the solid state. The influence of acidification, thermal treatment, and counter-ion form on transport properties was investigated. Finally, the influence of synthesis methods of polyamide TFC membranes from m-phenylenediamine (MPD) and trimesoyl chloride (TMC) via interfacial polymerization on transport properties is reported. Then, a disulfonated diamine monomer (S-BAPS) was used instead of MPD to prepare TFC membranes. The resulting membranes exhibited reduced chlorine tolerance than those prepared from MPD. However, introduction of S-BAPS to the MPD/TMC polymerization system increased the fouling resistance of the resulting polyamide TFC membranes.en
dc.description.departmentChemical Engineeringen
dc.format.mimetypeapplication/pdfen
dc.identifier.slug2152/ETD-UT-2011-12-4520en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2011-12-4520en
dc.language.isoengen
dc.subjectDisulfonated polysulfoneen
dc.subjectPolyamideen
dc.subjectThin film composite membranesen
dc.subjectDesalinationen
dc.subjectReverse osmosisen
dc.subjectFree volumeen
dc.titlePreparation and characterization of disulfonated polysulfone films and polyamide thin film composite membranes for desalinationen
dc.type.genrethesisen

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