Synthesis, Characterization and Application of Poly (Styrene-4- Vinyl Pyridine) Membranes Assembled With Single-Wall Carbon Nanotubes

  • Haoze He

Student thesis: Master's Thesis

Abstract

Poly(styrene-4-vinylpyridine) (PS-P4VP) isoporous membranes were prepared and their properties were evaluated in this research. The solution was prepared by dissolving PS-P4VP polymer with necessary additives into a 1:1:1 1,4-dioxane – N,N-dimethyl formamide – tetrahydrofuran (DOX-DMF-THF, DDT) solvent. Then 0.5-1.0 mL of the primary solution was cast onto the non-woven substrate membrane on a glass slide, evaporated for 15-20 sec and immersed into de-ionized water for more than 30 min for the solidification of isoporous structure and for the formation of the primary films, which could be post-processed in different ways for different tests. The membrane surface presents a well-ordered, hexagonal self-assembly structure, which is fit for aqueous and gaseous filtration. The pore size of the isoporous surface is 30~40 nm. The pore size is also sensitive to [H+] in the solution and a typical pair of S-shape pH-correlation curves with significant hysteresis was found. Four techniques were tried to improve the properties of the membranes in this research: 1) 1,4-diiodobutane was introduced to chemically change the structure as a cross-linking agent. 2) single-wall carbon nanotube (SWCNT) was linked to the membranes in order to strengthen the stability and rigidity and to reduce the hysteresis. 3) Homo-poly(4-vinylpyridine) (homo-P4VP) was added and inserted into the PS-P4VP micelles to affect the pore size and surface structure. 4) Copper acetate (Cu(Ac)2) was used as substitute of dioxane to prepare the Cu(Ac)2-DMF-THF (CDT) mixed solvent, for a better SWCNT dispersion. All the possible improvements were judged by the atomic force microscopy (AFM) images, water and gas flux tests and pH-correlation curves. The introduction of SWCNT was the most important innovation in this research and is promising in future applications.
Date of AwardJun 2011
Original languageEnglish (US)
Awarding Institution
  • Physical Science and Engineering
SupervisorKlaus-Victor Peinemann (Supervisor)

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