טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentInbal Ozeri
SubjectPolysulfone Based Membranes for Filteration Applications
DepartmentDepartment of Chemistry
Supervisor Full Professor Eisen Moris
Full Thesis textFull thesis text - English Version


Abstract

Polysulfone (PSu) was modified by carboxylation, sulfonation and bromination. Asymmetric membranes were prepared from modified PSu by phase inversion method. Effects like substitution degree, thickness, site of modification on the polymer backbone, membrane surface modification, cross linking on the membrane surface and different solvents, on the membranes performance were investigated. Polymers were characterized by 1H NMR, 13C NMR, infrared spectroscopy (IR) and differential scanning calometry (DSC). The rejection properties of the membranes were estimated by measuring the solute rejection for various sizes of polyethylene glycol molecules in the range of 10,000 to 600,000 Dalton by total organic carbon (TOC) analysis. Carboxylation with DS of 2, only on the ortho ether site of PSu via lithiation was successfully established. Sulfonation levels from 30 to 70 % were achieved by varying the content of the sulfonating agent. Results showed that substitution with carboxylic acid groups, at different sites on the polymer backbone, had no effect on the performance of the resulting membranes.  In both carboxylated and sulfonated PSu membranes, increase in degree of substitution, increased the water flux through the membrane. Membranes made from carboxylated PSu Showed higher flux performance than pristine PSu membrane. Membranes made from sulfonated PSu showed higher flux and PEG rejection compared to unmodified PSu membranes. This overall higher performance of the modified PSu membranes is believed to be a result of increased hydrophilicity compared to unmodified PSu membranes.