University of Illinois Urbana-Champaign

Nanofiltration membranes modified with aromatic polyamide dendrimers active layers

Gao, Yuan

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https://hdl.handle.net/2142/24409

Description

Title
Nanofiltration membranes modified with aromatic polyamide dendrimers active layers
Author(s)
Gao, Yuan
Issue Date
2011-05-25T14:38:36Z
Director of Research (if dissertation) or Advisor (if thesis)
Moore, Jeffrey S.
Department of Study
Chemistry
Discipline
Chemistry
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Keyword(s)
  • Water purification
  • Thin film composite membrane
  • Nanofiltration
  • Aromatic polyamide dendrimers
  • Percolation
Abstract
This thesis describes the modification of the commercial TFC-S nanofiltration membrane with shape-persistent dendritic architectures. Amphiphilic aromatic polyamide dendrimers (G1-G3) are synthesized via a divergent approach and used for membrane modification by direct percolation. The permeate samples collected from the percolation experiments are analyzed by UV-Vis spectroscopy to instantly monitor the influence of dendrimer generations on percolation behaviors and new active layer formation. The membrane structures are further characterized by Rutherford backscattering spectrometry (RBS) and atomic force microscopy (AFM) techniques, suggesting a low-level accumulation of dendrimers inside the TFC-S NF membranes and subsequent formation of an additional aramide dendrimer active layer. Thus, all the modified TFC-S membranes have a double active layer structure. A PES-PVA film is used as a control membrane showing that structural compatibility between the dendrimer and supports plays an important role in the membrane modification process. The performance of modified TFC-S membrane is evaluated on the basis of rejection abilities of a variety of water contaminants having a range of sizes and chemistry. As the water flux is inversely proportional to the thickness of the active layer, we optimize the amount of dendrimers deposited for specific contaminants to improve the solute rejection while maintaining high water flux.
Graduation Semester
2011-05
Permalink
http://hdl.handle.net/2142/24409
Copyright and License Information
Copyright 2011 Yuan Gao

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