Abstract
Membranes are major components of many water-intensive
industrial processes. Fouling, one of membrane
technology's main challenges, decreases permeability and
increases the need for cleaning. Anti-fouling properties
of membranes can be enhanced for example by surface
treatment by chemical modification. Additionally, smart
cleaning behaviour can be achieved by incorporating
stimuli-responsive polymers onto filtration membrane
surfaces. When fouling occurs, membrane pores can be
temporarily and reversibly enlarged by an external
stimulus to aid cleaning.
In this study, polysaccharides were chemically modified
by adding allylic double bonds to their backbone.
Furthermore, these highly reactive double bonds were used
for crosslinking and grafting poly(N-isopropylacrylamide)
(PNIPAM) to integrate a temperature-responsive property.
Hydrogel and membrane samples were prepared. 13C NMR,
SEM, chromatographic bromine analysis, DSC, elementary
analysis and CR-filtration tests were used to
characterize prepared samples.
Results of this study demonstrated that cellulosic
materials were modified into cellulosic derivatives
containing moderate amounts of allyl double bonds. These
derivatives were capable of crosslinking and could be
grafted with PNIPAM with high grafting efficiencies. LCST
of PNIPAM altered slightly depending on the matrix
material. Commercial membranes and filter materials were
modified by applying these cellulosic derivatives. Stable
coatings that changed the surface morphologies were
formed, but a temperature-response was not observed
around the LCST of PNIPAM in permeability measurements.
Original language | English |
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Qualification | Master Degree |
Awarding Institution |
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Place of Publication | Espoo |
Publisher | |
Publication status | Published - 2013 |
MoE publication type | G2 Master's thesis, polytechnic Master's thesis |
Keywords
- stimuli-responsive poymers
- filtration membranes
- cellulose
- grafting
- surface functionalization
- PNIPAM