Isoporous membranes are attractive for the regulation and detection of transport at the
molecular level. A well-defined asymmetric membranes from diblock copolymers with an
ordered nanoporous membrane morphologies were fabricated by the combination of block
copolymer self-assembly and non-solvent-induced phase separation (NIPS) technique.
This is a straightforward and fast one step procedure to develop integrally anisotropic
(“asymmetric”) membranes having isoporous top selective layer. Membranes prepared via
this method exhibit an anisotropic cross section with a thin separation layer supported from
underneath a macroporous support. These membrane poses cylindrical pore structure with
ordered nanopores across the entire membrane surfaces with pore size in the range from 20
to 40 nm. Tuning the pore morphology of the block copolymer membranes before and after
fabrication are of great interest.
In this thesis, we first investigated the pore morphology tuning of asymmetric block
copolymer membrane by complexing with small organic molecules. We found that the
occurrence of hydrogen-bond formation between PS-b-P4VP block copolymer and –OH/
–COOH functionalized organic molecules significantly tunes the pore morphology of
asymmetric nanoporous membranes. In addition, we studied the complexation behavior of
ionic liquids with PS-b-P4VP block copolymer in solutions and investigated their effect on
final membrane morphology during the non-solvent induced phase separation process. We
found that non-protic ionic liquids facilitate the formation of hexagonal nanoporous block
copolymer structure, while protic ionic liquids led to a lamella-structured membrane.
Secondly, we demonstrated the catalytic activity of the gold nanoparticle-enhanced hollow
fiber membranes by the reduction of nitrophenol. Also, we systematically investigated the
pore morphology of isoporous PS-b-P4VP using 3D imaging technique.
Thirdly, we developed well-distributed silver nanoparticles on the surface and pore walls
of PS-b-P4VP block copolymer membranes and then investigated the biocidal activity of
the silver nanoparticles grown membranes.
Finally, a novel photoresponsive nanostructured triblock copolymer membranes were
developed by phase inversion technique. In addition, the photoresponsive behavior on
irradiation with light and their membrane flux and retention properties were studied.
|Date of Award||Jun 2016|
|Original language||English (US)|
- Biological, Environmental Science and Engineering
|Supervisor||Suzana Nunes (Supervisor)|
- Block Copolymer
- Ionic liquids
- Fluorescent Membranes
- Metal Complexation
- antibacterial activity