(573a) Manufacturing Functional Membranes from Nanostructured Polymers

Manufacturing
Functional Membranes from Nanostructured Polymers

William
A. Phillip

Department
of Chemical & Biomolecular Engineering

University
of Notre Dame

Abstract:

Responsible
management of the world’s water resources is essential to supporting human life
on earth and the growing global population will only increase the demand for
clean water resources. The success of seawater desalination by reverse osmosis
highlights the large role membrane separations will play in helping society
meet the demand for fresh water. In this talk, a next generation membrane
platform fabricated from self-assembled block polymer precursors that can be
modified post-assembly, in a facile and scalable manner, will be discussed.
Most state-of-the-art membranes utilize a size-selective, steric exclusion
mechanism to filter dissolved solutes from solution. In this regard,
self-assembled block polymers are a promising platform for producing
high-performance membranes because large areas of membrane that contain a high
density of well-defined nanoscale pores can be readily produced using the
self-assembly and non-solvent induced phase separation (SNIPS) technique.
Furthermore, the performance profile of the block polymer membranes can be
controlled through clever design of the macromolecular precursors. The
performance of these membranes is pushing the limits of size-selective
separation mechanisms, which is driving interest in chemically-selective
membranes that allow for efficient separations based on chemical factors. As
such, block polymer membranes with nanoscale pores lined by moieties that can
be easily reacted to other functionalities further demonstrate the promise of
this platform. In one example, the pore-lining groups are converted to coordinating
groups that act as high capacity binding sites for heavy metal ion adsorption.
In another example, chemically-patterned charge mosaic membranes, are prepared
by modifying the pore wall chemistry of the copolymer membrane precursors using
ink-jet printing devices. The well-defined counter-charged domains that cover
the surface of the resulting charge mosaic membranes allow dissolved salts to
permeate more rapidly than water—even though water is three times smaller in
size. Through these examples, we will demonstrate that membranes that are based
on self-assembled block polymer materials provide a scalable platform that can
be tailored to myriad separations for the purification and conservation of
fresh water resources.