Nanoporous materials from ABAC tetrablock terpolymers
2013-07
Loading...
View/Download File
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
Nanoporous materials from ABAC tetrablock terpolymers
Authors
Published Date
2013-07
Publisher
Type
Thesis or Dissertation
Abstract
This dissertation describes efforts towards the preparation of tough nanoporous membranes from ABAC tetrablock terpolymers. This architecture was strategically chosen to combine an etchable C block, PLA, with a mechanically tough ABA triblock into one ABAC terpolymer. Multiple series of poly(styrene-b-isoprene-bstyrene-lactide) (PS-PI-PS-PLA) tetrablock terpolymers were synthesized. Morphological behavior was characterized for terpolymers containing both a 50:50 and 30:70 PS:PI ratio with between 0 and ~20% PLA by volume. Observed bulk morphologies include hexagonally packed cylinders (HEX), core(PLA)-shell(PS) cylinders (CSC), and a PLA sphere in cylinder morphology. Mechanical properties of PS-PEEP-PS-PLA tetrablocks were also investigated. All materials exhibited mechanical properties characteristic of tough thermoplastic elastomers. Composite membranes were prepared from a thin film of PS-PI-PS-PLA terpolymer and a macroporous polyethersulfone support. Described within are the efforts related to the fabrication and filtration performance of these nanoporous PSPI-PS composite membranes. As part of this process, solvent casting and annealing conditions were varied to investigate effects on tetrablock thin film morphology. Optimum conditions were determined to achieve PS-PI-PS-PLA films with perpendicular PLA cylinder orientation. These conditions included use of a mixed solvent system and the addition of a small amount of homopolymer PLA. Highly ordered films with vertically oriented nanopores were obtained.
Keywords
Description
University of Minnesota Ph.D. dissertation. July 2013. Major: Chemistry. Advisor: Marc A. Hillmyer. 1 computer file (PDF); xiii, 216 pages, appendix A.
Related to
Replaces
License
Collections
Series/Report Number
Funding information
Isbn identifier
Doi identifier
Previously Published Citation
Suggested citation
Jackson, Elizabeth. (2013). Nanoporous materials from ABAC tetrablock terpolymers. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/158430.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.