Thesis Defense by Chris Buelke on July 20th
Space Studies master’s student, Chris Buelke, will defend his thesis as follows. All Space Studies students, faculty and staff are encouraged to attend.
When: Thursday, July 20th at 3:00 p.m. (Central Daylight Savings Time)
Where: Ryan Hall, Room 111
Title: Enhancing Water Purification via Graphene Oxide, Holey Graphene Oxide, and Lignin Membrane Architectures
About the research: Freshwater available for human consumption has declined in recent years due to many factors. Additionally, NASA has made it known that missions into deep space will require advances in water purification systems. Graphene oxide (GO) membranes have been demonstrated to be an effective purifier of water due to their unique architecture. Holey-graphene oxide (hGO), developed at NASA Langley Research Center, is similar to GO but hosts a more porous structure. Lignin-based membranes were also analyzed. This thesis investigates the membrane performances of these three membrane architectures to purify water. The membranes were prepared in varying thicknesses via vacuum filtration. Experiments were done in two phases. Phase I used a forward osmosis setup to examine membranes’ ion rejection. Phase II used dead-end filtration and examined ion rejection, organic molecule rejection and water flux. GO showed a significant increase in ion rejection for NaCl, but showed decreased water flux over hGO, whose porous structure was thought to increase water flux. hGO showed a significant increase in ion rejection for MgCl2. Poor overall performance for ion rejection for both membranes is attributable to an increase in the intersheet distance inside the membranes due to hydration.
About the presenter: Chris Buelke is an on-campus graduate student in the Space Studies department. He hails from Wisconsin where he obtained his B.S. in Applied Science – Nanoscience from UW-Stout. Summer 2013 saw him at the NASA Glenn Research Center in Cleveland, OH where he worked with ceramic matrix composites for the aerospace industry. He also partook in an internship at NASA Langley Research Center in Hampton, VA where he worked purifying water with graphene-based membranes. That internship culminated into the thesis being defended at present. Upon successful completion of his degree, Chris will be applying to Ph.D. programs as well as job opportunities while continuing his research in Harrington Hall.
******Those unable to attend in person may view the live webcast******
1) A live webcast which includes PowerPoint slides will be available here.
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