Tuesday, March 13, 2018
4:00 – 5:00 p.m.
Auditorium between Bldg. 4 & 5, level 0, room 0215
Jaehong Kim is currently Professor and Department Chair of Chemical and Environmental Engineering in School of Engineering and Applied Science at Yale University. His areas of interest include: 1) environmental application of nanomaterials; 2) development of photoluminescence / photocatalysis technology for environmental and energy application; and 3) membrane process and materials development. Kim received B.S. and M.S. degrees in chemical and biological engineering from Seoul National University in Korea in 1995 and 1997, respectively, and a Ph.D. degree in environmental engineering from the University of Illinois at Urbana-Champaign in 2002. After graduation, he joined the School of Civil and Environmental Engineering at Georgia Institute of Technology where he later held the title of Georgia Power Distinguished Professor and Associate Chair for Undergraduate Programs. He then moved to Yale University in 2013 as Barton L. Weller Endowed Professor. He has taught undergraduate courses such as Water Quality Engineering, Environmental Technology in the Developing World, and Environmental Engineering Laboratory, and graduate courses such as Physicochemical Processes and Design of Drinking Water Treatment Facilities. He is a recipient of various awards including Ackerman Award for Teaching and Mentoring from Yale University (2017), Bill Shultz Junior Faculty Teaching Award from School of Civil and Environmental Engineering (2013), Walter L. Huber Civil Engineering Research Prize from American Society of Civil Engineers (2013), Top Environmental Technology Paper Award from American Chemical Society (2012), Paul L. Busch Award from Water Environment Research Foundation (2009), Excellence in Research Award from Georgia Institute of Technology (2009), and CETL/BP Junior Faculty Teaching Excellence Award from Georgia Institute of Technology (2007).
Title: Toward Self-Healing Membranes: From Concept to Proof
Abstract:
Membranes are now considered an established technology for water treatment. However, membranes’ competitive advantage as a near-absolute rejection barrier holds only when their integrity is preserved throughout their lifetime. Even though the loss of membrane integrity is widely reported, neither existing integrity monitoring techniques nor costly maintenance and replacement practices effectively address this issue. We envision a membrane that self-heals and is therefore more versatile and sustainable. We imagine such a membrane would truly transform the use of membranes for safe potable water production not only in large-scale systems but also in decentralized facilities where proper infrastructure lacks. Recognizing significant advances made towards self-healing materials in structural, coating, and biomedical materials science, we aim to develop a next-generation water treatment membrane that can restore its original water permeation and particle/solute rejection properties when damaged. This talk presents the first instance of a self-healing water treatment membrane that restores its water flux and particle rejection properties autonomously. The first class of self-healing membrane was fabricated by embedding microcapsules with a polyurethane shell and an isophorone diisocyanate core within a conventional polyethersulfone membrane. A dual surfactant system and polydopamine coating were used to control the size of these microcapsules and avoid capsule buckling. When the membrane structure is physically damaged, the microcapsules release a reactive isocyanate healing agent that reacts with the surrounding water to form a polyurea matrix that plugs the damage. The second class of self-healing membrane, a hydrogel pore-filled self-healing membrane, was fabricated through in-situ graft polymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid, a hydrogel with known self-healing property, onto microporous polyethersulfone substrate.