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특별초청 세미나

미래를 창조하는 포스텍 화학공학과

Designed Polymers for Water Purification and Clean Energy Generation

일자
2019.08.09(금) 4:00PM
시간
4:00~5:15pm
연사
Dr. Yoonseob Kim
장소
환경공학동 111호
소속
Massachusetts Institute of Technology (MIT), USA

[Abstract]

During the past few decades, the field of polymer chemistry has developed dramatically, allowing for the synthesis of well-defined macromolecules with controlled composition, chain ends, chain lengths, molecular-weight distribution and topology.  With various modern synthetic strategies, polymers with precisely controlled molecular structures can be synthesized. Here we show how rationally designed polymeric systems can tackle engineering problems such as water purification and fuel cell applications.

Heavy metal ions, especially mercury (Hg) in water, are highly toxic, so become a threat to public health and environment.  Here we demonstrate the use of redox active polyaniline to achieve electrochemically controlled reversible capture and release of Hg(II) in water.  Polyaniline naturally adsorbs Hg(II), and subsequent dose of oxidation potential induces the release.  Nanofiber geometry of polyaniline offered faster adsorption kinetics.  Additional sulfur chelating groups enhanced uptake capacity.

Anion exchange membrane fuel cells are a clean and efficient promising future energy source. However, the development of stable high-performance membranes remains a major challenge. Herein we demonstrate that the addition of unfunctionalized - free-volume promoting - triptycene copolymer into 1-methylimidazolium poly(ether sulfone) enhances membrane’s conductivity, minimizes dimensional changes, and enhances stability.  These enhancements appear to be the result of nanophase separation and internal free volume. Small angle X-ray scattering and transmission electron microscopy reveal that the internal domain size increases (up to 7.44 nm) with increasing triptycene fraction.

Designed polymeric systems will further contribute to the development of new engineering tools that tackle problems of our society.