Publications by authors named "Jeong Pil Kim"

3 Publications

  • Page 1 of 1

Ultrafast H-selective nanoporous multilayer graphene membrane prepared by confined thermal annealing.

Chem Commun (Camb) 2021 Sep 9;57(70):8730-8733. Epub 2021 Aug 9.

Department of Chemical and Biomolecular Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 120-749, Republic of Korea.

H selective dense pores are generated in a graphene oxide (GO) layer by thermal-decomposition of oxygen-functional groups under high pressure. The nanoporous GO membrane shows H/CO selectivity of 12.1 and H permeability of 10360 Barrer.
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http://dx.doi.org/10.1039/d1cc02946kDOI Listing
September 2021

Graphene Oxide Nanoribbon Hydrogel: Viscoelastic Behavior and Use as a Molecular Separation Membrane.

ACS Nano 2020 09 9;14(9):12195-12202. Epub 2020 Sep 9.

Department of Chemical and Biomolecular Engineering, YONSEI University, Yonsei-ro 50, Seodaemun-gu, Seoul, (03722), Republic of Korea.

The preparation of carbon materials based hydrogels and their viscoelastic properties are essential for their broad application and scale-up. However, existing studies are mainly focused on graphene derivatives and carbon nanotubes, and the behavior of graphene nanoribbon (GNR), a narrow strip of graphene, remains elusive. Herein, we demonstrate the concentration-driven gelation of oxidized GNR (graphene oxide nanoribbon, GONR) in aqueous solvents. Exfoliated individual GONRs sequentially assemble into strings (∼1 mg/mL), nanoplates (∼20 mg/mL), and a macroporous scaffold (50 mg/mL) with increasing concentration. The GONR hydrogels exhibit viscoelastic shear-thinning behavior and can be shear-coated to form large-area GONR films on substrates. The entangled and stacked structure of the GONR film contributed to outstanding nanofiltration performance under high pressure, cross-flow, and long-term filtration, while the precise molecular separation with 100% rejection rate was maintained for sub-nanometer molecules.
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http://dx.doi.org/10.1021/acsnano.0c05902DOI Listing
September 2020

Transparent Bendable Secondary Zinc-Air Batteries by Controlled Void Ionic Separators.

Sci Rep 2019 Feb 28;9(1):3175. Epub 2019 Feb 28.

Department of Chemical and Biomolecular Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul, 120-749, South Korea.

First ever transparent bendable secondary zinc-air batteries were fabricated. Transparent stainless-steel mesh was utilized as the current collector for the electrodes due to its reliable mechanical stability and electrical conductivity. After which separate methods were used to apply the active redox species. For the preparation of the anode, zinc was loaded by an electroplating process to the mesh. For the cathode, catalyst ink solution was spray coated with an airbrush for desired dimensions. An alkaline gel electrolyte layer was used for the electrolyte. Microscale domain control of the materials becomes a crucial factor for fabricating transparent batteries. As for the presented cell, anionic exchange polymer layer has been uniquely incorporated on to the cathode mesh as the separator which becomes a key procedure in the fabrication process for obtaining the desired optical properties of the battery. The ionic resin is applied in a fashion where controlled voids exist between the openings of the grid which facilitates light passage while guaranteeing electrical insulation between the electrodes. Further analysis correlates the electrode dimensions to the transparency of the system. Recorded average light transmittance is 48.8% in the visible light region and exhibited a maximum power density of 9.77 mW/cm. The produced battery shows both transparent and flexible properties while maintaining a stable discharge/charge operation.
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http://dx.doi.org/10.1038/s41598-019-38552-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6395654PMC
February 2019
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