Publications by authors named "Kyoung Won Jung"

3 Publications

  • Page 1 of 1

Effect of functional group ratio in PEBAX copolymer on propylene/propane separation for facilitated olefin transport membranes.

Sci Rep 2019 08 7;9(1):11454. Epub 2019 Aug 7.

Department of Chemistry, Sangmyung University, Seoul, 03016, Republic of Korea.

PEBAX-5513/AgBF/Al(NO) membranes were fabricated for mixed olefin/paraffin separation. In order to improve the selectivity of the membranes utilizing PEBAX-1657, PEBAX-5513, which increased the ratio of amide groups from 40% to 60% in the copolymer, was used. The selectivity and permeance of the membranes were 7.7 and 11.1 GPU, respectively. Furthermore, the PEBAX-5513/AgBF/Al(NO) membranes had long-term stability because of Al(NO) to have the stabilizing effect on Ag ions acting as an olefin carrier. Unexpectedly, the performance of the membrane selectivity was not improved, and the permeance became rather lower. Generally, when Ag ions was added to the polymer containing amide groups, the selectivity increased with the content of the amide groups. However, Al(NO) was added for the stability of Ag ionsĀ and there was no increase in selectivity. Since the ratio of amide was high, Ag ions were favorably in coordination with the oxygen of the carbonyl group, but the NO ions in Al(NO) had the enhanced interaction with Ag ions as obstacles for olefin complexation. Therefore, the composition ratio of amide/ether in the polymer matrix was negligibleĀ for olefin separation.
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http://dx.doi.org/10.1038/s41598-019-47996-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6686014PMC
August 2019

Preparation of Nanoporous Polymer Membranes Utilizing Water Pressure and Solvent Mixtures.

J Nanosci Nanotechnol 2018 10;18(10):7151-7154

For the nanopore generation in cellulose acetate (CA), specific solvents consisting of water and acetone was utilized with water-pressure. Co-solvent ratio was changed w/w 8/2 to w/w 9/1 (Acetone/H2O) in 10% cellulose acetate solution. When the water pressure was vertically applied to CA free standing film with co-solvent, the water flux was observed, meaning the pore generation in polymer. The water flux of these CA polymer films was investigated depending on pressures. The polymers obtained from the 9:1 acetone/H2O mixture showed an improved water flux at 8 bar, which was attributable to the relative decrease in the water content with respect to acetone. The chemical and physical properties of the membranes were studied using SEM, FT-IR, porosimetry, and TGA experiments.
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http://dx.doi.org/10.1166/jnn.2018.15506DOI Listing
October 2018

[A case of superior mesenteric venous thrombosis due to protein C deficiency in a patient with duodenal ulcer bleeding].

Korean J Gastroenterol 2011 Jan;57(1):34-7

Department of Internal Medicine, Masan Samsung Hospital, Sungkyunkwan University School of Medicine, Masan, Korea.

Mesenteric venous thrombosis is a clinically very rare disease, and may cause bowel infarction and gangrene. Difficulty in the diagnosis the disease due to its non-specific symptoms and low prevalence can cause a clinically fatal situation. Mesenteric venous thrombosis may be caused by both congenital and acquired factors, and protein C deficiency, which is a very rare genetic disorder, is one of many causes of mesenteric thrombosis. The authors experienced a case of mesenteric venous thrombosis caused by protein C deficiency in a patient with duodenal ulcer bleeding, so here we report a case together with literature review.
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http://dx.doi.org/10.4166/kjg.2011.57.1.34DOI Listing
January 2011