Browsing by Author "Hwang, Taek Sung"

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An efficient and facile method of grafting Allyl groups to chemically resistant polyketone membranes
(ELSEVIER SCI LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND, 2018) Jung, Youn Seo; Canlier, Ali; Hwang, Taek Sung; 0000-0002-5462-6039; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
Polyketone is a thermoplastic polymer known for its strong mechanical properties and chemical resistance. Such superiorities make it difficult to process and chemically modify for further functionalizations and applications. In this work, we introduce a novel method for functionalizing the alpha carbon of polyketone. We succeeded to attach allyl groups to the backbone of polyketone by a heterogeneous reaction between polyketone enolate and allyl bromide. Allylated polyketone is not soluble in common solvents. Since we started with a membrane of polyketone, there is no need to cast again. Further functionalization is possible through pending allyl groups via alkene addition reactions and ionic or radicalic polymerization. FTIR, elemental analysis, solid NMR, FT-Raman, SEM and XPS methods were employed to confirm the elemental composition, molecular structure and morphology. In addition, X-ray diffractometer (XRD), UVeVisible spectroscopy and thermal analysis were used to investigate the crystal structure, physical and electronic properties. (c) 2018 Elsevier Ltd. All rights reserved.
Synthesis of polyketone-g-sodium styrene sulfonate cation exchange membrane via irradiation and its desalination properties
(POLYMER SOC KOREAROOM 601, HATCHON BUILDING, 831 YEOKSAM-DONG, KANGNAM-KU, SEOUL 135-792, SOUTH KOREA, 2017) Kim, In Sik; Hwang, Chi Won; Kim, Young Joong; Canlier, Ali; Jeong, Kyung Seok; Hwang, Taek Sung; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
Using the radiation grafting technique, polyketone membranes were graft copolymerized with sodium styrene sulfonate (SSS) in the presence of additives such as Mohr's salt and H2SO4. Fourier-transform infrared (FT-IR) spectroscopy was used to characterize the grafted membranes. Water uptake (WU), ion exchange capacity (IEC) and electrical resistance (ER) of the prepared membranes were measured in order to evaluate their physical properties The prepared membranes were applied to the membrane capacitive deionization (MCDI) process, in which their salt removal rates were evaluated and compared to those of CDI (capacitive deionization) process. The degree of grafting rose from 14.4% to 81.4% as the irradiation dose and the monomer concentration were increased. The water uptake ranged from 7.9% to 34.2%. The ionexchange capacity was observed between 0.43 meq/g and 1.1 meq/g, and the electrical resistance had values ranging from 12.2 Omega center dot cm(2) to 2.1 Omega center dot cm(2). The electrical resistance decreased as the ion-exchange capacity was extended. When the prepared cation exchange membrane was used in the MCDI process, the salt removal rate reached 87.6%, which was much higher than 28.8% of CDI process.
Synthesis of polyketone-g-vinylbenzyl chloride anion exchange membrane via irradiation and its properties
(POLYMER SOC KOREAROOM 601, HATCHON BUILDING, 831 YEOKSAM-DONG, KANGNAM-KU, SEOUL 135-792, SOUTH KOREA, 2017) Kim, Young Joong; Hwang, Chi Won; Hyeon, Seung Mi; Canlier, Ali; Hwang, Taek Sung; 0000-0002-5462-6039; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
A novel anion exchange membrane composed of aminated polyketone-g-vinylbenzyl chloride was synthesized via Co-60 gamma-ray irradiation grafting technique. Total irradiation dose and concentration of monomers were set as variables to determine degree of grafting. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy equipped with energy dispersive X-ray spectrometer (SEM-EDS) were used to characterize the grafted membranes. Water uptake (WU) and swelling ratio (SR) were measured with a gravimetric method. A titration method was used to detect ion exchange capacity (IEC), whereas electrical resistance (ER) and ion conductivity (IC) were measured with a LCR meter. Our method has boosted the degree of grafting up to 97.6% from 3.7% as total irradiation dose and monomer concentration have been increased. WU and SR were in the ranges 1.5%-35.6% and 0.35%-20.9%, respectively. Also, IEC has taken values ranging between 0.2 and 1.19 meq/g. IC has varied within the range 0.01-0.3 S cm(-1), and it has shown a rising trend as IEC increased. In this study, the optimum synthesis conditions have been 70 kGy of total irradiation dose and 50wt% of monomers. The membrane synthesized here is potentially superior to Nafion membrane in terms of several properties.