Exploration of Poly(ionic liquid) Having Lower Critical Solution Temperature as Draw Solutes in Forward Osmosis Processes

주창하,김태형,박찬혁,강효 한국고분자학회 2018 한국고분자학회 학술대회 연구논문 초록집 Vol.43 No.2

Thermo-responsive Homopolymer having Upper Critical Solution Temperature Property as Draw Solute for Forward Osmosis

주창하,김태형,박찬혁,강효 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

We synthesized the zwitterionic homopolymer polysulfobetaine (PBET), which has upper critical solution temperature property, via free radical polymerization in order to examine its suitability as a draw solute for the FO process. The UCST property of the monomer BET were not confirmed, while the UCST of the polymer PBET was observed to be about 41 °C. This result suggests that PBET can be easily recovered from aqueous solutions by cooling them to below the UCST. In an active layer facing feed solution (AL-FS) system containing 20 wt% PBET at a temperature of 50 °C, the water flux and reverse salt flux of PBET were observed to be about 3.22 LMH and 0.36 gMH, respectively. We investigated the suitability of homopolymer having UCST property as draw solute for the FO process for the first time. This study can provide for deep understanding of new method of proceeding draw solute and inspiration for the potential design and synthesis of thermo-responsive organic materials.

A New Strategy for Vertical Alignment of Liquid Crystal on Eugenol Substituted Polystyrene Films

주창하,김태형,박찬혁,강효 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

We synthesized a series of plant-based and renewable eugenol substituted polystyrene (PEUG#) (# = 20, 40, 60, 80, and 100, where # is the substitution ratio of eugenol moiety in the polymer). Eugenol is an oil extracted from cloves. We used polymer modification reactions to investigate LC alignment behavior of polymer films. We found that polymers with higher substitution ratios of eugenol side groups have general trend to exhibit vertical LC alignment. LC cells made from polymer films with a higher molar content of eugenol side groups exhibited vertical LC alignment behavior. Vertical alignment behavior was correlated with polar surface energy value of polymer films. The vertical alignment could be formed when the low polar surface energy value of the polymer generated by the nonpolar carbon group. Electro-optical performances (VHR, R-DC, and thermal alignment stabilities) were good enough to be observed for LC cells using PEUG100 polymer as an eco-friendly LC alignment material.

2P-110 Zwitterionic polymers showing upper critical solution temperature behavior as draw solutes for forward osmosis

주창하,김태형,강효 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

We synthesized the zwitterionic homopolymer polysulfobetaine (PBET), which shows upper critical solution temperature characteristics, via free radical polymerization in order to investigate its suitability as a draw solute for the forward osmosis (FO) process. The UCST characteristics of the monomer (BET) were not confirmed, while the UCST of PBET was confirmed to be roughly 41°C. This result suggests that PBET can be easily recovered from aqueous solutions by cooling them to below the UCST. In a pressure retarded osmosis system containing 20 wt% PBET at 50°C, the water flux and reverse solute flux of PBET were found to be roughly 3.22 LMH and 0.36 gMH, respectively. Thus, we investigated the suitability of homopolymers having UCST characteristics as draw solutes for the FO process for the first time. This research provides a deep understanding of new ways of developing draw solutes, and could provide inspiration for the design and synthesis of thermo-responsive organic materials.

정삼투 공정을 위한 하한임계용액온도 특성을 가지는 polystyrene-based quaternaryammonium hexanesulfonate 구조의 유도용질

주창하,김태형,박찬혁,강효 한국막학회 2018 한국막학회 총회 및 학술발표회 Vol.2018 No.05

We synthesized the poly(4-vinylbenzyltributylammonium hexanesulfonate) P[VBTBA][HS] which was obtained via anion exchange with hexanesulfonate after acquiring monomer [VBTBA][Cl] by Menshutkin reaction to investigate its feasibility as draw solute for forward osmosis process. P[VBTBA][HS] shows lower critical solution temperature (LCST) property at about 21℃, while LCST property of [VBTBA][Cl] and P[VBTBA][Cl] was not confirmed. This result suggests that P[VBTBA][HS] can be recovered from solution by heating them to above LCST. In AL-FS mode with solution of 20 wt% P[VBTBA][HS] at 15℃, water flux and reverse solute flux were found to be about 6.43 LMH and 0.59 gMH. This study can provide an understanding of new way of proceeding draw solute and information for the potential design and synthesis of thermo-responsive organic material.

UCST 특성을 가지는 sulfobetaine 구조의 유도용질

주창하,김태형,강효 한국막학회 2017 한국막학회 총회 및 학술발표회 Vol.2017 No.11

We synthesized the zwitterionic homopolymer polysulfobetaine (PBET), which shows upper critical solution temperature property, in order to investigate its feasibility as a draw solute for the forward osmosis (FO) process. The UCST property of the monomer sulfobetaine (BET) was not confirmed, while the UCST property of PBET was confirmed to be roughly 41°C. This result suggests that PBET can be recovered from aqueous solutions by cooling them to below the UCST. In an active layer facing feed solution (AL-FS) method containing 20 wt% PBET at 50°C, the water flux and reverse solute flux of PBET were found to be roughly 3.22 LMH and 0.36 gMH, respectively. This research provides a deep understanding of new ways of developing draw solutes, and could provide inspiration for the design and synthesis of thermo-responsive organic materials.

Enhanced, Parallel Liquid Crystal Alignment Based on Polystyrene Substituted with Phthalimidoyl Group

김태형,주창하,강효 한국고분자학회 2018 한국고분자학회 학술대회 연구논문 초록집 Vol.43 No.2

Polymers with Diphosphonium Structure Showing Lower Critical Solution Temperature Behavior as Draw Solute for Forward Osmosis Process

박찬혁,주창하,김태형,강신우,강효 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

We synthesized thermo-responsive polymers, a series of poly(alkane-1, #-diylbis(tributylphosphonium) 4-vinylbenzenesulfonate) (PSSBP#, # = 8, 6, and 4), where # is number of carbons in centered bridge of diphosphonium moiety, to confirm potential application as draw solute in forward osmosis (FO) process. These polymers show lower critical solution temperature (LCST) property in aqueous solution, which is an essential factor for recovering draw solute from pure water. The LCST of aqueous solutions of PSSBP8, PSSBP6, and PSSBP4 were confirmed approximately 30, 38, 26 °C at 20 wt% concentration, respectively. When concentration of PSSBP8 draw solution was 20 wt%, water flux and reverse solute flux were determined to be 1.84 LMH, and 1.12 gMH approximately in pressure retarded osmosis (PRO) mode. PSSBP# can be a next-generation draw solute due to effective recovery. Therefore, this study can give inspiration for novel ideas in development of draw solute and availability as draw solute.

Phytochemical-based Tannic Acid Derivatives as Draw Solutes for Forward Osmosis Process

김태형,주창하,강효,Kim, Taehyung,Ju, Changha,Kang, Hyo The Membrane Society of Korea 2018 멤브레인 Vol.28 No.3

우리는 정삼투 공정의 유도용질로서 잠재적인 활용 가능성을 확인하기 위해 식물화학물질인 tannic acid (TA)에 알칼리 염 처리한 alkali tannate 염 중 하나인 potassium tannate (TA-K)를 평가하였다. TA-K의 정삼투 특성과 회수 특성은 체계적으로 조사되었다. 정삼투 공정을 active layer facing feed solution (AL-FS) 방식으로 적용했을 때, TA-K 유도용액의 투수량은 TA 유도용액의 투수량 보다 훨씬 많은 반면, TA 유도용액의 투수량이 거의 확인되지 않았다. 100 mM 저농도에서의 TA-K 유도용액의 삼투압(1,135 mOsmol/kg)은 NaCl 수용액의 삼투압(173 mOsmol/kg)의 약 6.5배로 확인되었다. 100 mM 농도의 TA-K의 투수량과 specific salt flux (6.14 LMH, 1.26 g/L)는 동일한 농도의 NaCl 유도용액의 투수량과 specific salt flux (2.46 LMH, 2.63 g/L)의 약 2.5배 및 0.5배로 각각 확인되었다. TA-K를 재사용하기 위해, 금속 이온 침전법을 이용하여 TA-K유도용질을 침전시킨 후, membrane filtration을 이용하여 유도용질을 회수하였다. 이 연구는 식물화학물질을 정삼투 공정의 유도용질로서의 적용 가능성을 보여준다. Potassium tannate (TA-K), which is prepared by base treatment of the bio-renewable tannic acid (TA), was evaluated for its potential application as a draw solute for water purification by forward osmosis. The forward osmosis and recovery properties of TA-K were systematically investigated. In the application of forward osmosis through the active layer facing feed solution (AL-FS) method, the water flux of TA-K draw solution was significantly higher than that of the TA draw solution, while that of the latter was not identified. At a low concentration of 100 mM, the osmotic pressure (1,135 mOsmol/kg) of the TA-K draw solution was approximately 6.5 times that (173 mOsmol/kg) of the NaCl draw solution. Furthermore, the water flux and specific salt flux (6.14 LMH, 1.26 g/L) of the TA-K draw solution at 100 mM were approximately 2.5 and 0.5 times those of the NaCl draw solution (2.46 LMH, 2.63 g/L) at the same concentration, respectively. For reuse, TA-K was precipitated by using a metal ion and recovered through membrane filtration. This study demonstrates the applicability of a phytochemical material as a draw solute for forward osmosis.

Vertical Liquid Crystal Alignment on Green Oryzanol-Substituted Polystyrene Films

김태형,주창하,박찬혁,강효 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Applying plant-extractive oryzanol, we synthesized a phytochemicalbased oryzanol-modified polystyrene (PORZ#, # = 20, 40, 60, 80, and 100, where # signify the molar ratio of the oryzanol moiety) series using polymer modification reactions to investigate their liquid crystal (LC) alignment behaviors. In general, an LC cell made of polymer films with a higher mole ratio of oryzanol side chain displayed vertical LC alignment behavior. The vertical alignment behavior had a relation with surface energy of these polymer films. For example, the vertical alignment was observed when the polymer's surface energy, which is affected by nonpolar and long carbon groups, was less than about 40.42 mJ/㎡. Good electro-optical properties, e.g. aligning stabilities at 250 ℃ and ultraviolet (UV) irradiation of 20 J/㎠, the voltage holding ratio, and the residual DC voltage (R-DC), were observed for the LC cells fabricated with PORZ100 as a green LC alignment layer.