Toward Advanced Ionic Liquids. Polar, Enzyme-friendly Solvents for Biocatalysis

Gorke, Johnathan,Srienc, Friedrich,Kazlauskas, Romas 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.1

Ionic liquids, also called molten salts, are mixtures of cations and anions that melt below $100^{\circ}C$. Typical ionic liquids are dialkylimidazolium cations with weakly coordinating anions such as ($MeOSO_3$) or ($PF_6$). Advanced ionic liquids such as choline citrate have biodegradable, less expensive, and less toxic anions and cations. Deep eutectic solvents are also included in the advanced ionic liquids. Deep eutectic solvents are mixtures of salts such as choline chloride and uncharged hydrogen bond donors such as urea, oxalic acid, or glycerol. For example, a mixture of choline chloride and urea in 1:2 molar ratio liquefies to form a deep eutectic solvent. Their properties are similar to those of ionic liquids. Water-miscible ionic liquids as cosolvents with water enhance the solubility of substrates or products. Although traditional water-miscible organic solvents also enhance solubility, they often inactivate enzymes, while ionic liquids do not. The enhanced solubility of substrates can increase the rate of reaction and often increases the regioor enantioselectivity. Ionic liquids can also be solvents for non-aqueous reactions. In these cases, they are especially suited to dissolve polar substrates. Polar organic solvent alternatives inactivate enzymes, but ionic liquids do not even when they have similar polarities. Besides their solubility properties, ionic liquids and deep eutectic solvents may be greener than organic solvents because ionic liquids are nonvolatile, and can be made from nontoxic components. This review covers selected examples of enzyme catalyzed reaction in ionic liquids that demonstrate their advantages and unique properties, and point out opportunities for new applications. Most examples involve hydrolases, but oxidoreductases and even whole cell reactions have been reported in ionic liquids.

피페리딘계 이온성 액체와 포스페이트 염으로 구성된 수상이성분계를 이용한 숙신산의 추출

이우윤 ( Woo Yun Lee ),홍연기 ( Yeon Ki Hong ) 한국화학공학회 2016 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.54 No.1

본 연구에서는 숙신산 추출을 위한 효과적인 분리공정으로서 피페리딘계 이온성 액체/K2HPO4에 의한 수상이성분계를 적용하여 수상이성분계 형성 특성 및 추출특성을 고찰하였다. 실험 결과 K2HPO4 수용액에 적정량의 피페리딘계 이온성 액체를 첨가함에 따라 안정한 수상이성분계가 형성됨을 확인할 수 있었으며 이성분계 형성능력은 이온성 액체내 양이온의 알킬 사슬길이에 따라 증가하였다. K2HPO4 수용액을 기준으로 피페리딘계 이온성 액체의 수상이성분계 형성 능력은 이미다졸계나 피롤리딘계에 비해 우수하였다. 피페리딘계 이온성 액체를 이용한 수상이성분계 추출에 있어 숙신산 추출 효율은 75~95%의 범위를 가지며 이 값들은 이미다졸계나 피롤리딘계와 큰 차이가 없었다. 그러므로 피페리딘계 이온성 액체를 이용한 수상이성분계를 숙신산 추출에 적용할 경우 이미다졸계 및 피롤리딘계에 비해 적은양의 이온성 액체를 사용하여 높은 추출효율을 얻을 수 있음을 확인할 수 있었다. As an effective method for extraction of succinic acid, aqueous two-phase systems based on piperidinium ionic liquids were used in this study. Effects of the alkyl chain length of cation in piperinidium ionic liquids on phase diagram and extraction efficiencies were investigated. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of piperidinium ionic liquids to aqueous K2HPO4 solutions. It can be found that the ability of piperidinium ionic liquids for phase separation followed the order [OMPip][Br]>[HMPip][Br]>[BMPip][Br]> [EMPip][Br]. The biphase-forming ability of piperidinium ionic liquids was higher than that of imidazolium and pyrrolidinium ionic liquids in the presence of K2HPO4. 75~95% of the succinic acid could be extracted into the ionic liquidrich phase in a single-step extraction. There was little difference in the extraction efficiency of succinic acid by piperidinium ionic liquids comparing to other ionic liquids such as imidazolium and pyrrolonidium ionic liquids. This aqueous two phase system by piperidinium ionic liquid is suggested to have effective application for the separation of succinic acid.

친수성 이온성 액체를 이용한 수상이성분계에서의 아크릴산 추출 평형

이용화 ( Yong Hwa Lee ),이우윤 ( Woo Youn Lee ),김기섭 ( Ki Sub Kim ),홍연기 ( Yeon Ki Hong ) 한국화학공학회 2014 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.52 No.5

본 연구에서는 아크릴산 추출을 위한 효과적인 분리공정으로서 모폴린계 이온성 액체/K2HPO4에 의한 수상이성분계를 적용하여 수상이성분계 형성 특성 및 아크릴산 추출 효율에 대한 모폴린계 이온성 액체의 양이온 알킬사슬 길이의영향을 고찰하였다. 실험 결과 K2HPO4 수용액에 적정량의 모폴린계 이온성 액체를 첨가함에 따라 안정한 수상이성분계가 형성됨을 확인할 수 있었으며 이성분계 형성능력은 [HMMor][Br]>[OMMor][Br]>[BMMor][Br]> [EMMor][Br]의순서로 나타났다. K2HPO4 수용액을 기준으로 모폴린계 이온성 액체의 수상이성분계 형성 능력은 기존의 이미다졸계와 큰 차이가 없었으며 친수성알콜/K2HPO4와 비교했을 경우에는 적은양으로도 수상이성분계 형성이 가능하였다. 모폴린계 이온성 액체를 이용한 수상이성분계 추출에 있어 아크릴산 추출 효율은 50~90%의 범위를 가지며 이 값들은이미다졸계와 큰 차이가 없었다. 모폴린계 이온성 액체가 이미다졸계 이온성 액체에 비해 경제적으로 생산할 수 있으므로 모폴린계 이온성 액체와 K2HPO4로 구성된 수상이성분계는 아크릴산을 포함한 각종 생물공정에 의한 제품 분리에 효과적임을 알 수 있었다. As an effective method for extraction of acrylic acid, aqueous two-phase systems based on morpholiniumionic liquids were used in this study. Effects of the alkyl chain length of cation in morpholinium ionic liquids on phasediagram and extraction efficiencies were investigated. Experimental results show that aqueous two phase systems can beformed by adding appropriate amount of morpholinium ionic liquids to aqueous K2HPO4 solutions. It can be found that theability of morpholinium ionic liquids for phase separation followed the order [HMMor][Br]>[OMMor][Br]>[BMMor][Br]>[EMMor][Br]. There was little difference between binodal curves of imidazolium ionic liquids and those of morpholiniumionic liquids. 50~90% of the extraction efficiency was observed for acrylic acid by aqueous two phase extraction ofacrylic acid with morpholinium ionic liquids. It can be concluded that morpholinium ionic liquids/K2HPO4 were effectivefor aqueous two phases extraction of acrylic acid comparing to imidazolium ionic liquids/K2HPO4 systems becauseof their lower cost.

Lubricating property of cyano-based ionic liquids against hard materials

Shouhei Kawada,Keisuke Sato,Seiya Watanabe,Shinya Sasaki 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.12

Ionic liquids are expected to be used as a new lubricants and lubricant additives because of their unique properties. However, cyanobased ionic liquids have exhibited poor lubricating property with steel/steel contacts. We evaluated the lubricating properties of cyanobased ionic liquids with steel/hard materials contacts. TiO 2 , Al 2 O 3 , and tetrahedral amorphous carbon (ta-C) DLC were used as hard materials. Six types of ionic liquids, as combination of two types of cations ([EMIM], [BMPL]) and three types of cyanide anions ([DCN], [TCC] and [TCB]), were selected. In sliding tests of steel/TiO 2 and steel/Al 2 O 3 lubricated with [EMIM][DCN], [BMPL][DCN], [EMIM][TCC], [BMPL][TCC] exhibited low friction coefficients of less than 0.1. In addition, steel/Al 2 O 3 and steel/ta-C DLC lubricated with [BMPL][TCB] exhibited very low friction coefficients less than 0.05. On the other hand, high friction coefficients were observed at steel/TiO 2 and steel/Al 2 O 3 contacts lubricated with [EMIM][TCB] and steel/ta-C DLC contact lubricated with [EMIM] cation group. Peeling of the ta-C DLC was observed when [EMIM] cation group was used. ToF-SIMS analysis indicated that the anion was adsorbed on the worn surfaces in the case of low frictional conditions. However, both ions were hardly observed in the case of high frictional conditions. It is considered that the ionic liquids underwent tribo-decomposition on the worn surfaces at low friction coefficient. To evaluate the degree of tribo-decomposition, Thermogravimetric analysis (TGA) was used. TGA results indicated that [EMIM][TCB], which exhibited high friction coefficient, had the most highest stability among all ionic liquids. Low stability ionic liquids, however, showed a tendency for low friction coefficient. These results suggest that lubricating properties are related to the stability of ionic liquids.

Phosphonium based ionic liquids: Potential green solvents for separation of butanol from aqueous media

Kalyani Ashok Motghare,Diwakar Zaparu Shende,Kailas Lachchhuram Wasewar 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.10

Depleting conventional resources leads to the development of alternate energy sources as a result of rising energy demand. As a result of its high energy content, bio-butanol is an appealing fuel. Yet, a fermentation method of butanol generation by acetone*butanol*ethanol using solventogenic Clostridium has significant limitations. In addition to repressing microbial movement (normally greater than 10 g/L), it also affects their production. In order to separate butanol from aging broth, various separation techniques can be used. As an alternative to traditional solvents, ionic liquids can be used as novel extractants to counter these problems. In the present paper, separation of butanol (simulated) from aqueous media utilizing typical hydrophobic ionic liquids was studied at 298±1 K. Various parameters, such as distribution coefficent (Kd), extraction efficiency (%), diffusion coefficient, solvent-to-feed ratio diffusion coefficient, and number of stages necessary for butanol separation, have been studied. Separation of butanol from aqueous solutions (0.25-2.5 wt%)Trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl) amide-CYPHOS IL 109 THTDP [NTF2] ionic liquid, (purity 95.0%), Trihexyltetradecylphosphonium chloride-CYPHOS IL 101 THTDP[Cl] (purity 95.0%), at ambient conditions (298.15±1 K) was carried out. The average separation efficiency of butanol was observed highest (%E 80.43) with hydrophobic THTDP [NTF2] ionic liquid. The maximum average distribution coefficient (Kd) 11.055 was found for RTIL ionic liquid THTDP [NTF2] compared to THTDP [Cl] ionic liquid. Minimum solvent-tofeed ratio was observed for ionic liquid, THTDP [NTF2], (S/Fmin, 0.3829) and for THTDP [Cl], (S/Fmin, 0.201). Due to excellent/better mixing blending properties with gasoline and diesel fuels, recovery of this prospective butanol by ionic liquid could be utilized in gasoline-driven combustion systems. It would be a more promising alternative to ethanol and gasoline for large-scale applications. Thus, after evaluating the above parameters, it has been determined that butanol would be the most effective renewable biofuel for commercialization using ionic liquids as an extractant.

Influence of Ionic Liquids on the Growth of Escherichia coli (Short Communication)

구윤모,이상목,장우진,Ah-Rom Choi 한국화학공학회 2005 Korean Journal of Chemical Engineering Vol.22 No.5

Ionic liquids are compounds that composed only of ions and are liquid at room temperature. Thus, it is normally named room temperature ionic liquid (RTIL). In this study, the application of RTILs to the extractive fermentation of biomaterials was investigated as a substitute of organic solvents. The relative toxicity of the RTILs on the growth of E. coli was tested. The inhibition of cell growth in the presence of various ionic liquids was measured using solid and liquid culture, and EC50 of each RTILs was calculated. The number of viable and total cells was measured by the number of colonies and optical density, respectively. Effective concentrations of toxicity (EC50) in these tested systems were similar with conventional solvents, such as acetone, acetonitrile, and ethanol. The viability of E. coli was affected by the polarity and ionic properties of ionic liquids. The resistance of the microorganisms against ionic liquids was different with the cations and anions composing ionic liquids. No general influence of the anionic compound of the ionic liquids was found on toxicity comparing with distinctive influence of cationic moiety.

이온성 액체를 이용한 생물분자의 추출

이우윤,이용화,이준,홍연기,Lee, Woo Yun,Lee, Yong Hwa,Lee, Jun,Hong, Yeon Ki 한국교통대학교 융복합기술연구소 2014 융ㆍ복합기술연구소 논문집 Vol.4 No.2

As an effective separation method for biomolecules, aqueous two-phase systems based on ionic liquids were suggested. Hydrophobic ionic liquids are more expensive and viscous in spite of their usage in the ionic liquid/water biphasic extraction compared with hydrophilic ionic liquids. In case of aqueous two-phase systems using hydrophilic ionic liquids, they can be diluted in aqueous phase. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of ionic liquids to aqueous salts solutions. The viscosity of ionic liquid aqueous phase is proportional to the cation chain length in ionic liquids. It is founded that the ionic liquid based aqueous two phase systems are effective for the separation of biomolecules such as acrylic acid.

Measurement of CO2 solubility in cyanide anion based ionic liquids; [c4mim][SCN], [c4mim][N(CN)2], [c4mim][C(CN)3]

Ji Eun Kim,강정원,임종성 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.8

To investigate the effect of cyanide ions on the solubility of CO2 in ionic liquid, we measured the solubility of CO2 in three ionic liquids which contain three different numbers of cyanide anions, 1-butyl-3-methylimidazolium thiocyanate ([c4mim][SCN]), 1-butyl-3-methylimidazolium dicyanamide ([c4mim][N(CN)2]) and 1-butyl-3-methylimidazolium tricyanomethanide ([c4mim][C(CN)3]). The solubility of CO2 in ionic liquids was determined by measuring bubble-point pressure in high-pressure variable-volume view cell at temperatures from 303.15 to 373.15 K in 10 K intervals. The measured data were correlated with the Peng-Robinson equation of state (PR-EoS) using the van der Waals one fluid mixing rules. The critical properties and acentric factor of ionic liquids were estimated by using the modified Lydersen-Joback-Reid method. As a result, the calculated data were relatively well agreed with the experimental results and, as is commonly known, the solubility of CO2 was observed to increase with increasing pressure and with decreasing temperature. The results also show that the highest solubility was obtained by [c4mim][C(CN)3] among those three experimented ionic liquids while [c4mim][SCN] had the lowest. This implies that the CO2 solubility is affected by the number of cyanide anions contained in ionic liquid. From this result, it is concluded that the cyanide anion enhances the CO2 solubility in ionic liquid and that the ionic liquid which contains more cyanide anions has higher CO2 solubility.

Enzyme-catalyzed reactions in ionic liquids (Review)

구윤모,이상목,하성호,Yun Hee Moon 한국화학공학회 2006 Korean Journal of Chemical Engineering Vol.23 No.2

liquids have been suggested as potential “green solvents” due to their unique properties such as non-volatility, nonflamability, and a wide temperature range for liquid phase. This review describes recent advances ofbiocatalyst reactions in ionic liquids. Enzyme-catalyzed reactions in ionic liquids-transesterification, synthesis, conver-folding/refolding and the toxicity of ionic liquids are also discussed.

Task-Specific Strategies: Pyrrolinium-based Ionic Liquids as Non-flammable Electrolytes for LIBs

김형태,임태은,문준영,오승모,김영규 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

For last 2 decades, a large electronic devices such as energy storage systems, and electric vehicles have come into the spotlight in the field of lithium ion batteries (LIBs). However, the safety issue of LIBs has to be overcome for reaching a high level of battery systems. Under this circumstance, ionic liquids (ILs) are considered as one of the candidate, they are salts that remain as liquids state at room temperature even if they are composed of ionic species. In these various ionic liquids, we suggest the task-specific ionic liquids having a double bond, ether linkage, and no unstable C-H bond for improved stability, i.e. pyrrolinium-based ionic liquids. In this work, we study not only the thermal and physicochemical properties but also the electrochemical performance of pyrrolinium-based ionic liquids while change the substituted alkyl of prepared ILs. Also, to verify the electrochemical properties of electrolytes, we measured the transference of lithium ion in each electrolyte.