Design of lithium selective crown ethers: Synthesis, extraction and theoretical binding studies

Torrejos, Rey Eliseo C.,Nisola, Grace M.,Song, Ho Seong,Limjuco, Lawrence A.,Lawagon, Chosel P.,Parohinog, Khino J.,Koo, Sangho,Han, Jeong Woo,Chung, Wook-Jin Elsevier 2017 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.326 No.-

<P><B>Abstract</B></P> <P>Lithium-selective (Li<SUP>+</SUP>) di-hydroxy crown ethers (CEs 3a–3h) were efficiently synthesized via intermolecular cyclization of bulky bis-epoxide with 1,2-dihydroxybenzene. Bis-epoxides were produced by etherifying allyl bromides with bulky diols to afford diene intermediates, which were subsequently epoxidized. Optimized cyclization reactions were established by changing the solvent, catalyst, and reaction temperature. Complexation abilities of CEs 3a–3h with Li<SUP>+</SUP> and other alkali metals (Na<SUP>+</SUP>, K<SUP>+</SUP>, Cs<SUP>+</SUP>) were assessed by liquid-liquid extraction in dichloromethane-water system. Among the CEs, the highest Li<SUP>+</SUP>/Na<SUP>+</SUP> selectivities were obtained from 3d (α<SUB>Li/Na</SUB> =2519) and 3e (α<SUB>Li/Na</SUB> =1768). DFT calculations reveal that 3d (1.28–1.37Å) and 3e (1.23–1.38Å) had the closest cavity sizes with Li<SUP>+</SUP> diameter (1.36Å). This result affirms that the size-match selectivity of CEs with Li<SUP>+</SUP> was due to the presence of bulky tetramethyl (3d) or bicyclopentyl (3e) subunits with the rigid benzo groups. Complexation with larger cations like Na<SUP>+</SUP>, K<SUP>+</SUP> and Cs<SUP>+</SUP> greatly distorted the 3d and 3e rings as indicated by the larger O-M<SUP>+</SUP> distances on their bulky sides than on their benzo sides. Thus, their (3d, 3e) superior selectivities were due to their Li<SUP>+</SUP> preference and unstable complexation with larger M<SUP>+</SUP>. Enthalpy exchange reaction mechanisms reveal the tendency of all CEs to form 2:1 CE-M<SUP>+</SUP> complexes with larger cations except for 3d, which mainly forms 1:1 CE-M<SUP>+</SUP> hence it is considered most suitable for Li<SUP>+</SUP>. The efficient synthesis of di-hydroxy CEs widens their application not only as extractants but also as solid-supported Li<SUP>+</SUP> adsorbents given the amenability of their OH– groups to further functionalization.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Li<SUP>+</SUP> selective crown ethers (CEs) with bulky and rigid subunits were efficiently synthesized. </LI> <LI> Suitable solvents, catalysts, and reaction conditions for CE synthesis were determined. </LI> <LI> Rigid subunits prevented preorganization effect while bulky groups acted as blocking moiety for bigger metals. </LI> <LI> Liquid-liquid extraction and DFT calculations provided insights on CE-M<SUP>+</SUP> complexes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Identification and characterization of a thermostable endolytic β-agarase Aga2 from a newly isolated marine agarolytic bacteria <i>Cellulophaga omnivescoria</i> W5C

Ramos, Kristine Rose M.,Valdehuesa, Kris Niñ,o G.,Nisola, Grace M.,Lee, Won-Keun,Chung, Wook-Jin Elsevier 2018 New biotechnology Vol.40 No.2

<P><B>Abstract</B></P> <P>Research on the enzymatic breakdown of seaweed-derived agar has recently gained attention due to the progress in green technologies for marine biomass utilization. The enzymes known as agarases catalyze the cleavage of glycosidic bonds within the polysaccharide. In this study, a new β-agarase, Aga2, was identified from <I>Cellulophaga omnivescoria</I> W5C. Aga2 is one of four putative agarases from the W5C genome, and it belongs to the glycoside hydrolase 16 family. It was shown to be exclusive to the <I>Cellulophaga</I> genus. Agarase activity assays showed that Aga2 is an endolytic-type β-agarase that produces tetrameric and hexameric neoagaro-oligosaccharides, with optimum activity at 45°C and pH 8.0. Zinc ions slightly enhanced its activity while manganese ions had inhibitory effects even at very low concentrations. Aga2 has a K<SUB>m</SUB> of 2.59mgmL<SUP>−1</SUP> and V<SUB>max</SUB> of 275.48Umg<SUP>−1</SUP>. The K<SUB>cat</SUB> is 1.73×10<SUP>2</SUP> s<SUP>−1</SUP>, while the K<SUB>cat</SUB>/K<SUB>m</SUB> is 8.04×10<SUP>6</SUP> s<SUP>−1</SUP> M<SUP>−1</SUP>. Aga2 also showed good thermostability at 45°C and above, and retained >90% of its activity after repeated freeze-thaw cycles. Bioinformatic analysis of its amino acid sequence revealed that intrinsic properties of the protein (e.g. presence of certain dipeptides and the relative volume occupied by aliphatic amino acids) and tertiary structural elements (e.g. presence of salt bridges, hydrophobic interactions and H-bonding) contributed to its thermostability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Endolytic β-agarase Aga2 was identified from <I>Cellulophaga omnivescoria</I> W5C. </LI> <LI> Aga2 optimum activity was at 45°C, pH 8.0, with NA4 and NA6 as major products. </LI> <LI> Aga2 was thermostable at high temperatures as well as after many freeze-thaw cycles. </LI> <LI> Intrinsic properties and tertiary structural elements confer the thermostability. </LI> </UL> </P>

The Effects of Cavity Size and Denticity of Thia-14-Crown-4 Ether Derivatives: Synthesis, DFT Studies, and its Application for the Separation of Pd and Pt from Spent Auto-catalyst Leachate

( Rey Eliseo C. Torrejos ),( Grace M. Nisola ),( Sang Hoon Min ),( Jeong Woo Han ),( Khino J. Parohinog ),( Seongpoong Lee ),( Wook-jin Chung ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 ISSE 초록집 Vol.2019 No.-

Dihydroxy-dithia-, -trithia-, and -tetrathia-14-crown-4 ether derivatives (2g-2m) were effectively synthesized by bis-epoxide ring-opening cyclization reaction with 1,2-benzenedithiol using a mild base triethylamine and LiCl as template in water. Experimental liquid-liquid extraction (LLE) and density functional theory (DFT) calculations reveal that the cavity size and denticity of the synthesized thiacrown ethers (CEs) affected their selectivity towards palladium (Pd) and platinum (Pt). Among the CE derivatives, bidentate dihydroxy-dibenzo-dioxadithia-14-crown ether (2i) with a calculated cavity size of 1.58-1.65 Ǻ was most selective towards Pd (1.56 Ǻ) whereas tetradentate dihydroxy-benzo-dimethyl-tetrathia-14-crown-4 ether (2m) with a cavity size of 1.31-1.60 Ǻ towards Pt (1.48 Ǻ), due to the CE cavity size-match relationship. The metals, Mⁿ⁺ (Pd or Pt) are situated perfectly inside the CE cavity with an S4 CE-Mⁿ⁺complex coordination geometry and the lowest DFT calculated binding energies (ΔE_CE-M ⁿ⁺).The dihydroxy thiacrown ethers can be further modified by alkylation for LLE application or polymerized via epoxy functionalization for solid-liquid extraction application of Pd or Pt from highly acidic auto-catalyst leachate. LLE performance of 2i in toluene-water system showed 99.99% Pd extraction efficiency with selectivity up to 10⁵ in comparison to other competing metals from highly acidic auto-catalyst leachate. Epoxy-polymerization of epoxide functionalized CEs with diamine as curing agent to afford highly selective adsorbents for Pd or Pt separation were also investigated and showed excellent Pd and Pt separation performance. This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No. 2017R1D1A1B03028102).

Dual-layered nanocomposite substrate membrane based on polysulfone/graphene oxide for mitigating internal concentration polarization in forward osmosis

Lim, Sungil,Park, Myoung Jun,Phuntsho, Sherub,Tijing, Leonard D.,Nisola, Grace M.,Shim, Wang-Geun,Chung, Wook-Jin,Shon, Ho Kyong Elsevier 2017 Polymer Vol.110 No.-

<P><B>Abstract</B></P> <P>A novel thin-film composite (TFC) forward osmosis (FO) membrane with dual-layered substrate membrane was fabricated by a double-blade casting technique using different polysulfone (PSf) concentrations for top (15 wt%) and bottom (7 wt%) substrate layers. Graphene oxide (GO) was incorporated in the substrate layer, and the dual casting approach resulted in a membrane support with a highly porous bottom structure and a dense top skin layer on which the polyamide active layer was effectively formed. The dual-layered TFC PSf/GO membrane (TFC-PSf<SUB>d</SUB>GO) exhibited high water permeability, and ion selectivity was enhanced by the presence of well dispersed hydrophilic GO in the PSf substrate. The TFC-PSf<SUB>d</SUB>GO also exhibited the lowest specific reverse salt flux (<I>J</I> <SUB> <I>s</I> </SUB> <I>/J</I> <SUB> <I>v</I> </SUB> = 0.19 g L<SUP>-1</SUP>) and a more favorable structural parameter (S = 130 μm) compared to GO-free membranes. Using deionized water as feed solution and 1 M NaCl as draw solution (DS), TFC-PSf<SUB>d</SUB>GO had <I>J</I> <SUB> <I>v</I> </SUB> = 33.8 L m<SUP>−2</SUP> h<SUP>−1</SUP> and <I>J</I> <SUB> <I>s</I> </SUB> = 6.9 g<SUP>−2</SUP> h<SUP>−1</SUP> under AL-FS mode, and <I>J</I> <SUB> <I>v</I> </SUB> = 61.5 L m<SUP>−2</SUP>h<SUP>−1</SUP> and <I>J</I> <SUB> <I>s</I> </SUB> = 14.0 g<SUP>−2</SUP> h<SUP>−1</SUP> under AL-DS mode. The potential of TFC-PSf<SUB>d</SUB>GO for commercial application was further evaluated by fabricating it with a fabric backing support (denoted as TFC-PSf<SUB>d</SUB>GO<SUB>f</SUB>). Compared to TFC-PSf<SUB>d</SUB>GO, TFC-PSf<SUB>d</SUB>GO<SUB>f</SUB> exhibited only 14% decline in its water flux. The overall results reveal that, fabrication of TFC substrate membrane via dual-blade casting approach along with GO incorporation produced high-performance TFC FO membranes which likely reduced the internal concentration polarization effects.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The dual-layered PSf/GO membrane was developed to mitigate the ICP effect. </LI> <LI> The dual-layered PSf substrates exhibited higher porosity and water permeability. </LI> <LI> Incorporation of GO further improved hydrophilicity of membrane substrate. </LI> <LI> The dual-layered PSf/GO membrane demonstrated the best membrane performances. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The potential of monocationic imidazolium-, phosphonium-, and ammonium-based hydrophilic ionic liquids as draw solutes for forward osmosis

Zeweldi, Hana G.,Limjuco, Lawrence A.,Bendoy, Anelyn P.,Kim, Han-Seung,Park, Myoung Jun,Shon, Ho Kyong,Johnson, Eldin M.,Lee, Hanki,Chung, Wook-Jin,Nisola, Grace M. Elsevier 2018 Desalination Vol.444 No.-

<P><B>Abstract</B></P> <P>The widespread implementation of forward osmosis (FO) is highly constrained by the limited availability of suitable draw solutes (DS). Herein, monocationic hydrophilic ionic liquids (ILs) were probed as FO DS. Water (<I>J</I> <SUB> <I>v</I> </SUB>), reverse solute (<I>J</I> <SUB> <I>s</I> </SUB>), and specific reverse solute (<I>J</I> <SUB> <I>s</I> </SUB>/<I>J</I> <SUB> <I>v</I> </SUB>) fluxes were determined and correlated with IL properties: Van't Hoff factor (<I>i</I>), ionic strength, hydrated ionic radius (<I>r</I> <SUB> <I>H</I> </SUB>), diffusivity and membrane affinity. Most of the ILs have comparable <I>J</I> <SUB> <I>v</I> </SUB> with the benchmark draw solute NaCl but their <I>J</I> <SUB> <I>s</I> </SUB> were significantly lower, particularly under PRO mode. Their remarkably lower <I>J</I> <SUB> <I>s</I> </SUB>/<I>J</I> <SUB> <I>v</I> </SUB> (i.e. <0.010 ± 7.45 × 10<SUP>−4</SUP> mol L<SUP>−1</SUP>) than NaCl (0.021 ± 0.003 mol L<SUP>−1</SUP>) validates their potential use as FO DS. Tetraethylammonium bromide ([N2222]Br) is the most suitable IL DS due to its high <I>π</I>, high ionic strength, small <I>r</I> <SUB> <I>H</I> </SUB>, least membrane permeability (<I>B</I> = 0.14 L m<SUP>−2</SUP> h<SUP>−1</SUP>) and lowest <I>J</I> <SUB> <I>s</I> </SUB>/<I>J</I> <SUB> <I>v</I> </SUB> = 0.004 ± 5.53 × 10<SUP>−4</SUP> mol L<SUP>−1</SUP>. Moreover, [N2222]Br effectively desalinated seawater (0.6 M NaCl). It is thermally stable and can be effectively regenerated through direct contact membrane distillation. The final permeated water had only trace [N2222]Br, which is safe for consumption as confirmed by <I>in vitro</I> toxicity tests. These results demonstrate that certain ILs like [N2222]Br can be identified as suitable draw solutes for FO desalination process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ionic liquids (ILs) were effectively employed as draw solutes for forward osmosis (FO). </LI> <LI> IL dissociation in water, conductivity and molecular size was important for <I>J</I> <SUB> <I>v</I> </SUB>. </LI> <LI> Hydrated radii and membrane sorption properties of ILs were critical to <I>J</I> <SUB> <I>s</I> </SUB>. </LI> <LI> All ILs especially [N2222]Br performed better than NaCl in terms of <I>J</I> <SUB> <I>s</I> </SUB>/<I>J</I> <SUB> <I>v</I> </SUB>. </LI> <LI> [N2222]Br is regenerable, has low toxicity, and has high potential as FO draw solute. </LI> </UL> </P>

Poly(octylmethylsiloxane)/oleyl alcohol supported liquid membrane for the pervaporative recovery of 1-butanol from aqueous and ABE model solutions

Arnel B. Beltran,정욱진,Grace M. Nisola,Eleazer L. Vivas,조원회 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.1

Supported liquid membranes (SLM) composed of oleyl alcohol (OA) and poly(octylmethylsiloxane)(POMS) in microporous flat sheets were investigated for the pervaporation of 1-butanol. Water contact angle and partition coefficients were used to characterize the SLMs. Optimum pervaporation performance was attained at 30 wt% OA SLM wherein high separation factor (a = 279) and total flux (JT = 95.9 g/(m2 h)) were achieved from 2.5% (w/v) 1-butanol/water feed, at 60 8C. In these conditions,27% reduction in JT was observed when fed with model fermentation broths but remained highly selective toward 1-butanol (a = 76.4). SLM stability was demonstrated with <4% LM loss after operation.

Thia-crown Ether based Composite Adsorbents for Selective Recovery of Gold (Au³⁺) and Silver (Ag⁺) ions from Electronic Wastes

( Hiluf Tekle Fissaha ),( Grace M. Nisola ),( Wook-jin Chung ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 ISSE 초록집 Vol.2019 No.-

Global electronic waste (E-waste) is increasing due to the fast-technological advancement of electrical and electronic devices with short life cycles, and lack of suitable recycling technologies. Inappropriate disposal of these waste materials causes severe environmental impacts. Furthermore, E-waste is attractive for recycling of precious metals like gold and silver, even compared to their mineral ore sources. Many lixiviants and adsorbents have been developed for the recycling of these valuable metals. However, most of the adsorbents are not selective towards specific precious metal ions. Crown ethers (CEs) are attractive macrocyclic complexing agents as their cavity structures can be tailored to accommodate the ionic size of a precious metal and their heteroatoms (i.e. O, N, or S) can be selected to afford the right affinity towards the target ion. In this work, CEs with sulfur donor atoms or thia-CEs (TCEs) were synthesized and proved to form stable complexes with Au³⁺ and Ag⁺. The TCEs were prepared by intermolecular cyclization of bulky epoxides with 1,2-benzenedithiol. The TCEs were immobilized on porous polypropylene membrane (PPM) and silica (SBA-15) to enhance their reusability. Different types of composite adsorbents were fabricated containing TCEs with different cavity sizes to render them metal-ion specific.The composite adsorbents were prepared through immobilization of TCEs onto the surface of PPM and SBA-15, respectively. The developed composite adsorbents (TCE@PPMs and TCE@SBA-15) were thoroughly characterized by high-resolution spectroscopic methods such as NMR, HRMS,FTIR,TGA, SEM, XRD and BET. Adsorption experiments reveal the high selectivity of the composite adsorbents towards Au³⁺((αAu³⁺/Pd²⁺= 1.22)and Ag⁺(αAg⁺/Mⁿ⁺= 8 - 177) as compared to other cations (Mⁿ⁺) present in leached spent mobile PCBs, such as Cu²⁺, Ni²⁺, Zn²⁺, and Pb²⁺. Overall results demonstrate the suitability of the composite adsorbents (TCE@PPM and TCE@SBA-15) for valuable metal recovery applications. This work was supported by National Research Foundation of Korea (NRF) funded by the Ministry of Education (2009-0093816 and 22A20130012051 (BK21Plus)).

Assessment and Process Optimization of the Chemical Treatment Methods for the Removal of Heavy Metals and Cyanide from Plating Wastewater in a Typical Diminutive Treatment Plant

Nisola Grace M.,Eun Mi Kwon,Seung Se Chon,Wook Jin Chung,Dae Won Pak 대한환경공학회 2004 대한환경공학회 학술발표논문집 Vol.2004 No.12

Hydrogen sulfide degradation characteristics of Bordetella sp. Sulf-8 in a biotrickling filter

Nisola, Grace M.,Tuuguu, Enkhdul,Farnazo, Danvir Mark D.,Han, Mideok,Kim, Younghee,Cho, Eulsaeng,Chung, Wook-Jin Springer-Verlag 2010 BIOPROCESS AND BIOSYSTEMS ENGINEERING Vol.33 No.9

Sulfate Removal by Ultra High Lime with Aluminum Process (UHLA) from Sulfur-Oxidizing Denitrification Effluent

( Grace M. Nisola ),( Jennica D. Orata ),( Eul Saeng Cho ),( Eun Yong Sim ),( Nam Jong Yoo ),( Wook Jin Chung ) 한국물환경학회 ( 구 한국수질보전학회 ) 2008 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2008 No.-