Co-reporter:Xu Zhou, Mona M. Obadia, Surendar R. Venna, Elliot A. Roth, Anatoli Serghei, David R. Luebke, Christina Myers, Zhengmian Chang, Robert Enick, Eric Drockenmuller, Hunaid B. Nulwala
European Polymer Journal 2016 Volume 84() pp:65-76
Publication Date(Web):November 2016
DOI:10.1016/j.eurpolymj.2016.09.001
•A monotopic approach yields cross-linked 1,2,3-triazolium-based membranes.•Huisgen 1,3-dipolar azide-alkyne cycloaddition and N-alkylation are combined.•Free-standing membranes with Tg ∼ −60 °C, Td5 ∼ 230 °C, E′ ∼ 4 MPa are obtained.•Anhydrous ionic conductivities >10−6 S/cm at 30 °C are reached.•Membranes show CO2 permeabilities of 59–110 Barrer and CO2/N2 selectivity of 25–48.A series of cross-linked polyether-based 1,2,3-triazolium ion conducting membranes are prepared via the combination of thermally promoted Huisgen 1,3-dipolar cycloaddition of a dialkyne and a diazide poly(trimethylene ether glycol) monomers with in-situ N-alkylation of the resulting poly(1,2,3-triazole)s with varying contents of 1,10-diiododecane as cross-linking agent. The resulting free-standing membranes have Tgs below −60 °C, Tds up to 230 °C, and Young’s modulus up to 4.2 MPa. The overall combined reaction kinetics were studied by DSC yielding an activation energy of 76 kJ/mol by the Kissinger method. These ion conducting membranes have conductivities up to 10−6 S/cm at 30 °C under anhydrous conditions. They have potential to be used in CO2 separation applications as they exhibit CO2 permeability of 59–110 Barrer and CO2/N2 selectivity of 25–48.
Co-reporter:M. Lartey, J. Meyer-Ilse, J. D. Watkins, E. A. Roth, S. Bowser, V. A. Kusuma, K. Damodaran, X. Zhou, M. Haranczyk, E. Albenze, D. R. Luebke, D. Hopkinson, J. B. Kortright and H. B. Nulwala
Physical Chemistry Chemical Physics 2015 vol. 17(Issue 44) pp:29834-29843
Publication Date(Web):06 Oct 2015
DOI:10.1039/C5CP04756K
A series of four isomeric 1,2,3-triazolium-based ionic liquids (ILs) with vary degree of branching were synthesized and characterized to investigate the effect of ion branching on thermal and physical properties of the resulting IL. It was found that increased branching led to a higher ionicity and higher viscosity. The thermal properties were also altered significantly and spectral changes in the near edge X-ray absorption fine structure (NEXAFS) spectra show that branching affects intermolecular interaction. While the ionicity and viscosity varying linearly with branching, the MDSC and NEXAFS measurements show that the cation shape has a stronger influence on the melting temperature and absorptive properties than the number of branched alkyl substituents.
Co-reporter:Anna S. Ivanova, Thomas Brinzer, Elliot A. Roth, Victor A. Kusuma, John D. Watkins, Xu Zhou, David Luebke, David Hopkinson, Newell R. Washburn, Sean Garrett-Roe and Hunaid B. Nulwala
RSC Advances 2015 vol. 5(Issue 63) pp:51407-51412
Publication Date(Web):26 May 2015
DOI:10.1039/C5RA06561E
A simple binary system of compounds resembling short-chain versions of popular ionic liquids has been shown to have surprisingly complex properties. Combining methylated versions of pyridinium and pyrrolidinium bis[(trifluoromethyl)sulfonyl]imide gave desirable properties such as low viscosity and high conductivity solubility per unit volume. The binary combinations studied in this study showed that these materials were stable liquids at 50 °C and had a threefold improvement in conductivity over [C6C1im][Tf2N]. Despite the high densities of these materials, 2D-IR studies indicate increased ion mobility, likely due to the lack of hindering alkyl chains.
Co-reporter:Hongkun He;Heesung Chung;Elliot Roth;David Luebke;David Hopkinson;Hunaid Nulwala;Krzysztof Matyjaszewski
Polymers for Advanced Technologies 2015 Volume 26( Issue 7) pp:823-828
Publication Date(Web):
DOI:10.1002/pat.3529
Well-defined poly(ionic liquid)s (PILs) were synthesized by normal and activators regenerated by electron transfer atom transfer radical polymerization (ATRP) using a new ionic liquid monomer, N-(4-vinylbenzyl)-tris[2-(2-methoxyethoxy)ethyl]ammonium bis(trifluoromethylsulfonyl)imide (VBTA+Tf2N−). ATRP was also used for the preparation of PIL block copolymers using di-functional PIL macroinitiators. Differential scanning calorimetry measurement showed the polyVBTA+Tf2N− had a rather low glass transition temperature of −43°C. Copyright © 2015 John Wiley & Sons, Ltd.
Co-reporter:Victor A. Kusuma;Elliot A. Roth;William P. Clafshenkel;Steven S. Klara;Xu Zhou;Surendar R. Venna;Erik Albenze;David R. Luebke;Meagan S. Mauter;Richard R. Koepsel;Alan J. Russell;David Hopkinson
Journal of Polymer Science Part A: Polymer Chemistry 2015 Volume 53( Issue 13) pp:1548-1557
Publication Date(Web):
DOI:10.1002/pola.27594
ABSTRACT
Homogenous amphiphilic crosslinked polymer films comprising of poly(ethylene oxide) and polysiloxane were synthesized utilizing thiol-ene “click” photochemistry. A systematic variation in polymer composition was Carried out to obtain high quality films with varied amount of siloxane and poly(ethylene oxide). These films showed improved gas separation performance with high gas permeabilities with good CO2/N2 selectivity. Furthermore, the resulting films were also tested for its biocompatibility, as a carrier media which allow human adult mesenchymal stem cells to retain their capacity for osteoblastic differentiation after transplantation. The obtained crosslinked films were characterized using differential scanning calorimetry, dynamic mechanical analysis, thermogravimetric analysis, FTIR, Raman-IR, and small angle X-ray scattering. The synthesis ease and commercial availability of the starting materials suggests that these new crosslinked polymer networks could find applications in wide range of applications. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1548–1557
Co-reporter:Brian J. Adzima, Surendar R. Venna, Steven S. Klara, Hongkun He, Mingjiang Zhong, David R. Luebke, Meagan S. Mauter, Krzysztof Matyjaszewski and Hunaid B. Nulwala
Journal of Materials Chemistry A 2014 vol. 2(Issue 21) pp:7967-7972
Publication Date(Web):13 Mar 2014
DOI:10.1039/C4TA00661E
The continuing discovery of broad classes of materials, such as ionic liquids, zeolites, metal–organic frameworks, and block copolymers, presents an enormous opportunity in developing materials for new applications. Polymerized ionic liquid block copolymers (PIL-BCPs) fall at the union of two already large sets of materials, and are an emerging class of materials useful in gas separation membranes, ion and electron conducting materials, and as mechanical actuators. A wide range of ionic liquid moieties can be used as pendant groups along the polymer backbone, potentially allowing for a wide variation in the resulting material properties; however in practice the range of ionic liquids explored is hindered by the need to optimize polymerization conditions for each new monomer. Here, we present a modular approach to PIL-BCP synthesis where a variety of olefin bearing cations are readily conjugated to polymers using thiol-Michael click chemistry. This approach allowed for the rapid development of a diverse material library including phase separated thin films, ion-gels, and liquid PIL-BCPs, with a reduced investment in synthetic time. Finally, we demonstrate that this approach identified PIL-BCPs with increased CO2 permeability relative to PILs, which could find use in carbon capture from flue gas.
Co-reporter:Hongkun He, Brian Adzima, Mingjiang Zhong, Saadyah Averick, Richard Koepsel, Hironobu Murata, Alan Russell, David Luebke, Atsushi Takahara, Hunaid Nulwala and Krzysztof Matyjaszewski
Polymer Chemistry 2014 vol. 5(Issue 8) pp:2824-2835
Publication Date(Web):08 Jan 2014
DOI:10.1039/C3PY01708G
A facile approach was developed to prepare crosslinked ionic polymer hydrogel films by photo-crosslinking utilizing p-vinylbenzyl trimethylammonium chloride (VBTMACl) or p-vinylbenzyl trimethylammonium hydroxide (VBTMAOH) as the monomer and poly(ethylene oxide) dimethacrylate (PEODMA, Mn = 750) as the crosslinker. The films with different crosslinking degrees (20%, 40%, 60%, 80%, and 100%) were prepared and characterized by swelling measurements, scanning electron microscopy (SEM), UV-visible spectroscopy, attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and small-angle X-ray scattering (SAXS). It was found that the mechanical and thermal properties of the films were largely influenced by the contents of the crosslinker in the films. By ion-exchange of the anions in the films with various other anions, the hydrophobicity/hydrophilicity of the films was changed. In addition, fluorescent films were prepared by treatment with fluorescein, and paramagnetic films with FeCl4− as a counter anion showed catalytic activity for Friedel–Crafts alkylation. The ionic films with quaternary ammonium chloride groups displayed antimicrobial activity against Escherichia coli (E. coli) with almost 100% killing efficiency. Multifunctional films with various tunable properties have significant potential for a wide range of applications.
Co-reporter:Robert L. Thompson, Wei Shi, Erik Albenze, Victor A. Kusuma, David Hopkinson, Krishnan Damodaran, Anita S. Lee, John R. Kitchin, David R. Luebke and Hunaid Nulwala
RSC Advances 2014 vol. 4(Issue 25) pp:12748-12755
Publication Date(Web):18 Feb 2014
DOI:10.1039/C3RA47097K
Development of the next generation materials for effective separation of gases is required to address various issues in energy and environmental applications. Ionic liquids (ILs) are among the most promising material types. To overcome the many hurdles in making a new class of materials technologically applicable, it is necessary to identify, access, and scale up a range of representative substances. In this work, CO2 reactive triazolide ILs were synthesized and characterized with the aim of developing a deeper understanding of how structural changes affect the overall properties of these substances. It was found that substituents on the anion play a crucial role in dictating the physical properties for CO2 capture. Depending upon the anion substituent, CO2 capacities between 0.07 and 0.4 mol CO2 per mol IL were observed. It was found that less sterically-hindered anions and anions containing electron donating groups were more reactive towards CO2. Detailed spectroscopic, CO2 absorption, rheological, and simulation studies were carried out to understand the nature and influence of these substituents. The effect of water content was also evaluated, and it was found that water had an unexpected impact on the properties of these materials, resulting in an increased viscosity, but little change in the CO2 reactivity.
Co-reporter:Hongkun He, Saadyah Averick, Elliot Roth, David Luebke, Hunaid Nulwala, Krzysztof Matyjaszewski
Polymer 2014 Volume 55(Issue 16) pp:3330-3338
Publication Date(Web):5 August 2014
DOI:10.1016/j.polymer.2014.01.045
Covalent attachment of poly(ionic liquid)s (PILs) by click chemistry on glass or silicon (Si) surfaces was performed. Poly[1-(4-vinylbenzyl)-3-butylimidazolium bis(trifluoromethylsulfonyl)imide] (polyVBBI+Tf2N−), and copolymers of polyVBBI+Tf2N− with fluorescein O-methacrylate were synthesized by conducting an atom transfer radical polymerization (ATRP) from initiators containing azide or thioacetate groups. The azide- and thiol-terminated PILs were then successfully grafted onto alkyne and alkene modified glass/Si wafers by thermal azide–alkyne cycloaddition and photoinitiated thiol-ene click reactions, respectively. The modified surfaces were characterized by contact angle measurements and ellipsometry. The fluorescent PIL functionalized surfaces showed strong fluorescence under UV irradiation. This procedure of tethering PILs to substrates also provides an easy way to change the surface hydrophilicity by replacing the anions in the grafted PILs. The present approach could be readily applied for surface modifications with other types of PILs or their copolymers to achieve different functionalities on various surfaces.
Co-reporter:Hongkun He, David Luebke, Hunaid Nulwala, and Krzysztof Matyjaszewski
Macromolecules 2014 Volume 47(Issue 19) pp:6601-6609
Publication Date(Web):September 17, 2014
DOI:10.1021/ma501487u
Well-defined poly(ionic liquid)s (PILs) were synthesized by activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The ionic liquid monomer 1-(4-vinylbenzyl)-3-butylimidazolium bis(trifluoromethylsulfonyl)imide (VBBI+Tf2N–) was directly polymerized with tris(2-pyridylmethyl)amine (TPMA) ligand and ppm level of copper catalyst. The addition of reducing agent tin(II) 2-ethylhexanoate (SnII(EH)2) to continuously regenerate the catalyst in the ARGET ATRP enabled the synthesis of PILs with a significantly lower concentration of catalysts than required for a normal ATRP. PILs with well-controlled molecular weight and relatively low dispersity (Mw/Mn < 1.3) were obtained. ATRP chain extension of the resulting PILs with polystyrene revealed that the chain-end functionality of the PILs was significantly improved by slow feeding of the reducing agent during the polymerization. Simple and effective methods were developed to remove the residual halide ions from the ionic liquid monomer by ion exchange with LiTf2N or precipitation with AgTf2N, which allowed ARGET ATRP of the purified ionic liquid monomer to occur with as low as 20 ppm copper catalyst. Additionally, ARGET ATRP was used for the preparation of PIL block copolymers, including AB diblock and ABA triblock with PIL segment(s) as the middle or side blocks, using ionic liquid monomer or mono/difunctional PIL macroinitiators.
Co-reporter:Brian J. Adzima;Steve C. Taylor;Hongkun He;David R. Luebke;Krzysztof Matyjaszewski
Journal of Polymer Science Part A: Polymer Chemistry 2014 Volume 52( Issue 3) pp:417-423
Publication Date(Web):
DOI:10.1002/pola.27016
ABSTRACT
A set of eight functional 4-vinyl-1,2,3-triazolium monomers were synthesized using copper catalyzed azide-alkyne 2 + 3 Hüisgen cycloaddition. These vinyl-trizolium monomers readily polymerized via free radical polymerization. The physical properties of the vinyl-triazolium based poly(ionic liquid)s (PILs) are strongly dependent on the pendant functional groups. These polymers were characterized for glass transition temperature (Tg), solubility, and the thermal decomposition. The vinyl-triazolium based PILs offer an efficient route to highly functional PILs with the advantage of facile synthesis and the ability to incorporate many desirable functional moieties. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 417–423
Co-reporter:Hongkun He;Mingjiang Zhong;David Luebke;Hunaid Nulwala;Krzysztof Matyjaszewski
Journal of Polymer Science Part A: Polymer Chemistry 2014 Volume 52( Issue 15) pp:2175-2184
Publication Date(Web):
DOI:10.1002/pola.27229
ABSTRACT
Understanding the influence of salt/counterion on atom transfer radical polymerization (ATRP) is important to optimize the conditions for ATRP of ionic monomers, such as ionic liquid monomer. This article reports the results of a systematical investigation of the variables associated with ATRP in the presence of different types and amounts of salts, solvents, ligands, and monomers. A series of control ATRP experiments were conducted under various polymerization conditions. The kinetics of the polymerizations, the molecular weight, and molecular weight distribution of the formed polymers were studied by nuclear magnetic resonance and gel permeation chromatography. The results indicated that all of the studied variables influenced the ATRP process to different degrees. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2175–2184
Co-reporter:Fangyong Yan, Michael Lartey, Kuldeep Jariwala, Sage Bowser, Krishnan Damodaran, Erik Albenze, David R. Luebke, Hunaid B. Nulwala, Berend Smit, and Maciej Haranczyk
The Journal of Physical Chemistry B 2014 Volume 118(Issue 47) pp:13609-13620
Publication Date(Web):October 30, 2014
DOI:10.1021/jp506972w
The Materials Genome Approach (MGA) aims to accelerate development of new materials by incorporating computational and data-driven approaches to reduce the cost of identification of optimal structures for a given application. Here, we use the MGA to guide the synthesis of triazolium-based ionic liquids (ILs). Our approach involves an IL property-mapping tool, which merges combinatorial structure enumeration, descriptor-based structure representation and sampling, and property prediction using molecular simulations. The simulated properties such as density, diffusivity, and gas solubility obtained for a selected set of representative ILs were used to build neural network models and map properties for all enumerated species. Herein, a family of ILs based on ca. 200 000 triazolium-based cations paired with the bis(trifluoromethanesulfonyl)amide anion was investigated using our MGA. Fourteen representative ILs spreading the entire range of predicted properties were subsequently synthesized and then characterized confirming the predicted density, diffusivity, and CO2 Henry’s Law coefficient. Moreover, the property (CO2, CH4, and N2 solubility) trends associated with exchange of the bis(trifluoromethanesulfonyl)amide anion with one of 32 other anions were explored and quantified.
Co-reporter:Hongkun He ; Mingjiang Zhong ; Brian Adzima ; David Luebke ; Hunaid Nulwala ;Krzysztof Matyjaszewski
Journal of the American Chemical Society 2013 Volume 135(Issue 11) pp:4227-4230
Publication Date(Web):March 4, 2013
DOI:10.1021/ja4012645
Poly(ionic liquid)s (PILs) are an important class of technologically relevant materials. However, characterization of well-defined polyionic materials remains a challenge. Herein, we have developed a simple and versatile gel permeation chromatography (GPC) methodology for molecular weight (MW) characterization of PILs with a variety of anions. PILs with narrow MW distributions were synthesized via atom transfer radical polymerization, and the MWs obtained from GPC were further confirmed via nuclear magnetic resonance end group analysis.
Co-reporter:Michael Lartey;Martijn Gillissen;Brian J. Adzima;Kenichi Takizawa;David R. Luebke
Journal of Polymer Science Part A: Polymer Chemistry 2013 Volume 51( Issue 16) pp:3359-3364
Publication Date(Web):
DOI:10.1002/pola.26723
ABSTRACT
The free radical reactivity ratios between styrene and different vinyl-1,2,3-triazole regioisomeric monomers in 1,4-dioxane at 65 °C have been established using nonlinear least square method. The results obtained for the reactivity ratio between regioisomers show exceptionally different polymerization behavior, highlighting the effects of the electronic and steric factors of these regioisomeric monomers. The experimental results highlight the effects of the electronic and sterics on the copolymerization behavior. In case of 1,4-vinyl-triazoles, it was found that without the steric effects, the reactivity is very similar to that of styrene and forms random copolymers. However, it was found that 1,5-vinyl-triazoles are more reactive than 1,4-vinyl triazoles. In the case of styrene-co-1,4-vinyl-1,2,3-triazoles, the reactivity ratios were calculated to be rstyrene: r1-octyl-4-vinyl-triazole = 1.97:0.54, rstyrene : r1-benzyl-4-vinyl-triazole = 1.62:0.50, and rstyrene: r1-methyl-4-vinyl-triazole = 0.90:0.87. On the other hand, reactivity ratios for styrene-co-1,5-vinyl-1,2,3-triazoles were found to be rstyrene: r1-octyl-5-vinyl-triazole = 0.13:0.66 and rstyrene: r1-benzyl-5-vinyl-triazole = 0.34:0.49. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3359–3364
Co-reporter:Mingjiang Zhong, Sittichai Natesakhawat, John P. Baltrus, David Luebke, Hunaid Nulwala, Krzysztof Matyjaszewski and Tomasz Kowalewski
Chemical Communications 2012 vol. 48(Issue 94) pp:11516-11518
Publication Date(Web):11 Oct 2012
DOI:10.1039/C2CC36652E
Nitrogen-enriched porous carbon materials made via the carbonization of polyacrylonitrile containing block copolymer act as efficient and highly selective CO2 sorbents. Nitrogen content and surface area, which are both influenced by pyrolysis temperature and atmosphere, are crucial for CO2 adsorption performance.
Co-reporter:Mingjiang Zhong, Sittichai Natesakhawat, John P. Baltrus, David Luebke, Hunaid Nulwala, Krzysztof Matyjaszewski and Tomasz Kowalewski
Chemical Communications 2012 - vol. 48(Issue 94) pp:NaN11518-11518
Publication Date(Web):2012/10/11
DOI:10.1039/C2CC36652E
Nitrogen-enriched porous carbon materials made via the carbonization of polyacrylonitrile containing block copolymer act as efficient and highly selective CO2 sorbents. Nitrogen content and surface area, which are both influenced by pyrolysis temperature and atmosphere, are crucial for CO2 adsorption performance.
Co-reporter:Brian J. Adzima, Surendar R. Venna, Steven S. Klara, Hongkun He, Mingjiang Zhong, David R. Luebke, Meagan S. Mauter, Krzysztof Matyjaszewski and Hunaid B. Nulwala
Journal of Materials Chemistry A 2014 - vol. 2(Issue 21) pp:NaN7972-7972
Publication Date(Web):2014/03/13
DOI:10.1039/C4TA00661E
The continuing discovery of broad classes of materials, such as ionic liquids, zeolites, metal–organic frameworks, and block copolymers, presents an enormous opportunity in developing materials for new applications. Polymerized ionic liquid block copolymers (PIL-BCPs) fall at the union of two already large sets of materials, and are an emerging class of materials useful in gas separation membranes, ion and electron conducting materials, and as mechanical actuators. A wide range of ionic liquid moieties can be used as pendant groups along the polymer backbone, potentially allowing for a wide variation in the resulting material properties; however in practice the range of ionic liquids explored is hindered by the need to optimize polymerization conditions for each new monomer. Here, we present a modular approach to PIL-BCP synthesis where a variety of olefin bearing cations are readily conjugated to polymers using thiol-Michael click chemistry. This approach allowed for the rapid development of a diverse material library including phase separated thin films, ion-gels, and liquid PIL-BCPs, with a reduced investment in synthetic time. Finally, we demonstrate that this approach identified PIL-BCPs with increased CO2 permeability relative to PILs, which could find use in carbon capture from flue gas.
Co-reporter:M. Lartey, J. Meyer-Ilse, J. D. Watkins, E. A. Roth, S. Bowser, V. A. Kusuma, K. Damodaran, X. Zhou, M. Haranczyk, E. Albenze, D. R. Luebke, D. Hopkinson, J. B. Kortright and H. B. Nulwala
Physical Chemistry Chemical Physics 2015 - vol. 17(Issue 44) pp:NaN29843-29843
Publication Date(Web):2015/10/06
DOI:10.1039/C5CP04756K
A series of four isomeric 1,2,3-triazolium-based ionic liquids (ILs) with vary degree of branching were synthesized and characterized to investigate the effect of ion branching on thermal and physical properties of the resulting IL. It was found that increased branching led to a higher ionicity and higher viscosity. The thermal properties were also altered significantly and spectral changes in the near edge X-ray absorption fine structure (NEXAFS) spectra show that branching affects intermolecular interaction. While the ionicity and viscosity varying linearly with branching, the MDSC and NEXAFS measurements show that the cation shape has a stronger influence on the melting temperature and absorptive properties than the number of branched alkyl substituents.
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