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Two new, cross-linkable, phosphobetaine zwitterionic amphiphiles were found to form a type II bicontinuous cubic (QII) phase with aq. NH4Cl. Upon polymerization, they form 3D-nanoporous membrane materials that are not susceptible to ion exchange.

Direct, living ring-opening metathesis polymerization of a highly paramagnetic, norbornene-based imidazolium FeCl

We demonstrate that an ether-based

Seven homologues of an amphiphilic gemini monomer were synthesized and screened for the ability to form a bicontinuous cubic (Q) lyotropic liquid crystal phase. Four of these homologues form a Q phase with glycerol or water that can be cross-linked with retention of the nanoporous structure, with one exhibiting a well-ordered Q phase with a wider phase window than the parent monomer.

An ordered, nanoporous polymer resin was prepared from the self-assembly of lyotropic liquid crystal monomers and employed as a heterogeneous, bifunctional catalyst. This material contains antagonistic acid and base sites in the periodic nanopores and efficiently catalyzes a model tandem reaction (i.e., the deacetalization–nitroaldol reaction between benzaldehyde dimethyl acetal and nitromethane to yield β-nitrostyrene) with excellent product selectivity. This lyotropic liquid crystal-based solid catalyst represents one of the few examples of polymeric tandem catalysts synthesized by a “bottom-up” strategy that imparts control over the stoichiometry of acidic and basic monomers and is the only reported example of a lyotropic liquid crystal-based polymer that contains mutually incompatible catalytic groups. Furthermore, this heterogeneous catalyst is highly active, exhibiting a turnover frequency for this tandem test reaction that exceeds other reported catalytic polymeric materials.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare life-threatening hypersensitivity conditions associated with epidermal detachment and mucositis. The indication for flexible nasoendoscopy (FNE) and overall predictive factors for early intubation are unclear.To describe the incidence of airway involvement and the key indicators for intubation in our SJS or TEN patient cohort. To determine the association between FNE findings and early intubation.A retrospective review of 45 patients with biopsy proven SJS or TEN admitted to an Australian tertiary burns centre from 2010 to 2017.Thirty-five patients were diagnosed with TEN (77.8%), followed by overlap syndrome (SJS-TEN) (n = 6, 13.3%) and SJS (n = 4, 8.9%). Twenty (44.4%) patients were intubated; and all 20 had a diagnosis of TEN (100.0%) (p 0.05). Intubated patients had a higher increase in total body surface area percentage(%) from day 1-3 [10.0% (IQR 0.0-23.8%)] and a longer length of stay [26.0 days (IQR 12.5-34.0)], compared to non-intubated patients [0.0% (IQR 0.0-4.0%)], [10.0 days (IQR 6.0-14.0)] (p 0.05) respectively. The main indications for intubation were to facilitate operative and dressing management (47.4%) followed by airway involvement (26.3%). FNE was performed on 32 patients (71.1%), however FNE findings did not significantly influence intubation rates.More than half (n = 20, 57.1%) of the 35 patients diagnosed with TEN underwent intubation, mainly to facilitate operative and dressing management. FNE was performed on most patients, however there was no clear association between FNE findings and early intubation.

Direct, living ring-opening metathesis polymerization of a highly paramagnetic, norbornene-based imidazolium FeCl4– ionic liquid monomer was achieved using the Grubbs third-generation catalyst and starting the polymerization off with an uncharged, nonparamagnetic norbornene monomer in a sequential block copolymerization. Preparing the paramagnetic norbornene imidazolium FeCl4– monomer in high purity was found to be crucial for enabling living polymerization behavior and generating paramagnetic diblock copolymers with predictable block lengths and compositions.

Anion-exchange membranes (AEMs) often dehydrate and lose ionic conductivity in ferric chloride solutions used in all-iron or iron–chromium redox flow batteries (RFB). In this work, the change in ma...

A laminated thin-film composite (TFC) membrane system consisting of an ultrafiltration support, an ordered, nanoporous, polymerized lyotropic liquid crystal (LLC) intermediate layer, and an ultrath...

A single-head/single-tail surfactant with a polymerizable group at each end is presented as a new simplified motif for intrinsically cross-linkable, gyroid-phase lyotropic mesogens. The resulting nanoporous polymer networks exhibit excellent structural stability in various solvents and are capable of molecular size discrimination.

The nanopores of an as-synthesized cross-linked, cationic, type I bicontinuous cubic (QI)-phase lyotropic liquid crystal network were modified by exchange of its Br– counteranions in the pores with...

Creating well-defined single-crystal textures in materials requires the biaxial alignment of all grains into desired orientations, which is challenging to achieve in soft materials. Here we report the formation of single crystals with rigorously controlled texture over macroscopic areas (>1 cm2) in a soft mesophase of a columnar discotic liquid crystal. We use two modes of directed self-assembly, physical confinement and magnetic fields, to achieve control of the orientations of the columnar axes and the hexagonal lattice along orthogonal directions. Field control of the lattice orientation emerges in a low-temperature phase of tilted discogens that breaks the field degeneracy around the columnar axis present in non-tilted states. Conversely, column orientation is controlled by physical confinement and the resulting imposition of homeotropic anchoring at bounding surfaces. These results extend our understanding of molecular organization in tilted systems and may enable the development of a range of new materials for distinct applications. Macroscopic single crystals with controlled texture are formed from a self-assembled columnar discotic liquid crystal.

A three-component (cross-linked poly(ionic liquid) (PIL)–ionic liquid (IL)–zeolite), mixed-matrix membrane (MMM) platform based on curable IL prepolymers of controlled length has been developed for...

A series of thermally processable, phase-separating diblock copolymers made via sequential ATRP of styrene and styrenic ionic liquid (IL) monomers with various alkyl imidazolium substituents were synthesized to cover a wide range of volume fractions, most notably those on the IL-rich side of the phase diagram. Small-angle X-ray scattering (SAXS) analysis was used to confirm melt-state (and glassy state) phase behavior in which all four classic equilibrium diblock copolymer morphologies – body-centered cubic spheres (SBCC), hexagonally packed cylinders (Hex), lamellae (Lam), and notably, bicontinuous gyroid (Gyr) – were observed. These PS-PIL diblock copolymers were found to have a high degree of conformational asymmetry and/or electrostatic cohesion within the PIL block, highlighted by the shift of the Lam phase window with boundaries falling between fPIL = 0.31 and 0.55. Variation of the alkyl group appeared to influence the strength of the Flory-like interaction parameter of the system, χPS/PIL, such that simple substitution of methyl by n-butyl on the imidazolium IL substituent resulted in the emergence of the (notoriously segregation-sensitive) Gyr phase, superseding the persistent coexistence of Lam and Hex in the methyl-substituted imidazolium diblock copolymer phase diagram.

Periodic, nanostructured porous polymer membranes made from the cross-linked inverted hexagonal phase of self-assembled lyotropic liquid crystals (LLCs) are a promising class of materials for selective separations. In this work, we investigate an experimentally characterized LLC polymer membrane using atomistic molecular modeling. In particular, we compare simulated X-ray diffraction (XRD) patterns with experimental XRD data to quantify and understand the differences between simulation and experiment. We find that the nanopores are likely composed of five columns of stacked LLC monomers which surround each hydrophilic core. Evidence suggests that these columns likely move independently of each other over longer time scales than accessible via atomistic simulation. We also find that wide-angle X-ray scattering structural features previously attributed to monomer tail tilt are likely instead due to ordered tail packing. Although this system has been reported as dry, we show that small amounts of water are necessary to reproduce all features from the experimental XRD pattern because of asymmetries introduced by hydrogen bonds between the monomer head groups and water molecules. Finally, we explore the composition and structure of the nanopores and reveal that there exists a composition gradient rather than an abrupt partition between the hydrophilic and hydrophobic regions. A caveat is that the time scales of the dynamics are extremely long for this system, resulting in simulated structures that appear too ordered, thus requiring careful examination of the metastable states observed in order to draw any conclusions. The clear picture of the nanoscopic structure of these membranes provided in this study will enable a better understanding of the mechanisms of small-molecule transport within these nanopores.

Current commercial nanofiltration and reverse osmosis membranes are limited in scope and performance due to their physicochemical properties. Desalination of hydraulic fracturing wastewater poses a particular challenge to membrane filtration given the high concentrations of both organic compounds and salts present in these waters. The recently-developed nanoporous, bicontinuous cubic, lyotropic liquid crystal, thin-film-composite polymer membrane (TFC QI membrane), having unique physicochemical properties, enables an alternative treatment of hydraulic fracturing wastewater. Specifically, the TFC QI membrane recovers the organic compounds from this high-salinity wastewater, enabling biodegradation to occur after desalination. However, other performance criteria must be demonstrated for a membrane to reach application. The work presented herein demonstrates the stable performance of the TFC QI membrane during 66 h of cross-flow filtration of hydraulic fracturing produced water. Compared to the commercial NF90 membrane, the TFC QI membrane recovered a larger portion of the organic compounds, had a higher thickness-normalized water flux, and fouled less. The combination of the TFC QI membrane’s selectivity with its reduced fouling propensity makes possible a treatment for hydraulic fracturing wastewater and other complex aqueous streams inaccessible by most commercial membranes, motivating the further study and development of the TFC QI membrane.

A peelable gel coating based on a curable ammonium-alcohol ionic liquid (IL) prepolymer has been developed for the decontamination of toxic industrial chemicals (TICs) from porous substrates. The physical properties of these coatings can be tuned by controlling the prepolymer molecular weight (prepared by RAFT polymerization) and by altering the formulation of the initial coating mixture. The initially applied (uncured) solutions can be applied onto porous wood and ceramic substrates with minimal soak-in, and these films cure quickly in situ under ambient conditions. These coatings were tested in a series of assays meant to demonstrate their effectiveness as TIC vapor barriers and materials that absorb liquid TICs from the aforementioned substrates. The coatings were found to suppress ∼80% of the vapor released by a TIC simulant (o-dichlorobenzene) from these substrates and to extract up to 85% of the mass of the originally applied simulant that soaked into these substrates.

The influence of free IL structure and loading level in phosphonium-based poly(ionic liquid)/ionic liquid (PIL/IL) ion gel composite membranes was studied with regards to their ion conductivity and light gas separation performance. The resulting series of ion gels demonstrated ion conductivity values of 10–7–10–5 S/cm at 25 °C and 10–5–10–3 S/cm at 110 °C. It was found that shorter alkyl chain lengths on the phosphonium cation of the IL resulted in increased thermal stability of the ionic conductivity for the resulting PIL/IL membrane materials with negligible changes in ionic conductivity performance at temperatures up to 110 °C. Further, an increase of free IL loading resulted in an increase in overall ion conductivity and membrane mechanical stability. Similar structure/composition/function relationships were observed for the light gas separation performance of these phosphonium-based PIL/IL ion gel membranes. However, the resulting performance is lower than PIL/IL ion gel membranes based on imidazoliu...

An ordered, nanoporous, TEMPO-based polymer resin formed from lyotropic liquid crystal monomers catalyzes the hetereogeneous oxidation of alcohols with high activity and substrate size selectivity under transition-metal-free, aerobic conditions.

A thin-film composite, bicontinuous cubic lyotropic liquid crystal polymer (TFC Q I ) membrane with uniform-size, ionic nanopores was studied for the treatment of hydraulic fracturing flowback water. The TFC Q I membrane performance was compared to those of a commercial nanofiltration (NF) membrane (NF270) and a commercial reverse osmosis (RO) membrane (SW30HR) for the filtration of flowback water from the Denver-Julesburg Basin. The permeability, salt rejection, and organic solute rejection for each membrane was evaluated. The results illustrate that the TFC Q I membrane maintained its performance to a similar degree as the commercial NF and RO membranes while demonstrating a unique selectivity not observed in the commercial membranes. Specifically, the TFC Q I membrane rejected 75% of the salt while recovering 9.6% of the dissolved organic carbon (DOC) and 50% of the water. Of particular interest was the recovery of labile DOC, which was assessed through biodegradation experiments. Analysis following biodegradation of the TFC Q I membrane permeate demonstrates the membrane's ability to recover labile DOC in a reduced-saline permeate. Improved recovery of labile DOC (increased to 22%) was demonstrated by reducing the pH of the flowback water. Therefore, the selectivity of the TFC Q I membrane provides an opportunity to recover resources from hydraulic fracturing flowback.

Supramolecular organic frameworks (SOFs) represent a class of microporous solids with excellent light-gas selectivity, as well as good solubility/dispersibility in common organic solvents. We created new mixed-matrix membrane (MMM) materials by blending the microporous, solid supramolecular organic framework material, pillar[5]arene (P5-SOF) with the commercial polymer, Matrimid-5218™, and tested their light gas separation performance. These purely organic MMM materials were found to have very high (light gas/CH 4 ) selectivity values (CO 2 /CH 4 : 180, N 2 /CH 4 : 6.5, and H 2 /CH 4 : 600), illustrating that they have promise as membranes for high-purity CH 4 separations.

The selectivity of a bicontinuous cubic, lyotropic liquid crystal (LLC) polymer nanofiltration membrane containing uniform cationic nanopores was manipulated via anion-exchange at the pore wall by soaking the fabricated membranes in aqueous salt solutions. Monovalent organosulfonate anions of various sizes were completely exchanged as the counterion at the pore walls to explore the impact of anion size on uncharged molecular solute rejection and water permeance. It was found that larger organosulfonate anions associated at the pore walls induced a higher rejection of uncharged solutes and a lower water permeance. The change in selectivity of the nanopores was described quantitatively through the calculation of the effective pore radius. The effective pore radius in these modified membranes was found to vary from 0.9±0.2 to 0.55±0.08 nm depending on the resident organosulfonate counterion, demonstrating sub-1-nm resolution in pore size manipulation. An empirical model was used to demonstrate that physicochemical properties (molecular volume and hydrophobicity) of the resident counterion correlate with the observed solute rejection, suggesting that the counterion can be chosen to target a desired membrane performance. The ability to manipulate uniform, nm-sized pores with sub-1-nm resolution via simple anion-exchange offers a new avenue to tailor nanofiltration membrane performance.

The CO2/CH4 separation performance under humidified mixed feed conditions relevant to biogas separation is reported for supported, epoxy-amine-based ion gel membranes containing fixed-site amine facilitated CO2 transport carriers. The chemical composition of the ion gel membranes consists of combination of the bis(epoxide)-IL monomer and trifunctional amine monomer in a mole ratio 3:2 plus either 50 or 75 wt% free [EMIM][Tf2N], impregnated into a Omnipore™ support film. Prepared samples were examined for fundamental structure/property relationships via permeation and sorption methods. Gas sorption confirmed specific gas interactions, showing elevated CO2 sorption compared to CH4 with increasing equilibrium feed pressure. Single gas permeation demonstrated almost a three-fold increase in CO2 permeability from 195 barrer for 50 wt% of free [EMIM][Tf2N] to 525 barrer for 75 wt% of ionic liquid while the ideal selectivity α(CO2/CH4) stayed almost the same (20 and 18, respectively). The effects of feed composition, feed pressure, and relative humidity (32% and 54%) on the CO2/CH4 separation performance were elucidated for mixed-gas feeds. Under simulated biogas processing conditions, an increase of CO2/CH4 separation factor from 25 to 35 with increasing humidity and low feed pressure was observed. Such behavior indicates that the fixed-site-carrier facilitated CO2 transport mechanism enhances also the CO2/CH4 separation performance of studied membranes, as observed for the CO2/N2 mixtures studied previously. This feature also enables them to reach a performance level close to the 2008 Robeson plot upper bound.

A series of ammonium-diol and -triol ionic liquid (IL) monomers were synthesized and used in step-growth polymerization with the commercial di-isocyanate monomer, toluene-di-isocyanate (TDI), in the presence of free ammonium IL to form new curable ammonium-based polymerized ionic liquid/ionic liquid (PIL/IL) composite film coatings. The use of polyurethane chemistry allows for the near-complete curing of the alcohol and isocyanate monomers to yield solid, homogeneous, cross-linked polyurethane-based PIL/IL composite materials with no volatile side product formation. The physical properties and curing rates of these PIL/IL films were altered by tailoring the structures of the ammonium-alcohol IL monomers, the ratio of the linear vs. cross-linking IL monomers employed, and the amount of free IL in the curing reactions. Although ammonium-based PILs have been reported to be less thermally and electrochemically stable than their imidazolium counterparts in the literature, TGA results indicated a Tonset of up to 300 °C under air for the ammonium PIL/IL composites prepared in this study. These new PIL/IL materials were also tested as curable coatings in a toxic industrial chemical (TIC) vapor suppression and liquid uptake assay using o-dichlorobenzene (o-DCB) as a simulant for polychlorinated biphenyls. The curable PIL/IL coatings were found to suppress 88% of the o-DCB vapor on o-DCB-contaminated painted steel substrates and 79% of the o-DCB vapor on o-DCB-contaminated rubber substrates, relative to uncoated control samples. However, although effective for TIC vapor suppression, these ammonium PIL/IL coatings only sorbed less than 50% of the applied liquid o-DCB from the same test substrates, making them slightly less effective for this latter application than previously reported imidazolium-based curable PIL/IL coatings. These materials exhibited comparable ionic conductivity values to other types of PIL/IL systems previously reported in the literature. However, it was found that the more heavily cross-linked ammonium-based PIL/IL films were more prone to free IL leach-out at higher temperatures, leading to their unexpectedly higher ionic conductivity at elevated temperatures.

In this study, a new family of poly(ethylene glycol) (PEG)-based membranes for CO2 separation was developed using PEG diglycidyl ether (PEGDE) cross-linked with a low-molecular-weight diamine (2,2′-(ethylenedioxy)bis(ethylamine)) and a polyamine-based ionic liquid (triethylenetetramine trifluoroacetate, [TETA][Tfa]) in a solvent-free process. A mass fraction up to 80% PEG dimethyl ether (PEGDME, average Mn~250) was added to the cross-linked matrix to enhance the gas transport properties. The cross-linking reaction mechanism, thermal stability of the resulting membranes, as well as water uptakes of the formed membranes were systematically investigated. The CO2, N2, and CH4 gas transport properties of these new membranes were studied. Both CO2/N2 and CO2/CH4 binary mixed gas separation performances of the membranes at various humidity levels were tested. The gas permeation results showed that the free PEGDME additive acts as plasticizer in the polymeric matrix, resulting in excellent CO2/ N2 and CO2/CH4 separation properties.

Histoplasmosis is an opportunistic fungal infection that occurs predominantly in immunocompromised patients. Cutaneous lesions in histoplasmosis are rare and typically occur in the absence of extra-cutaneous manifestations. We present a rare case of disseminated cutaneous-only histoplasmosis in a patient with recently diagnosed AIDS.

Background Despite widespread use of steroid-sparing agents, particularly cyclosporine, for treatment of alopecia areata (AA), there are no clinical trials investigating the efficacy of these agents. Objective To evaluate the efficacy of cyclosporine compared with placebo at 3 months in patients aged 18 to 65 years with moderate-to-severe AA. Methods A double-blind, randomized, placebo-controlled trial was conducted. Adults aged 18 to 65 years of age with moderate-to-severe AA were randomized in a 1:1 ratio to receive 3 months of cyclosporine (4 mg/kg/d) or matching placebo. Blinded assessments included physical examination, blood biochemistry, photography, quality of life measurements, and efficacy evaluation using Severity of Alopecia Tool score and eyelash and eyebrow assessment scales. Results The results obtained for 32 participants (16 who received cyclosporine and 16 who received placebo) were analyzed. Compared with the placebo group, the cyclosporine group had a greater proportion of participants achieving at least a 50% reduction in Severity of Alopecia Tool score (31.3% vs 6.3% [P = .07]) and greater proportion of participants achieving a 1-grade improvement in eyelash (18.8% vs 0% [P = .07]) and eyebrow (31.3% vs 0% [P = .02]) scale score. Limitations Small sample size and single-institution trial may limit interpretation and generalizability of these results. Conclusion Response approached but did not reach a statistically significant difference between cyclosporine and placebo.

Three-component mixed-matrix membranes composed of a polymerized room-temperature ionic liquid (poly(RTIL)), a room-temperature ionic liquid (RTIL), and a zeolite were synthesized and evaluated for CO2/CH4 permeability under binary gas feeds, and operating pressures and temperatures of up to 40 bar and 50 °C, respectively. A CO2/CH4 selectivity of 43 with a CO2 permeability of 202 barrers was achieved by a MMM containing 30 wt % SAPO-34 at 40 bar and 17 °C with an equimolar CO2/CH4 feed. The differences in selectivity and permeability between membranes containing 30 wt% SAPO-34 vs. SSZ-13 suggest that CO2-induced swelling of the poly(RTIL) + RTIL matrix may lead to delamination of the matrix from the zeolite particle surface. This effect may detrimentally affect zeolites with a weaker surface charge. For membranes containing 30 wt % SAPO-34, at 17 °C, both CO2 permeability and CO2/CH4 selectivity increase when the feed composition increases from 25 mol % to 50 mol % CO2, likely due to competitive sorption. At 50 °C, the highest recorded selectivity was 26, which can be attributed to selectivity losses from decreased CO2 adsorption onto the zeolites and thermally induced poly(RTIL) + RTIL matrix swelling by CO2.

Solvent-free, melt-state self-assembly of sphere-forming polystyrene-b-poly(ethylene oxide) diblock copolymer/polystyrene-b-poly(ethylene oxide)-b-polystyrene triblock copolymer (SO/SOS) blends was used to produce free-standing, room-temperature ionic liquid (RTIL) composite membranes with excellent mechanical properties and CO2/N2 separation performance. Membranes were prepared from vitrified SO/SOS diblock/triblock melts by swelling to greater than 94 wt% 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]) ionic liquid. These free-standing composite membranes were evaluated for their CO2/N2 separation performance over a range of transmembrane pressures (26-413 kPa), with results traversing the 2008 Robeson upper bound. Even with such high loadings of neat [EMIM][TFSI], these membranes exhibit the mechanical properties of solid elastomers, evident by the ultimate tensile strength of 250 kPa and the compressive modulus at 40% strain of 348 kPa for the membranes with 46% triblock copolymer content (SOS46). Cyclic loading and unloading in both tension and compression revealed reversible elasticity, with no mechanical property degradation or permanent hysteresis detected. For each composition studied, membrane failure occurred at uniaxial extension ratios of 3.8. The CO2 permeability performance of these membranes was stable for 28 days of testing with no detectable RTIL leakage. Transmembrane pressures exceeding 400 kPa could be accommodated, with cyclic application of transmembrane pressure differentials at 230 kPa producing neither plastic deformation nor diminished performance in gas separations. Such behavior is intimately tied to the highly distensible and elastic nature of the melt-assembled diblock/triblock network underpinning this RTIL-based composite membrane design.

Zeolite particles, cross-linked poly(room-temperature ionic liquid)s (poly(RTIL)s), and room-temperature ionic liquids (RTILs) are combined to form mixed-matrix-membranes (MMMs) that exhibit a CO2/CH4 selectivity of 90±10 and a CO2 permeability of 260±20 barrers. This ideal (i.e., single-gas) separation performance is among the best reported in the literature, comparable to that of thermally rearranged polymers. The MMMs reported herein are physically robust and easily processed into membranes via conventional solvent-casting techniques. The elucidation and optimization of factors responsible for generating high-performance MMMs for CO2/CH4 separations were found to include: zeolite particle type, zeolite particle loading, poly(RTIL) structure, amount of cross-linking, and zeolite dispersion method in the RTIL. Optimization of these factors produced enhanced CO2/CH4 separation that significantly exceeds the 2008 Robeson upper bound, while the MMMs remain mechanically robust and easy to process.

We demonstrate that an ether-based n-alkoxy-2,4-hexadiene polymerizable tail system is an effective and modular alternative to traditional ester-based polymerizable tail groups (i.e., acrylate, methacrylate, sorbate) and alkyl-1,3-diene tails for the design of radically polymerized ionic liquid crystal (ILC) monomers. Several series of nonsymmetric 1-vinylimidazolium-bromide-based ILC monomers containing these different polymerizable tail systems were synthesized and compared for their ability to form thermotropic liquid crystal (TLC) phases and to be photo-cross-linked with TLC phase retention. The n-alkoxy-2,4-hexadiene tail system was found to be more favorable/conducive to TLC phase formation than acrylate, methacrylate, and sorbate tails. It was more similar to the alkyl-1,3-diene tail system in terms of its more favorable effect on TLC behavior; however, it is more modular/easier to synthesize, more resistant to thermal Diels–Alder side reaction, and more isomerically pure, making it better for ILC ...

A curable, imidazolium-based room-temperature ionic liquid (RTIL) coating system has been developed for the containment and decontamination of toxic industrial chemical-contacted surfaces. The curing times and mechanical properties of this poly(RTIL)/RTIL platform, which is based on alcohol–isocyanate step-growth polymerization chemistry, can be tuned by modifying the structures of the step-growth monomers, the stoichiometric ratio of linear (diol, A2) to cross-linking (triol, A3) RTIL monomers used, and the amount of free RTIL in the formulation. When applied to painted steel and rubber test substrates contacted with o-dichlorobenzene (o-DCB) (a polychlorinated biphenyl simulant), a 50:50 (A2:A3) step-growth alcohol-RTIL monomer mixture cross-linked with a stoichiometric amount of a commercial di-isocyanate monomer (B2) and containing 43 wt % free RTIL in the coating, reduced the o-DCB vapor amount by 96–99% compared to the uncoated, o-DCB-contacted control samples. This peelable, flexible, solid coating...

Ionic liquid (IL)-based ion-gel membranes were prepared from a curable poly(IL)-based materials platform with the free ILs 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]), bis(fluorosulfonyl)imide ([EMIM][FSI]), 1-butylimidazolium bis(trifluoromethylsulfonyl)imide ([C4 IMH][TFSI]), and ethylmethylammonium nitrate [EAN][NO3 ] and evaluated for their ionic conductivity performance at ambient and elevated temperatures. The resulting cross-linked, free-standing ion-gel membranes were found to have less than 1 wt% water (with the exception of [EAN][NO3 ] which contained ≈20 wt% water). Increasing free IL content from 50 to 80 wt% produces materials with ionic conductivity values ≥10(-2) S cm(-1) at 25 °C and ≈10(-1) S cm(-1) at 110 °C. Additionally, ion-gels containing 70 wt% of the protic ILs [C4 IMH][TFSI] and [EMIM][FSI] display ionic conductivity values of ≈10(-3) to 10(-2) S cm(-1) over the temperature range of 25-110 °C.

Molecularly imprinted polymers (MIPs) are an important class of selective materials for molecular specific sensors and separations. Molecular imprinting using non-covalent interactions in aqueous conditions still remains a difficult challenge due to interruption of hydrogen-bonding or electrostatic interactions water. Newly developed crosslinking ionic liquids are demonstrated herein to overcome problems of synthesizing aqueous MIPs, adding to previous examples of ionic liquids used as monomers in non-aqueous conditions or used as MIP solvents. Vinylimidazole ionic liquid crosslinkers were synthesized and subsequently explored as matrix supports for fabrication of molecularly imprinted polymeric nanoGUMBOS (nanoparticles derived from a group of uniform materials based on organic salts). Each of the four crosslinkers incorporated a unique functional spacer between the vinylimidazole groups, and the performance of the corresponding molecularly imprinted polymers was evaluated using chiral recognition as the diagnostic. High uptake values for l-tryptophan were found in the 13-87μmol/g range; and chiral recognition was determined via binding ratios of l-tryptophan over d-tryptophan that ranged from 5:1 to 13:1 for polymers made using different crosslinkers. Not only are these materials good for chiral recognition, but the results highlight the utility of these materials for imprinting aqueous templates such as biological targets for theranostic agents.

Nanostructured composite electrolyte films consisting of a cross-linked lyotropic liquid crystal (LLC) monomer, an organic carbonate liquid electrolyte (propylene carbonate, dimethylcarbonate, diethylcarbonate) and a Li salt (LiClO_4, LiBF_4, LiPF_6) were systematically prepared and characterized at two electrolyte concentrations (0.245 and 1.0 m) and four liquid loading levels (5, 15, 30, 50 wt %). The LLC morphology of the films was investigated using polarized light microscopy and powder X-ray diffraction; their ionic conductivity was investigated using AC impedance measurements. Higher liquid electrolyte loadings and Li salt concentrations generally increased ionic conductivity, regardless of the liquid electrolyte or salt used. Some mixed-phase LLC morphologies displayed good ionic conductivity; however, as initially prepared, these formulations were at the limit of liquid uptake. In contrast, composites with a type II bicontinuous cubic (QII) LLC phase containing ordered, three-dimensional interconnected nanopores exhibited good conductivity using much less liquid electrolyte and a lower Li salt concentration, indicating that this structure is more amenable to ion transport than less ordered/uniform morphologies. When wetted with electrolyte solution and integrated into Li/fluorinated carbon coin cells, the QII films were sufficiently strong to act as an ion-conductive separator and displayed stable open-circuit potentials. Many of the mixed-phase films gave shorted cells.

Phosphonium poly(ionic liquid)s (PILs) have been studied as alternatives to more common ammonium and imidazolium PILs for potential transport and separation applications. This work characterizes the CO2, H2, N2, O2, CH4, and C2H4 single-gas permeability, diffusivity, solubility, and selectivity of free-standing films of poly([(tri-n-alkyl)vinylbenzylphosphonium][bis(trifluoromethylsulfonyl)imide]) PILs (i.e., poly([PnnnVB][Tf2N]) where n=4, 6, 8). The gas permeability was found to increase approximately linearly with increasing alkyl chain length on the phosphonium group. To our knowledge, the CO2 permeability of 186 barrers observed for poly([P888VB][Tf2N]) is the highest reported for neat PIL materials. In contrast, gas selectivity was observed to decrease with an increase in phosphonium alkyl chain length from n=4 to n=6, then remain approximately constant between n=6 and n=8. Additionally, the ionic conductivity of these materials was observed to increase from ca. 10−8 to ca. 10−5 S cm−1 as the measurement temperature was increased from 25 to 105 °C. At 25 °C, the PIL with the shortest cation alkyl chain (n=4) was observed to have the lowest ionic conductivity. However at ca. 90 °C, the expected trend of increasing ionic conductivity in the order n=4>n=6>n=8 was observed.

This paper presents details of recent research progress on CO2 separation membranes and membrane processes using ionic liquids (ILs) over the past few years, including supported ionic liquid membranes (SILMs), poly(ionic liquid) membranes (PILMs), poly(ionic liquid)–ionic liquid (PIL–IL) composite membranes, polymer-ionic liquid composite membranes, ion-gel membranes, and membrane absorption processes based on ILs. Descriptions of different approaches to membrane preparation, use of gas transport mechanisms, and state-of-the-art separation results are discussed in the context of breakthroughs and challenges. Furthermore, comprehensive assessment of recently improved membranes and possible future R&D prospective are also discussed.

Membrane separations are critically important in areas ranging from health care and analytical chemistry to bioprocessing and water purification. An ideal nanoporous membrane would consist of a thin film with physically continuous and vertically aligned nanopores and would display a narrow distribution of pore sizes. However, the current state of the art departs considerably from this ideal and is beset by intrinsic trade-offs between permeability and selectivity. We demonstrate an effective and scalable method to fabricate polymer films with ideal membrane morphologies consisting of submicron thickness films with physically continuous and vertically aligned 1 nm pores. The approach is based on soft confinement to control the orientation of a cross-linkable mesophase in which the pores are produced by self-assembly. The scalability, exceptional ease of fabrication, and potential to create a new class of nanofiltration membranes stand out as compelling aspects.

The amine functional groups in room-temperature ionic liquid (RTIL)-based epoxy-amine ion gel membranes allow for the fixed-site-carrier facilitated transport of CO 2 . These membranes were tested under humidified mixed-gas (CO 2 /N 2 ) feeds in order to evaluate the effects of relative humidity, CO 2 partial pressure, and hydrophobicity of the added free RTIL on CO 2 /N 2 separation performance. Changes in relative humidity were found to have little effect on CO 2 /N 2 separation performance at constant CO 2 partial pressure. However, comparison to dry-gas measurements showed that the presence of water vapor is necessary to observe facilitated CO 2 transport in these systems. Increased CO 2 permeability and CO 2 /N 2 selectivity were observed for these epoxy-amine ion gel membranes with decreasing CO 2 partial pressure, as expected for materials operating via the fixed-site-carrier facilitated transport mechanism. The hydrophilicity of the free RTIL was found to influence CO 2 transport, with a more hydrophilic RTIL able to facilitate CO 2 transport at lower relative humidity. Facilitated transport enhances the CO 2 /N 2 separation performance of these epoxy-amine ion gel membranes and enables them to exceed the 2008 Robeson plot upper bound.

A range of systemic treatments are used for alopecia areata with variable evidence supporting efficacy. In this systematic review, we evaluated the evidence surrounding systemic treatments for alopecia areata, alopecia totalis and alopecia universalis. A systematic search was conducted of the peer-reviewed literature published between 1946 and March 2018 via Medline, Embase, Amed, the Cochrane Central Register of Controlled Trials, PsychINFO and Lilacs. All randomised controlled trials (RCTs) that evaluated the effectiveness of systemic treatments for individuals with alopecia areata, totalis or universalis were included. Sixteen studies were included with a total of 768 participants. We found eight placebo-controlled RCTs, three RCTs comparing two systemic treatments and five RCTs comparing three treatments. A total of 15 different systemic therapies were investigated. The most frequently investigated therapy was oral prednisolone pulse therapy and oral inosiplex. There was significant variability in the definition of treatment success. No study evaluated the impact of pharmacotherapy on quality of life using complete quantitative quality of life instruments. Adverse events were reported in 13 studies and were corticosteroid related or otherwise well tolerated. Relapse rates were considerable in the four studies that reported this outcome. There is currently no specific systemic therapy that is supported by robust body of evidence from RCTs. The current evidence suggests efficacy of oral prednisolone pulse therapy and oral inosiplex. Evidence does not support the use of oral zinc sulphate, alefacept and efalizumab. Future RCTs should be adequately powered and employ clearly defined clinical response endpoints to allow future meta-analyses.

Creating well-defined single-crystal textures in materials requires the biaxial alignment of all grains into desired orientations, which is challenging to achieve in soft materials. Here we report the formation of single crystals with rigorously controlled texture over macroscopic areas (1 cm