The physical properties of ionic liquids (ILs) have led to intense research interest, but for many applications, high viscosity is problematic. Mixing the IL with a diluent that lowers viscosity offers a solution if the favorable IL physical properties are not compromised. Here we show that mixing an IL or IL electrolyte (ILE, an IL with dissolved metal ions) with a nonsolvating fluorous diluent produces a low viscosity mixture in which the local ion arrangements, and therefore key physical properties, are retained or enhanced. The locally concentrated ionic liquids (LCILs) examined are 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (HMIM TFSI), 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate (HMIM FAP), or 1-butyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate (BMIM FAP) mixed with 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (TFTFE) at 2:1, 1:1, and 1:2 (w/w) IL:TFTFE, as well as the locally concentrated ILEs (LCILEs) formed from 2:1 (w/w) HMIM TFSI-TFTFE with 0.25, 0.5, and 0.75 m lithium bis(trifluoromethylsulfonyl)imide (LiTFSI). Rheology and conductivity measurements reveal that the added TFTFE significantly reduces viscosity and increases ionic conductivity, and cyclic voltammetry (CV) reveals minimal reductions in electrochemical windows on gold and carbon electrodes. This is explained by the small- and wide-angle X-ray scattering (S/WAXS) and atomic force microscopy (AFM) data, which show that the local ion nanostructures are largely retained in LCILs and LCILEs in bulk and at gold and graphite electrodes for all potentials investigated.

Capturing CO2 and H2 purification from gas mixtures such as CO2/N2 and H2/N2 are vital in addressing greenhouse gas emission abatement and global energy strategy. Here, we present a systematic investigation of tubular polyetherimide (PEI) membranes prepared by combining dip-coating and multilayer assembly techniques to target CO2 and H2 transports and CO2/N2 and H2/N2 selectivities. The effects of deposition cycle during dipcoating on H2, CO2 and N2 single gas permeations and binary gas separations were evaluated. The membranes prepared by three deposited layers produced gas permeances (10-12 mol m- 2 s- 1 Pa-1) of 310, 150 and 1 for H2, CO2 and N2 respectively, corresponding to CO2/N2 and H2/N2 permselectivities of 149 and 308. For binary gas mixture separation, an exclusive 100% CO2 and H2 permeate purity was observed irrespective of feed gas concentration. The PEI membrane exhibited a suppression of glass transition temperature and crystallinity compared to the bulk polymer indicating interfacial confinement phenomenon, which was further confirmed by X-ray diffraction and Raman spectroscopic analyses. Due to a subtle change of imide group conformation of the obtained membrane layer, it was inferred that an increase in the polymer amorphicity and interfacial confinement facilitated the exclusive H2 and CO2 transports without much affecting the N2 permeance.

The narrow pore channels of cobalt-silica (CoSi) catalyst generated by conventional sol-gel process limited the active site accessibility. In this work, mesoporous CoSi catalysts containing highly dispersed Co sites were synthesized by a facile sol-gel derived soft-templating technique and tested for the Fenton-like oxidation of dyes and antibiotics. By controlling the concentration of triblock polymer Pluronic F127 template, the textural and chemical properties of CoSi catalysts were fine-tuned to improve the accessibility of their active sites. The CoSi catalyst achieved -96% removal of acid orange 7 (AO7) within 15 min using a low catalyst loading (50 mg L-1) and H2O2 dosage (11 mM) at pH of 7-8. Moreover, thin-film CoSi coated on Al2O3 foam, as a monolithic catalyst prepared by the washcoating method, maintained high oxidation activity (-99% removal for AO7) over 10 days, demonstrating excellent operational stability and process intensification for practical wastewater treatment applications.

Cylindrical polymer brushes (CPBs) are macromolecules with nanoparticle proportions. Their modular synthesis enables tailoring of their chemical composition as well as the dialing-up of overall dimensions and physicochemical properties. In this study, two rod-like poly[(ethylene glycol) methyl ether methacrylate] (PEGMA)-based CPBs with varying stiffness but otherwise comparable features and functionality, are synthesized. Differences in particle stiffness are assessed using small angle neutron scattering (SANS). It is observed that the fate of the two CPBs within cells is distinctly different. Stiffer CPBs seem to gravitate toward the mitochondria, whereas CPBs with reduced stiffness are present in different intracellular vesicles.

Understanding fluid flow in shale rocks is critical for the recovery of unconventional energy resources. Despite the extensive research conducted on water and oil flow in shales, significant uncertainties and discrepancies remain in reported experimental data. The most noted being that while oil spreads more than water on shale surfaces in an inviscid medium, its uptake by shale pores is much less than water during capillary flow. This leads to misjudgement of wettability and the underlying physical phenomena. In this study, therefore, we performed a combined experimental and digital rock investigation on an organic-rich shale including contact angle and spontaneous imbibition, X-ray and neutron computed tomography, and small angle X-ray scattering tests to study the potential physical processes. We also used non-equilibrium thermodynamics to theoretically derive constitutive equations to support our experimental observations. The results of this study indicate that the pre-existing fractures (first continuum) imbibe more oil than water consistent with contact angle measurements. The overall imbibition is, however, higher for water than oil due to greater water diffusion into the shale matrix (second continuum). It is shown that more water uptake into shale is controlled by pore size and accessibility in addition to capillary or osmotic forces i.e. configurational diffusion of water versus oil molecules. While the inorganic pores seem more oil-wet in an inviscid medium, they easily allow passage of water molecules compared to oil due to the incredibly small size of water molecules that can pass through such micro-pores. Contrarily, these strongly oil-wet pores possessing strong capillarity are restricted to imbibe oil simply due to its large molecular size and physical inaccessibility to the micro-pores. These results provide new insights into the previously unexplained discrepancy regarding water and oil uptake capacity of shales.

Capturing CO2 and H2 purification from gas mixtures such as CO2/N2 and H2/N2 are vital in addressing greenhouse gas emission abatement and global energy strategy. Here, we present a systematic investigation of tubular polyetherimide (PEI) membranes prepared by combining dip-coating and layer-by-layer assembly techniques to target CO2 and H2 transports and CO2/N2 and H2/N2 selectivities. The effects of polymer infiltration, membrane thickness, and surface morphology by controlling polymer solution concentration, withdrawal speed, and deposition cyle during dip-coating on H2, CO2 and N2 single gas permeations and binary gas separations were evaluated. The membranes prepared by 10 wt.% of PEI solution, 300 μm s-1, and three deposited layers produced gas permeances (10-12 mol m-2 s-1 Pa-1) of 310, 150 and 1 for H2, CO2 and N2 respectively, corresponding to CO2/N2 and H2/N2 permselectivities of 149 and 308. For binary gas mixture separation, an exclusive 100% CO2 and H2 permeate purity was observed irrespective of feed gas concentration. The PEI membrane exhibited a suppression of glass transition temperature and crystallinity compared to the bulk polymer indicating interfacial confinement phenomenon, which was further confirmed by X-ray diffraction and Raman spectroscopic analyses. Due to a subtle change of imide group conformation of the obtained membrane layer, it was inferred that an increase in the polymer amorphicity and interfacial confinement facilitated the exclusive H2 and CO2 transports without much affecting the N2 permeance.

We synthesized cobalt tetroxide (Co3O4) silica nanocomposites based on the conventional tetraethyl orthosilicate (TEOS) monomer and ethoxy polysiloxane (ES40) oligomer by sol-gel chemistry coupled with rapid thermal process (RTP). The physicochemical properties and structural formation of cobalt oxide silica nanocomposites were comprehensive characterized. By using ES40, well-controlled, homogeneous nanoparticle dispersion and size of Co3O4 with 5 nm within the silica matrix were achieved leading to fractal-like morphology. The concentration of the Co3O4 nanocatalyst was also significantly enhanced by more than 50 folds. Fenton-like HCO3-/H2O2 catalytic system using acid orange 7 and nanocomposites was examined for organic degradation. 98% AO7 and naphthalene intermediates degradation efficiency was achieved after 20 min with ES40-derived catalyst, which was three to ten folds faster than that of the TEOS-derived catalyst and the commercial Co3O4 catalyst. The combined use of ES40 sol-gel and RTP enabled a simple way to nanomaterial preparation and lowers overall processing time.

Mice are used for models of almost all human diseases and are routinely scanned by micro-CT scanners. Mouse phantoms are often used for image-quality assessment. With recent developments in deep-learning-based preclinical imaging, there is a major need for large micro-CT datasets in which ground truth is known. In this study, we investigate the feasibility of making cost-effective deformable and reconfigurable mouse phantoms to generate real micro-CT datasets that reflect realistic underlying physical characteristics. Such datasets are highly desirable; for example, complicated photon-counting micro-CT datasets are needed for deep-learning-based material decomposition. In our scheme, mouse body parts are 3Dprinted with high precision using rigid or flexible materials. Liquid tissue surrogates (LTSs) or bioinks/cell lines could be used to emulate mouse organs and physiological fluid in the animals. LTSs provide realistic x-ray properties of their biological counterparts. The LTS organs could be contained in not only 3D-printed chambers, but also dialysis tubing, which emulates the cell membrane. Furthermore, through bioprinting and tissue engineering, organs and tissues can be made even more realistic for micro-CT and other types of tomographic scanning.

Hypothesis: The solvation characteristics of poly(ethylene oxide) (PEO) in nanostructured protic ionic liquids (PILs) are driven by polymer-solvent interactions in the polar domains of the PIL. This work hypothesises that the nanostructure of a PIL can be altered via halide addition, directly affecting the solvation of PEO. Experiments: Small angle neutron scattering (SANS) is used to explore the conformation of 38 kDa PEO dissolved in the PIL propylammonium nitrate (PAN), a mol fraction of 10% propylammonium chloride (PACl) in PAN, and a mole fraction of 10% propylammonium bromide (PABr) in PAN. Findings: Each of these solutions are shown to behave as a good solvent for PEO, as determined by their Flory exponents and Zimm plot analysis. The quality of solvation is reduced by the addition of the halide salt, with the order of solvation as follows: PAN > Br- addition > Cl- addition. Our experimental observations are consistent with the recently reported solvation structure of PEO in these solutions (Stefanovic et al., 2018). The increased charge density from NO3- to Br- to Cl- results in greater net ionic interaction between the ionic charge centres. As PEO interacts with PAN primarily through the ammonium hydrogens of the cation, this increased ionic interaction effectively displaces the PEO, resulting in poorer solvation. (C) 2018 Elsevier Inc. All rights reserved.

Hypothesis: The conformation of poly(ethylene oxide) (PEO) in deep eutectic solvents (DESs) is determined by the polymer-solvent interactions, especially hydrogen bonding interactions. The hypothesis for this work is that the hydrogen bonding environment of a DES can be varied via changing the cation or hydrogen bond donor (HBD), and therefore the solvent quality for PEO; the anion species will also effect hydrogen bonding, but this is not examined here. Experiments: Small angle neutron scattering (SANS) is used to probe the concentration dependent conformation of 36 kDa PEO dissolved in DESs formed by mixing ethyl or butyl ammonium bromide with a molecular HBD (glycerol or ethylene glycol) in a 1:2 molar ratio. Findings: The radius of gyration (R-g), Flory exponent and crossover concentration (c*) from the dilute to the semi-dilute regime of PEO in the DESs revealed by SANS and Zimm plot analysis show that these DESs are moderately good solvents for PEO. When the ammonium alkyl chain length is increased, the hydrogen bond density per unit volume decreases, and with it the solvent quality for PEO. The solvent quality is improved when the HBD is changed from glycerol to ethylene glycol due to differences in the hydrogen bonding environment for PEO. (C) 2017 Elsevier Inc. All rights reserved.

The phase behavior and self-assembly structures of a series of amphiphilic diblock co-oligomers comprising an ionizable hydrophilic block (5 to 10 units of acrylic acid) and a hydrophobic block (5 to 20 units of n-butyl acrylate, t-butyl acrylate, or ethyl acrylate), synthesized by RAFT polymerization, have been examined by polarizing optical microscopy and small-angle X-ray scattering (SAXS). Self-assembled structure and lyotropic phase stability in these systems is highly responsive to the degree of ionization of the acrylic acid hydrophilic block (i.e., pH), concentration, and nature of the hydrophobic block. Increasing headgroup ionization switched the amphiphiles from behaving like soluble to insoluble surfactants. Liquid isotropic (micellar), hexagonal, lamellar, and discrete cubic phases were found under different solution conditions. The surfactant packing parameter was adapted to understand the self-assembly structures in these diblock co-oligomers. The hydrophobic chain structure and length were shown to strongly affect the relative stabilities of these phases, allowing the self-assembled structure to be varied at will.

We present a fundamental study into the self-assembly of (cyclic peptide)-polymer conjugates as a versatile supramolecular motif to engineer nanotubes with defined structure and dimensions, as characterised in solution using small-angle neutron scattering (SANS). This work demonstrates the ability of the grafted polymer to stabilise and/or promote the formation of unaggregated nanotubes by the direct comparison to the unconjugated cyclic peptide precursor. This ideal case permitted a further study into the growth mechanism of self-assembling cyclic peptides, allowing an estimation of the cooperativity. Furthermore, we show the dependency of the nanostructure on the polymer and peptide chemical functionality in solvent mixtures that vary in the ability to compete with the intermolecular associations between cyclic peptides and ability to solvate the polymer shell.

The conformation of 36 kDa polyethylene oxide (PEO) dissolved in three glyme-Li(+) solvate ionic liquids (SILs) has been investigated by small angle neutron scattering (SANS) and rheology as a function of concentration and compared to a previously studied SIL. The solvent quality of a SIL for PEO can be tuned by changing the glyme length and anion type. Thermogravimetric analysis (TGA) reveals that PEO is dissolved in the SILs through Li(+)-PEO coordinate bonds. All SILs (lithium triglyme bis(trifluoromethanesulfonyl)imide ([Li(G3)]TFSI), lithium tetraglyme bis(pentafluoroethanesulfonyl)imide ([Li(G4)]BETI), lithium tetraglyme perchlorate ([Li(G4)]ClO4) and the recently published [Li(G4)]TFSI) are found to be moderately good solvents for PEO but solvent quality decreases in the order [Li(G4)]TFSI ∼ [Li(G4)]BETI > [Li(G4)]ClO4 > [Li(G3)]TFSI due to decreased availability of Li(+) for PEO coordination. For the same glyme length, the solvent qualities of SILs with TFSI(-) and BETI(-) anions ([Li(G4)]TFSI and [Li(G4)]BETI) are very similar because they weakly coordinate with Li(+), which facilitates Li(+)-PEO interactions. [Li(G4)]ClO4 presents a poorer solvent environment for PEO than [Li(G4)]BETI because ClO4(-) binds more strongly to Li(+) and thereby hinders interactions with PEO. [Li(G3)]TFSI is the poorest PEO solvent of these SILs because G3 binds more strongly to Li(+) than G4. Rheological and radius of gyration (Rg) data as a function of PEO concentration show that the PEO overlap concentrations, c* and c**, are similar in the three SILs.

The conformation of 38 kDa PEO in a solvate ionic liquid (SIL), lithium tetraglyme bis(trifluoromethanesulfonyl) amide ([Li(G4)]TFSI) from dilute to concentrated solution regimes has been determined by small angle neutron scattering and rheology. SANS analysis reveals that [Li(G4)]TFSI is better than a theta solvent (theta-good) for PEO. The variation of the radius of gyration (R-g) and viscosity as a function of polymer concentration allow the overlap concentrations, c* and c**, to be identified at 13 mg mL(-1) and 50 mg mL(-1), respectively, which are similar to values reported previously for conventional ionic liquids. Unlike water and conventional ionic liquids, [Li(G4)]TFSI cannot form hydrogen bonds with PEO. Thermal gravimetric analysis indicates that the solvation of PEO by [Li(G4)]TFSI is a consequence of PEO forming coordinate bonds with the lithium by displacing the anion, but without displacing the glyme molecule.

Small angle neutron scattering has been used to probe the self-assembled structures formed by novel block copolymers in water and two protic ionic liquids (ILs), ethylammonium nitrate (EAN) and propylammonium nitrate (PAN). The block copolymers consist of solvophilic poly(ethylene oxide) (PEO) tethered to either poly(ethyl glycidyl ether) (PEGE) or poly(glycidyl propyl ether) (PGPrE) solvophobic blocks. Four block copolymers (EGE(109)EO(54), EGE(113)EO(115), EGE(104)EO(178), and GPrE(98)EO(260)) have been investigated between 10 and 100 degrees C, showing how aggregate structure changes with increasing the EO block length, by changing the insoluble block from EGE to the more bulky, hydrophobic GPrE block, and with temperature. EO solubility mainly depends on the hydrogen bond network density, and decreases in the order H2O, EAN, and then PAN. The solubility of the EGE and GPrE blocks decreases in the order PAN, EAN then water because the large apolar domain of PAN increase the solubility of the solvophobic blocks more effectively than the smaller apolar domains in EAN, and water, which is entirely hydrophilic; GPrE is less soluble than EGE because its larger size hinders solubilization in the IL apolar domains. Large disk-shaped structures were present for EGE(109)EO(54) in all three solvents because short EO chains favor flat structures, while GPrE(98)EO(260) formed spherical structures because long EO chains lead to curved aggregates. The aggregate structures of EGE(113)EO(115) and EGE(104)EO(178), which have intermediate EO chain lengths, varied depending on the solvent and the temperature. Solubilities also explain trends in critical micelle concentrations (cmc) and temperatures (cmt).

Photoresponsive micellar systems of 4-butylazobenzene-4'- (oxyethyl)trimethylammonium bromide (AZTMA) were examined with and without ethylbenzene using small-angle neutron scattering (SANS). Analysis of SANS profiles showed that an aqueous solution containing 5, 10, and 50 mM AZTMA forms prolate spheroids with a long radius (Ra) of 38 Å and a short radius (Rb) of 21 Å. In the 5 mM AZTMA solution, the concentration of micelles decreased upon UV light irradiation, while their size and shape remained almost unchanged. Subsequent visible light irradiation reversed the decrease and increased the number of micelles. In contrast, 10 and 50 mM AZTMA solutions showed that the number and long radius of the micelles decreased with UV light irradiation, while subsequent exposure to visible light irradiation restored them. For AZTMA micellar solutions equilibrated with excess ethylbenzene, the solubilized amount of ethylbenzene increased upon UV light irradiation due to enhanced swelling of the micelles with cis-AZTMA. This photoinduced uptake of the solubilizate has potential applicability for the collection and removal of hazardous oily substances.

The structure and interactions of different (Li salt + glyme) mixtures, namely equimolar mixtures of lithium bis(trifluoromethylsulfonyl)imide, nitrate or trifluoroacetate salts combined with either triglyme or tetraglyme molecules, are probed using Molecular Dynamics simulations. structure factor functions, calculated from the MD trajectories, confirmed the presence of different amounts of lithium-glyme solvates in the aforementioned systems. The MD results are corroborated by S(q) functions derived from diffraction and scattering data (HEXRD and SAXS/WAXS). The competition between the glyme molecules and the salt anions for the coordination to the lithium cations is quantified by comprehensive aggregate analyses. Lithium-glyme solvates are dominant in the lithium bis(trifluoromethylsulfonyl)imide systems and much less so in systems based on the other two salts. The aggregation studies also emphasize the existence of complex coordination patterns between the different species (cations, anions, glyme molecules) present in the studied fluid media. The analysis of such complex behavior is extended to the conformational landscape of the anions and glyme molecules and to the dynamics (solvate diffusion) of the bis(trifluoromethylsulfonyl)imide plus triglyme system.

Micelle structure and composition has been determined by small-angle neutron scattering for mixed micellar solutions of in situ polymerized ω-methacryloyloxyundecyl-trimethylammonium bromide (MUTAB) in equilibrium with its monomeric form at various concentrations, as well as in mixtures with a fluorinated cationic surfactant, heptadecafluorodecylpyridinium chloride (HFDePC), and the non-ionic surfactant, C12E7. Whereas polymerized MUTAB is immiscible with HFDePC and forms two populations of distinct spheroidal micelles, it mixes with C12E7 in all proportions and forms a single average micelle structure depending on composition. These results allow us to explain the origin of the previously reported formation of mixed worm-like micelles of polymerized and monomeric MUTAB that coexist with globular monomeric MUTAB micelles as a consequence of the unfavourable electrostatic interactions that accompany the uncoiling of polymerized MUTAB chains in unimer micelles when swollen by monomeric cationic surfactants.