| 1. |
- Wang, Yong-Lei, et al.
(author)
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Microstructural and Dynamical Heterogeneities in Ionic Liquids
- 2020
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In: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 120:13, s. 5798-5877
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Research review (peer-reviewed)abstract
- Ionic liquids (ILs) are a special category of molten salts solely composed of ions with varied molecular symmetry and charge delocalization. The versatility in combining varied cation–anion moieties and in functionalizing ions with different atoms and molecular groups contributes to their peculiar interactions ranging from weak isotropic associations to strong, specific, and anisotropic forces. A delicate interplay among intra- and intermolecular interactions facilitates the formation of heterogeneous microstructures and liquid morphologies, which further contributes to their striking dynamical properties. Microstructural and dynamical heterogeneities of ILs lead to their multifaceted properties described by an inherent designer feature, which makes ILs important candidates for novel solvents, electrolytes, and functional materials in academia and industrial applications. Due to a massive number of combinations of ion pairs with ion species having distinct molecular structures and IL mixtures containing varied molecular solvents, a comprehensive understanding of their hierarchical structural and dynamical quantities is of great significance for a rational selection of ILs with appropriate properties and thereafter advancing their macroscopic functionalities in applications. In this review, we comprehensively trace recent advances in understanding delicate interplay of strong and weak interactions that underpin their complex phase behaviors with a particular emphasis on understanding heterogeneous microstructures and dynamics of ILs in bulk liquids, in mixtures with cosolvents, and in interfacial regions.
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| 2. |
- Anton, Arthur Markus, et al.
(author)
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Hydrogen bonding and charge transport in a protic polymerized ionic liquid
- 2020
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In: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-683X .- 1744-6848. ; 16:26, s. 6091-6101
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Journal article (peer-reviewed)abstract
- Hydrogen bonding and charge transport in the protic polymerized ionic liquid poly[tris(2-(2-methoxyethoxy)ethyl)ammoniumacryloxypropyl sulfonate] (PAAPS) are studied by combining Fourier transform infrared (FTIR) and broadband dielectric spectroscopy (BDS) in a wide temperature range from 170 to 300 K. While the former enables to determine precisely the formation of hydrogen bonds and other moiety-specific quantized vibrational states, the latter allows for recording the complex conductivity in a spectral range from 10(-2)to 10(+9) Hz. A pronounced thermal hysteresis is observed for the H-bond network formation in distinct contrast to the reversibility of the effective conductivity measured by BDS. On the basis of this finding and the fact that the conductivity changes with temperature by orders of magnitude, whereas the integrated absorbance of the N-H stretching vibration (being proportional to the number density of protons in the hydrogen bond network) changes only by a factor of 4, it is concluded that charge transport takes place predominantly due to hopping conduction assisted by glassy dynamics (dynamic glass transition assisted hopping) and is not significantly affected by the establishment of H-bonds.
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| 3. |
- Dong, Zhiyue, et al.
(author)
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A cationitrile sequence encodes mild poly(ionic liquid) crosslinking for advanced composite membranes
- 2020
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In: Materials Horizons. - : Royal Society of Chemistry (RSC). - 2051-6347 .- 2051-6355. ; 7:10, s. 2683-2689
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Journal article (peer-reviewed)abstract
- Polymer crosslinking is crucial for the preparation and consolidation of hierarchical nano- and micro-structures, hybrid interfaces, and collective assemblies. Here, for the first time, we showed that a cation-methylene-nitrile (CMN) functionality sequence encoded within repeating units of poly(ionic liquid)s (PILs) allowed for mild cyclizations of nitriles, processes otherwise requiring high temperatures and harsh catalysts. These new reactions facilitated by the CMN sequence were readily translated into freestanding nanomembranes (similar to 19 nm in thickness) and nanocomposite membranes by treating the PILs with mild ammonia vapor (0.2 bar, 20 degrees C). These materials were observed to be stable in various solvents, at different pH levels, and even in boiling water, exhibiting exceptional mechanical strength and solar-thermal desalination performance. The sequence was easy to synthesize, transferable in copolymers, and applicable to various cations, such as imidazolium, pyridinium, and triazolium. We expect it to provide a molecular code promoting programmable polymer crosslinking and the formation of hybrid structures for sustainable energy and water applications.
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| 4. |
- Geng, Hongya, et al.
(author)
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Biomimetic Antigravity Water Transport and Remote Harvesting Powered by Sunlight
- 2020
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In: Global Challenges. - : Wiley. - 2056-6646. ; 4
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Journal article (peer-reviewed)abstract
- Antigravity water transport plays important roles in various applications ranging from agriculture, industry, and environmental engineering. In natural trees, ubiquitous water-flow over 100 m high from roots through the hierarchical xylem to leaves is driven by sunlight-powered continuous evaporation and the negative pressure. Inspired by natural trees, herein an artificial trunk-leaf system is built up to structurally mimic natural trees for a continuous antigravity water delivery. The artificial tree consists of directional microchannels for antigravity water transport, and a top leaf-like hybrid hydrogel that are acts as continuous solar steam evaporator, plus a purposely engineered steam collector. It is found that continuous uniform microchannels of acetylated chitin optimize and enhance capillary rise (approximate to 37 cm at 300 min) and reduce vertical water transport resistance. A remote water harvesting, and purification is performed with a high rate of 1.6 kg m(-2) h(-1) and 184 cm in height under 1 sun irradiation and the collection efficiency up to 100% by evaporative cooling technique. It is envisioned that the basic design principles underlying the artificial tree can be used to transform solar energy into potential energy.
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| 5. |
- He, Jianqiao, et al.
(author)
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Ferrocene-integrated conjugated microporous polymer nanosheets : Active and regenerative catalysts for photomediated controlled radical polymerization
- 2020
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In: Applied materials today. - : Elsevier BV. - 2352-9407. ; 18
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Journal article (peer-reviewed)abstract
- The challenge of light-driven controlled radical polymerization through non-noble metal catalyst remains the most significant issue. Ferrocene-bearing microporous aromatic polymer nanosheets (termed FeMAP-11) that feature high chemical stability were reported here to synergistically combine the advantageous properties of the redox-active ferrocene units and the conjugated microporous polymers (CMPs), and to be able to serve as photocatalyst for activators regenerated by electron transfer atom transfer radical polymerization (AGET-ATRP). It succeeded in initiating polymerizations of 3 common vinyl monomers, i.e. methyl methacrylate (MMA), methacrylate (MA) and styrene (St), and produced polymers with controlled molecular weight and relatively low molecular weight dispersity ((1) over tilde .3). Benefiting from steric hindrance through ketone-amine chemistry, the microporous catalyst with tolerance to acidic and basic media was found stable under the AGET-ATRP conditions. It showed negligible metal leaching and good recyclability for at least 10 cycles without sacrifice of its catalytic performance. Our tests proved that FeMAP-11 exceeded the state-of-the-art ATRP photocatalysts such as UiO-66-NH2, titanium MOF-901 and the commercial P-25 Titania, demonstrating promising potential in catalysis in view of green chemistry.
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| 6. |
- Ke, Yuqi, et al.
(author)
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beta-Cyclodextrin-derived Room Temperature Macromolecular Ionic Liquids by PEGylated Anions
- 2020
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In: Macromolecular rapid communications. - : Wiley. - 1022-1336 .- 1521-3927. ; 41:8
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Journal article (peer-reviewed)abstract
- A series of cyclodextrin-derived room temperature macromolecular ionic liquids carrying rather low glass transition temperatures of -20 to -40 degrees C are synthesized via sequential esterification, quaternization, and anion metathesis reactions. In addition to being ionic in nature, they are viscous liquids at room temperature with more fluidic behavior at elevated temperatures. They serve as a solvent for organic dyes or iodine separation via a liquid-liquid extraction approach. This strategy is useful for the development of various sugar (macro)molecule-based functional ionic liquids as well as macromolecular ionic liquids.
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| 7. |
- Kochovski, Zdravko, et al.
(author)
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Cryo-Electron microscopy for the study of self-assembled poly(ionic liquid) nanoparticles and protein supramolecular structures
- 2020
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In: Colloid and Polymer Science. - : Springer Science and Business Media LLC. - 0303-402X .- 1435-1536. ; 298:7, s. 707-717
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Journal article (peer-reviewed)abstract
- Cryo-electron microscopy (cryo-EM) is a powerful structure determination technique that is well-suited to the study of protein and polymer self-assembly in solution. In contrast to conventional transmission electron microscopy (TEM) sample preparation, which often times involves drying and staining, the frozen-hydrated sample preparation allows the specimens to be kept and imaged in a state closest to their native one. Here, we give a short overview of the basic principles of Cryo-EM and review our results on applying it to the study of different protein and polymer self-assembled nanostructures. More specifically, we show how we have applied cryo-electron tomography (cryo-ET) to visualize the internal morphology of self-assembled poly(ionic liquid) nanoparticles and cryo-EM single particle analysis (SPA) to determine the three-dimensional (3D) structures of artificial protein microtubules.
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| 8. |
- Li, Xiaoting, et al.
(author)
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Nano-confinement-inspired metal organic framework/polymer composite separation membranes
- 2020
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In: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 8:33, s. 17212-17218
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Journal article (peer-reviewed)abstract
- A defect-free, robust and selective barrier is essential for manufacturing membranes with targeted high permeability and selectivity. Here we report a new route to engineering a separation composite membrane by confining both channels in nanoscale metal organic frameworks (MOFs) and charges in a polyelectrolyte in the inner space of a porous supportviaa counter-diffusion method. A simple thermal annealing treatment of the interface between the MOF, polymer and support favorably reduced voids inside this nano-confinement environment. As this composite membrane combines both the support and barrier as one, it minimizes mass transfer resistance of water molecules. In a separation test, it readily achieved the state-of-the-art permeance. This simple chemical approach to upgrade membrane structures will offer wide opportunities in separation devices.
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| 9. |
- Lin, Huijuan, et al.
(author)
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Poly(ionic liquid)s with engineered nanopores for energy and environmental applications
- 2020
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In: Polymer. - : Elsevier BV. - 0032-3861 .- 1873-2291. ; 202
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Journal article (peer-reviewed)abstract
- Poly(ionic liquid) (PIL) integrates some intrinsic characteristics of ionic liquids (ILs) with classic merits of polymeric materials, and opens up a new dimension to research ionic polymers. Nanoporous PILs with controlled nanopores combine the advantages of two classes of functional materials, i.e., porous polymers and ILs, which greatly expand their applicability to energy storage and conversion, environmental sensing, gas sorption and catalysis. In this short review, we summarize the recent advances in the design and synthesis of nanoporous PILs, focusing on pore generation and engineering, electrostatic interactions, and potential applications to address energy and environmental issues. Porous carbons from nanoporous PIL templates/precursors are also briefly discussed as an extension of nanoporous PILs for energy research. Finally, our future perspectives on the potential of nanoporous PILs are presented.
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| 10. |
- Patinha, David J. S., et al.
(author)
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Thin Porous Poly(ionic liquid) Coatings for Enhanced Headspace Solid Phase Microextraction
- 2020
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In: Polymers. - : MDPI AG. - 2073-4360. ; 12:9
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Journal article (peer-reviewed)abstract
- In this contribution, thin poly(ionic liquid) (PIL) coatings with a well-defined pore structure built up from interpolyelectrolyte complexation between a PIL and poly(acrylic acid) (PAA) were successfully used for enhanced solid phase microextraction (SPME). The introduction of porosity with tunable polarity through the highly versatile PIL chemistry clearly boosts the potential of SPME in the detection of compounds at rather low concentrations. This work will inspire researchers to further explore the potential of porous poly(ionic liquid) materials in sensing and separation applications.
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