| 1. |
- Wang, Tongzhou, et al.
(författare)
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Atomically Dispersed Semi-Metallic Selenium on Porous Carbon Membrane as an Electrode for Hydrazine Fuel Cells
- 2019
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 58:38, s. 13466-13471
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemically functional porous membranes of low cost are appealing in various electrochemical devices used in modern environmental and energy technologies. Herein we describe a scalable strategy to construct electrochemically active, hierarchically porous carbon membranes containing atomically dispersed semi-metallic Se, denoted SeNCM. The isolated Se atoms were stabilized by carbon atoms in the form of a hexatomic ring structure, in which the Se atoms were located at the edges of graphitic domains in SeNCM. This configuration is different from that of previously reported transition/noble metal single atom catalysts. The positively charged Se, enlarged graphitic layers, robust electrochemical nature of SeNCM endow them with excellent catalytic activity that is superior to state-of-the-art commercial Pt/C catalyst. It also has long-term operational stability for hydrazine oxidation reaction in practical hydrazine fuel cell.
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| 2. |
- Chen, Zhi, et al.
(författare)
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Large-Area Crystalline Zeolitic Imidazolate Framework Thin Films
- 2021
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 60:25, s. 14124-14130
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Tidskriftsartikel (refereegranskat)abstract
- We report that continuous MOF films with highly controlled thickness (from 44 to 5100 nm) can be deposited over length scales greater than 80 centimeters by a facile, fast, and cost-effective spray-coating method. Such success relies on our discovery of unprecedented perfectly dispersed colloidal solutions consisting of amorphous MOF nanoparticles, which we adopted as precursors that readily converted to the crystalline films upon low-temperature in situ heating. The colloidal solutions allow for the fabrication of compact and uniform MOF films on a great deal of substrates such as fluorine-doped tin oxide, glass, SiO2, Al2O3, Si, Cu, and even flexible polycarbonate, widening their technological applications where substrates are essential. Despite the present work focuses on the fabrication of uniform cobalt-(2-methylimidazole)2 and zinc-(2-methylimidazole)2 films, our findings mark a great possibility in producing other high-quality MOF thin films on a large scale.
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| 3. |
- Pang, Kanglei, 1993-, et al.
(författare)
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Redirecting configuration of atomically dispersed selenium catalytic sites for efficient hydrazine oxidation
- 2024
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Ingår i: Matter. - 2590-2393 .- 2590-2385. ; 7:2, s. 655-667
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the reconstruction of surface sites is crucial for gaining insights into the true active sites and catalytic mechanisms. While extensive research has been conducted on reconstruction behaviors of atomically dispersed metallic catalytic sites, limited attention has been paid to non-metallic ones despite their potential catalytic activity comparable or even superior to their noble-metal counterpart. Herein, we report a carbonaceous, atomically dispersed non-metallic selenium catalyst that displayed exceptional catalytic activity in the hydrazine oxidation reaction (HzOR) in alkaline media, outperforming the noble-metal Pt catalysts. In situ X-ray absorption spectroscopy (XAS) and Fourier transform infrared spectroscopy revealed that the pristine SeC4 site pre-adsorbs an ∗OH ligand, followed by HzOR occurring on the other side of the OH–SeC4. Theoretical calculations proposed that the pre-adsorbed ∗OH group pulls electrons from the Se site, resulting in a more positively charged Se and a higher polarity of Se–C bonds, thereby enhancing surface reactivity toward HzO/R.
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| 4. |
- Wang, Binmin, et al.
(författare)
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Multifunctional Underwater Adhesive Film Enabled by a Single-Component Poly(ionic liquid)
- 2023
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 17:6, s. 5871-5879
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Tidskriftsartikel (refereegranskat)abstract
- Tremendous efforts have been devoted to exploiting synthetic wet adhesives for real-life applications. However, developing low-cost, robust, and multifunctional wet adhesive materials remains a considerable challenge. Herein, a wet adhesive composed of a single-component poly(ionic liquid) (PIL) that enables fast and robust underwater adhesion is reported. The PIL adhesive film possesses excellent stretchability and flexibility, enabling its anchoring on target substrates regardless of deformation and water scouring. Surface force measurements show the PIL can achieve a maximum adhesion of 56.7 mN·m–1 on diverse substrates (both hydrophilic and hydrophobic substrates) in aqueous media, within ∼30 s after being applied. The adhesion mechanisms of the PIL were revealed via the force measurements, and its robust wet adhesive capacity was ascribed to the synergy of different non-covalent interactions, such as of hydrogen bonding, cation−π, electrostatic, and van der Waals interactions. Surprisingly, this PIL adhesive film exhibited impressive underwater sound absorption capacity. The absorption coefficient of a 0.7 mm-thick PIL film to 4–30 kHz sound waves could be as high as 0.80–0.92. This work reports a multifunctional PIL wet adhesive that has promising applications in many areas and provides deep insights into interfacial interaction mechanisms underlying the wet adhesion capability of PILs.
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| 5. |
- Wang, Hong, et al.
(författare)
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Ambient Electrosynthesis of Ammonia : Electrode Porosity and Composition Engineering
- 2018
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 57:38, s. 12360-12364
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Tidskriftsartikel (refereegranskat)abstract
- Ammonia, a key precursor for fertilizer production, convenient hydrogen carrier, and emerging clean fuel, plays a pivotal role in sustaining life on Earth. Currently, the main route for NH3 synthesis is by the heterogeneous catalytic Haber-Bosch process (N-2+ 3H(2) -> 2NH(3)), which proceeds under extreme conditions of temperature and pressure with a very large carbon footprint. Herein we report that a pristine nitrogen-doped nanoporous graphitic carbon membrane (NCM) can electrochemically convert N-2 into NH3 in an acidic aqueous solution under ambient conditions. The Faradaic efficiency and rate of production of NH3 on the NCM electrode reach 5.2% and 0.08 gm(-2) h(-1), respectively. Functionalization of the NCM with Au nanoparticles dramatically enhances these performance metrics to 22% and 0.36 gm(-2) h(-1), respectively. As this system offers the potential to be scaled to industrial levels it is highly likely that it might displace the century-old Haber-Bosch process.
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| 6. |
- Wang, Yu-Cheng, et al.
(författare)
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Porous Carbon Membrane-Supported Atomically Dispersed Pyrrole-Type Fe-N-4 as Active Sites for Electrochemical Hydrazine Oxidation Reaction
- 2020
-
Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 16:31
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Tidskriftsartikel (refereegranskat)abstract
- The rational design of catalytically active sites in porous materials is essential in electrocatalysis. Herein, atomically dispersed Fe-N-x sites supported by hierarchically porous carbon membranes are designed to electrocatalyze the hydrazine oxidation reaction (HzOR), one of the key techniques in electrochemical nitrogen transformation. The high intrinsic catalytic activity of the Fe-N-x single-atom catalyst together with the uniquely mixed micro-/macroporous membrane support positions such an electrode among the best-known heteroatom-based carbon anodes for hydrazine fuel cells. Combined with advanced characterization techniques, electrochemical probe experiments, and density functional theory calculation, the pyrrole-type Fe-N-4 structure is identified as the real catalytic site in HzOR.
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| 7. |
- Yi, Ming, et al.
(författare)
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Poly(ionic liquid)-Armored MXene Membrane : Interlayer Engineering for Facilitated Water Transport
- 2022
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 61:27
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional (2D) MXene-based lamellar membranes bearing interlayers of tunable hydrophilicity are promising for high-performance water purification. The current challenge lies in how to engineer the pore wall's surface properties in the subnano-confinement environment while ensuring its high selectivity. Herein, poly(ionic liquid)s, equipped with readily exchangeable counter anions, succeeded as a hydrophilicity modifier in addressing this issue. Lamellar membranes bearing nanochannels of tailorable hydrophilicity are constructed via assembly of poly(ionic liquid)-armored MXene nanosheets. By shifting the interlayer galleries from being hydrophilic to more hydrophobic via simple anion exchange, the MXene membrane performs drastically better for both the permeance (by two-fold improvement) and rejection (≈99 %). This facile method opens up a new avenue for building 2D material-based membranes of enhancing molecular transport and sieving effect.
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| 8. |
- Li, Xiaoting, et al.
(författare)
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"Mix-Then-On-Demand-Complex" : In Situ Cascade Anionization and Complexation of Graphene Oxide for High-Performance Nanofiltration Membranes
- 2021
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 15:3, s. 4440-4449
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Tidskriftsartikel (refereegranskat)abstract
- Assembling two-dimensional (2D) materials by polyelectrolyte often suffers from inhomogeneous microstructures due to the conventional mixing-and-simultaneous-complexation procedure (mix-and-complex) in aqueous solution. Herein a mix-then-on-demand-complex concept via on-demand in situ cascade anionization and ionic complexation of 2D materials is raised that drastically improves structural order in 2D assemblies, as exemplified by classical graphene oxide (GO)-based ultrathin membranes. Specifically, in dimethyl sulfoxide, the carboxylic acid-functionalized GO sheets (COOH-GOs) were mixed evenly with a cationic poly(ionic liquid) (PIL) and upon filtration formed a well-ordered layered composite membrane with homogeneous distribution of PIL chains in it; next, whenever needed, it was alkali-treated to convert COOH-GO in situ into its anionized state COO--GO that immediately complexed ionically with the surrounding cationic PIL chains. This mix-then-on-demand-complex concept separates the ionic complexation of GO and polyelectrolytes from their mixing step. By synergistically combining the PIL-induced hydrophobic confinement effect and supramolecular interactions, the as-fabricated nanofiltration membranes carry interface transport nanochannels between GO and PIL, reaching a high water permeability of 96.38 L m(-2) h(-1) bar(-1) at a maintained excellent dye rejection 99.79% for 150 h, exceeding the state-of-the-art GO-based hybrid membranes. The molecular dynamics simulations support the experimental data, confirming the interface spacing between GO and PIL as the water transport channels.
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| 9. |
- Li, Yuyang, et al.
(författare)
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A General Carboxylate-Assisted Approach to Boost the ORR Performance of ZIF-Derived Fe/N/C Catalysts for Proton Exchange Membrane Fuel Cells
- 2021
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 31
-
Tidskriftsartikel (refereegranskat)abstract
- An Fe/N/C catalyst derived from the pyrolysis of metal-organic frameworks, for example, a zeolitic-imidazolate-framework-8 (ZIF-8), has been regarded as one of the most promising non-precious metal catalysts toward oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). However, its ORR mass activity is still much inferior to that of Pt, partly because of the lack of general and efficient synthetic strategies. Herein, a general carboxylate-assisted strategy that dramatically enhances the ORR mass activity of ZIF-derived Fe/N/C catalysts is reported. The carboxylate is found to promote the formation of Fe/N/C catalysts with denser accessible active sites and entangled carbon nanotubes, as well as a higher mesoporosity. These structural advantages make the carboxylate-assisted Fe/N/C catalysts show a 2-10 fold higher ORR mass activity than the common carboxylate-free one in various cases. When applied in H-2-O-2 PEMFCs, the active acetate-assisted Fe/N/C catalyst generates a peak power density of 1.33 W cm(-2), a new record of peak power density for a H-2-O-2 PEMFC with non-Pt ORR catalysts.
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| 10. |
- Shao, Yue, et al.
(författare)
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All-Poly(ionic liquid) Membrane-Derived Porous Carbon Membranes : Scalable Synthesis and Application for Photothermal Conversion in Seawater Desalination
- 2018
-
Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 12:11, s. 11704-11710
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we introduce a straightforward, scalable, and technologically relevant strategy to manufacture charged porous polymer membranes (CPMs) in a controllable manner. The pore sizes and porous architectures of CPMs are well-controlled by rational choice of anions in poly(ionic liquid)s (PILs). Continuously, heteroatom-doped hierarchically porous carbon membrane (HCMs) can be readily fabricated via morphology-maintaining carbonization of as-prepared CPMs. These HCMs, as photothermal membranes, exhibited excellent performance for solar seawater desalination, representing a promising strategy to construct advanced functional nanomaterials for portable water production technologies.
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| 11. |
- Shao, Yue, et al.
(författare)
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Crosslinking of a Single Poly(ionic liquid) by Water into Porous Supramolecular Membranes
- 2020
-
Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 59:39, s. 17187-17191
-
Tidskriftsartikel (refereegranskat)abstract
- Reversible regulation of membrane microstructures via non-covalent interactions is of considerable interest yet remains a challenge. Herein, we discover a general one-step approach to fabricate supramolecular porous polyelectrolyte membranes (SPPMs) from a single poly(ionic liquid) (PIL). The experimental results and theoretical simulation suggested that SPPMs were formed by a hydrogen-bond-induced phase separation of a PIL between its polar and apolar domains, which were linked together by water molecules. This unique feature was capable of modulating microscopic porous architectures and thus the global mechanical property of SPPMs by a rational design of the molecular structure of PILs. Such SPPMs could switch porosity upon thermal stimuli, as exemplified by dynamically adaptive transparency to thermal fluctuation. This finding provides fascinating opportunities for creating multifunctional SPPMs.
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| 12. |
- Wang, Jianshe, et al.
(författare)
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Age- and gender-related accumulation of perfluoroalkyl substances in captive Chinese alligators (Alligator sinensis)
- 2013
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Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 179, s. 61-67
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Tidskriftsartikel (refereegranskat)abstract
- Fourteen perfluoroalkyl substances (PFASs) were measured in serum of the highly endangered captive Chinese alligators, whole body homogenates of six kinds of fish (alligator prey species), and pond water (alligator habitat) in the Anhui Research Center for Chinese Alligator Reproduction. Six PFASs, including PFOS and five perfluorinated carboxylates, were detected in all alligator samples. The most dominant PFAS was PFUnDA, with a mean value of 31.4 ng/mL. Significant positive correlations were observed among the six PFASs, suggesting that they shared similar sources of contamination. Significantly higher PFOS and PFUnDA levels were observed in males, but the other four PFCAs did not differ between genders. An age related PFAS bioaccumulation analysis showed a significant negative correlation of the concentrations for five PFCAs to age, which means that higher concentrations were found in younger animals. Bioaccumulation factors (BAF) in fish for PFASs ranged from 21 to 28,000, with lower BAF for PFOA than that for longer carbon chain PFCAs, including PFUnDA, PFDA, and PFNA.
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| 13. |
- Wang, Yucheng, et al.
(författare)
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Advanced Heteroatom-Doped Porous Carbon Membranes Assisted by Poly(ionic liquid) Design and Engineering
- 2020
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Ingår i: Accounts of materials research. - : American Chemical Society (ACS). - 2643-6728. ; 1:1, s. 16-29
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Tidskriftsartikel (refereegranskat)abstract
- Heteroatom-doped porous carbon membranes (HPCMMs) with a tailor-made pore architecture, chemical composition, atomic structural order, and surface state represent an exciting family of porous carbon materials for diverse potential applications in catalysis, water treatment, biofiltration, energy conversion/storage, and so forth. Conventional porous carbon membranes possess intrinsic structural integrity, interconnectivity, and chemical purity across the atomic-to-macro world and have been popularly incorporated into devices as separators or chemically inert conductive supports, circumventing otherwise the inevitable complicated processing and structure weakness of their fine powderous counterpart. Motivated by the distinguished heteroatom-doping effect that revolutionizes the chemical and physical nature of carbon materials, the HPCMM research surges very recently, and focuses not only on the eminent conductive supports or separators but also on electro(co)catalysts in energy devices. Synergy of the porous nature, incorporation of heteroatoms, and the membrane state creates a vivid profile pattern and new task-specific usage. It is also noteworthy that the inherent structural merits of HPCMMs plus a high electron conductivity imbue them as a reliable binder-free model electrode to derive the intrinsic structure-property relationship of porous carbons in electrochemical environments, excluding the complex and adverse factors in association with polymer binders in carbon powder-based electrodes. HPCMMs are of both intense academic interest and practical value because of their well-defined properties endowed by controllable structure and porosity at both atomic and macroscopic scales in a membrane form. The sole aim of this article is to bring this group of porous carbon materials to the forefront so their comprehensive properties and functions can be better understood to serve the carbon community to address pressing materials challenges in our society.In this Account, we highlight the latest discovery and proceedings of HPCMMs, particularly the advancements in how to tailor structures and properties of HPCMMs by rational structure design of porous polymer membranes as sacrificial template built up especially from heteroatom-rich poly(ionic liquid)s (PILs). We will also stress the carbonization craft and the state-of-the-art electrochemical applications for HPCMMs. Key factors and thoughts in heteroatom doping and porous systems in HPCMMs are discussed. A future perspective of the challenges and promising potential of HPCMMs is cast on the basis of these achievements.
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| 14. |
- Xu, Hui, et al.
(författare)
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Impact of Pore Structure on Two-Electron Oxygen Reduction Reaction in Nitrogen-Doped Carbon Materials : Rotating Ring-Disk Electrode vs. Flow Cell
- 2022
-
Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 15:5
-
Tidskriftsartikel (refereegranskat)abstract
- The impact of pore structure on the two-electron oxygen reduction reaction (ORR) in nitrogen-doped carbon materials is currently under debate, and previous studies are mainly limited to the rotating ring-disk electrode (RRDE) rather than the practical flow cell (FC) system. In this study, assisted by a group of reliable pore models, the impact of two pore structure parameters, that is, Brunauer–Emmett–Teller surface area (SBET) and micropore surface fraction (fmicro), on ORR activity and selectivity are investigated in both RRDE and FC. The ORR mass activity correlates positively to the SBET in the RRDE and FC because a higher SBET can host more active sites. The H2O2 selectivity is independent of fmicro in the RRDE but correlates negatively to fmicro in the FC. The inconsistency results from different states of the electrode in the RRDE and the FC. These insights will guide the design of carbon materials for H2O2 synthesis.
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| 15. |
- Yang, Chen, 1993-, et al.
(författare)
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Nanofibrous Porous Organic Polymers and Their Derivatives : From Synthesis to Applications
- 2024
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Ingår i: Advanced Science. - 2198-3844.
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Forskningsöversikt (refereegranskat)abstract
- Engineering porous organic polymers (POPs) into 1D morphology holds significant promise for diverse applications due to their exceptional processability and increased surface contact for enhanced interactions with guest molecules. This article reviews the latest developments in nanofibrous POPs and their derivatives, encompassing porous organic polymer nanofibers, their composites, and POPs-derived carbon nanofibers. The review delves into the design and fabrication strategies, elucidates the formation mechanisms, explores their functional attributes, and highlights promising applications. The first section systematically outlines two primary fabrication approaches of nanofibrous POPs, i.e., direct bulk synthesis and electrospinning technology. Both routes are discussed and compared in terms of template utilization and post-treatments. Next, performance of nanofibrous POPs and their derivatives are reviewed for applications including water treatment, water/oil separation, gas adsorption, energy storage, heterogeneous catalysis, microwave absorption, and biomedical systems. Finally, highlighting existent challenges and offering future prospects of nanofibrous POPs and their derivatives are concluded.
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| 16. |
- Zhang, Miao, et al.
(författare)
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From wood to thin porous carbon membrane : Ancient materials for modern ultrafast electrochemical capacitors in alternating current line filtering
- 2021
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Ingår i: Energy Storage Materials. - : Elsevier BV. - 2405-8289 .- 2405-8297. ; 35, s. 327-333
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Tidskriftsartikel (refereegranskat)abstract
- Ultrafast electrochemical capacitors with alternating current line filtering function have attracted growing attention owing to their potential to replace the state-of-the-art bulky aluminum electrolyte capacitors. In spite of rapid advance recently involving nanomaterials as electrode building units, it remains largely unexplored how to structurally and chemically engineer electrodes out of renewable resource with competitive or better rate performance. Herein, wood as a renewable resource was used to fabricate highly conductive, robust, porous thin carbon membranes as free-standing electrodes for ultrafast electrochemical capacitors. Transformation of wood slice to carbon membrane proceeds via wet-chemical treatment of wood slices and subsequent morphology maintaining carbonization by spark plasma sintering. Judiciously combining high conductivity, characteristic porous architecture with low tortuosity and high continuity, and the ultrathin thickness down to 20 ism, the carbon membrane-based electrochemical capacitor exhibits excellent frequency response with efficient 120 Hz filtering (phase angle = - 83.5 degrees). Compared to the latest electrodes for line filtering application that are fabricated from carbon nanotubes, graphene, and MXene, the wood-derived carbon membranes possess a competitive specific areal capacitance of up to 509.7 mu F cm(-2), and extremely low resistance-capacitance constant of 164.7 mu s, plus the inexpensive scalable fabrication strategy.
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| 17. |
- Zhang, Weiyi, et al.
(författare)
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Poly(Ionic Liquid)-Derived Graphitic Nanoporous Carbon Membrane Enables Superior Supercapacitive Energy Storage
- 2019
-
Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 13:9, s. 10261-10271
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Tidskriftsartikel (refereegranskat)abstract
- High energy/power density, capacitance, and long-life cycles are urgently demanded for energy storage electrodes. Porous carbons as benchmark commercial electrode materials are underscored by their (electro)chemical stability and wide accessibility, yet are often constrained by moderate performances associated with their powdery status. Here via controlled vacuum pyrolysis of a poly(ionic liquid) membrane template, advantageous features including good conductivity (132 S cm(-1) at 298 K), interconnected hierarchical pores, large specific surface area (1501 m(2) g(-1)), and heteroatom doping are realized in a single carbon membrane electrode. The structure synergy at multiple length scales enables large areal capacitances both for a basic aqueous electrolyte (3.1 F cm(-2)) and for a symmetric all-solid-state supercapacitor (1.0 F cm(-2)), together with superior energy densities (1.72 and 0.14 mW h cm(-2), respectively) without employing a current collector. In addition, theoretical calculations verify a synergistic heteroatom co-doping effect beneficial to the supercapacitive performance. This membrane electrode is scalable and compatible for device fabrication, highlighting the great promise of a poly(ionic liquid) for designing graphitic nanoporous carbon membranes in advanced energy storage.
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| 18. |
- Cao, Wei, et al.
(författare)
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Dual-Cationic Poly(ionic liquid)s Carrying 1,2,4-Triazolium and Imidazolium Moieties : Synthesis and Formation of a Single-Component Porous Membrane
- 2021
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Ingår i: ACS Macro Letters. - : American Chemical Society (ACS). - 2161-1653. ; 10:1, s. 161-166
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Tidskriftsartikel (refereegranskat)abstract
- Both imidazolium and 1,2,4-triazolium cations are important functional moieties widely incorporated as building blocks in poly(ionic liquid)s (PILs). In a classical model, a PIL usually contains either imidazolium or 1,2,4-triazolium in its repeating unit. Herein, via exploiting the slight reactivity difference of alkyl bromide with imidazole and 1,2,4-triazole at room temperature, we synthesized dual-cationic PIL homopolymers carrying both imidazolium and 1,2,4-triazolium moieties in the same repeating unit, that is, an asymmetrically dicationic unit. We investigated their fundamental properties, for example, thermal stability and solubility, as well as their unique function in forming supramolecular porous membranes via a water-initiated phase-separation and cross-linking process. With such knowledge, we identified a water-based fabricate strategy toward air-stable porous membranes from single-component Pits. This study will enrich the design tools and chemical structure library of PILs and expand their application spectrum.
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| 19. |
- Chang, Jian, et al.
(författare)
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Smart Sand by Surface Engineering : Toward Controllable Oil/Water Separation
- 2021
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 60:26, s. 9475-9481
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Tidskriftsartikel (refereegranskat)abstract
- Sand, an abundant resource from the nature, is a promising candidate for oil/water separation. Herein, raw sand was designed with switchable surface wettability to enable recyclability and versatility in practical oil/water separation. The smart sand was fabricated by grafting pH-responsive poly(4-vinylpyridine) (P4VP) and oleophilic/hydrophobic octadecyltrimethoxysilane (OTS) onto its surface. The decorated sand can be used as the oil sorbent for controllable oil sorption and desorption in response to different pHs, as well as a filter to selectively separate either oil or water on demand. This novel design offers an intelligent, low-cost, large-scale, and highly efficient route to potentially settle the issues of industrial oily wastewater and oil spill.
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| 20. |
- Chang, Jian, 1990-, et al.
(författare)
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Tailor-Made White Photothermal Fabrics : A Bridge between Pragmatism and Aesthetic
- 2023
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 35:41
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Tidskriftsartikel (refereegranskat)abstract
- Maintaining human thermal comfort in the cold outdoors is crucial for diverse outdoor activities, e.g., sports and recreation, healthcare, and special occupations. To date, advanced clothes are employed to collect solar energy as a heat source to stand cold climates, while their dull dark photothermal coating may hinder pragmatism in outdoor environments and visual sense considering fashion. Herein, tailor-made white webs with strong photothermal effect are proposed. With the embedding of cesium–tungsten bronze (CsxWO3) nanoparticles (NPs) as additive inside nylon nanofibers, these webs are capable of drawing both near-infrared (NIR) and ultraviolet (UV) light in sunlight for heating. Their exceptional photothermal conversion capability enables 2.5–10.5 °C greater warmth than that of a commercial sweatshirt of six times greater thickness under different climates. Remarkably, this smart fabric can increase its photothermal conversion efficiency in a wet state. It is optimal for fast sweat or water evaporation at human comfort temperature (38.5 °C) under sunlight, and its role in thermoregulation is equally important to avoid excess heat loss in wilderness survival. Obviously, this smart web with considerable merits of shape retention, softness, safety, breathability, washability, and on-demand coloration provides a revolutionary solution to realize energy-saving outdoor thermoregulation and simultaneously satisfy the needs of fashion and aesthetics.
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| 21. |
- Dong, Zhiyue, et al.
(författare)
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A cationitrile sequence encodes mild poly(ionic liquid) crosslinking for advanced composite membranes
- 2020
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Ingår i: Materials Horizons. - : Royal Society of Chemistry (RSC). - 2051-6347 .- 2051-6355. ; 7:10, s. 2683-2689
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Tidskriftsartikel (refereegranskat)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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| 22. |
- Fan, Zhiwen, et al.
(författare)
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Porous Ionic Network/CNT Composite Separator as a Polysulfide Snaring Shield for High Performance Lithium–Sulfur Battery
- 2023
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Ingår i: Macromolecular rapid communications. - 1022-1336 .- 1521-3927. ; 44:24
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Tidskriftsartikel (refereegranskat)abstract
- Lithium–sulfur (Li–S) battery features a high theoretical energy density, but the shuttle of soluble polysulfides between the two electrodes often results in a rapid capacity decay. Herein, a straightforward electrostatic adsorption strategy based on a cross-linked polyimidazolium separator as a snaring shield of polysulfides is reported, which suppresses the undesirable migration of polysulfides to the anode. The porous ionic network (PIN)-modified carbon nanotubes (CNTs) are successfully prepared and coated onto a commercial porous polypropylene membrane in a vacuum-filtration step. The favorable affinity of the imidazolium ring toward polysulfide via the polar interaction and the electrostatic effect of ions mitigates the undesirable shuttle of polysulfides in the electrolyte, improving the Li─S battery in terms of rate performance and cycling life. Compared to the reference PIN-free CNT-coated separator, the PIN/CNT-coated one has an increased initial capacity of 1.3 folds (up to 1394.8 mAh g−1 for PIN/CNT/PP-3) at 0.1 C.
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| 23. |
- He, Jianqiao, et al.
(författare)
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Ferrocene-integrated conjugated microporous polymer nanosheets : Active and regenerative catalysts for photomediated controlled radical polymerization
- 2020
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Ingår i: Applied materials today. - : Elsevier BV. - 2352-9407. ; 18
-
Tidskriftsartikel (refereegranskat)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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| 24. |
- Jiang, Zhiping, et al.
(författare)
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Fine tuning the hydrophobicity of counter-anions to tailor pore size in porous all-poly(ionic liquid) membranes
- 2019
-
Ingår i: Polymer international. - : Wiley. - 0959-8103 .- 1097-0126. ; 68:9, s. 1566-1569
-
Tidskriftsartikel (refereegranskat)abstract
- Charged porous polymer membranes (CPMs) emerging as a multifunctional platform for diverse applications in chemistry, materials science and biomedicine have been attracting widespread attention. Fabrication of CPMs in a controllable manner is of particular significance for optimizing their function and maximizing practical values. Herein, we report the fabrication of CPMs exclusively from poly(ionic liquid)s (PILs), and their pore size and wettability were precisely tailored by rational choice of counter-anions. Specifically, a stepwise subtle increase in hydrophobicity of the counter-anions by extending the length of fluorinated alkyl substituents, i.e. from bis(trifluoromethane sulfonyl)imide to bis(pentafluoroethane sulfonyl)imide and bis(heptafluoropropane sulfonyl)imide, decreased the average pore size gradually from 1546 to 157 and 77 nm, respectively. Meanwhile, the corresponding water contact angles increased from 90 degrees to 102 degrees and 120 degrees. The sensitive control over the porous architectures and surface wettability of CPMs by systematic variation of anion hydrophobicity provides solid proof of the impact of PIL anions on CPM structure.
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| 25. |
- Khorsand Kheirabad, Atefeh, et al.
(författare)
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Hydrazine-Enabled One-Step Synthesis of Metal Nanoparticle-Functionalized Gradient Porous Poly(ionic liquid) Membranes
- 2021
-
Ingår i: Macromolecular rapid communications. - : Wiley. - 1022-1336 .- 1521-3927. ; 42:8
-
Tidskriftsartikel (refereegranskat)abstract
- In this communication, a one-step synthetic route is reported toward free-standing metal-nanoparticle-functionalized gradient porous polyelectrolyte membranes (PPMs). The membranes are produced by soaking a glass-plate-supported blend film that consists of a hydrophobic poly(ionic liquid) (PIL), poly(acrylic acid), and a metal salt, into an aqueous hydrazine solution. Upon diffusion of water and hydrazine molecules into the blend film, a phase separation process of the hydrophobic PIL and an ionic crosslinking reaction via interpolyelectrolyte complexation occur side by side to form the PPM. Simultaneously, due to the reductive nature of hydrazine, the metal salt inside the polymer blend film is reduced in situ by hydrazine into metal nanoparticles that anchor onto the PPM. The as-obtained hybrid porous membrane is proven functional in the catalytic reduction of p-nitrophenol. This one-step method to grow metal nanoparticles and gradient porous membranes can simplify future fabrication processes of multifunctional PPMs.
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| 26. |
- Lan, Meng, et al.
(författare)
-
Highly redispersible CNT dough for better processiblity
- 2023
-
Ingår i: Journal of Materials Science & Technology. - : Elsevier BV. - 1005-0302. ; 152, s. 65-74
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon nanotubes (CNTs) have received considerable attention for their excellent thermal and electrical conductivity as well as scalable production. However, CNT dispersions are prone to settling and have a short shelf time, especially under high concentration, which significantly hinders their further processing and increases transportation costs. Here, we report a highly concentrated CNT dough enabled by ionic liquid crystal (ILC) as auxiliaries. Benefiting from the temperature-controlled physical transformation of the ILC, the CNTs of the powder state are successfully transferred to highly processable dough with excellent electrical conductivity, flame retardancy, and outstanding redispersibility even after 180 days of storage. In particular, the CNT dough exhibits excellent self-healing properties and good reshapable capability. Various bulk form CNT derived from the ILC armored CNT dough are realized by facile processing technique. Hybrid nanocomposite papers with ANF nanofiber exhibited excellent photothermal conversion and Joule heating properties. The redispersible CNT doughs presented here promise to revolutionize traditional CNT powder and dispersions as the primary raw material for building CNT-based architectures and facilitate the large-scale application of CNTs.
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| 27. |
- Li, Xiaoting, et al.
(författare)
-
Nano-confinement-inspired metal organic framework/polymer composite separation membranes
- 2020
-
Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 8:33, s. 17212-17218
-
Tidskriftsartikel (refereegranskat)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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| 28. |
- Li, Xinghao, et al.
(författare)
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Porous organic polycarbene nanotrap for efficient and selective gold stripping from electronic waste
- 2023
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 14
-
Tidskriftsartikel (refereegranskat)abstract
- The role of N-heterocyclic carbene, a well-known reactive site, in chemical catalysis has long been studied. However, its unique binding and electron-donating properties have barely been explored in other research areas, such as metal capture. Herein, we report the design and preparation of a poly(ionic liquid)-derived porous organic polycarbene adsorbent with superior gold-capturing capability. With carbene sites in the porous network as the “nanotrap”, it exhibits an ultrahigh gold recovery capacity of 2.09 g/g. In-depth exploration of a complex metal ion environment in an electronic waste-extraction solution indicates that the polycarbene adsorbent possesses a significant gold recovery efficiency of 99.8%. X-ray photoelectron spectroscopy along with nuclear magnetic resonance spectroscopy reveals that the high performance of the polycarbene adsorbent results from the formation of robust metal-carbene bonds plus the ability to reduce nearby gold ions into nanoparticles. Density functional theory calculations indicate that energetically favourable multinuclear Au binding enhances adsorption as clusters. Life cycle assessment and cost analysis indicate that the synthesis of polycarbene adsorbents has potential for application in industrial-scale productions. These results reveal the potential to apply carbene chemistry to materials science and highlight porous organic polycarbene as a promising new material for precious metal recovery.
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| 29. |
- Liu, Si-hua, et al.
(författare)
-
Smart Hydrogen Atoms in Heterocyclic Cations of 1,2,4-Triazolium-Type Poly(ionic liquid)s
- 2022
-
Ingår i: Accounts of Chemical Research. - : American Chemical Society (ACS). - 0001-4842 .- 1520-4898. ; 55:24, s. 3675-3687
-
Forskningsöversikt (refereegranskat)abstract
- Discovering and constructing molecular functionality platforms for materials chemistry innovation has been a persistent target in the fields of chemistry, materials, and engineering. Around this task, basic scientific questions can be asked, novel functional materials can be synthesized, and efficient system functionality can be established. Poly(ionic liquid)s (PILs) have attracted growing interest far beyond polymer science and are now considered an interdisciplinary crossing point between multiple research areas due to their designable chemical structure, intriguing physicochemical properties, and broad and diverse applications. Recently, we discovered that 1,2,4-triazolium-type PILs show enhanced performance profiles, which are due to stronger and more abundant supramolecular interactions ranging from hydrogen bonding to metal coordination, when compared with structurally similar imidazolium counterparts. This phenomenon in our view can be related to the smart hydrogen atoms (SHAs), that is, any proton that binds to the carbon in the N-heterocyclic cations of 1,2,4-triazolium-type PILs. The replacement of one carbon by an electron-withdrawing nitrogen atom in the broadly studied heterocyclic imidazolium ring will further polarize the C–H bond (especially for C5–H) of the resultant 1,2,4-triazolium cation and establish new chemical tools for materials design. For instance, the H-bond-donating strength of the SHA, as well as its Bro̷nsted acidity, is increased. Furthermore, polycarbene complexes can be readily formed even in the presence of weak or medium bases, which is by contrast rather challenging for imidazolium-type PILs. The combination of SHAs with the intrinsic features of heterocyclic cation-functionalized PILs (e.g., N-coordination capability and polymeric multibinding effects) enables new phenomena and therefore innovative materials applications.In this Account, recent progress on SHAs is presented. SHA-related applications in several research branches are highlighted together with the corresponding materials design at size scales ranging from nano- to micro- and macroscopic levels. At a nanoscopic level, it is possible to manipulate the interior and outer shapes and surface properties of PIL nanocolloids by adjusting the hydrogen bonds (H-bonds) between SHAs and water. Owing to the interplay of polycarbene structure, N-coordination, and the polymer multidentate binding of 1,2,4-triazolium-type PILs, metal clusters with controllable size at sub-nanometer scale were successfully synthesized and stabilized, which exhibited record-high catalytic performance in H2 generation via methanolysis of ammonia borane. At the microscopic level, SHAs are found to efficiently catalyze single crystal formation of structurally complex organics. Free protons in situ released from the SHAs serve as organocatalysts to activate formation of C–N bonds at room temperature in a series of imine-linked crystalline porous organics, such as organic cages, macrocycles and covalent organic frameworks; meanwhile the concurrent “salting-out” effect of PILs as polymers in solution accelerated the crystallization rate of product molecules by at least 1 order of magnitude. At the macroscopic scale, by finely regulating the supramolecular interactions of SHAs, a series of functional supramolecular porous polyelectrolyte membranes (SPPMs) with switchable pores and gradient cross-sectional structures were manufactured. These membranes demonstrate impressive figures of merit, ranging from chiral separation and proton recognition to switchable optical properties and real-time chemical reaction monitoring. Although the concept of SHAs is in the incipient stage of development, our successful examples of applications portend bright prospects for materials chemistry innovation.
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| 30. |
- Lu, Yahua, et al.
(författare)
-
Engineer Nanoscale Defects into Selective Channels : MOF-Enhanced Li+ Separation by Porous Layered Double Hydroxide Membrane
- 2023
-
Ingår i: Nano-Micro Letters. - 2311-6706. ; 15:1
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional (2D) membrane-based ion separation technology has been increasingly explored to address the problem of lithium resource shortage, yet it remains a sound challenge to design 2D membranes of high selectivity and permeability for ion separation applications. Zeolitic imidazolate framework functionalized modified layered double hydroxide (ZIF-8@MLDH) composite membranes with high lithium-ion (Li+) permeability and excellent operational stability were obtained in this work by in situ depositing functional ZIF-8 nanoparticles into the nanopores acting as framework defects in MLDH membranes. The defect-rich framework amplified the permeability of Li+, and the site-selective growth of ZIF-8 in the framework defects bettered its selectivity. Specifically speaking, the ZIF-8@MLDH membranes featured a high permeation rate of Li+ up to 1.73 mol m−2 h−1 and a desirable selectivity of Li+/Mg2+ up to 31.9. Simulations supported that the simultaneously enhanced selectivity and permeability of Li+ are attributed to changes in the type of mass transfer channels and the difference in the dehydration capacity of hydrated metal cations when they pass through nanochannels of ZIF-8. This study will inspire the ongoing research of high-performance 2D membranes through the engineering of defects.
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| 31. |
- Lu, Yahua, et al.
(författare)
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Heterostructure membranes of high permeability and stability assembled from MXene and modified layered double hydroxide nanosheets
- 2023
-
Ingår i: Journal of Membrane Science. - 0376-7388 .- 1873-3123. ; 688
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional (2D) MXene-based lamellar membranes play transformative roles in membrane filtration technology. Their practical use in water treatment is however hindered by several hurdles, e.g., unfavorable swelling due to weak interactions between adjacent MXene nanosheets, tortuous diffusion pathways of layered stacking, and the intrinsic aquatic oxidation-prone nature of MXene. Herein, nanoporous 2D/2D heterostructure membranes are elaborately constructed via solution-phase assembly of oppositely charged MXene and modified layered double hydroxide (MLDH) nanosheets. As a multifunctional component, positively charged holey MLDH nanosheets were first tailor-made to serve simultaneously as a binder, spacer and surface-modifier; next they were intercalated into negatively charged MXene lamella to enhance structural stability and mass transfer of membranes. As a result, the as-prepared MLDH@MXene heterostructure membranes successfully break the persistent trade-off between high permeability and selectivity while mitigating the common drawbacks in 2D MXene-based lamellar membranes, e.g., swelling issues, restacking problems, and vulnerable chemical stability. Noticeably, at an operating pressure of 4 bar and a feed solution of 100 ppm of Congo red, the heterostructure membranes enable a threefold jump in permeability (332.7 +/- 20 L m(-2) h(-1 )bar(-1)) when compared to the pristine MXene membrane (119.3 +/- 18 L m(-2 )h(-1) bar(-1)), and better operational stability without compromising the rejection.
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| 32. |
- Marschall, Tobias, et al.
(författare)
-
Computational pan-genomics : status, promises and challenges
- 2018
-
Ingår i: Briefings in Bioinformatics. - : Oxford University Press (OUP). - 1467-5463 .- 1477-4054. ; 19:1, s. 118-135
-
Tidskriftsartikel (refereegranskat)abstract
- Many disciplines, from human genetics and oncology to plant breeding, microbiology and virology, commonly face the challenge of analyzing rapidly increasing numbers of genomes. In case of Homo sapiens, the number of sequenced genomes will approach hundreds of thousands in the next few years. Simply scaling up established bioinformatics pipelines will not be sufficient for leveraging the full potential of such rich genomic data sets. Instead, novel, qualitatively different computational methods and paradigms are needed. We will witness the rapid extension of computational pan-genomics, a new sub-area of research in computational biology. In this article, we generalize existing definitions and understand a pan-genome as any collection of genomic sequences to be analyzed jointly or to be used as a reference. We examine already available approaches to construct and use pan-genomes, discuss the potential benefits of future technologies and methodologies and review open challenges from the vantage point of the above-mentioned biological disciplines. As a prominent example for a computational paradigm shift, we particularly highlight the transition from the representation of reference genomes as strings to representations as graphs. We outline how this and other challenges from different application domains translate into common computational problems, point out relevant bioinformatics techniques and identify open problems in computer science. With this review, we aim to increase awareness that a joint approach to computational pan-genomics can help address many of the problems currently faced in various domains.
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| 33. |
- Pan, Xuefeng, et al.
(författare)
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Poly(ionic liquid) nanovesicles via polymerization induced self-assembly and their stabilization of Cu nanoparticles for tailored CO2 electroreduction
- 2023
-
Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 637, s. 408-420
-
Tidskriftsartikel (refereegranskat)abstract
- Herein, we report a straightforward, scalable synthetic route towards poly(ionic liquid) (PIL) homopolymer nanovesicles (NVs) with a tunable particle size of 50 to 120 nm and a shell thickness of 15 to 60 nm via one-step free radical polymerization induced self-assembly. By increasing monomer concentration for polymerization, their nanoscopic morphology can evolve from hollow NVs to dense spheres, and finally to directional worms, in which a multilamellar packing of PIL chains occurred in all samples. The transformation mechanism of NVs’ internal morphology is studied in detail by coarse-grained simulations, revealing a correlation between the PIL chain length and the shell thickness of NVs. To explore their potential applications, PIL NVs with varied shell thickness are in situ functionalized with ultra-small (1 ∼ 3 nm in size) copper nanoparticles (CuNPs) and employed as electrocatalysts for CO2 electroreduction. The composite electrocatalysts exhibit a 2.5-fold enhancement in selectivity towards C1 products (e.g., CH4), compared to the pristine CuNPs. This enhancement is attributed to the strong electronic interactions between the CuNPs and the surface functionalities of PIL NVs. This study casts new aspects on using nanostructured PILs as new electrocatalyst supports in CO2 conversion to C1 products.
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| 34. |
- Pan, Yitao, et al.
(författare)
-
Analysis of emerging per- and polyfluoroalkyl substances : Progress and current issues
- 2020
-
Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier. - 0165-9936 .- 1879-3142. ; 124
-
Forskningsöversikt (refereegranskat)abstract
- The increasingly stringent restrictions on legacy per- and polyfluoroalkyl substances (PFASs) have led to the compensatory use of new fluorinated replacements. These new compounds, hereafter referred to as emerging PFASs, continue to be discovered and are now showing ubiquity in abiotic and biotic environments. Thus, there is an urgent need for robust, yet sensitive analytical methods to determine their occurrence and understand their behavior, fate, impact, and toxicity. Here, we review the up-to-date sample preparation and analytical methodologies for emerging PFASs based on peer-reviewed literature published in the past three years (2015-2018). The determination of emerging PFASs is similar to that of legacy PFASs, with satisfactory performances for most emerging PFASs achieved using conventional extraction and analytical approaches. However, the determination of certain specific analytes remains challenging due to the unavailability of standards and reference materials, low recoveries and matrix effects, background contamination, and poor sensitivities due to in-source fragmentation. Despite recent progress in identifying ionic semi-volatile PFASs with liquid chromatograph-high-resolution mass spectrometry (LC-HRMS), our knowledge on new types of neutral volatile PFASs remains poor due to limited non-target analysis using gas chromatograph (GC)-HRMS.
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| 35. |
- Pan, Yitao, et al.
(författare)
-
Dietary exposure to di-isobutyl phthalate increases urinary 5-methyl-2'-deoxycytidine level and affects reproductive function in adult male mice
- 2017
-
Ingår i: Journal of Environmental Sciences(China). - : Elsevier. - 1001-0742 .- 1878-7320. ; 61, s. 14-23
-
Tidskriftsartikel (refereegranskat)abstract
- Phthalates are a large family of ubiquitous environmental pollutants suspected of being endocrine disruptors. Epidemiological studies have associated phthalate metabolites with decreased reproductive parameters and linked phthalate exposure with the level of urinary 5-methyl-2'-deoxycytidine (5mdC, a product of methylated DNA). In this study, adult male mice were exposed to 450mg di-isobutyl phthalate (DiBP)/(kg·day) via dietary exposure for 28days. Mono-isobutyl phthalate (MiBP, the urinary metabolite) and reproductive function parameters were determined. The levels of 5mdC and 5-hydroxymethyl-2'-deoxycytidine (5hmdC) were measured in urine to evaluate if their contents were also altered by DiBP exposure in this animal model. Results showed that DiBP exposure led to a significant increase in the urinary 5mdC level and significant decreases in sperm concentration and motility in the epididymis, accompanied with reduced testosterone levels and down-regulation of the P450 cholesterol side-chain cleavage enzyme (P450scc) gene in the mice testes. Our findings indicated that exposure to DiBP increased the urinary 5mdC levels, which supported our recent epidemiological study about the associations of urinary 5mdC with phthalate exposure in the male human population. In addition, DiBP exposure impaired male reproductive function, possibly by disturbing testosterone levels; P450scc might be a major steroidogenic enzyme targeted by DiBP or other phthalates.
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| 36. |
- Patinha, David J. S., et al.
(författare)
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Thin Porous Poly(ionic liquid) Coatings for Enhanced Headspace Solid Phase Microextraction
- 2020
-
Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 12:9
-
Tidskriftsartikel (refereegranskat)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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| 37. |
- Pålsson, Björn, 1981, et al.
(författare)
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A comparison of track model formulations for simulation of dynamic vehicle–track interaction in switches and crossings
- 2023
-
Ingår i: Vehicle System Dynamics. - : Informa UK Limited. - 1744-5159 .- 0042-3114. ; 61:3, s. 698-724
-
Tidskriftsartikel (refereegranskat)abstract
- This paper compares different track model formulations for the simulation of dynamic vehicle–track interaction in switches and crossings (S&C, turnouts) in a multi-body simulation (MBS) environment. The investigations are an extension of the S&C simulation Benchmark with the addition of a finite element model of a 60E1-760-1:15 turnout. This model constitutes a common reference from which four different track formulations are derived: co-running, modal superposition, finite element incorporated into the MBS model and finite element coupled to MBS using a co-simulation approach. For the different track models, the difference in modelling technique, results, simulation time, and suitability for different simulation tasks is compared. A good agreement is found between the different track model formulations for wheel–rail contact forces and rail displacements. This study found a better agreement between co-running and structural track models compared to previous studies in the prediction of wheel–rail contact forces. This appears to be due to the increased complexity of co-running track model used in this study together with a tuning of the co-running track model to the reference model in a wider frequency range. For the reader interested to reproduce the results in this paper, the reference track model is available for download.
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| 38. |
- Qiu, Meikang, et al.
(författare)
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Three-phase time-aware energy minimization with DVFS and unrolling for Chip Multiprocessors
- 2012
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Ingår i: Journal of systems architecture. - : Elsevier BV. - 1383-7621 .- 1873-6165. ; 58:10, s. 439-445
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Tidskriftsartikel (refereegranskat)abstract
- Energy consumption has been one of the most critical issues in the Chip Multiprocessor (CMP). Using the Dynamic Voltage and Frequency Scaling (DVFS), a CMP system can achieve a balance between the performance and the energy-efficiency. In this paper, we propose a three-phase discrete DVFS algorithm for a CMP system dedicated to applications where the period of the applications' task graph is smaller than the deadline of tasks. In these applications, multiple task graphs are unrolled and then concatenated together to form a new task graph. The proposed DVFS algorithm is applied to the newly formed task graph to stretch tasks' execution time, lower operating frequencies of processors and achieve the system power efficiency. Experimental results show that the proposed algorithm reduces the energy dissipation by 25% on average, compared to previous DVFS approaches.
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| 39. |
- Sinisalu, Lisanna, 1993-, et al.
(författare)
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Prenatal exposure to poly-/per-fluoroalkyl substances is associated with alteration of lipid profiles in cord-blood
- 2021
-
Ingår i: Metabolomics. - : Springer-Verlag New York. - 1573-3882 .- 1573-3890. ; 17:12
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Poly-/per-fluoroalkyl substances (PFAS) are widespread environmental pollutants that may induce metabolic perturbations in humans, including particularly alterations in lipid profiles. Prenatal exposure to PFAS can cause lasting effects on offspring metabolic health, however, the underlying mechanisms are still unknown.OBJECTIVES: The goal of the study was to investigate the impact of prenatal PFAS exposure on the lipid profiles in cord blood.METHODS: Herein, we combined determination of bile acids (BAs) and molecular lipids by liquid chromatography with ultra-high-resolution mass spectrometry, and separately quantified cord blood concentrations of sixteen PFAS in a cohort of Chinese infants (104 subjects) in a cross-sectional study. We then evaluated associations between PFAS concentration and lipidome using partial correlation network analysis, debiased sparse partial correlation, linear regression analysis and correlation analysis.RESULTS: PFAS levels showed significant associations with the lipid profiles; specifically, PFAS exposure was positively correlated with triacylgycerols (TG) and several bile acids. Importantly, exposure to perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA) and perfluorohexane sulfonic acid (PFHxS) were associated with increased levels of TGs with saturated fatty acids while multiple classes of phospholipids were decreased. In addition, several free fatty acids showed significant positive correlations with PFOS.CONCLUSIONS: Our results indicated that prenatal exposure to PFAS mediated metabolic changes, which may explain the associations reported between PFAS exposure and metabolic health later in life.
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| 40. |
- Thomas, Minta, et al.
(författare)
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Combining Asian and European genome-wide association studies of colorectal cancer improves risk prediction across racial and ethnic populations
- 2023
-
Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- Polygenic risk scores (PRS) have great potential to guide precision colorectal cancer (CRC) prevention by identifying those at higher risk to undertake targeted screening. However, current PRS using European ancestry data have sub-optimal performance in non-European ancestry populations, limiting their utility among these populations. Towards addressing this deficiency, we expand PRS development for CRC by incorporating Asian ancestry data (21,731 cases; 47,444 controls) into European ancestry training datasets (78,473 cases; 107,143 controls). The AUC estimates (95% CI) of PRS are 0.63(0.62-0.64), 0.59(0.57-0.61), 0.62(0.60-0.63), and 0.65(0.63-0.66) in independent datasets including 1681-3651 cases and 8696-115,105 controls of Asian, Black/African American, Latinx/Hispanic, and non-Hispanic White, respectively. They are significantly better than the European-centric PRS in all four major US racial and ethnic groups (p-values < 0.05). Further inclusion of non-European ancestry populations, especially Black/African American and Latinx/Hispanic, is needed to improve the risk prediction and enhance equity in applying PRS in clinical practice.
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| 41. |
- Wan, Liyang, et al.
(författare)
-
A Mild CO2 Etching Method To Tailor the Pore Structure of Platinum-Free Oxygen Reduction Catalysts in Proton Exchange Membrane Fuel Cells
- 2021
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:38, s. 45661-45669
-
Tidskriftsartikel (refereegranskat)abstract
- The structural tailoring of pores is essential to high-performance Fe/N/C electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. Current strategies for pore structure engineering are usually accompanied with a drastic change of the intrinsic activity-related surface, which may mask the real effects of the porous structure on ORR activity. Herein, a mild carbon dioxide (CO2) etching method was used to flexibly tailor the pore structure of Fe/N/C electrocatalysts without drastic changes in their surface structure and property. In this way, via employing the Fe/N/C electrocatalysts as a model, the intrinsic impact of the pore structure on ORR activity was revealed. In addition, the CO2 etching method developed a high-quality electrocatalyst (sample Fe/N/C–5% CO2) with polarization performance exceeding that of the commercial Pt/C catalyst in the fuel cell working voltage region (>0.65 V). This work will promote the ongoing intensive studies on the rational design of the pore structures in the Fe/N/C electrocatalysts.
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| 42. |
- Wan, Liyang, et al.
(författare)
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Molecular Degradation of Iron Phthalocyanine during the Oxygen Reduction Reaction in Acidic Media
- 2022
-
Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 12:18, s. 11097-11107
-
Tidskriftsartikel (refereegranskat)abstract
- Molecular iron phthalocyanine (FePc) possesses an FeN4 active site structure similar to practical pyrolyzed Fe/N/C catalysts for the acidic oxygen reduction reaction (ORR), making it an ideal model system to derive the degradation mechanism of such catalysts. However, the degradation mechanism of FePc during the acidic ORR has been largely unclear to date. Herein, five most likely degradation factors affecting FePc-based ORR activity are individually investigated and compared. The attack by free radicals is found to be the main reason for the instability of FePc. Assisted by the combination of several spectroscopic methods, we successfully identify the degradation products and then propose a full structural evolution of molecular FePc degradation. Finally, high similarity in the decay mechanism between molecular FePc and practical Fe/N/C catalysts was present. This study provides a clear picture of the currently missing degradation mechanism of molecular FePc during acidic ORR, which will assist future investigations on the performance degradation of practical Fe/N/C catalysts.
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| 43. |
- Wang, Hong, et al.
(författare)
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Polymer-Derived Heteroatom-Doped Porous Carbon Materials
- 2020
-
Ingår i: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 120:17, s. 9363-9419
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Forskningsöversikt (refereegranskat)abstract
- Heteroatom-doped porous carbon materials (HPCMs) have found extensive applications in adsorption/separation, organic catalysis, sensing, and energy conversion/storage. The judicious choice of carbon precursors is crucial for the manufacture of HPCMs with specific usages and maximization of their functions. In this regard, polymers as precursors have demonstrated great promise because of their versatile molecular and nanoscale structures, modulatable chemical composition, and rich processing techniques to generate textures that, in combination with proper solid-state chemistry, can be maintained throughout carbonization. This Review comprehensively surveys the progress in polymer-derived functional HPCMs in terms of how to produce and control their porosities, heteroatom doping effects, and morphologies and their related use. First, we summarize and discuss synthetic approaches, including hard and soft templating methods as well as direct synthesis strategies employing polymers to control the pores and/or heteroatoms in HPCMs. Second, we summarize the heteroatom doping effects on the thermal stability, electronic and optical properties, and surface chemistry of HPCMs. Specifically, the heteroatom doping effect, which involves both single-type heteroatom doping and codoping of two or more types of heteroatoms into the carbon network, is discussed. Considering the significance of the morphologies of HPCMs in their application spectrum, potential choices of suitable polymeric precursors and strategies to precisely regulate the morphologies of HPCMs are presented. Finally, we provide our perspective on how to predefine the structures of HPCMs by using polymers to realize their potential applications in the current fields of energy generation/conversion and environmental remediation. We believe that these analyses and deductions are valuable for a systematic understanding of polymer-derived carbon materials and will serve as a source of inspiration for the design of future HPCMs.
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| 44. |
- Wang, Wei, 1995-, et al.
(författare)
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Mesoporous Ni-N-C as an efficient electrocatalyst for reduction of CO2 into CO in a flow cell
- 2022
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Ingår i: Applied Materials Today. - : Elsevier BV. - 2352-9407. ; 29
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Tidskriftsartikel (refereegranskat)abstract
- Recently, nitrogen-doped porous carbon materials containing non-precious metals (termed “M-N-C”) have formed a group of functional materials to replace precious metal-based catalysts for electrochemical CO2 reduction reaction. Here, a series of mesoporous Ni-N-C electrocatalysts (termed “mp-Ni-N-Cs”) were prepared via a gel-template method, and could effectively reduce CO2 into CO in a flow cell. The result in gas sorption tests exhibited a typical mesoporous structure, which would bring both sufficient exposed active sites and convenient mass transfer channels. Electrochemical tests showed excellent performance at an applied potential of -1.3 V (vs. RHE), e.g., a CO Faradaic efficiency (FECO) of 95.85 %, and a CO reduction current (jCO) of -21.29 mA cm−2. Significantly, its FECO exceeded 93 % in a wide range of potentials from -1.0 to -1.5 V, showing great tolerance to fluctuation in potential. The mp-Ni-N-C electrocatalysts have satisfactory features in terms of catalytic activity, facile preparation, and economic feasibility, and will offer a valuable reference for next exploration of cost-effective electrocatalysts for CO2 conversion.
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| 45. |
- Wang, Wei, et al.
(författare)
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Metal-Free SeBN Ternary-Doped Porous Carbon as Efficient Electrocatalysts for CO2 Reduction Reaction
- 2022
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 5:9, s. 10518-10525
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Tidskriftsartikel (refereegranskat)abstract
- Cost-effective heteroatom-doped porous carbons are considered promising electrocatalysts for CO2 reduction reaction (CO2RR). Traditionally porous carbons with N doping or N/X codoping (X denotes the second type of heteroatom) have been widely studied, leaving ternary doping a much less studied yet exciting topic to be explored. Herein, a series of electrocatalysts based on metal-free Se, B, and N ternary-doped porous carbons (termed “SeBN-Cs”) were synthesized and tested as metal-free electrocatalysts in CO2RR. Our study indicates that the major product of CO2RR on the SeBN-C electrocatalysts was CO with a small fraction (<5%) of H2 as the byproduct. The optimal electrocatalyst sample SeBN-C-1100 prepared at 1100 °C exhibits a high CO selectivity with a Faradaic efficiency of CO reaching 95.2%. After 10 h of continuous electrolysis operation, the Faradaic efficiency and the current density are maintained high at 97.6 and 84.7% of the initial values, respectively, indicative of a long-term operational stability. This study provides an excellent reference to deepen our understanding of the properties and functions of multi-heteroatom-doped porous carbon electrocatalysts in CO2RR.
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| 46. |
- Wang, Yong-Lei, et al.
(författare)
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Microstructural and Dynamical Heterogeneities in Ionic Liquids
- 2020
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Ingår i: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 120:13, s. 5798-5877
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Forskningsöversikt (refereegranskat)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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| 47. |
- Wang, Yong-lei, 1983-, et al.
(författare)
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The Effect of Phenyl Substitutions on Microstructures and Dynamics of Tetraalkylphosphonium Bis(trifluoro- methylsulfonyl)imide Ionic Liquids
- 2020
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Ingår i: ChemPhysChem. - : Wiley. - 1439-4235 .- 1439-7641. ; 21:11, s. 1202-1214
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Tidskriftsartikel (refereegranskat)abstract
- Extensive atomistic simulations demonstrated that a gradual substitution of hexyl chains with phenyl groups in tetraalkylphosphonium cations results in remarkable changes in hydrogen bonding interactions, liquid structures and scattering structural functions, and rotational dynamics of hexyl chains and phenyl groups in tetraalkylphosphonium bis(trifluoromethylsulfonyl)imide ionic liquids. Hydrogen donor sites in hexyl chains present competitive characteristics with those in phenyl groups in coordinating anions, as well as their continuous and intermittent hydrogen bonding dynamics. Cation-cation and anion-anion spatial correlations show concomitant shift to short distances with decreased peak intensities with variations of cation structures, whereas cation-anion correlations have a distinct shift to large radial distances due to decreased associations of anions with neighboring cations. These microstructural changes are qualitatively manifested in shifts of prominent peaks for prevalent charge alternations and adjacency correlations between ion species in scattering structural functions. Meanwhile, rotational dynamics of hexyl chains speed up, which, in turn, slow down rotations of phenyl groups, whereas anions exhibit imperceptible changes in their rotational dynamics. These computational results are intrinsically correlated with conformational flexibilities, molecular sizes, and steric hindrance effects of phenyl groups in comparison with hexyl chains, and constrained distributions of anions around cations in heterogeneous ionic environments.
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| 48. |
- Wang, Yang, et al.
(författare)
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Lamellar carbon nitride membrane for enhanced ion sieving and water desalination
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Membrane-based water treatment processes offer possibility to alleviate the water scarcity dilemma in energy-efficient and sustainable ways, this has been exemplified in filtration membranes assembled from two-dimensional (2D) materials for water desalination purposes. Most representatives however tend to swell or disintegrate in a hydrated state, making precise ionic or molecular sieving a tough challenge. Here we report that the chemically robust 2D carbon nitride can be activated using aluminum polycations as pillars to modulate the interlayer spacing of the conjugated framework, the noncovalent interaction concomitantly affords a well-interlinked lamellar structure, to be carefully distinguished from random stacking patterns in conventional carbon nitride membranes. The conformally packed membrane is characterized by adaptive subnanochannel and structure integrity to allow excellent swelling resistance, and breaks permeability-selectivity trade-off limit in forward osmosis due to progressively regulated transport passage, achieving high salt rejection (>99.5%) and water flux (6 L m−2 h−1), along with tunable permeation behavior that enables water gating in acidic and alkaline environments. These findings position carbon nitride a rising building block to functionally expand the 2D membrane library for applications in water desalination and purification scenarios.
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| 49. |
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| 50. |
- Xie, Dongjiu, et al.
(författare)
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Poly(ionic liquid) Nanovesicle-Templated Carbon Nanocapsules Functionalized with Uniform Iron Nitride Nanoparticles as Catalytic Sulfur Host for Li–S Batteries
- 2022
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 16:7, s. 10554-10565
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Tidskriftsartikel (refereegranskat)abstract
- Poly(ionic liquid)s (PIL) are common precursors for heteroatom-doped carbon materials. Despite a relatively higher carbonization yield, the PIL-to-carbon conversion process faces challenges in preserving morphological and structural motifs on the nanoscale. Assisted by a thin polydopamine coating route and ion exchange, imidazolium-based PIL nanovesicles were successfully applied in morphology-maintaining carbonization to prepare carbon composite nanocapsules. Extending this strategy further to their composites, we demonstrate the synthesis of carbon composite nanocapsules functionalized with iron nitride nanoparticles of an ultrafine, uniform size of 3–5 nm (termed “FexN@C”). Due to its unique nanostructure, the sulfur-loaded FexN@C electrode was tested to efficiently mitigate the notorious shuttle effect of lithium polysulfides (LiPSs) in Li–S batteries. The cavity of the carbon nanocapsules was spotted to better the loading content of sulfur. The well-dispersed iron nitride nanoparticles effectively catalyze the conversion of LiPSs to Li2S, owing to their high electronic conductivity and strong binding power to LiPSs. Benefiting from this well-crafted composite nanostructure, the constructed FexN@C/S cathode demonstrated a fairly high discharge capacity of 1085 mAh g–1 at 0.5 C initially, and a remaining value of 930 mAh g–1 after 200 cycles. In addition, it exhibits an excellent rate capability with a high initial discharge capacity of 889.8 mAh g–1 at 2 C. This facile PIL-to-nanocarbon synthetic approach is applicable for the exquisite design of complex hybrid carbon nanostructures with potential use in electrochemical energy storage and conversion.
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