Recent Submissions

  • Nickel-Catalyzed Reductive Cross-Couplings: New Opportunities for Carbon–Carbon Bond Formations through Photochemistry and Electrochemistry

    Yi, Liang; Ji, Tengfei; Chen, Kun-Quan; Chen, Xiang-Yu; Rueping, Magnus (CCS Chemistry, Chinese Chemical Society, 2021-10-15) [Article]
    Metal-catalyzed cross-electrophile couplings have become a valuable tool for carbon–carbon bond formation. This minireview provides a comprehensive overview of the recent developments in the topical field of cross-electrophile couplings, provides explanations of the current state-of-the-art, and highlights new opportunities arising in the emerging fields of photoredox catalysis and electrochemistry.
  • Efficient and chemoselective hydrogenation of aldehydes catalyzed by a well-defined PN3 -pincer manganese (II) catalyst precursor: an application in furfural conversion

    Huang, Kuo-Wei; Gholap, Sandeep S.; Al Dakhil, Abdullah; Chakraborty, Priyanka; Li, Huaifeng; Dutta, Indranil; Das, Pradip (Chemical Communications, Royal Society of Chemistry (RSC), 2021-10-15) [Article]
    Well-defined and air-stable PN3-pincer manganese (II) complexes were synthesized and used for the hydrogenation of aldehydes into alcohols under mild conditions using MeOH as a solvent. This protocol is applicable for a wide range of aldehydes containing various functional groups. Importantly, α,β-unsaturated aldehydes, including ynals, are hydrogenated with the C=C double bond/CΞC triple bond intact. Our methodology was demonstrated for biomass derived feedstock such as furfural and 2,5-diformyl furfural to furfuryl alcohol and 2-hydroxy furfuryl alcohol respectively.
  • An Efficient Metal-Organic Framework - Derived Nickel Catalyst for the Light Driven Methanation of CO2

    Khan, Il Son; Mateo, Diego; Shterk, Genrikh; Shoinkhorova, Tuiana; Poloneeva, Daria; Garzon Tovar, Luis Carlos; Gascon, Jorge (Angewandte Chemie, Wiley, 2021-10-14) [Article]
    We report the synthesis of a highly active and stable metal-organic framework derived Ni-based catalyst for the photo-thermal reduction of CO 2 to CH 4 . Through the controlled pyrolysis of MOF-74 (Ni), the nature of the carbonaceous species and therefore photo-thermal performance can be tuned. CH 4 production rates of 488 mmol g -1 h -1 under UV–visible-IR irradiation are achieved when the catalyst is prepared under optimized conditions. No particle aggregation or significant loss of activity were observed after five consecutive reaction cycles. Finally, as a proof-of-concept, we performed an outdoor experiment under ambient solar irradiation, demonstrating the potential of our catalyst to reduce CO 2 to CH 4 using only solar energy.
  • A New Thiophene-Appended Fluorescein-Hydrazone-Based Chromo-Fluorogenic Sensor for the Screening of Hg 2+ Ions in Real Water Samples

    Roy, Swapnadip; Mondal, Tapashree; Dey, Dhananjay; Mane, Manoj Vasisht; Panja, Sujit S. (ChemistrySelect, Wiley, 2021-10-12) [Article]
    A simple yet efficient, Hg2+ selective sensor, based on a fluroescein-thiophene conjugate, namely, (Z)-3′,6′-dihydroxy-2-(((3-methylthiophen-2-yl)methylene)amino)spiro[isoindoline-1,9′-xanthen]-3-one (FT) has been designed and synthesized. The compound was well characterized by analytical techniques such as HR-MS, FTIR, UV-visible absorption, steady-state fluorescence and time-resolved spectrophotometric techniques. Comprehensive analysis demonstrated FTas a highly specific and ultra-sensitive sensor towards Hg2+ ions in presence of several other interfering metal ions in ethanol/H2O (9 : 1, v/v) at pH=7.2 buffered with 10 mM HEPES buffer at room temperature. The complexation of the probe FT with Hg2+ was well confirmed by ESI-MS and FTIR spectral analysis. The detection limit of the probe FT towards Hg2+ was achieved down to 137 nM. The structure of ligand FT and FT-Hg2+ complex were well corroborated by theoretical studies as well. In addition, the FT-Hg2+ complex was found to be reversible in presence of di-sodium EDTA and hence decipher its recyclability capabilities. The significance of the present probe FT lies in its successful application for the detection and quantification of Hg2+ in real water samples and logic gate fabrication for future incorporation in small organic molecule based efficient molecular devices.
  • Selectivity descriptors for the direct hydrogenation of CO2 to hydrocarbons during zeolite-mediated bifunctional catalysis

    Galilea, Adrian; Gong, Xuan; Caglayan, Mustafa; Nastase, Stefan-Adrian F.; Abou-Hamad, Edy; Gevers, Lieven; Cavallo, Luigi; Chowdhury, Abhishek Dutta; Gascon, Jorge (Nature Communications, Springer Science and Business Media LLC, 2021-10-08) [Article]
    AbstractCascade processes are gaining momentum in heterogeneous catalysis. The combination of several catalytic solids within one reactor has shown great promise for the one-step valorization of C1-feedstocks. The combination of metal-based catalysts and zeolites in the gas phase hydrogenation of CO2 leads to a large degree of product selectivity control, defined mainly by zeolites. However, a great deal of mechanistic understanding remains unclear: metal-based catalysts usually lead to complex product compositions that may result in unexpected zeolite reactivity. Here we present an in-depth multivariate analysis of the chemistry involved in eight different zeolite topologies when combined with a highly active Fe-based catalyst in the hydrogenation of CO2 to olefins, aromatics, and paraffins. Solid-state NMR spectroscopy and computational analysis demonstrate that the hybrid nature of the active zeolite catalyst and its preferred CO2-derived reaction intermediates (CO/ester/ketone/hydrocarbons, i.e., inorganic-organic supramolecular reactive centers), along with 10 MR-zeolite topology, act as descriptors governing the ultimate product selectivity.
  • Efficient Iron Phosphide Catalyst as a Counter Electrode in Dye-Sensitized Solar Cells

    Yildiz, Abdullah; Chouki, Takwa; Atli, Aycan; Harb, Moussab; Verbruggen, Sammy W.; Ninakanti, Rajeshreddy; Emin, Saim (ACS Applied Energy Materials, American Chemical Society (ACS), 2021-10-07) [Article]
    Developing an efficient material as a counter electrode (CE) with excellent catalytic activity, intrinsic stability, and low cost is essential for the commercial application of dye-sensitized solar cells (DSSCs). Transition metal phosphides have been demonstrated as outstanding multifunctional catalysts in a broad range of energy conversion technologies. Here, we exploited different phases of iron phosphide as CEs in DSSCs with an I–/I3–-based electrolyte. Solvothermal synthesis using a triphenylphosphine precursor as a phosphorus source allows to grow a Fe2P phase at 300 °C and a FeP phase at 350 °C. The obtained iron phosphide catalysts were coated on fluorine-doped tin oxide substrates and heat-treated at 450 °C under an inert gas atmosphere. The solar-to-current conversion efficiency of the solar cells assembled with the Fe2P material reached 3.96 ± 0.06%, which is comparable to the device assembled with a platinum (Pt) CE. DFT calculations support the experimental observations and explain the fundamental origin behind the improved performance of Fe2P compared to FeP. These results indicate that the Fe2P catalyst exhibits excellent performance along with desired stability to be deployed as an efficient Pt-free alternative in DSSCs.
  • Designing a Multifunctional Catalyst for the Direct Production of Gasoline-Range Isoparaffins from CO2

    Dokania, Abhay; Ould-Chikh, Samy; Galilea, Adrian; Cerrillo, Jose Luis; Aguilar, Antonio; Russkikh, Artem; Alkhalaf, Ahmed S.; Hita, Idoia; Bavykina, Anastasiya; Shterk, Genrikh; Wehbe, Nimer; Prat, Alain; Lahera, Eric; Castaño, Pedro; Fonda, Emiliano; Hazemann, Jean-Louis; Gascon, Jorge (JACS Au, American Chemical Society (ACS), 2021-10-06) [Article]
    The production of carbon-neutral fuels from CO2 presents an avenue for causing an appreciable effect in terms of volume toward the mitigation of global carbon emissions. To that end, the production of isoparaffin-rich fuels is highly desirable. Here, we demonstrate the potential of a multifunctional catalyst combination, consisting of a methanol producer (InCo) and a Znmodified zeolite beta, which produces a mostly isoparaffinic hydrocarbon mixture from CO2 (up to ∼85% isoparaffin selectivity among hydrocarbons) at a CO2 conversion of >15%. The catalyst combination was thoroughly characterized via an extensive complement of techniques. Specifically, operando X-ray absorption spectroscopy (XAS) reveals that Zn (which plays a crucial role of providing a hydrogenating function, improving the stability of the overall catalyst combination and isomerization performance) is likely present in the form of Zn6O6 clusters within the zeolite component, in contrast to previously reported estimations.
  • Hydrogen production by Photocatalytic Degradation of Organic Substances Using Iron-Containing Metal-Ceramic Composites Under UV and Visible-Light Irradiation

    Artyukh, Ivan A.; Bolgaru, Konstantin A.; Dychko, Konstantin A.; Bavykina, Anastasiya; Sastre, Francesc; Skvortsova, Lidia N. (ChemistrySelect, Wiley, 2021-10-05) [Article]
    Metal-ceramic composites with ceramic matrix modified with semiconductors (SiN-SiC and TiN) were synthetized by Self-propagating high-temperature synthesis (SHS) technology. X-ray diffraction (XRD) analysis was used to determine the phase composition of the composites based on the nitrides of silicon, titanium, vanadium, and boron. Surface morphology of the composites was investigated by scanning electron microscopy (SEM), and the surface iron content was estimated using an energy-dispersive X-ray spectrometer for SEM (EDX-SEM). Optical properties of the composites were studied, and the band gap values of ceramic matrix semiconducting components were calculated. The comparative evaluation of photocatalytic efficiency of the composites has been done for hydrogen production from solutions of organic substances (HCOOH, H2C2O4, malic acid, citric acid, sucrose, and N2H4) under UV and visible light irradiation. It has been shown, that the high efficiency of photocatalytic hydrogen production under visible light irradiation depends on the composition of ceramic matrix containing semiconducting constituents, the nature of organic substances used, and the addition of H2O2 to the solution causing a photo-Fenton reaction. Also, the effect of eosin on photosensitization of the process was studied. The system of VN/N2H4 has been established to exhibit the highest efficiency of hydrogen production (300–560 μmol h−1 g−1).
  • Hydrogen production by Photocatalytic Degradation of Organic Substances Using Iron-Containing Metal-Ceramic Composites Under UV and Visible-Light Irradiation

    Artyukh, Ivan A.; Bolgaru, Konstantin A.; Dychko, Konstantin A.; Bavykina, Anastasiya; Sastre, Francesc; Skvortsova, Lidia N. (ChemistrySelect, Wiley, 2021-10-05) [Article]
    Metal-ceramic composites with ceramic matrix modified with semiconductors (SiN-SiC and TiN) were synthetized by Self-propagating high-temperature synthesis (SHS) technology. X-ray diffraction (XRD) analysis was used to determine the phase composition of the composites based on the nitrides of silicon, titanium, vanadium, and boron. Surface morphology of the composites was investigated by scanning electron microscopy (SEM), and the surface iron content was estimated using an energy-dispersive X-ray spectrometer for SEM (EDX-SEM). Optical properties of the composites were studied, and the band gap values of ceramic matrix semiconducting components were calculated. The comparative evaluation of photocatalytic efficiency of the composites has been done for hydrogen production from solutions of organic substances (HCOOH, H2C2O4, malic acid, citric acid, sucrose, and N2H4) under UV and visible light irradiation. It has been shown, that the high efficiency of photocatalytic hydrogen production under visible light irradiation depends on the composition of ceramic matrix containing semiconducting constituents, the nature of organic substances used, and the addition of H2O2 to the solution causing a photo-Fenton reaction. Also, the effect of eosin on photosensitization of the process was studied. The system of VN/N2H4 has been established to exhibit the highest efficiency of hydrogen production (300–560 μmol h−1 g−1).
  • Understanding Halide Counterion Effects in Enantioselective Ruthenium-Catalyzed Carbonyl (α-Aryl)allylation: Alkynes as Latent Allenes and Trifluoroethanol-Enhanced Turnover in The Conversion of Ethanol to Higher Alcohols via Hydrogen Auto-transfer

    Ortiz, Eliezer; Shezaf, Jonathan Z.; Chang, Yu-Hsiang; Goncalves, Theo; Huang, Kuo-Wei; Krische, Michael J. (Journal of the American Chemical Society, American Chemical Society (ACS), 2021-10-04) [Article]
    Crystallographic characterization of RuX(CO)(η3-C3H5)(JOSIPHOS), where X = Cl, Br, or I, reveals a halide-dependent diastereomeric preference that defines metal-centered stereogenicity and, therefrom, the enantioselectivity of C-C coupling in ruthenium-catalyzed anti-diastereo- and enantioselective C-C couplings of primary alcohols with 1-aryl-1-propynes to form products of carbonyl anti-(α-aryl)allylation. Computational studies reveal that a non-classical hydrogen bond between iodide and the aldehyde formyl CH bond stabilizes the favored transition state for carbonyl addition. An improved catalytic system enabling previously unattainable transformations was developed that employs an iodide-containing precatalyst, RuI(CO)3(η3-C3H5), in combination with trifluoroethanol, as illustrated by the first enantioselective ruthenium-catalyzed C-C couplings of ethanol to form higher alcohols.
  • Boron-Catalyzed Polymerization of Phenyl-Substituted Allylic Arsonium Ylides toward Nonconjugated Emissive Materials from C3/C1 Monomeric Units

    Liu, Pibo; Hadjichristidis, Nikos (ACS Macro Letters, American Chemical Society (ACS), 2021-10-04) [Article]
    Two novel allylic arsonium ylide monomers with a phenyl (steric and electronic effect) group at different positions were synthesized and used in boron-catalyzed polymerization to produce a series of well-defined polymers, poly(2-phenyl-propenylene-co-2-phenyl-propenylidene) (P2-PhAY) and poly(3-phenyl-propenylene-co-3-phenyl-propenylidene) (P3-PhAY), with unusual structures but a controllable molecular weight and relatively low polydispersity. The backbone of these polymers consists of a mixture of C1 (chain grows by one carbon atom at a time) and C3 (chain grows by three carbon atoms at a time) monomeric units, as determined by 1H, 13C, and 1H–13C HSQC 2D NMR. Based on the experimental results and density functional theoretical (DFT) calculations, we were able to propose a mechanism that takes into account not only the steric hindrance, but also the electron effect of the phenyl group. In addition, a nontraditional intrinsic luminescence was observed from the nonconjugated P2-PhAY and P3-PhAY; such unexpected emission is attributed to the formation of C3-unit clusters, as evidenced by ultraviolet–visible and fluorescence spectroscopy.
  • Advances and Challenges in Tin Halide Perovskite Nanocrystals

    Chen, Jia-Kai; Zhang, Bin-Bin; Liu, Qi; Shirahata, Naoto; Mohammed, Omar F.; Bakr, Osman; Sun, Hong-Tao (ACS Materials Letters, American Chemical Society (ACS), 2021-10-01) [Article]
    A major application limit for lead halide perovskite nanocrystals (NCs) is the presence of the highly toxic lead element, raising critical concerns of environmental pollution and health problems. To address this issue, tin halide perovskite NCs have been pushed to the forefront of perovskite research owing to their eco-friendly merit and tantalizing photophysical properties. In this Review, we critically summarize and assess the latest advances in the synthesis approaches of tin halide perovskite NCs including the hot injection, ligand-assisted reprecipitation, and chemical vapor deposition. More specifically, we detail the state-of-the-art preliminary studies in modulating their photophysical properties and in enhancing the stability with a variety of strategies such as precursor engineering, ligand engineering, and alloyed structure construction. Finally, we highlight the remaining challenges that need to be overcome to attain tin halide perovskite NCs with clear structure–property relationships and comparable physical and chemical properties to their lead-based cousins.
  • Enhanced Photocatalytic Activity in Strain Engineered Janus WSSe Monolayers

    Verma, Hemant; kale, Abhijeet J.; Prakash, Chandra; Harb, Moussab; Dixit, Ambesh (Journal of Electronic Materials, Springer Science and Business Media LLC, 2021-09-29) [Article]
    The relevant fundamental properties of Janus WSSe monolayers to photocatalytic water-splitting performance are presented here and investigated using density functional theory. The Janus WSSe monolayer with a direct band gap of 1.75 eV is subjected to biaxial strain, and related optoelectronic properties are investigated. The effect of strain is reflected in band gap change from direct to indirect. Hydrogen evolution reaction (HER) is active all over, whereas oxygen evolution reaction (OER) is active only at 4% and 6% compressive strains. The red- and blue-shifts under tensile and compressive strains, respectively, substantiate possible control over exciton-phonon interaction making it suitable for the water-splitting application. Graphic Abstract: Upon being irradiated by sunlight with sufficient energy, the biaxially strained Janus WSSe monolayer complying with HER/OER requirement produces hydrogen gas along with oxygen as a secondary product.[Figure not available: see fulltext.].
  • One-Pot Chemoenzymatic Conversion of Alkynes to Chiral Amines

    Mathew, Sam; Sagadevan, Arunachalam; Renn, Dominik; Rueping, Magnus (ACS Catalysis, American Chemical Society (ACS), 2021-09-29) [Article]
    A one-pot chemoenzymatic sequential cascade for the synthesis of chiral amines from alkynes was developed. In this integrated approach, just ppm amounts of gold catalysts enabled the conversion of alkynes to ketones (>99%) after which a transaminase was used to catalyze the production of biologically valuable chiral amines in a good yield (up to 99%) and enantiomeric excess (>99%). A preparative scale synthesis of (S)-methylbenzylamine and (S)-4-methoxy-methylbenzylamine from its alkyne form gave a yield of 59 and 92%, respectively, with ee > 99%.
  • Single-Particle Spectroscopy as a Versatile Tool to Explore Lower-Dimensional Structures of Inorganic Perovskites

    Bose, Riya; Zhou, Xiaohe; Guo, Tianle; Yang, Haoze; Yin, Jun; Mishra, Aditya; Slinker, Jason D.; Bakr, Osman; Mohammed, Omar F.; Malko, Anton V. (ACS Energy Letters, American Chemical Society (ACS), 2021-09-27) [Article]
    The remarkable defect-tolerant nature of inorganic cesium halide perovskites, leading to near unity photoluminescence (PL) quantum yield and narrow emission line width across the entire visible spectrum, has provided a tantalizing platform for the development of a plethora of light-emitting applications. Recently, lower-dimensional (2D, 1D, and 0D) perovskites have attracted further attention due to their enhanced thermal, photo, and chemical stability as compared to their three-dimensional (3D) analogues. The combination of external size quantization and internal octahedral organization provides a unique opportunity to study and harness “multi-dimensional” electronic properties engineered on both atomic scale and nanoscale. However, crucial research to understand the elementary charge carrier dynamics in lower-dimensional perovskites lags far behind the enormous effort to incorporate them into optoelectronic devices. In this Perspective, we provide a review of recent developments that focus on studies of the dynamics of excitonic complexes in Cs-based perovskite nanocrystals using single-particle time-resolved PL spectroscopy and photon correlation measurements. Single-photon statistical studies not only offer an unprecedented level of detail to directly assess various recombination pathways, but also provide insights into specifics of the charge carriers' localization. We discuss the underlying physicochemical processes that govern PL emission and draw attention to a number of attributes within this class of the materials, especially lower-dimensional perovskites, that may indicate the common origin of the PL emission as well as provide a route map for the vast unexplored territories where single-particle spectroscopy can be a powerful tool to unravel crucial information.
  • Phosphatidylcholine-mediated regulation of growth kinetics for colloidal synthesis of cesium tin halide nanocrystals

    Wang, Lu-Ming; Chen, Jia-Kai; Zhang, Bin-Bin; Liu, Qi; Zhou, Yang; Shu, Jie; Wang, Zuoshan; Shirahata, Naoto; Song, Bo; Mohammed, Omar F.; Bakr, Osman; Sun, Hong-Tao (Nanoscale, Royal Society of Chemistry (RSC), 2021-09-27) [Article]
    Cesium tin halide (CsSnX3, where X is halogen) perovskite nanocrystals (NCs) are one of the most representative alternatives to their lead-based cousins. However, a fundamental understanding of how to regulate the growth kinetics of colloidal CsSnX3 NCs is still lacking and, specifically, the role of surfactants in affecting their growth kinetics remains incompletely understood. Here we report a general approach for colloidal synthesis of CsSnX3 perovskite NCs through a judicious combination of capping agents. We demonstrate that introducing a small amount of zwitterionic phosphatidylcholine in the reaction is of vital importance for regulating the growth kinetics of CsSnX3 NCs, which otherwise merely leads to the formation of large-sized powders. Based on a range of experimental characterization, we propose that the formation of intermediate complexes between zwitterionic phosphatidylcholine and the precursors and the steric hindrance effect of branched fatty acid side-chains of phosphatidylcholine can regulate the growth kinetics of CsSnX3, which enables us to obtain CsSnX3 NCs with emission quantum yields among the highest values ever reported. Our finding of using zwitterionic capping agents to regulate the growth kinetics may inspire more research on the synthesis of high-quality tin-based perovskite NCs that could speed up their practical applications in optoelectronic devices.
  • Efficient and Spectrally Stable Blue Perovskite Light-Emitting Diodes Employing a Cationic π-Conjugated Polymer

    Yuan, Shuai; Cui, Lin-Song; Dai, Linjie; Liu, Yun; Liu, Qing-Wei; Sun, Yu-Qi; Auras, Florian; Anaya, Miguel; Zheng, Xiaopeng; Ruggeri, Edoardo; Yu, You-Jun; Qu, Yang-Kun; Abdi-Jalebi, Mojtaba; Bakr, Osman; Wang, Zhao-Kui; Stranks, Samuel D.; Greenham, Neil C.; Liao, Liang-Sheng; Friend, Richard H. (Advanced Materials, Wiley, 2021-09-24) [Article]
    Metal halide perovskite semiconductors have demonstrated remarkable potentials in solution-processed blue light-emitting diodes (LEDs). However, the unsatisfied efficiency and spectral stability responsible for trap-mediated non-radiative losses and halide phase segregation remain the primary unsolved challenges for blue perovskite LEDs. In this study, it is reported that a fluorene-based π-conjugated cationic polymer can be blended with the perovskite semiconductor to control film formation and optoelectronic properties. As a result, sky-blue and true-blue perovskite LEDs with Commission Internationale de l'Eclairage coordinates of (0.08, 0.22) and (0.12, 0.13) at the record external quantum efficiencies of 11.2% and 8.0% were achieved. In addition, the mixed halide perovskites with the conjugated cationic polymer exhibit excellent spectral stability under external bias. This result illustrates that π-conjugated cationic polymers have a great potential to realize efficient blue mixed-halide perovskite LEDs with stable electroluminescence.
  • Crystallization and Morphology of Triple Crystalline Polyethylene-b-poly(ethylene oxide)-b-poly(ε-caprolactone) PE-b-PEO-b-PCL Triblock Terpolymers

    Matxinandiarena, Eider; Múgica, Agurtzane; Zubitur, Manuela; Ladelta, Viko; Zapsas, Georgios; Cavallo, Dario; Hadjichristidis, Nikos; Müller, Alejandro J. (Polymers, MDPI AG, 2021-09-16) [Article]
    The morphology and crystallization behavior of two triblock terpolymers of polymethylene, equivalent to polyethylene (PE), poly (ethylene oxide) (PEO), and poly (ε-caprolactone) (PCL) are studied: PE227.1-b-PEO4615.1-b-PCL3210.4 (T1) and PE379.5-b-PEO348.8-b-PCL297.6 (T2) (superscripts give number average molecular weights in kg/mol and subscripts composition in wt %). The three blocks are potentially crystallizable, and the triple crystalline nature of the samples is investigated. Polyhomologation (C1 polymerization), ring-opening polymerization, and catalyst-switch strategies were combined to synthesize the triblock terpolymers. In addition, the corresponding PE-b-PEO diblock copolymers and PE homopolymers were also analyzed. The crystallization sequence of the blocks was determined via three independent but complementary techniques: differential scanning calorimetry (DSC), in situ SAXS/WAXS (small angle X-ray scattering/wide angle X-ray scattering), and polarized light optical microscopy (PLOM). The two terpolymers (T1 and T2) are weakly phase segregated in the melt according to SAXS. DSC and WAXS results demonstrate that in both triblock terpolymers the crystallization process starts with the PE block, continues with the PCL block, and ends with the PEO block. Hence triple crystalline materials are obtained. The crystallization of the PCL and the PEO block is coincident (i.e., it overlaps); however, WAXS and PLOM experiments can identify both transitions. In addition, PLOM shows a spherulitic morphology for the PE homopolymer and the T1 precursor diblock copolymer, while the other systems appear as non-spherulitic or microspherulitic at the last stage of the crystallization process. The complicated crystallization of tricrystalline triblock terpolymers can only be fully grasped when DSC, WAXS, and PLOM experiments are combined. This knowledge is fundamental to tailor the properties of these complex but fascinating materials.
  • Interfacial Model Deciphering High-Voltage Electrolytes for High Energy Density, High Safety, and Fast-Charging Lithium-Ion Batteries

    Zou, Yeguo; Cao, Zhen; Zhang, Junli; Wahyudi, Wandi; Wu, Yingqiang; Liu, Gang; Li, Qian; Cheng, Haoran; Zhang, Dongyu; Park, Geon-Tae; Cavallo, Luigi; Anthopoulos, Thomas D.; Wang, Limin; Sun, Yang-Kook; Ming, Jun (Advanced Materials, Wiley, 2021-09-12) [Article]
    High-voltage lithium-ion batteries (LIBs) enabled by high-voltage electrolytes can effectively boost energy density and power density, which are critical requirements to achieve long travel distances, fast-charging, and reliable safety performance for electric vehicles. However, operating these batteries beyond the typical conditions of LIBs (4.3 V vs Li/Li+) leads to severe electrolyte decomposition, while interfacial side reactions remain elusive. These critical issues have become a bottleneck for developing electrolytes for applications in extreme conditions. Herein, an additive-free electrolyte is presented that affords high stability at high voltage (4.5 V vs Li/Li+), lithium-dendrite-free features upon fast-charging operations (e.g., 162 mAh g−1 at 3 C), and superior long-term battery performance at low temperature. More importantly, a new solvation structure-related interfacial model is presented, incorporating molecular-scale interactions between the lithium-ion, anion, and solvents at the electrolyte–electrode interfaces to help interpret battery performance. This report is a pioneering study that explores the dynamic mutual-interaction interfacial behaviors on the lithium layered oxide cathode and graphite anode simultaneously in the battery. This interfacial model enables new insights into electrode performances that differ from the known solid electrolyte interphase approach to be revealed, and sets new guidelines for the design of versatile electrolytes for metal-ion batteries.
  • Thermo-Responsive Membranes from Blends of PVDF and PNIPAM-b-PVDF Block Copolymers with Linear and Star Architectures

    Algarni, Fatimah; Musteata, Valentina-Elena; Falca, Gheorghe; Chisca, Stefan; Hadjichristidis, Nikos; Nunes, Suzana Pereira (Macromolecules, American Chemical Society (ACS), 2021-09-10) [Article]
    We report the synthesis of poly(n-isopropylacrylamide)-b-poly(vinylidene fluoride), (PNIPAM-b-PVDF), copolymers with linear and star structures, as well as the self-assembly and fabrication of thermo-responsive membranes from blends of these block copolymers and a linear PVDF homopolymer. The synthesis was achieved by reversible addition–fragmentation chain-transfer sequential copolymerization using mono- or multifunctional transfer agents. The self-assembly in bulk and selective solvents was investigated. The PVDF blocks are crystallizable and hydrophobic and the PNIPAM thermo-responsive in water. The morphology is dominated by the breakout crystallization of the PVDF block. Nanoporous membranes were fabricated by non-solvent-induced phase-separation method. The membranes revealed a macroscale zig–zag morphology, which is dependent on the block copolymer architecture. Due to the presence of PNIPAM, these membranes exhibited thermo-responsive behavior with water permeability and rejection alternately varying with the operating temperature, which is reversible in multiple heating–cooling cycles.

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