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Polyethylene oxide (PEO)-based electrolytes are the most widely used solid polymer electrolyte (SPE) due to their high safety, excellent ability to dissociate lithium salts, low cost, and ease of preparation. However, low ionic conductivity and narrow electrochemical stability window limit their potential for further development. "Polymer-in-salt" electrolytes exhibit superior electrochemical performance; however, the high lithium salt concentration makes the SPE mechanically fragile when facing lithium dendrites. Therefore, preparing an SPE that can withstand a high concentration of lithium salt while still maintaining good mechanical properties has become a valuable challenge. In this study, a macroscopically homogeneous but nanoscopically phase-separated polymer matrix was designed as an electrolyte that can withstand a high concentration of lithium salt while retaining good mechanical properties, and this study investigated changes in the Li+ solvation structure within the electrolyte and analyzed the reasons for the simultaneous achievement of good ionic conductivity (1.02 × 10-3 S cm-1 at 60 °C) and mechanical properties (7 MPa at room temperature). The formation of large ion clusters at the phase interface and selective enrichment of lithium salt in specific regions are found to play crucial roles, and the critical current density (CCD) can reach a value of 2.2 mA cm-2. This work demonstrates a promising design approach for polymer electrolytes that achieves an optimal balance between SPE conductivity and mechanical properties through microstructure control.

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Light-driven soft actuators based on photoresponsive materials can be used to mimic biological motion, such as hand movements, without involving rigid or bulky electromechanical actuations. However, to our knowledge, no robust photoresponsive material with desireable mechanical and biological properties and relatively simple manufacture exists for robotics and biomedical applications. Herein, we report a new visible-light-responsive thermoplastic elastomer synthesized by introducing photoswitchable moieties (i.e., azobenzene derivatives) into the main chain of poly(ε-caprolactone) based polyurethane urea (PAzo). A PAzo elastomer exhibits controllable light-driven stiffness softening due to its unique nanophase structure in response to light, while possessing excellent hyperelasticity (stretchability of 575.2%, elastic modulus of 17.6 MPa, and strength of 44.0 MPa). A bilayer actuator consisting of PAzo and polyimide films is developed, demonstrating tunable bending modes by varying incident light intensities. Actuation mechanism via photothermal and photochemical coupling effects of a soft-hard nanophase is demonstrated through both experimental and theoretical analyses. We demonstrate an exemplar application of visible-light-controlled soft "fingers" playing a piano on a smartphone. The robustness of the PAzo elastomer and its scalability, in addition to its excellent biocompatibility, opens the door to the development of reproducible light-driven wearable/implantable actuators and lightweight soft robots for clinical applications.

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Anion exchange membranes (AEMs) are the heart of alkaline fuel cells and water electrolysis, and have made a great progress in recent years. However, AEMs are still unable to satisfy the needs of high conductivity and stability, hindering their widespread commercialization. Side chain regulations have been widely used to prepare highly conductive and durable AEMs. Here, we construct a series of polyaromatic AEMs grafted with fluorinated cation side chains and cation-free alkyl chains with different end groups to explore the polar discrimination of side chains on membrane performance. This work demonstrates that AEMs grafting the cation side chains with superhydrophobic fluorine pendent and alkyl side chains with hydrophilic pendent enhance water content and ion conductivity. This is due to the strong immiscibility between the hydrophilic and hydrophobic head groups which promotes the establishments of microphase separation and ion highways. Specifically, poly(binaphthyl-co-terphenyl piperidinium) containing fluorinated piperidinium side chains and alkyl chains with methoxy pendent (QBNTP-QFM) possesses a satisficed OH- conductivity (170.6 mS cm-1 at 80 °C) and can tolerate 5 M hot NaOH for 2100 h with only 3.4 % conductivity loss. Expectedly, the single cell with QBNTP-QFM yields a prominent maximum power density of 1.62 W cm-2 and the water electrolysis cell with QBNTP-QFM achieves a pronounced current density of 3.0 A cm-2 at 1.8 V, both cells also display a prominent durability for 120 h operation. The results prove that this side chain optimization can improve ion conductivity and is a promising method for AEM development.

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This study describes the formation, size control, and penetration behavior of polymer nanodots (Pdots) consisting of single or few chain polythiophene-based conjugated polyelectrolytes (CPEs) via nanophase separation between good solvent and poor solvent of CPE. Though the chain singularity may be associated with dilution nanophase separation suggests that molecules of a good solvent create a thermodynamically driven solvation layer surrounding the CPEs and thereby separating the single chains even in their poor solvents. This statement is therefore corroborated with emission intensity/lifetime, particle size, and scattering intensity of polyelectrolyte in good and poor solvents. Regarding the augmented features, Pdots are implemented into cell imaging studies to understand the nuclear penetration and to differentiate the invasive characteristics of breast cancer cells. The python based red, green, blue (RGB) color analysis   depicts that Pdots have more nuclear penetration ability in triple negative breast cancer cells due to the different nuclear morphology in shape and composition and Pdots have penetrated cell membrane as well as extracellular matrix in spheroid models. The current Pdot protocol and its utilization in cancer cell imaging are holding great promise for gene/drug delivery to target cancer cells by explicitly achieving the very first priority of nuclear intake.

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A polymer separator plays a pivotal role in battery safety, overall electrochemical performance, and cell assembly process. Traditional separators are separately produced from the electrodes and dominated by porous polyolefin thin films. In spite of their commercial success, today's separators are facing growing challenges with the increasing demand on the device safety and performance. As an attempt to address this urgent need, here, we propose a concept of in situ separator technology by manipulating the two-dimensional (2D) microfluid nanophase separation (2D-MFPS) of a poly(vinylidene difluoride)/lithium salt solution during drying. Particularly, nanophase separation is effectively regulated by low humidity, salt type, and compositions. For application studies, this 2D-MFPS is directly performed onto commercial electrodes under drying conditions with low humidity to fabricate a high-performance in situ separator with thickness and porous structures comparable to those of commercial Celgard separators. This in situ separator shows superior performance in high-temperature stability and wetting capability to a variety of liquid electrolytes. Finally, pouch cells with this in situ separator technology are successfully assembled with an extremely simplified separator-stacking-free process and demonstrate stable cycle performance due to the well-controlled porous structures and electrode-separator interface.

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A copper-zirconia composite having an evenly distributed lamellar texture, Cu#ZrO2, was synthesized by promoting nanophase separation of the Cu51Zr14 alloy precursor in a mixture of carbon monoxide (CO) and oxygen (O2). High-resolution electron microscopy revealed that the material consists of interchangeable Cu and t-ZrO2 phases with an average thickness of 5 nm. Cu#ZrO2 exhibited enhanced selectivity toward the generation of formic acid (HCOOH) by electrochemical reduction of carbon dioxide (CO2) in aqueous media at a Faradaic efficiency of 83.5% at -0.9 V versus the reversible hydrogen electrode. In situ Raman spectroscopy has revealed that a bifunctional interplay between the Zr4+ sites and the Cu boundary leads to amended reaction selectivity along with a large number of catalytic sites.

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Can commodity polymers are made to be healable just by blending with self-healable polymers? Here we report the first study on the fundamental aspect of this practically challenging issue. Poly(ether thiourea) (PTUEG3 ; Tg =27 °C) reported in 2018 is extraordinary in that it is mechanically robust but can self-heal even at 12 °C. In contrast, poly(octamethylene thiourea) (PTUC8 ; Tg =50 °C), an analogue of PTUEG3 , cannot heal below 92 °C. We found that their polymer blend self-healed in a temperature range above 32 °C even when its PTUEG3 content was only 20 mol %. Unlike PTUEG3 alone, this polymer blend, upon exposure to high humidity, barely plasticized, keeping its excellent mechanical properties due to the non-hygroscopic nature of the PTUC8 component. CP/MAS 13 C NMR analysis revealed that the polymer blend was nanophase-separated, which possibly accounts for why such a small amount of PTUEG3 provided the polymer blend with humidity-tolerant self-healable properties.

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Proton exchange membrane (PEM) is pivotal for proton exchange membrane fuel cells (PEMFCs). In the present work, a block copolymer with hydrophilic alkyl sulfonated side groups and hydrophobic flexible alkyl ether side groups, poly(5'-hexyloxy-1',4-biphenyl)-b-poly(2',4'-bispropoxysulfonate-1',4-biphenyl) (HBP-b-xBPSBP), is designed and synthesized by copolymerization of the hydrophilic and hydrophobic oligomers. The oligomers are synthesized via a Pd-catalyzed Suzuki cross-coupling of 1,3-dibromo-5-hexyloxybenzene, and 3,3'-[(4,6-dibromo-1,3-phenylene)bis(oxy)]bis(propane-1-sulfonate) or 1,4-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzene. The good solubility and film-forming characteristics are achieved via the introduction of flexible hexyloxy side groups, and high ion exchange capacity (IEC) is achieved via the introduction of high density of alkyl sulfonated side groups. The HBP-b-0.5BPSBP has the highest IEC of 3.17 mmol/g, the highest proton conductivity of 43.5 mS/cm at 95 °C and 90% relative humidity (RH) and low methanol permeability of 6.45×10-7  cm2 /s. Meanwhile, crosslinked HBP-b-xBPSBP exhibits promising water uptake, swelling ratio and low methanol permeability. These characteristics are attributed to the crosslinked structure and the hydrophilic/hydrophobic nanophase separation morphology promoted by the poly(m-phenylene) main chains, flexible alkyl ether groups, and alkyl sulfonated side groups.

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Charge-governed ion transport is crucial to numerous industries, and the advanced membrane is the essential component. In nature, the efficient and selective ion transport is mainly governed by the charged ion channels located in cell membrane, indicating the architecture with functional differentiation. Inspired by this architecture, a membrane by ionic crosslinking sulfonated poly(arylene ether ketone) and imidazolium-functionalized poly(arylene ether sulfone) is designed and fabricated to make full use of the charges. This ionic crosslinking is designed to realize nanophase separation to aggregate the ion pathways in the membrane, which results in excellent ion selectivity and high ion conductivity. With the excellent ion transport behavior, ionic crosslinking membrane shows great potential in osmotic energy conversion, which maximum power density can be up to 16.72 W m-2 . This design of ionic crosslinking-induced nanophase separation offers a roadmap for ion transport promotion.

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The glass transition temperature (Tg) is one of the most important properties of polymeric materials. In order to reveal whether the scissors effect, i.e., the Fox-Flory relationship between Tg and the average molecular weight between crosslinking points (Mc), reported only in one case for polymer conetworks so far, is more generally effective or valid only for a single case, a series of poly(methyl methacrylate)-l-polyisobutylene (PMMA-l-PIB) conetworks was prepared and investigated. Two Tgs were found for the conetworks by DSC. Fox-Flory type dependence between Tg and Mc of the PMMA component (Tg = Tg,∞ - K/Mc) was observed. The K constants for the PMMA homopolymer and for the PMMA in the conetworks were the same in the margin of error. AFM images indicated disordered bicontinuous, mutually nanoconfined morphology with average domain sizes of 5-20 nm, but the correlation between Tg and domain sizes was not found. These new results indicate that the macrocrosslinkers act like molecular scissors (scissors effect), and the Tg of PMMA depend exclusively on the Mc in the conetworks. Consequently, these findings mean that the scissors effect is presumably a general phenomenon in nanophase-separated polymer conetworks, and this finding could be utilized in designing, processing, and applications of these novel materials.

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The fluorescent dye 8-hydroxypyrene-1,3,6-trisulfonate (pyranine) combines high photostability with ratiometric pH detection in the physiological range, making it a prime candidate for optical sensors in biomedical applications, such as pH-based chronic wound monitoring. However, pyranine's high water solubility and the difficulty of covalent attachment pose severe limitations in terms of leaching from sensor matrices. Herein, pyranine-modified nanophase-separated amphiphilic polymer conetworks (APCNs) are reported as fluorescent ratiometric pH sensors. The thin, freestanding APCN membranes composed of one hydrophilic and one hydrophobic polymer provide an optically transparent, flexible, and stable ideal matrix that enables contact between dye and aqueous environment. An active ester-based conjugation approach results in a highly homogeneous and stable pyranine modification of the APCN's hydrophilic phase. This concept effectively solves the leaching challenge for pyranine without compromising its functionality, which is demonstrated by ratiometric pH detection in the range of pH 5-9.

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The crystalline cooperativity of the donor and acceptor segment in double-cable conjugated polymers plays an important role in the nanophase separation and photovoltaic performance in single-component organic solar cells (SCOSCs). Two double-cable conjugated polymers with the same conjugated backbone and perylene bisimide (PBI) side units were designed in which PBIs were positioned symmetrically and perpendicularly (P1) and asymmetrically and slantingly (P2) along the conjugated backbones. After thermal annealing, both conjugated backbones and PBI side units in P1 tend to form ordered nanostructures, while PBI side units in P2 dominated the crystallization and hamper the crystallization of conjugated backbones. P1 showed good crystalline cooperativity between conjugated backbones and PBI side units, resulting in improved power conversion efficiencies (PCEs) up to 3.43 % in SCOSCs, while P2 with poor crystalline cooperativity exhibited PCEs below 2.42 %.

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Mesoporous precious metals with abundant active sites and high surface area have been widely recognized as high-performance catalytic materials. However, the templated synthesis is complex and costly. Herein, we report a mesoporous rhodium (m-Rh) that can be readily synthesized from entangled nanofibres of Rh and Y2 O3 without templates. The entangled nanofibres, prepared from uniform Rh-Y alloys under redox atmosphere, were the key precursor in the synthesis processes. Moreover, the m-Rh efficiently catalyzed carbon dioxide reforming of methane (DRM) at a low reaction temperature of 683 K. Further, electrochemical methods of CO electro-oxidation were innovatively used to demonstrate the stability of CO and oxygen species for the DRM reaction.

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The understanding of the relationship between the chemical structure and the hydrophilic structure is crucial for the designing of high-performance PEMs. Comparative studies in typical Nafion and sulfonated poly (ether ether ketone) (SPEEK) were performed using a combined experimental and theoretical method. SPEEK showed suppressed fuel crossover and good mechanical property but low water uptake, weak phase separation, and inadequate proton conductivity. Molecular dynamics (MD) simulation approaches were employed to get a molecular-level understanding of the structure-property relationship of SPEEK and Nafion membranes. In SPEEK membranes, the local aggregation of hydrophilic clusters is worse, and much stronger electrostatic interaction between Os-Hh was verified, resulting in less delocalized free H3O+ and much lower DH3O+. In addition, the probability of H2O-H3O+ association varied with water content. Particularly, SPEEK exhibited much lower H9O4+ probability at various relative water contents, leading to lower structural diffusivity than Nafion. Eventually, SPEEK possessed low vehicular and structural diffusivities, which resulted in a low proton conductivity. The results indicated that the structure of hydrated hydronium complexes would deform to adapt the confining hydrophilic channels. The confinement effect on diffusion of H2O and H3O+ is influenced by the water content and the hydrophilic morphologies. This study provided a new insight into the exploration of high-performance membranes in fuel cell.

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The toughness of a high-performance thermosetting epoxy network can be greatly improved by generating polyether sulfone-based macro- to nano-scale morphologies. Two polyethersulfones (PES) which only differ by their chain-end nature have been successively investigated as potential tougheners of a high-Tg thermoset matrix based on a mixture of trifunctional and difunctional aromatic epoxies and an aromatic diamine. For a given PES content, morphologies and toughness of the resulting matrices have been tuned by changing curing conditions and put into perspective with PES chain-end nature.

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Block molecules belong to a rapidly growing research field in materials chemistry in which discrete macromolecular architectures bridge the gap between block copolymers (BCP) and liquid crystals (LCs). The merging of characteristics from both BCP and LCs is expected to result in exciting breakthroughs, such as the discovery of unexpected morphologies or significant shrinking of domain spacings in materials that possess the high definition of organic molecules and the processability of polymers. Here we report the bulk self-assembly of two families of monodisperse block molecules comprised of naphthalenediimides (NDIs) and oligodimethylsiloxanes (ODMS). These materials are characterized by waxy texture, strong long-range order, and very low mobility, typical properties of conformationally disordered crystals. Our investigation unambiguously reveals that thermodynamic immiscibility and crystallization direct the self-assembly of ODMS-based block molecules. We show that a synergy of high incompatibility between the blocks and crystallization of the NDIs causes nanophase separation, giving access to hexagonally packed columnar (Colh) and lamellar (LAM) morphologies with sub-10 nm periodicities. The domain spacings can be tuned by mixing molecules with different ODMS lengths and the same number of NDIs, introducing an additional layer of control. X-ray scattering experiments reveal macrophase separation whenever this constitutional bias is not observed. Finally, we highlight our "ingredient approach" to obtain perfect order in sub-10 nm structured materials with a simple strategy built on a crystalline "hard" moiety and an incompatible "soft" ODMS partner. Following this simple rule, our recipe can be extended to a number of systems.

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We review basic principles of low-resolution proton NMR spin diffusion experiments, relying on mobility differences in nm-sized phases of inhomogeneous organic materials such as block-co- or semicrystalline polymers. They are of use for estimates of domain sizes and insights into nanometric dynamic inhomogeneities. Experimental procedures and limitations of mobility-based signal decomposition/filtering prior to spin diffusion are addressed on the example of as yet unpublished data on semicrystalline poly(ϵ-caprolactone), PCL. Specifically, we discuss technical aspects of the quantitative, dead-time free detection of rigid-domain signals by aid of the magic-sandwich echo (MSE), and magic-and-polarization-echo (MAPE) and double-quantum (DQ) magnetization filters to select rigid and mobile components, respectively. Such filters are of general use in reliable fitting approaches for phase composition determinations. Spin diffusion studies at low field using benchtop instruments are challenged by rather short (1)H T1 relaxation times, which calls for simulation-based analyses. Applying these, in combination with domain sizes as determined by small-angle X-ray scattering, we have determined spin diffusion coefficients D for PCL (0.34, 0.19 and 0.032nm(2)/ms for crystalline, interphase and amorphous parts, respectively). We further address thermal-history effects related to secondary crystallization. Finally, the state of knowledge concerning the connection between D values determined locally at the atomic level, using (13)C detection and CP- or REDOR-based "(1)H hole burning" procedures, and those obtained by calibration experiments, is summarized. Specifically, the non-trivial dependence of D on the magic-angle spinning (MAS) frequency, with a minimum under static and a local maximum under moderate-MAS conditions, is highlighted.

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All-polymer solar cells with 4.8% power conversion efficiency are achieved via solution processing from a co-solvent. The observed short-circuit current density of 10.5 mA cm(-2) and external quantum efficiency of 61.3% are also the best reported in all-polymer solar cells so far. The results demonstrate that processing the active layer from a co-solvent is an important strategy in achieving highly efficient all-polymer solar cells.