Intrinsically stretchable organic light-emitting diodes (ISOLEDs) are becoming essential components of wearable electronics. However, the efficiencies of ISOLEDs have been highly inferior compared with their rigid counterparts, which is due to the lack of ideal stretchable electrode materials that can overcome the poor charge injection at 1D metallic nanowire/organic interfaces. Herein, highly efficient ISOLEDs that use graphene-based 2D-contact stretchable electrodes (TCSEs) that incorporate a graphene layer on top of embedded metallic nanowires are demonstrated. The graphene layer modifies the work function, promotes charge spreading, and impedes inward diffusion of oxygen and moisture. The work function (WF) of 3.57 eV is achieved by forming a strong interfacial dipole after deposition of a newly designed conjugated polyelectrolyte with crown ether and anionic sulfonate groups on TCSE; this is the lowest value ever reported among ISOLEDs, which overcomes the existing problem of very poor electron injection in ISOLEDs. Subsequent pressure-controlled lamination yields a highly efficient fluorescent ISOLED with an unprecedently high current efficiency of 20.3 cd A−1, which even exceeds that of an otherwise-identical rigid counterpart. Lastly, a 3 inch five-by-five passive matrix ISOLED is demonstrated using convex stretching. This work can provide a rational protocol for designing intrinsically stretchable high-efficiency optoelectronic devices with favorable interfacial electronic structures.

Electroorganic synthesis is a sustainable technique that effectively combines electrochemistry and organic synthesis. However, the investigation of its mechanism remains a challenge owing to the complexity of the heterogeneous electron transfer process. Electroanalytical methods can offer valuable insights into its mechanism through simple and rapid procedures. In this short review, we highlight the advancements achieved in the last two years in electroanalytical methods used for the mechanistic investigation of electroorganic synthesis, from widely used cyclic voltammetry to other advanced electroanalytical techniques. Finally, we discuss our perspective on these methods

The all-solid-state battery (ASSB) has become one of the most promising next-generation battery systems, since the aspect of safety has emerged as a crucial criterion for new large-scale applications such as in electric vehicles. Despite the recent remarkable progress in the performance enhancement, the real-world implementation of the ASSB still requires full comprehension/evaluation of its properties and performance under various practical operational conditions. Unlike batteries employed in conventional electronic devices, those in electric vehicles—the major application that the ASSB is expected to be employed—would be exposed to wide temperature variations (−20 to ∼70 °C) at various states of charges due to their outdoor storage and irregular discharge/rest/charge conditions depending on vehicle drivers' usage patterns. Herein, we investigate the reliability of a Li6PS5Cl-based ASSB system in practically harsh but plausible storage conditions and reveal that it is vulnerable to elevated-temperature storage as low as 70 °C, which, in contrast to the common belief, causes significant degradation of the electrolyte and consequently irreversible buildup of the cell resistance. It is unraveled that this storage condition induces the decomposition of Li6PS5Cl in contact with the cathode material, involving the SOx gas evolution particularly at charged states, which creates a detrimental porous cathode/electrolyte interface, thereby leading to the large interfacial resistance. Our findings indicate that the stability of the solid electrolyte, which has been believed to be failsafe, needs to be carefully revisited at various practical operational conditions for actual applications in ASSBs.

Polyesters exhibiting a protein-like absolute atomic precision have unlimited potential for application as biomaterials and polymeric materials. Herein, we report the synthesis of enantiomeric ω-hydroxy acids (OHAs) from terminal epoxides and alkenes as starting materials. Our synthetic strategy allows the synthesis of a library of OHAs with a well-defined atomic composition (carbon number), stereochemical configuration, and substituent chemistry. These monomers can serve as building blocks for the preparation of discrete and sequence-defined polyesters, wherein various functional groups can be introduced at specific locations via the cross-convergent method. We demonstrated that the specific locations of the reactive functional groups of the sequence-defined polyester could be utilized to form a concentrically cyclic polymer upon cyclization. Our results provide a facile platform for engineering polyesters with the structural sophistication exhibited only by biopolymers, such as proteins and nucleic acids.

Sequence-defined synthetic oligomers and polymers are promising molecular media for permanently storing digital information. However, the information decoding process relies on degradative sequencing methods such as mass spectrometry, which consumes the information-storing polymers upon decoding. Here, we demonstrate the nondestructive decoding of sequence-defined oligomers of enantiopure α-hydroxy acids, oligo(l-mandelic-co-d-phenyl lactic acid)s (oMPs), and oligo(l-lactic-co-glycolic acid)s (oLGs) by 13C nuclear magnetic resonance spectroscopy. We were able to nondestructively decode a bitmap image (192 bits) encoded using a library of 12 equimolar mixtures of an 8-bit-storing oMP and oLG, synthesized through semiautomated flow chemistry in less than 1% of the reaction time required for the repetition of conventional batch reactions. Our results highlight the potential of bundles of sequence-defined oligomers as efficient media for encoding and decoding large-scale information based on the automation of their synthesis and nondestructive sequencing processes.

Core/shell quantum dots (QDs) have been extensively studied, yet their optical properties widely vary among studies. Such variation may arise from the variation in interfacial structures induced by the subtle difference in each synthetic procedure. Here, we studied the interfacial structures of CdSe/ZnS QDs using the time-of-flight medium energy ion-scattering spectroscopy (TOF-MEIS), which offers the radial elemental distributions as well as the overall elemental compositions of QDs. The TOF-MEIS spectra provided strong evidence for the existence of an alloyed layer at the interface between CdSe and ZnS in typical CdSe/ZnS QDs. On the basis of the emission and absorption spectra of QDs sampled during the synthesis, we conclude that such interfacial alloying is caused by the dissolution of CdSe seeds during the synthesis steps. Such a dissolution mechanism is further corroborated by the observation that the ligand environment of solvent (X or L type) leads to different shapes of interfaces.

Conformational changes in macromolecules significantly affect their functions and assembly into high-level structures. Despite advances in theoretical and experimental studies, investigations into the intrinsic conformational variations and dynamic motions of single macromolecules remain challenging. Here, liquid-phase transmission electron microscopy enables the real-time tracking of single-chain polymers. Imaging linear polymers, synthetically dendronized with conjugated aromatic groups, in organic solvent confined within graphene liquid cells, directly exhibits chain-resolved conformational dynamics of individual semiflexible polymers. These experimental and theoretical analyses reveal that the dynamic conformational transitions of the single-chain polymer originate from the degree of intrachain interactions. In situ observations also show that such dynamics of the single-chain polymer are significantly affected by environmental factors, including surfaces and interfaces.

Porous organic polymers (POPs) have emerged as promising materials for electrochemical devices on account of their diverse functional groups and morphologies. Herein, we describe a one-pot two-step synthesis of redox-active and permeable POPs as uniformly shaped fibrils with homogeneous micropores and hierarchical mesoporous channels. Owing to the high fraction of redox-active groups and porous structure, the active material (PI-Fiber) exhibited a high charge capacity of 83.3 mA h g−1 over 0.5 V even at a current density of 75 A g−1, a coulombic efficiency of over 95%, and stability to endure nearly 10 000 cycles. Additionally, high energy and power densities were observed in a two-electrode cell, indicating that PI-Fiber can be adapted for pseudocapacitive energy storage systems. Therefore, our work illustrates that a novel molecular design, supramolecular assembly, and hierarchical architecture of POPs can aid the development of novel and versatile energy-storage materials.

Artificial metalloenzymes have fed our understanding of how inorganic reactivities emerge, evolve, and diversify in protein environments. Herein, we created dinuclear copper oxidases by genetically encoding a metal-ligating unnatural amino acid (bpy-Ala) per protomer in the vicinity of the innate C2 rotational axis of a homo-oligomeric protein. The inherent protein symmetry allows the precise multiplication and placement of two Cu(bpy) species. Depending on the location of bpy-Ala, the tailor-made metalloenzymes exhibited electronically uncoupled or coupled dicopper sites. Consequently, they displayed various reactivities with dioxygen associated with multiple protons and electrons, illustrating a diverse chemical repertoire of artificial copper-dependent enzymes.

Artificial, synthetic chaperones have attracted much attention in biomedical research due to their ability to control the folding of proteins and peptides. Here, we report bio-inspired multifunctional porous nanoparticles to modulate proper folding and intracellular delivery of therapeutic α-helical peptide. The Synthetic Nano-Chaperone for Peptide (SNCP) based on porous nanoparticles provides an internal hydrophobic environment which contributes in stabilizing secondary structure of encapsulated α-helical peptides due to the hydrophobic internal environments. In addition, SNCP with optimized inner surface modification not only improves thermal stability for α-helical peptide but also supports the peptide stapling methods in situ, serving as a nanoreactor. Then, SNCP subsequently delivers the stabilized therapeutic α-helical peptides into cancer cells, resulting in high therapeutic efficacy. SNCP improves cellular uptake and bioavailability of the anti-cancer peptide, so the cancer growth is effectively inhibited in vivo. These data indicate that the bio-inspired SNCP system combining nanoreactor and delivery carrier could provide a strategy to expedite the development of peptide therapeutics by overcoming existing drawbacks of α-helical peptides as drug candidates.