Designed wrinkles for optical encryption and flexible integrated circuit carrier board.

Patterns on polymers usually have different mechanical properties as those of the substrates, causing deformation or distortion and even detachment of the patterns from the polymer substrates. Herein, we present a wrinkling strategy, which utilizes photolithography to define the area of stress distribution by light-induced physical crosslinking of polymers and controls diffusion of residual solvent to redistribute the stress and then offers the same material for patterns as substrate by thermal polymerization, providing uniform wrinkles without worrying about force relaxation. The strategy allows the recording and hiding of up to eight switchable images in one place that can be read by the naked eye without crosstalk, applying the wrinkled polymer for optical anti-counterfeiting.

Robust, Ultrafast and Reversible Photoswitching in Bulk Polymers Enabled by Octupolar Molecule Design.

Improving the photoswitching rate and robustness of photochromic molecules in bulk solids is paramount for practical applications but remains an on-going challenge. Here, we introduce an octupolar design paradigm to develop a new family of visible light organic photoswitches, namely multi-branched octupolar Stenhouse Adducts (MOPSAs) featuring a C-symmetrical A-(D-core) architecture with a dipolar donor-acceptor (D-A) photochrome in each branch. Our design couples multi-dimensional geometric and electronic effects of MOPSAs to enable robust ultrafast reversible photoswitching in bulk polymers.

Photo-Assisted Metal-Air Batteries: Recent Progress, Challenges and Opportunities.

To meet the need of high energy density, long durability, safe and cost-efficient energy conversion and storage devices, metal-air batteries like Li-O and Zn-O batteries have received enormous attention and were subject to exciting development in the past decade. Photo-assisted strategies that enable the effective combination of photo/electric energy conversion/storage render a new dimension for the conventional metal-air batteries techniques with mere electric energy utilization. Therefore, tremendous research is ongoing in search of more efficient and durable devices with photo-assisted strategies.

Elongational Flow Field Processed Ultrahigh Molecular Weight Polyethylene/Polypropylene Blends with Distinct Interlayer Phase for Enhanced Tribological Properties.

Herein, we produced a series of ultrahigh molecular weight polyethylene/polypropylene (UHMWPE/PP) blends by elongational-flow-field dominated eccentric rotor extruder (ERE) and shear-flow-field dominated twin screw extruder (TSE) respectively and presented a detailed comparative study on microstructures and tribological properties of UHMWPE/PP by different processing modes. Compared with the shear flow field in TSE, the elongational flow field in ERE facilitates the dispersion of PP in the UHMWPE matrix and promotes the interdiffusion of UHMWPE and PP molecular chains. For the first time, we discovered the presence of the interlayer phase in blends with different processing modes by using Raman mapping inspection.

Recent Advances in Elongational Flow Dominated Polymer Processing Technologies.

The continuous development of plasticizing conveying methods and devices has been carried out to meet the needs of the polymer processing industry. As compared to the conventional shear-flow-dominated plasticizing and conveying techniques, a new method for processing polymers based on elongational flow was proposed. This new method and the related devices such as vane extruders, eccentric rotor extruders and so on, exhibited multiple advantages including shorter processing time, higher mixing effectiveness, improved product performance and better adaptability to various material systems.

Erratum: In Situ Activating Strategy to Significantly Boost Oxygen Electrocatalysis of Commercial Carbon Cloth for Flexible and Rechargeable Zn-Air Batteries.

[This corrects the article DOI: 10.1002/advs.201800760.

Structural Color Materials for Optical Anticounterfeiting.

The counterfeiting of goods is growing worldwide, affecting practically any marketable item ranging from consumer goods to human health. Anticounterfeiting is essential for authentication, currency, and security. Anticounterfeiting tags based on structural color materials have enjoyed worldwide and long-term commercial success due to their inexpensive production and exceptional ease of percept.

Donor-Acceptor Nanocarbon Ensembles to Boost Metal-Free All-pH Hydrogen Evolution Catalysis by Combined Surface and Dual Electronic Modulation.

A combined surface and dual electronic modulation strategy is used to realize metal-free all-pH catalysis towards the hydrogen evolution reaction (HER) by coupling a N-doped carbon framework (MHCF, electron acceptors) derived from MOFs with higher-Fermi-level pure carbon nanotubes (CNTs, electron donors), followed by surface modification with carboxyl-group-rich polymers. Although the three constituents are inactive, as-assembled ternary membranes yield superior HER performance with low overpotentials and high durability (≤5 % activity loss over 100 h) at all pH values. The C adjacent to pyrrolic N in MHCF is the most active site and the induced directional interfacial electron transfer from CNTs to MHCF coupled with N-driven intramolecular electron transfer in MHCF optimizes Gibbs free energy for hydrogen adsorption (ΔG ) near zero, while the polymer modulation enables local H enrichment in acidic media and enhanced water adsorption and activation in neutral and basic media.

Ultrathin Black Phosphorus-on-Nitrogen Doped Graphene for Efficient Overall Water Splitting: Dual Modulation Roles of Directional Interfacial Charge Transfer.

Few-layered exfoliated black phosphorus (EBP) has attracted surging interest for electronics, optoelectronics, and catalysis. As compared to excellent progress in electronic and optoelectronic applications, very few reports are available for electrocatalysis by metal-free EBPs. Herein, we couple solution-processable ultrathin EBP nanosheets with higher Fermi level of N-doped graphene (NG) into a new metal-free 2D/2D heterostructure (EBP@NG) with well-designed interfaces and unique electronic configuration, as efficient and durable bifunctional catalysts toward hydrogen evolution and oxygen evolution reactions (HER/OER) for overall water splitting in alkaline media.

In Situ Activating Strategy to Significantly Boost Oxygen Electrocatalysis of Commercial Carbon Cloth for Flexible and Rechargeable Zn-Air Batteries.

An in situ strategy to simultaneously boost oxygen reduction and oxygen evolution (ORR/OER) activities of commercial carbon textiles is reported and the direct use of such ubiquitous raw material as low-cost, efficient, robust, self-supporting, and bifunctional air electrodes in rechargeable Zn-air batteries is demonstrated. This strategy not only furnishes carbon textiles with a large surface area and hierarchical meso-microporosity, but also enables efficient dual-doping of N and S into carbon skeletons while retaining high conductivity and stable monolithic structures. Thus, although original carbon textile has rather poor catalytic activity, the activated textiles without loading other active materials yield effective ORR/OER bifunctionality and stability with a much lower reversible overpotential (0.

Self-Assembled Graphene-Based Architectures and Their Applications.

Due to unique planar structures and remarkable thermal, electronic, and mechanical properties, chemically modified graphenes (CMGs) such as graphene oxides, reduced graphene oxides, and the related derivatives are recognized as the attractive building blocks for "bottom-up" nanotechnology, while self-assembly of CMGs has emerged as one of the most promising approaches to construct advanced functional materials/systems based on graphene. By virtue of a variety of noncovalent forces like hydrogen bonding, van der Waals interaction, metal-to-ligand bonds, electrostatic attraction, hydrophobic-hydrophilic interactions, and π-π interactions, the CMGs bearing various functional groups are highly desirable for the assemblies with themselves and a variety of organic and/or inorganic species which can yield various hierarchical nanostructures and macroscopic composites endowed with unique structures, properties, and functions for widespread technological applications such as electronics, optoelectronics, electrocatalysis/photocatalysis, environment, and energy storage and conversion. In this review, significant recent advances concerning the self-assembly of CMGs are summarized, and the broad applications of self-assembled graphene-based materials as well as some future opportunities and challenges in this vibrant area are elucidated.

A General Electrode Design Strategy for Flexible Fiber Micro-Pseudocapacitors Combining Ultrahigh Energy and Power Delivery.

Herein, a general strategy is proposed to boost the energy storage capability of pseudocapacitive materials (i.e., MnO) to their theoretical limits in unconventional 1D fiber configuration by rationally designing bicontinuous porous Ni skeleton@metal wire "sheath-core" metallic scaffold as a versatile host.

One-Pot Large-Scale Synthesis of Carbon Quantum Dots: Efficient Cathode Interlayers for Polymer Solar Cells.

Cathode interlayers (CILs) with low-cost, low-toxicity, and excellent cathode modification ability are necessary for the large-scale industrialization of polymer solar cells (PSCs). In this contribution, we demonstrated one-pot synthesized carbon quantum dots (C-dots) with high production to serve as efficient CIL for inverted PSCs. The C-dots were synthesized by a facile, economical microwave pyrolysis in a household microwave oven within 7 min.