Sustainable and recyclable super engineering thermoplastic from biorenewable monomer

Environmental and health concerns force the search for sustainable super engineering plastics (SEPs) that utilise bio-derived cyclic monomers, e.g. isosorbide instead of restricted petrochemicals. However, previously reported bio-derived thermosets or thermoplastics rarely offer thermal/mechanical properties, scalability, or recycling that match those of petrochemical SEPs. Here we use a phase transfer catalyst to synthesise an isosorbide-based polymer with a high molecular weight >100 kg mol−1, which is reproducible at a 1-kg-scale production. It is transparent and solvent/melt-processible for recycling, with a glass transition temperature of 212 °C, a tensile strength of 78 MPa, and a thermal expansion coefficient of 23.8 ppm K−1. Such a performance combination has not been reported before for bio-based thermoplastics, petrochemical SEPs, or thermosets. Interestingly, quantum chemical simulations show the alicyclic bicyclic ring structure of isosorbide imposes stronger geometric restraint to polymer chain than the aromatic group of bisphenol-A.11Ysciescopu

High performance Ge nanowire anode sheathed with carbon for lithium rechargeable batteries

We present a single crystalline Ge nanowire anode material sheathed with carbon prepared by a solid-liquid solution method. The composite electrode composed of Ge nanowires shows impressive electrochemical properties, exhibiting a very high reversible charge capacity (after lithium removal) of 963 mA h g(-1) with a coulombic efficiency of 91%.close11810

FabAsset: Unique Digital Asset Management System for Hyperledger Fabric

—Business is innovating with the advent of blockchain that tokenizes digital assets. To expand the blockchain’s potential, Ethereum, a representative permissionless blockchain platform, supports the fungible token (FT) standard ERC-20 and the non-fungible token (NFT) standard ERC-721. Hyperledger Fabric (Fabric), a representative permissioned blockchain platform, proposed FabToken to support tokens in version 2.0.0 alpha. But FabToken contains only FTs, not NFTs. Given the market share in the enterprise blockchains, Fabric needs to support NFTs as soon as possible. This paper presents a unique digital asset management system called FabAsset so that Fabric can run decentralized applications that require NFTs. This paper describes the design of FabAsset, consisting of chaincode and SDK (Software Development Kit), and the prototype of a decentralized signature service leveraging FabAsset to validate its usefulness. ©2020 IEEE1

Dynamic interaction in polyurethane containing the boronic ester groups

Dynamic interaction can impart useful functionality to the polymer. Boronic esters are known to form a variety of dynamic-covalent bonds by reacting with diols. Dynamic-covalent bonds can be readily controlled by temperature or the addition of water. Boronic ester-containing molecules have been noted in a number of self-healing applications. The self-healing material restores their function by restoring the physical damage, fracture, cracks and prevents destruction. When boronic ester-containing molecules exposed to moisture in the atmosphere, hydrolysis occurs on the surface and healing is caused by re-esterification. Here in, the polyurethane-based polymers were synthesized with boronic ester compounds and Polytetrahydrofuran (PTMEG). The restored property of boronic esters was observed under ambient conditions. The re-esterification experiments of boronic esters were carried out in surface force apparatus (SFA) through water and dry environments. These bulk materials confirmed by mechanical testing, polymer properties.2

NFT를 활용한 메신저 서비스 보안 지원 기법

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Flexible Poly(Lactic acid) suitable for deep freeze packaging synthesized using lactic acid-based ester precursors

Polylactide (PLA) is an alternative to traditional petroleum-based polymers; however, its brittleness and tendency to produce rustling in the film form limit its applications in deep freeze packaging and at quiet public facilities. Herein, a PLA-based biodegradable packaging material was prepared by blending transparent flexible PLA (TF-PLA) with various lactic acid-based ester precursors (LAEPs), which were synthesized using l-lactic acid, poly (tetrahydrofuran), sebacic acid, and 1,4-butanediol, thereby producing TF-PLAs with good transparency and biodegradability, low-level migration, low rustling, and improved mechanical properties. The glass transition temperature (Tg) values and chemical structures of the synthesized LAEPs were studied using differential scanning calorimetry (DSC) with the Gordon–Taylor equation and proton nuclear magnetic resonance (1H NMR) spectroscopy. The obtained TF-PLA showed better elongation at room temperature as well as flexibility, with a bending angle comparable to that of neat PLA at extremely low temperatures. The evaluated barrier property and migration level of the TF-PLA film indicated the untapped market potential of TF-PLA. The biodegradability test of sorted TF-PLAs over eight weeks indicated good biodegradability, similar to that of neat PLA. Therefore, TF-PLAs have a high potential for deep freeze packaging applications

P2PCheck: Digital Check Platform based on Non-Fungible Token in Hyperledger Fabric Utilizing Open Banking API

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Nanochitin and Nanochitosan: Chitin Nanostructure Engineering with Multiscale Properties for Biomedical and Environmental Applications

Nanochitin and nanochitosan (with random copolymer-based multiscale architectures of glucosamine and N-acetylglucosamine units) have recently attracted immense attention for the development of green, sustainable, and advanced functional materials. Nanochitin and nanochitosan are multiscale materials from small oligomers, rod-shaped nanocrystals, longer nanofibers, to hierarchical assemblies of nanofibers. Various physical properties of chitin and chitosan depend on their molecular- and nano-structures; translational research has utilized them for a wide range of applications (biomedical, industrial, environmental, and so on). Instead of reviewing the entire extensive literature on chitin and chitosan, this paper highlights recent developments in multiscale-dependent material properties and their applications; immune, medical, reinforcing, adhesive, green electrochemical materials, biological scaffolds, and sustainable food packaging have been discussed considering the size, shape, and assembly of chitin nanostructures. In summary, new perspectives for the development of sustainable advanced functional materials based on nanochitin and nanochitosan by understanding and engineering their multiscale properties are described.11Nsciescopu