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Macromolecular Rapid Communications

Worarin Meesorn, Justin O Zoppe, Christoph Weder
Bio-inspired, water-responsive, mechanically adaptive nanocomposites are reported based on cellulose nanocrystals (CNCs), poly(ethylene oxide-co-epichlorohydrin) (EO-EPI), and a small amount of poly(vinyl alcohol) (PVA), which is added to aid the dispersion of the CNCs. In the dry state, the CNCs form a reinforcing network within the polymer matrix, and the substantial stiffness increase relative to the neat polymer is thought to be the result of hydrogen-bonding interactions between the nanocrystals. Exposure to water, however, causes a large stiffness reduction, due to competitive hydrogen bonding of water molecules and the CNCs...
February 20, 2019: Macromolecular Rapid Communications
Zhongying Ji, Xiaoqin Zhang, Changyou Yan, Xin Jia, Yanqiu Xia, Xiaolong Wang, Feng Zhou
Three-dimensional (3D) printing elastomers, as a combination of transformative technology and widely used materials, have received great demand in many fields. However, commercial photocuring elastomer inks for 3D printing usually exhibit poor mechanical strength, inferior resilience, and lower elongation at break. In this study, photocuring inks that can be employed for digital light processing 3D printing are developed with acryloyl-modified polyethylene glycol (Acryl@PEG). The resultant photocuring inks exhibit not only high tensile strength of 14...
February 19, 2019: Macromolecular Rapid Communications
Shaorong Huang, Wanying Gu, Lie Chen, Zhihui Liao, Yongkang An, Cunbin An, Yiwang Chen, Jianhui Hou
A trade-off between open-circuit voltage (V OC ) and high short-circuit (J SC ) becomes one of the most vital problems limiting further improvement in polymer solar cells' (PSCs) efficiency. In this work, two asymmetric polymer donors PBDT-F-2TC and PBDT-SF-2TC are designed and synthesized. When blended with a state-of-the-art acceptor IT-4F with low lowest-unoccupied molecular orbital level, simultaneously high V OC (up to 0.94 V) and J SC (up to 20.73 mA cm-2 ) are obtained for both copolymers. Note that the V OC value of 0...
February 19, 2019: Macromolecular Rapid Communications
Hoyeol Lee, Yongjin Kim, Seijiro Fukuta, Hwajeong Kim, Youngkyoo Kim, Tomoya Higashihara, Moonhor Ree
Various molecular weight π-conjugated donor-acceptor polymers based on thiadiazole and thiophene units are investigated with respect to nanoscale film morphology and digital memory performance. Interestingly, all polymers reveal excellent n-type digital permanent memory characteristics, which are governed by the combination of Ohmic and trap-limited space charge limited conductions via a hopping process using thiadiazole and thiophene units as charge traps and stepping stones. The digital memory performance is significantly influenced by the film morphology details that vary with the polymer molecular weight as well as the film thickness...
February 19, 2019: Macromolecular Rapid Communications
Yu Tian, Ran Tian, Li Chen, Ronghua Jin, Yiming Feng, Yongkang Bai, Xin Chen
A tumor-selective drug delivery nanogel with redox-responsive size swelling and co-instantaneous drug release is developed. The nanogel is formed by poly(ethylene glycol) diglycidyl ether and cystamine double crosslinked hyaluronic acid (HA). The disulfide bond in cystamine (Cys) is in charge of the responsiveness, while the compact polymer network turns the nanogel a capsule for effective drug loading. The tumor targeting is achieved by the known HA-receptor mediated endocytosis. The responsive swelling of this nanogel and co-instantaneous drug releases happen with the cleavage of the disulfide bond following tumor targeting and cell endocytosis, which is triggered by massive glutathione (GSH) in the cytoplasm of tumor cells...
February 19, 2019: Macromolecular Rapid Communications
Yu Ma, Aijie Li, Xiaonan Gao, Fang Huang, Xuan Kuang, Peng Yang, Jieyu Yue, Bo Tang
Metal-organic gel (MOG) matrices with tunable pore sizes ranging from micropore to macropore, derived from microporous metal-organic coordination polymers (PCPs), has attracted great attention for their enhanced pore accessibility compared with the multifunctional PCP materials themselves. The enhanced pore accessibility of chiral MOGs is especially imperative for mass transfer applications, including enantioseparations and purifications. Here, for the first time, a novel hierarchical porous MOG-coated SiO2 , derived from a chiral metal-organic coordination polymer, is employed as chiral stationary phase for effective high-performance liquid chromatography (HPLC) separation of enantiomers...
February 13, 2019: Macromolecular Rapid Communications
Tobias Klein, Joshua Parkin, Patrick A J M de Jongh, Lars Esser, Tara Sepehrizadeh, Gang Zheng, Michael De Veer, Karen Alt, Christoph E Hagemeyer, David M Haddleton, Thomas P Davis, Mukundan Thelakkat, Kristian Kempe
Brush polymers are highly functional polymeric materials combining the properties of different polymer classes and have found numerous applications, for example, in nanomedicine. Here, the synthesis of functional phosphonate-ester-bearing brush polymers based on poly(2-oxazine)s is reported through a combination of cationic ring-opening polymerization (CROP) of 2-ethyl-2-oxazine and reversible addition-fragmentation chain transfer (RAFT) polymerization. In this way, a small library of well-defined (Đ ≤ 1...
February 12, 2019: Macromolecular Rapid Communications
Ehsan Rezabeigi, Nicole R Demarquette
Electrospinning of nonsolvent-induced phase-separated ternary (NIPST) systems has gained a lot of interest due to its potential to produce (nano)fibers, which are superficially and internally porous with nanoscale surface roughness. Membranes produced from such systems are expected to have a high specific surface area (SSA; e.g., more than 50 m2 g-1 ), an essential requirement for many of their applications. In spite of their advantages and potential, there are major issues regarding the electrospinning of NIPST systems that are not systematically addressed in the literature...
February 12, 2019: Macromolecular Rapid Communications
Ruobing Bai, Jiawei Yang, Xavier P Morelle, Zhigang Suo
New applications of hydrogels draw growing attention to the development of tough hydrogels. Most tough hydrogels are designed through incorporating large energy dissipation from breaking sacrificial bonds. However, these hydrogels still fracture under prolonged cyclic loads with the presence of even small flaws. This paper presents a principle of flaw-insensitive hydrogels under both static and cyclic loads. The design aligns the polymer chains in a hydrogel at the molecular level to deflect a crack. To demonstrate this principle, a hydrogel of polyacrylamide and polyvinyl alcohol is prepared with aligned crystalline domains...
February 10, 2019: Macromolecular Rapid Communications
Julia Cuthbert, Michael R Martinez, Mingkang Sun, Jacob Flum, Lingchun Li, Mateusz Olszewski, Zhenhua Wang, Tomasz Kowalewski, Krzysztof Matyjaszewski
Soft, elastomeric, non-tacky polymer networks are synthesized by reversible deactivation radical polymerization (RDRP). First, the pristine, structurally tailored and engineered macromolecular (STEM) networks are synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization and incorporated an atom transfer radical polymerization (ATRP) inimer into the network. Subsequently, poly(n-butyl acrylate) (PBA) and/or poly(octafluoropentyl acrylate) (POFPA) side chains are grafted from the network by photo-induced ATRP...
February 10, 2019: Macromolecular Rapid Communications
Jakob Konieczny, Katja Loos
The polyurethane industry is strongly dependent on fossil-based polyols and polyisocyanates. Developing novel sustainable polyols from valuable biobased building blocks is a first step toward strong and durable development. The synthesis and properties of PU films based on pristine and acylated white dextrins (AVEDEX W80) as polyol and an aliphatic, low-viscosity, solvent-free triisocyanate based on hexamethylene diisocyanate (trimer-Desmodur N3300) as crosslinker is reported. After optimizing several conditions, such as the reaction time, reaction temperature, amount of solvent, isocyanate index, and amount per surface area, it is possible to obtain smooth PU films with good thermal properties...
February 7, 2019: Macromolecular Rapid Communications
Debaditya Bera, Lars Verdonck, Mathias Glassner, Annemieke Madder, Richard Hoogenboom
Thermoresponsive polymeric materials are important building blocks for smart materials. In this work, the transformation of dsDNA into a thermoresponsive polymer is reported by intercalation of short, oligoethylene-glycol-modified proflavine intercalators. The thermoresponsiveness of the dsDNA-intercalator complex originates from the heating-induced dehydration of the ethylene glycol side chains, which leads to aggregation of the intercalated dsDNA. This work demonstrates the possibility of designing small-molecule intercalators to prepare thermoresponsive dsDNA complexes with tunable lower critical solution temperature behavior...
February 6, 2019: Macromolecular Rapid Communications
Xi Yu, Xiaohui Wu, Yang Si, Xianfeng Wang, Jianyong Yu, Bin Ding
Waterproof and breathable (W&B) membranes combine fascinating properties of resistance to liquid water penetration and transmitting of water vapor, playing a key role in addressing problems related to health, resources, and energy. Electrospinning is an efficient and advanced way to construct nanofibrous materials with easily tailored wettability and adjustable pore structure, therefore providing an ideal strategy for constructing W&B membranes. In this review, recent progress on electrospun W&B membranes is summarized, involving materials design and fabrication, basic properties of electrospun W&B membranes associated with waterproofness and breathability, as well as their applications...
February 6, 2019: Macromolecular Rapid Communications
Tuan Liu, Shuai Zhang, Cheng Hao, Christina Verdi, Wangcheng Liu, Hang Liu, Jinwen Zhang
Epoxy vitrimers prepared from anhydride-cured epoxies exhibit, repairable and reprocessable properties; however, they generally rely on a large amount of catalyst for accelerating the dynamic transesterification (DTER). If the catalyst loading is not enough, the vitrimer properties will be limited. In this work, a preparation method of catalyst-free epoxy vitrimer is demonstrated by adding glycerol to an epoxy-anhydride curing system. The hydroxyls of glycerol first react with the anhydride to induce the ring-opening of anhydride and form a carboxylic acid, and the latter attacks the epoxy and form a β-hydroxyester linkage, so the curing can be performed in the absence of catalyst...
February 5, 2019: Macromolecular Rapid Communications
Yao Li, Felix H Schacher, Jun Ling
Janus polymerization is a novel and efficient way to synthesize diblock and multiblock copolymers in one step by using Lu(OTf)3 and propylene epoxide as a catalytic system. By modifying the epoxide initiator, which is located at the block junction with various functional groups, the possibility for future topological design is provided. Herein, 2-bicyclo[2.2.1]hept-5-en-2-yl oxirane (NB-EO) is used as an alternative for propylene epoxide to synthesize a poly(THF-co-CL)-b-PCL diblock copolymer featuring a norbornene group at this position...
February 5, 2019: Macromolecular Rapid Communications
Fei Xu, Yuqian Qiu, Guangshen Jiang, Baichuan Ding, Jingyuan Li, Qianhui Liu, Jianping Wu, Xiaosa Xu, Hongqiang Wang, Yeru Liang
Understanding correlation between the nanostructure of porous carbons and their ion transport behavior is critical for achieving high-performance supercapacitors. Herein, the relationship between size and shell thickness of carbon nanospheres (CNSs) and capacitive electrochemical performance is clarified. Structural uniform CNSs with controlled diameters, prepared via template-free interfacial copolymerization, are emerging as an ideal platform for investigating the ion transport behavior. It is found that ionic transport is significantly enhanced while the introduction of hollow cores with thinner shell, by virtue of the hollow nanopore-accelerated mass transport to reduce ion diffusion length...
January 30, 2019: Macromolecular Rapid Communications
Simone Lazar, Omar Garcia-Valdez, Emily Kennedy, Pascale Champagne, Michael Cunningham, Jaime Grunlan
Chitosan-based films exhibit good oxygen barrier that degrades when exposed to high humidity. In an effort to overcome this drawback, a multilayer nanocoating consisting of crosslinkable chitosan (CHQ) and poly(acrylic acid) [PAA] is deposited on polyethylene terephthalate (PET) using layer-by-layer assembly. Chitosan is functionalized with glycidyl methacrylate to introduce acrylic functionalities within the film. The deposited films are crosslinked using a free radical initiator and this crosslinking is confirmed by FTIR and reduced film thickness...
January 30, 2019: Macromolecular Rapid Communications
Dongliang Ding, Haitao Wang, Zhiqiang Wu, Yanhui Chen, Qiuyu Zhang
Easy and high efficient methods are in great demand to obtain polyimide (PI) composites with high thermal conductivity in the electronic packaging field. In this work, PI/boron nitride (BN) composites with high thermal conductivity are easily fabricated. Tightly connected and well-arranged BN platelets construct effective 3D thermally conductive networks in the PI matrix upon hot pressing, after BN platelets are coated on the surface of PI granules by the help of a kind of PI adhesive. The thermal conductivity of the PI/BN composites reaches as high as 4...
January 23, 2019: Macromolecular Rapid Communications
Yan Ge, Hanlin Gong, Jie Shang, Lin Jin, Tiezheng Pan, Qiao Zhang, Shengyi Dong, Yangxin Wang, Zhenhui Qi
A new type of dynamic covalent macrocycle with self-promoted supramolecular gelation behavior is developed. Under oxidative conditions, the dithiol compound containing a diamide alkyl linker with an odd number (7) of carbon chain and an appended crown ether shows a remarkable gelation ability in acetonitrile, without any template molecules. Due to the existence of crown ethers and disulfide bonds, the obtained gel shows a multiple stimuli-responsiveness behavior. The mechanical properties and reversibility of the gel are investigated...
January 23, 2019: Macromolecular Rapid Communications
Xiangwei Zhu, Congying Wei, Fang Zhang, Qingquan Tang, Qiang Zhao
Counterion exchange of charged macromolecules has comprehensive implications in biological and synthetic systems such as protein function, biosignaling, ion conducting, and separation, but the correlation between the dynamic ion exchange, polyelectrolyte phase separation, and functionality remains elusive. Here, counterion exchange is exploited as a means to facilitate liquid-liquid phase separation and coacervates featuring higher stability and versatility compared with conventional complex coacervate. Self-coacervation of a cationic polyelectrolyte (polyamidoamine-epichlorohydrin, PAE-Cl) occurs in broader conditions when its original counter anion (Cl- ) is exchanged by bis(trifluoromethane-sulphonyl)imide anion (TFSI- ), as a result of TFSI- counter anions association instead of polyelectrolyte complexation...
January 23, 2019: Macromolecular Rapid Communications
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