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Macromolecular Rapid Communications

Anne Kutz, Wiebke Alex, Anja Krieger, Franziska Gröhn
In this study, a new type of functional, self-assembled nanostructure formed from porphyrins and polyamidoamine dendrimers based on hydrogen bonding in an aqueous solution is presented. As the aggregates formed are promising candidates for solar-energy conversion, their photocatalytic activity is tested using the model reaction of methyl viologen reduction. The self-assembled structures show significantly increased activity as compared to unassociated porphyrins. Details of interaction forces driving the supramolecular structure formation and regulating catalytic efficiency are fundamentally discussed...
July 20, 2017: Macromolecular Rapid Communications
Hui Guo, Cécile Mussault, Alba Marcellan, Dominique Hourdet, Nicolas Sanson
Dual thermoresponsive chemical hydrogels, combining poly(N-isopropylacrylamide) side-chains within a poly(N-acryloylglycinamide) network, are designed following a simple and versatile procedure. These hydrogels exhibit two phase transitions both at low (upper critical solution temperature) and high (lower critical solution temperature) temperatures, thereby modifying their swelling, rheological, and mechanical properties. These novel thermo-schizophrenic hydrogels pave the way for the development of thermotoughening wet materials in a broad range of temperatures...
July 18, 2017: Macromolecular Rapid Communications
Oleksandr S Bushuyev, Miho Aizawa, Atsushi Shishido, Christopher J Barrett
The development of stimuli-responsive polymers is among the key goals of modern materials science. The structure and properties of such switchable materials can be designed to be controlled via various stimuli, among which light is frequently the most powerful trigger. Light is a gentle energy source that can target materials remotely, and with extremely high spatial and temporal resolution easily and cheaply. Reversible light-control over molecular mechanical properties in particular has in recent years attracted great interest due to potential applications as optical-to-mechanical conversion actuators and 'devices', enabling 'molecular robotic machines'...
July 10, 2017: Macromolecular Rapid Communications
Yamin Abdouni, Gokhan Yilmaz, C Remzi Becer
Glycopolymers are synthetic-carbohydrate-containing materials capable of interacting and binding to specific targeting lectins, which are crucially important in many biologically active processes. Over the last decade, advances in synthetic chemistry and polymerization techniques have enabled the development of sequence and architecturally controlled glycopolymers for different types of bioapplications, such as drug delivery and release purposes, gene therapy, lectin-based biosensors, and much more in the future...
July 10, 2017: Macromolecular Rapid Communications
Martin Wåhlander, Fritjof Nilsson, Richard L Andersson, Anna Carlmark, Henrik Hillborg, Eva Malmström
Field-grading materials (FGMs) are used to reduce the probability for electrical breakdowns in critical regions of electrical components and are therefore of great importance. Usually, FGMs are heavily filled (40 vol.%) with semi-conducting or conducting particles. Here, polymer-grafted reduced graphene oxide (rGO) is used as a filler to accomplish percolated networks at very low filling ratios (<2 vol.%) in a semi-crystalline polymer matrix: poly(ethylene-co-butyl acrylate) (EBA). Various simulation models are used to predict the percolation threshold and the flake-to-flake distances, to complement the experimental results...
July 10, 2017: Macromolecular Rapid Communications
Xiaozhuang Zhou, Guoqiang Ma, Huaixia Zhao, Jiaxi Cui
Gelation-mediated phase separation is applied to prepare immiscible polymer bilayer films with an interlocking interface structure. Polymer systems consisting of copolymer of urea and polydimethylsiloxane and epoxy are selected to demonstrate the feasibility. When the epoxy fraction exceeds 25 wt%, well-defined bilayer structures self-form by a one-pot casting method in which the phase separation state is fixed by an evaporation-induced gelation. Microscopy studies of the resulting bilayers clearly reveal that interlocking structures form during the bilayer films construct...
July 10, 2017: Macromolecular Rapid Communications
Nannan Yang, Huili Yang, Zengwu Shao, Mingyu Guo
Strong and tough synthetic hydrogels have received ever-increasing interests due to their potential applications as load-bearing structural materials. However, strong, tough, and recyclable hydrogels in different forms that can be generated by different methods according to various practical applications still remain an intrinsic bottleneck. A simple one-pot synthesis of multiurea linkage segmented linear copolymers with easy recyclability, hybridization, and processability, including compression molding, solution casting, and spinning methods, to yield ultrastrong and tough hydrogel films or stretchable hydrogel fibers with diameters ranged from macro-, micro-, to nanoscale, is reported here...
July 10, 2017: Macromolecular Rapid Communications
Nasser Alaslai, Xiaohua Ma, Bader Ghanem, Yingge Wang, Fahd Alghunaimi, Ingo Pinnau
An intrinsically microporous polyimide is synthesized in m-cresol by a one-pot high-temperature condensation reaction of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and newly designed 2,6 (7)-dihydroxy-3,7(6)-diaminotriptycene (DAT1-OH). The 6FDA-DAT1-OH polyimide is thermally stable up to 440 °C, shows excellent solubility in polar solvents, and has moderately high Brunauer-Teller-Emmett (BET) surface area of 160 m(2) g(-1) , as determined by nitrogen adsorption at -196 °C. Hydroxyl functionalization applied to the rigid 3D triptycene-based diamine building block results in a polyimide that exhibits moderate pure-gas CO2 permeability of 70 Barrer combined with high CO2 /CH4 selectivity of 50...
July 10, 2017: Macromolecular Rapid Communications
Hui Cao, Zhigang Cui, Pan Gao, Yi Ding, Xuechao Zhu, Xinhua Lu, Yuanli Cai
Easy access to discrete nanoclusters in metal-folded single-chain nanoparticles (metal-SCNPs) and independent ultrafine sudomains in the assemblies via coordination-driven self-assembly of hydrophilic copolymer containing 9% imidazole groups is reported herein. (1) H NMR, dynamic light scattering, and NMR diffusion-ordered spectroscopy results demonstrate self-assembly into metal-SCNPs (>70% imidazole-units folded) by neutralization in the presence of Cu(II) in water to pH 4.6. Further neutralization induces self-assembly of metal-SCNPs (pH 4...
July 10, 2017: Macromolecular Rapid Communications
Jiuyang Zhang, Jing Li, Mengmeng Huo, Naixu Li, Jiancheng Zhou, Tuoqi Li, Jing Jiang
Photochromic materials are an important class of "smart materials" and are broadly utilized in technological devices. However, most photochromic materials reported so far are composed of inorganic compounds that are challenging to process and suffer from poor mechanical performance, severely limiting their applications in various markets. In this paper, inorganic photochromic tungsten trioxide (WO3 ) nanocrystals are conveniently grafted with polymers to hurdle the deficiency in processability and mechanical properties...
July 10, 2017: Macromolecular Rapid Communications
Alireza Zehtab Yazdi, Ivonne Otero Navas, Ahmed Abouelmagd, Uttandaraman Sundararaj
The current state-of-the-art mixing strategies of nanoparticles with insulating polymeric components have only partially utilized the unique electrical conductivity of graphene in nanocomposite systems. Herein, this paper reports a nonmixing method of direct creation of polymer/graphene nanocomposites from polymer blends via laser irradiation. Polycarbonate-laser-induced graphene (PC-LIG) nanocomposite is produced from a PC/polyetherimide (PC/PEI) blend after exposure to commercially available laser scribing with a power of ≈6 W and a speed of ≈2 cm s(-1) ...
July 4, 2017: Macromolecular Rapid Communications
Tanja K Claus, Junliang Zhang, Liam Martin, Matthias Hartlieb, Hatice Mutlu, Sébastien Perrier, Guillaume Delaittre, Christopher Barner-Kowollik
A photochemical strategy for the sequential dual compaction of single polymer chains is introduced. Two photoreactive methacrylates, with side chains bearing either a phenacyl sulfide (PS) or an α-methylbenzaldehyde (photoenol, PE) moiety, are selectively incorporated by one-pot iterative reversible-addition fragmentation chain transfer copolymerization into the outer blocks of a well-defined poly(methyl methacrylate) based ABC triblock copolymer possessing a nonfunctional spacer block (Mn = 23 400 g mol(-1) , Đ = 1...
July 4, 2017: Macromolecular Rapid Communications
Cian Cummins, Matthew T Shaw, Michael A Morris
Polymer brush films with chemical functionality to attach to site specific substrate areas are introduced for area selective deposition (ASD) application. It is demonstrated that polymer brushes with chemically defined end sites can be selectively bound to copper-specific regions of patterned copper/silica (Cu/SiO2 ) substrates. The process described overcomes various limitations of currently used technology including cost, complexity, and throughput, with potential implications for future electronic devices and nanomanufacturing...
July 3, 2017: Macromolecular Rapid Communications
Jelle Penders, Anand K Rajasekharan, Mats Hulander, Martin Andersson
Herein, the development and characterization of a 3D gradient structure of gold nanoparticles is described. The gradient of gold nanoparticles is made in situ in a macroporous nonionic block copolymer hydrogel matrix, through gold ion diffusion control. The polymer provides a matrix for diffusion of gold ions, acts as a template for controlling nanoparticle growth, and facilitates the in situ reduction of gold ions to gold nanoparticles. A clear gradient in gold nanoparticles is observed across the 3D space of the polymer matrix using scanning electron microscopy, fluorescence microscopy, atomic force microscopy, and thermogravimetric analysis...
July 3, 2017: Macromolecular Rapid Communications
Zipeng Ma, Yuhan Xie, Jie Mao, Xuxu Yang, Tiefeng Li, Yingwu Luo
Dielectric elastomer (DE) actuators have been shown to have promising applications as soft electromechanical transducers in many emerging technologies. The DE actuators, which are capable of large actuation strain over a wide range of excitation frequencies, are highly desirable. Here, the first single-component DE of a triblock copolymer with attractive electromechanical performance is reported. Symmetric poly(styrene-b-butyl acrylate-b-styrene) (SBAS) is designed and synthesized. The SBAS actuator exhibits about 100% static actuation area strain and excellent dynamic performance, as evidenced by a wide half bandwidth of 300 Hz and a very high specific power of 1...
July 3, 2017: Macromolecular Rapid Communications
Ruey-Chorng Lin, Mohamed Gamal Mohamed, Shiao-Wei Kuo
A series of thermally polymerizable dendrimers of various generations, equipped with triphenylamine (TPA) and benzoxazine (BZ) groups, is synthesized through facile one-pot Mannich condensations of N(1) ,N(1) -bis(4-aminophenyl)benzene-1,4-diamine (TPA-3NH2 , as the core group), 4-(bis(4-aminophenyl)amino)phenol (TPA-2NH2 -OH, as the AB2 branching group), and CH2 O in 1,4-dioxane. The ratios of the integrated areas in the (1) H nuclear magnetic resonance spectra of these dendrimers are consistent with the theoretical numbers of protons, suggesting their successful syntheses...
July 3, 2017: Macromolecular Rapid Communications
A Di Luca, J R de Wijn, C A van Blitterswijka, S Camarero-Espinosa, L Moroni
The functionalization of biomaterials substrates used for cell culture is gearing towards an increasing control over cell activity. Although a number of biomaterials have been successfully modified by different strategies to display tailored physical and chemical surface properties, it is still challenging to step from 2D substrates to 3D scaffolds with instructive surface properties for cell culture and tissue regeneration. In this study, additive manufacturing and thermally induced phase separation are combined to create 3D scaffolds with tunable surface morphology from polymer gels...
July 3, 2017: Macromolecular Rapid Communications
Jianfei Liu, Xiangli Chen, Pei Wang, Xuwei Fu, Kaiqiang Liu, Yu Fang
Porous polymeric monoliths with densities as low as ≈0.060 g cm(-3) are prepared in a gel-emulsion template way, of which the stabilizer employed is a newly discovered acidified aramid fiber that is so efficient that 0.05% (w/v, accounts for continuous phase) is enough to gel the system. The porous monoliths as obtained can be dried at ambient conditions, avoiding energy-consuming processes. Importantly, the monoliths show selective adsorption to HCHO, and the corresponding adsorption capacity (M6) is ≈2700 mg g(-1) , the best result that is reported until now...
July 3, 2017: Macromolecular Rapid Communications
Xinlei Pang, Bo Xu, Xin Qing, Jia Wei, Yanlei Yu
Photoresponsive blend films with post-crosslinked liquid crystalline polymer (CLCP) as a photosensitive component and flexible polyurethane (PU) as the matrix are successfully fabricated. After being uniaxially stretched, even at low concentration, the azobenzene-containing CLCP effectively transfers its photoresponsiveness to the photoinert PU matrix, resulting in the fast photo-induced bending behavior of whole blend film thanks to the effective dispersion of CLCP. Specifically, the blend film shows photo-induced deformations upon exposure to unpolarized UV light at ambient temperature...
June 30, 2017: Macromolecular Rapid Communications
Arman R Ashraf, Justin J Ryan, Michael M Satkowski, Byeongdu Lee, Steven D Smith, Richard J Spontak
Block copolymers have been extensively studied due to their ability to spontaneously self-organize into a wide variety of morphologies that are valuable in energy-, medical-, and conservation-related (nano)technologies. While the phase behavior of bicomponent diblock and triblock copolymers is conventionally governed by temperature and individual block masses, it is demonstrated here that their phase behavior can alternatively be controlled through the use of blocks with random monomer sequencing. Block random copolymers (BRCs), i...
June 29, 2017: Macromolecular Rapid Communications
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