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Macromolecular Rapid Communications

Jianbo Tan, Xuechao Zhang, Dongdong Liu, Yuhao Bai, Chundong Huang, Xueliang Li, Li Zhang
Carbon dioxide (CO2 )-responsive polymer nano-objects are prepared by photoinitiated reversible addition-fragmentation chain transfer dispersion polymerization of 2-hydroxypropyl methacrylate and 2-(dimethylamino)ethyl methacrylate (DMAEMA) in water at room temperature using a poly(poly(ethylene glycol) methyl ether methacrylate) macromolecular chain transfer agent. Kinetic studies confirm that full monomer conversions are achieved in all cases within 10 min of visible-light irradiation (405 nm, 0.5 mW cm(-2) )...
October 25, 2016: Macromolecular Rapid Communications
Alexander Dundua, Steffen Franzka, Mathias Ulbricht
Nonspecific adsorption of proteins is a challenging problem for the development of biocompatible materials, as well as for antifouling and fouling-release coatings, for instance for the marine industry. The concept of preparing amphiphilic systems based on low surface energy hydrophobic materials via their hydrophilic modification is being widely pursued. This work describes a novel two-step route for the preparation of interpenetrating polymer networks of otherwise incompatible poly(dimethylsiloxane) and zwitterionic polymers...
October 25, 2016: Macromolecular Rapid Communications
Xueling Feng, Kaihuan Zhang, Peng Chen, Xiaofeng Sui, Mark A Hempenius, Bo Liedberg, G Julius Vancso
Highly swellable, dual-responsive hydrogels, consisting of thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) and redox-responsive poly(ferrocenylsilane) (PFS) based poly(ionic liquid)s (PILs) are formed by photo-polymerization. PFS chains bearing cross-linkable vinylimidazolium (VIm) side groups are copolymerized with NIPAM in aqueous solutions under ultraviolet light (λ = 365 nm) in the presence of a photoinitiator. The PFS-PILs serve as a macro-cross-linker and also provide redox responsiveness. The swelling ratio, morphology, and lower critical solution temperature (LCST) of the hydrogels are studied as a function of the PNIPAM/PFS ratio...
October 24, 2016: Macromolecular Rapid Communications
Yosuke Iwai, Yoshiaki Uchida, Hiroshi Yabu, Norikazu Nishiyama
Microfluidic devices, which can continuously fabricate single emulsion with monodispersed droplets having a pore diameter of more than 100 μm in large numbers, can be applied to manufacture ordered macroporous films. 3D ordered macroporous films with a diameter of more than 100 μm can be fabricated using ordered arrays of the monodispersed droplets as templates of the macropores, which are self-assembled in the space between two parallel flat glass plates. As the gap between the glass plates increases, the number of the layer increases...
October 24, 2016: Macromolecular Rapid Communications
Lindsay N Woodard, Vanessa M Page, Kevin T Kmetz, Melissa A Grunlan
Thermoresponsive shape memory polymers (SMPs) based on poly(ε-caprolactone) (PCL) whose shape may be actuated by a transition temperature (T trans ) have shown utility for a variety of biomedical applications. Important to their utility is the ability to modulate mechanical and degradation properties. Thus, in this work, SMPs are formed as semi-interpenetrating networks (semi-IPNs) comprised of a cross-linked PCL diacrylate (PCL-DA) network and thermoplastic poly(l-lactic acid) (PLLA). The semi-IPN uniquely allows for requisite crystallization of both PCL and PLLA...
October 24, 2016: Macromolecular Rapid Communications
Jiajia Li, Chunlai Ding, Zhengbiao Zhang, Xiangqiang Pan, Na Li, Jian Zhu, Xiulin Zhu
Butyl acrylate is polymerized in the living way under the irradiation of purple light-emitting diode (LED) or sunlight without photocatalyst at ambient temperature. 2-((Phenoxycarbonothioyl)thio) ethyl propanoate) is exclusively added and acted as an initiator and a chain transfer agent simultaneously in the current system. Poly(butyl acrylate) with well-regulated molecular weight and relatively narrow molecular weight distribution (Ð < 1.30) is synthesized. High conversion (>95%) can be achieved within several minutes...
October 21, 2016: Macromolecular Rapid Communications
Joana Roßberg, Falko O Rottke, Burkhard Schulz, Andreas Lendlein
The influence of terminal functionalization of oligo(ε-caprolactone)s (OCL) with phenylboronic acid pinacol ester or phenylboronic acid on the enzymatic degradation behavior at the air-water interface is investigated by the Langmuir monolayer degradation technique. While the unsubstituted OCL immediately degrades after injection of the enzyme lipase from Pseudomonas cepacia, enzyme molecules are incorporated into the films based on end-capped OCL before degradation. This incorporation of enzymes does not inhibit or suppress the film degradation, but retards it significantly...
October 20, 2016: Macromolecular Rapid Communications
Thavasyappan Thambi, V H Giang Phan, Doo Sung Lee
Stimuli-sensitive injectable polymeric hydrogels are one of the promising delivery vehicles for the controlled release of bioactive agents. In aqueous solutions, these polymers are able to switch sol-to-gel transitions in response to various stimuli including pH, temperature, light, enzyme and magnetic field. Therapeutic agents, including chemotherapeutic agents, protein drugs or cells, are easily mixed with the low-viscous polymer solution at room temperature. Therapeutic-agents-containing solutions are readily injected into target sites through syringe or catheter, which could form hydrogel depot and serve as bioactive molecules release carriers...
October 18, 2016: Macromolecular Rapid Communications
Kyu Won Lee, Jae Woo Chung, Seung-Yeop Kwak
A highly self-plasticized poly(vinyl chloride) (PVC) is demonstrated for the first time via click grafting of hyperbranched polyglycerol (HPG). The plasticizing effect of the grafted HPG on PVC is systematically investigated by various analytical methods. The amorphous and bulky dendritic structure of HPG efficiently increases the free volume of the grafted PVC, which leads to a remarkably lower glass transition temperature comparable to that of the conventional plasticized PVC. Viscoelastic analysis reveals that HPG considerably improves the softness of the grafted PVC at room temperature and promotes the segmental motion in the system...
October 14, 2016: Macromolecular Rapid Communications
Kai Hou, Huiyi Wang, Yunyin Lin, Shaohua Chen, Shengyuan Yang, Yanhua Cheng, Benjamin S Hsiao, Meifang Zhu
Hydrogel microfibers have been considered as a potential biomaterial to spatiotemporally biomimic 1D native tissues such as nerves and muscles which are always assembled hierarchically and have anisotropic response to external stimuli. To produce facile hydrogel microfibers in a mathematical manner, a novel dynamic-crosslinking-spinning (DCS) method is demonstrated for direct fabrication of size-controllable fibers from poly(ethylene glycol diacrylate) oligomer in large scale, without microfluidic template and in a biofriendly environment...
October 14, 2016: Macromolecular Rapid Communications
Lei Wu, Ulrich Glebe, Alexander Böker
Binary polystyrene and poly(4-vinylpyridine) mixed grafted silica nanoparticles (PSt/P4VP-g-SNPs) are fabricated using Cu(I) -catalyzed azide-alkyne Huisgen cycloaddition (CuAAC) via grafting-to method. Azide-terminated PSt and P4VP are synthesized via post- and pre-atom transfer radical polymerization modification, respectively. Then, the polymers are simultaneously anchored onto alkyne-modified SNPs by CuAAC yielding mixed brushes as shown by Raman spectroscopy, dynamic light scattering, and thermogravimetric analysis...
October 13, 2016: Macromolecular Rapid Communications
Ying Chen, Zhiyang Zhao, Alamgir Karim, R A Weiss
Surface memory effects for micropattern and nanopattern are demonstrated for shape memory compounds composed of mixtures of the zinc salt of a sulfonated poly(ethylene-co-propylene-co-ethylidene norbornene) ionomer and three different low molar mass fatty acids (FAs): lauric acid (LA), stearic acid (SA), and zinc stearate (ZnSt). This work shows the ability to tune the surface pattern switching temperature (Tc ) by simply varying the FA melting point. The melting point of the FA in the ionomer compound is depressed from that of the pure FA due to strong dipolar interactions between the ionomer and the FAs...
October 10, 2016: Macromolecular Rapid Communications
Syamal S Tallury, Behnam Pourdeyhimi, Melissa A Pasquinelli, Richard J Spontak
As emerging technologies continue to require diverse materials capable of exhibiting tunable stimuli-responsiveness, shape-memory materials are of considerable significance because they can change size and/or shape in controllable fashion upon environmental stimulation. Of particular interest, shape-memory polymers (SMPs) have secured a central role in the ongoing development of relatively lightweight and remotely deployable devices that can be further designed with specific surface properties. In the case of thermally-activated SMPs, two functional chemical species must be present to provide (i) an elastic network capable of restoring the SMP to a previous strain state and (ii) switching elements that either lock-in or release a temporary strain at a well-defined thermal transition...
October 6, 2016: Macromolecular Rapid Communications
Jing Yang, Qian Li, Xiao Yang, Yakai Feng, Xiangkui Ren, Changcan Shi, Wencheng Zhang
Gene therapy demonstrates promising prospects on cardiovascular diseases. However, nonviral gene delivery system has relatively low transfection efficiency, especially for endothelial cells (ECs). Herein, typical cell-penetrating peptide (TAT), nuclear localization signals (NLSs), and REDV functional peptide have been used to prepare multitargeting complexes. These complexes exhibit higher transfection efficiency owing to the targeting sequences of REDV and NLSs as well as the cell-penetrating function of TAT...
September 28, 2016: Macromolecular Rapid Communications
Richard d'Arcy, Arianna Gennari, Roberto Donno, Nicola Tirelli
Families of amphiphilic oxidation-responsive polymers (poly(ethylene glycol)-polysulfides) with different architectures (linear, 4, 6, and 8-armed stars and 10, 15, and 20-armed combs) and compositions (variable ethylene sulfide/propylene sulfide ratio) are prepared. In water, all the polymers assemble in spherical micelles, with critical micellar concentrations <0.01 mg mL(-1) for all the branched polymers. Triple-detection gel permeation chromatography (GPC) and asymmetric field flow fractionation (AFFF) with dynamic and static light scattering detection, respectively, show an increasing compaction of the polymeric coil and a strong reduction of the aggregation number with increasing degree of branching...
September 27, 2016: Macromolecular Rapid Communications
Bart Stevens, Tyler Guin, Owais Sarwar, Alyssa John, Keith R Paton, Jonathan N Coleman, Jaime C Grunlan
Rapid, large-scale exfoliation of graphene in water has expanded its potential for use outside niche applications. This work focuses on utilizing aqueous graphene dispersions to form thin films using layer-by-layer processing, which is an effective method to produce large-area coatings from water-based solutions of polyelectrolytes. When layered with polyethyleneimine, graphene flakes stabilized with cholate are shown to be capable of producing films thinner than 100 nm. High surface coverage of graphene flakes results in electrical conductivity up to 5500 S m(-1) ...
September 27, 2016: Macromolecular Rapid Communications
Timothy C Boire, Daniel A Balikov, Yunki Lee, Christy M Guth, Joyce Cheung-Flynn, Hak-Joon Sung
Veins used as grafts in heart bypass or as access points in hemodialysis exhibit high failure rates, thereby causing significant morbidity and mortality for patients. Interventional or revisional surgeries required to correct these failures have been met with limited success and exorbitant costs, particularly for the US Centers for Medicare & Medicaid Services. Vein stenosis or occlusion leading to failure is primarily the result of neointimal hyperplasia. Systemic therapies have achieved little long-term success, indicating the need for more localized, sustained, biomaterial-based solutions...
September 27, 2016: Macromolecular Rapid Communications
Sebnem Baysec, Eduard Preis, Sybille Allard, Ullrich Scherf
Five different poly(arylene-diarylvinylene)s have been synthesized by reductive polyolefination starting from the corresponding bis(α,α-dichlorobenzyl)-substituted monomers and dicobaltoctacarbonyl as reducing agent. The resulting polymers all contain main chain tetraphenylethylene units. Thanks to the aggregation-induced emission effect, the corresponding polymer films show remarkably high photoluminescence quantum yields (PLQYs) of 32%-73%. The polymer with the highest PLQY is tested as solid state sensing material for the PL-quenching-based detection of nitroaromatic analytes (1,3,5-trinitrobenzene as prototypical analyte)...
September 26, 2016: Macromolecular Rapid Communications
Pengfei Zhang, Marc Behl, Xingzhou Peng, Muhammad Yasar Razzaq, Andreas Lendlein
Inspired by the application of ultrasonic cavitation based mechanical force (CMF) to open small channels in natural soft materials (skin or tissue), it is explored whether an artificial polymer network can be created, in which shape-changes can be induced by CMF. This concept comprises an interconnected macroporous rhodium-phosphine (Rh-P) coordination polymer network, in which a CMF can reversibly dissociate the Rh-P microphases. In this way, the ligand exchange of Rh-P coordination bonds in the polymer network is accelerated, resulting in a topological rearrangement of molecular switches...
September 26, 2016: Macromolecular Rapid Communications
Peipei Zuo, Yumiao Su, Wenmu Li
Highly conductive anion exchange membranes (AEMs), along with the ability to suppress swelling, are critical but challenging requirements for alkaline fuel cell applications. To achieve this criterion, a series of poly(ether sulfone)s (PESFs) with flexible alkyl imidazolium pendants attached directly on large planar 6,12-bis(4-hydroxyphenyl)-5,11-dihydroindolo[3,2-b]carbazole (DCP) units is reported. The planar DCP units stabilize the hydrophobic phase through strong π-π interactions and also facilitate the formation of ionic conducting channels through self assembly of hydrophilic pendants...
September 26, 2016: Macromolecular Rapid Communications
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