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Polymer Chemistry

Tibor Teplický, Andrej Vincze, Anton Mateašík, Zuzana Garaiová, Miroslav Michalka, Beata Čunderlíková
Polysiloxanes have shown exquisite properties for fabrication of microstructures for various biomedical and biotechnological applications. Nevertheless, their biocompatibility in terms of cell adhesion and survival ability is controversial. A simple polysiloxane modifying procedure that reproducibly enhances cell adhesion was proposed. Sonication of the hybrid organic-inorganic polymer of polysiloxane type, Ormocomp, in potassium hydroxide (KOH)/ethanol solution enhanced adhesion and subsequent survival of a panel of four cell lines...
August 10, 2018: Biointerphases
Aline Lueckgen, Daniela S Garske, Agnes Ellinghaus, Rajiv M Desai, Alexander G Stafford, David J Mooney, Georg N Duda, Amaia Cipitria
Degradable biomaterials aim to recapitulate the dynamic microenvironment that cells are naturally exposed to. By oxidizing the alginate polymer backbone, thereby rendering it susceptible to hydrolysis, and crosslinking it via norbornene-tetrazine click chemistry, we can control rheological, mechanical, and degradation properties of resulting hydrogels. Chemical modifications were confirmed by nuclear magnetic resonance (NMR) and the resulting mechanical properties measured by rheology and unconfined compression testing, demonstrating that these are both a function of norbornene coupling and oxidation state...
July 24, 2018: Biomaterials
Xiao-Song Wang, Kai Cao, Liao Peng, Aklilu Worku, Junli Zhu, Anchao Feng, Dapeng Liu, Senyang Liu, Jiaping Lin, Jinying Yuan
Biological cyclization is highly efficient, which is attributed to the conformation of the backbone of biopolymer. Taking advantage of metal coordination geometry, we realized a conformation-directed polymerization cyclization, via a rational design of metal carbonyl monomers, which could be used to produce cyclic macromolecules even in bulk. PFpR [PFp = (PPh2(CH2)3Cp)Fe(CO)2 with the phosphine group tethered on the cyclopentadiene (Cp) ring, R = CH3 or (CH2)5CH3] was designed and synthesized for migration insertion polymerization (MIP), generating P(PFpR) with the polymer backbone containing Cp-Fe bonds...
August 7, 2018: Chemistry: a European Journal
Ziyi Zhang, Yufeng Jiang, Caili Huang, Yu Chai, Elise Goldfine, Feng Liu, Wenqian Feng, Joe Forth, Teresa E Williams, Paul D Ashby, Thomas P Russell, Brett A Helms
Mesostructured matter composed of colloidal nanocrystals in solidified architectures abounds with broadly tunable catalytic, magnetic, optoelectronic, and energy storing properties. Less common are liquid-like assemblies of colloidal nanocrystals in a condensed phase, which may have different energy transduction behaviors owing to their dynamic character. Limiting investigations into dynamic colloidal nanocrystal architectures is the lack of schemes to control or redirect the tendency of the system to solidify...
August 2018: Science Advances
John W Nicholson
Glass-ionomer cements are used for a variety of tooth-repair functions in clinical dentistry. They are formed by reaction of a basic glass powder with a solution of polymeric water-soluble acid, usually polyacrylic acid. After the initial neutralization reaction, by which the cement hardens, various maturation reactions occur. Changes induced by these maturation reactions are identified as: increase in strength; reduction in plasticity; improvement in opacity; and increase in proportion of tightly bound water...
2018: Acta Biomaterialia Odontologica Scandinavica
Fatima Naaz, M C Preeti Pallavi, Syed Shafi, Naveen Mulakayala, M Shahar Yar, H M Sampath Kumar
To evaluate the role of COX-2 and 5-LOX as dual inhibitors in controlling the cancer cell proliferation, a set of two series having 42 compounds of 1, 2, 3-Tethered Indole-3-glyoxamide derivatives were synthesized by employing click chemistry approach and were also evaluated for their in vitro cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) inhibitory activities with in vivo anti-inflammatory and in vitro anti-proliferative potencies. Among the compounds tested, compounds 11q and 13s displayed excellent inhibition of COX-2 (IC50 0...
July 27, 2018: Bioorganic Chemistry
Ruaa M Almotawa, Ghadah Aljomaih, Daniela Vargas Trujillo, Vladimir N Nesterov, Manal A Rawashdeh-Omary
Five coordination polymers and one hexanuclear cluster have been obtained, and their crystal structures were determined upon reaction of Cu(I) or Ag(I) precursors with pyrazine (Pyz) or piperazine (Ppz). Five complexes are mixed-imine-ligand with anionic-fluorinated pyrazolate [3,5-(CF3 )2 Pz]- ([PzF ]- ) besides Pyz or Ppz, whereas the sixth had the neutral diimine as a single chromophore. Complexes 1-3 are isomers of the same Cu/PzF /Pyz composition with the same or different unit cell stoichiometry, namely, {Cu6 [3,5-(CF3 )2 Pz]6 (Pyz)3 (CH2 Cl2 )}∞ (1·CH2 Cl2 ), {Cu2 [3,5-(CF3 )2 Pz]}2 (Pyz)2 ·toluene}∞ (2·toluene), and {Cu3 [3,5-(CF3 )2 Pz]3 (Pyz)1...
August 6, 2018: Inorganic Chemistry
Hao Wang, Hari Bisoyi, Augustine Urbas, Timothy Bunning, Quan Li
Owing to their dynamic attributes, non-covalent supramolecular interactions have enabled a new paradigm in the design and fabrication of multifunctional material systems with programmable properties, performances, and reconfigurable traits. Recently, the "halogen bond" is rising as an enticing supramolecular synthetic tool that displays a plethora of promising and advantageous characteristics. Consequently, this versatile and dynamic non-covalent interaction has been extensively harnessed in various fields such as crystal engineering, self-assembly, materials science, polymer chemistry, biochemistry, medicinal chemistry and nanotechnology...
August 3, 2018: Chemistry: a European Journal
Reinack Varghese Hansen, Jinglei Yang, Lianxi Zheng
Materials that change color in response to external stimuli can cater to diverse applications from sensing to art. If made flexible, stretchable and weavable, they may even be directly integrated with advanced technologies such as smart textiles. A new class of engineered composite based on polydiacetylene (PDA) functionalized carbon nanotubes (CNT) shows tremendous potential in this regard. While the inherent multi stimuli chromatic response of the polymer (blue to red) is retained, the underlying conducting CNTs invoke electrochromism in PDA...
July 24, 2018: Advances in Colloid and Interface Science
Nathaniel Corrigan, Jonathan Yeow, Peter Judzewitsch, Jiangtao Xu, Cyrille Andre Jean Marie Boyer
The application of photochemistry to polymer science has led to the development of complex yet efficient systems for polymerization, polymer post-functionalization, and materials production. Using light to activate chemical pathways in these systems not only leads to exquisite control over reaction dynamics, but also allows complex synthetic protocols to be easily achieved. Compared to polymerization systems mediated by thermal, chemical, or electrochemical means, photoinduced polymerization systems can potentially offer more versatile methods for macromolecular synthesis...
July 31, 2018: Angewandte Chemie
Zahid Hassan, Eduard Spuling, Daniel M Knoll, Joerg Lahann, Stefan Bräse
Planar chiral [2.2]paracyclophane-based ligands and employment of such enantiopure representative ligands to facilitate selective transformation of prochiral or racemic substances into enantiopure products are rarely explored compared to the complex chiral scaffolds such as ferrocenes. This tutorial discusses recent findings and inspiring progress in design, synthetic tunability and applications of planar chiral [2.2]paracyclophane systems as a practical class of catalysts for asymmetric synthesis. Here, we summarize a series of planar chiral [2...
August 1, 2018: Chemical Society Reviews
Masaya Ito, Koki Takano, Haruka Hanochi, Yuta Asaumi, Shin-Ichi Yusa, Yoshinobu Nakamura, Syuji Fujii
Free radical dispersion polymerization was conducted to synthesize near-monodispersed, micrometer-sized polystyrene (PS) particles carrying pH-responsive poly(4-vinylpyridine) (P4VP) colloidal stabilizer (P4VP-PS particles). The P4VP-PS particles were extensively characterized in terms of morphology, size, size distribution, chemical composition, surface chemistry, and pH-response using optical and scanning electron microscopies, elemental microanalysis, X-ray photoelectron spectroscopy, laser diffraction particle size analysis, and zeta potential measurement...
2018: Frontiers in Chemistry
Fred A M G van Geenen, Maurice C R Franssen, Han Zuilhof, Michel W F Nielen
Reactions in confined compartments like charged microdroplets are of increasing interest, notably because of their substantially increased reaction rates. When combined with ambient ionization mass spectrometry, reactions in charged microdroplets can be used to improve the detection of analytes or to study the molecular details of the reactions in real time. Here, we introduce a reactive laser ablation electrospray ionization (reactive LAESI) time-resolved mass spectrometry (TRMS) method to perform and study reactions in charged microdroplets...
July 31, 2018: Analytical Chemistry
Ivan S Golovanov, Galina S Mazeina, Yulia V Nelyubina, Roman A Novikov, Anton S Mazur, Sergey N Britvin, Vladimir A Tartakovsky, Sema L Ioffe, Alexey Yu Sukhorukov
Click-like condensation of boronic acids with specifically designed triols (boronate-triol coupling) produces stable diamantane adducts in aqueous medium, which can be controllably cleaved to initial components under acidic conditions or by using boric acid as a chemical trigger. This novel "click-declick" strategy allows to create temporary covalent connections between two or more modular units that was demonstrated by the synthesis of new fluorophore-labeled natural molecules (peptides, steroids), supramolecular assemblies, modified polymers, boronic acid scavengers, solid-supported organocatalysts, biodegradable COF-like materials and dynamic combinatorial libraries...
July 31, 2018: Journal of Organic Chemistry
Shingo Miyauchi, Anaïs Rancon, Elodie Drula, Hayat Hage, Delphine Chaduli, Anne Favel, Sacha Grisel, Bernard Henrissat, Isabelle Herpoël-Gimbert, Francisco J Ruiz-Dueñas, Didier Chevret, Matthieu Hainaut, Junyan Lin, Mei Wang, Jasmyn Pangilinan, Anna Lipzen, Laurence Lesage-Meessen, David Navarro, Robert Riley, Igor V Grigoriev, Simeng Zhou, Sana Raouche, Marie-Noëlle Rosso
Background: Plant biomass conversion for green chemistry and bio-energy is a current challenge for a modern sustainable bioeconomy. The complex polyaromatic lignin polymers in raw biomass feedstocks (i.e., agriculture and forestry by-products) are major obstacles for biomass conversions. White-rot fungi are wood decayers able to degrade all polymers from lignocellulosic biomass including cellulose, hemicelluloses, and lignin. The white-rot fungus Polyporus brumalis efficiently breaks down lignin and is regarded as having a high potential for the initial treatment of plant biomass in its conversion to bio-energy...
2018: Biotechnology for Biofuels
Camille Bergthold, Daniel Hauser, Alain Chaumont, Salima El Yakhlifi, Mihaela Mateescu, Florent Meyer, Marie-Hélène Metz-Boutigue, Benoit Frisch, Pierre Schaaf, Dris Ihiawakrim, Ovidiu Ersen, Christophe A Monnier, Alke Petri-Fink, Barbara Rothen-Rutishauser, Vincent Ball
The oxidation of dopamine and of other catecholamines leads to the formation of conformal films on the surface of all known materials and to the formation of a precipitate in solution. In some cases, it has been shown that the addition of additives in the dopamine solution, like certain surfactants or polymers, polyelectrolytes and certain proteins allow to get polydopamine nanoparticles of controlled size and the concomitant decrease, in an additive/dopamine dependent manner, in film formation on the surface of the reaction beaker...
July 30, 2018: Biomacromolecules
Rüstem Keçili, Chaudhery Mustansar Hussain
Molecularly imprinted polymers (MIPs) are a type of tailor-made materials that have ability to selectively recognize the target compound/s. MIPs have gained significant research interest in solid-phase extraction, catalysis, and sensor applications due to their unique properties such as low cost, robustness, and high selectivity. In addition, MIPs can be prepared as composite nanomaterials using nanoparticles, multiwalled carbon nanotubes (MWCNTs), nanorods, quantum dots (QDs), graphene, and clays. This review paper aims to demonstrate and highlight the recent progress of the applications of imprinted nanocomposite materials in analytical chemistry...
2018: International Journal of Analytical Chemistry
William Thompson, Diane Kennedy, Timothy Gillece, Roger L McMullen, Larry Senak, Hani Fares
A mechanistic understanding of the role of polymers in waterproofing anhydrous sunscreen formulations has been hypothesized in the past, but has never been clearly established. In this article, we demonstrate the utility of field emission scanning electron microscopy (SEM) to generate images of sunscreen films in the presence and absence of several polymers. VA/butyl maleate/isobornyl acrylate copolymer was studied alone and in combination with hydroxypropyl cellulose and acrylates/dimethicone copolymer. Anhydrous sunscreen formulations were sprayed onto stratum corneum substrates and left to dry...
May 2018: Journal of Cosmetic Science
Silke Lucke, Uwe Walschus, Andreas Hoene, Matthias Schnabelrauch, J Barbara Nebe, Birgit Finke, Michael Schlosser
Biomaterials can cause a chronic local inflammation called foreign body reaction, with formation of foreign body giant cells (FBGC) by monocyte/macrophage fusion. However, FBGC appearance and role for biomaterials with different physicochemical properties are not yet fully understood. This study aimed at examining FBGC and inflammatory cells after intramuscular implantation of poly(l-lactide-co-d/l-lactide) (PLA) as membranes and uncoated electro-spun fiber meshes or meshes with a positively charged plasma-polymer coating into rats...
July 27, 2018: Journal of Biomedical Materials Research. Part A
Youdong Cheng, Yunpan Ying, Susilo Japip, Shu-Dong Jiang, Tai-Shung Chung, Sui Zhang, Dan Zhao
Membrane technology has gained great interest in industrial separation processing over the past few decades owing to its high energy efficiency, small capital investment, environmentally benign characteristics, and the continuous operation process. Among various types of membranes, mixed matrix membranes (MMMs) combining the merits of the polymer matrix and inorganic/organic fillers have been extensively investigated. With the rapid development of chemistry and materials science, recent studies have shifted toward the design and application of advanced porous materials as promising fillers to boost the separation performance of MMMs...
July 26, 2018: Advanced Materials
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