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861.
David Serrano-Ruiz Sofia Rangou Apostolos Avgeropoulos Nikolaos E. Zafeiropoulos Enrique López-Cabarcos Jorge Rubio-Retama 《Journal of polymer science. Part A, Polymer chemistry》2010,48(14):1668-1675
The present article offers a new approach to create a multifunctional material based on magnetic nanoparticles, which can be dispersed in aqueous and organic media. The preparation of this material was performed by binding covalently polymer chains based on a reactive diblock-copolymer of the polystyrene-SiCl2-poly(2-vinylpyridine) type, with average molecular weight per number (Mn) equal to 14,700 g/mol and a polydispersity index (PDI) less than 1.1, onto the surface of γ-Fe2O3 magnetic nanoparticles. The dichlorosilane moiety of the diblock-copolymer reacted with the OH groups of the magnetic nanoparticles immobilizing the polymer chain onto its surface. This reaction was monitored by FTIR and the polymer grafting density was determined by TGA and BET. Dynamic light scattering revealed that the hydrodynamic diameter of the nanoparticles increased after immobilizing the polymer. Contact angle measurements demonstrated the ability of the hybrid material to interact with organic and aqueous media allowing its dispersion in solvents with different polarities. This property was used to prepare a magnetically active emulsion. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1668–1675, 2010 相似文献
862.
George Zapsas Dimitrios Moschovas Konstantinos Ntetsikas Sofia Rangou Jae‐Hwang Lee Edwin L. Thomas Nikolaos E. Zafeiropoulos Apostolos Avgeropoulos 《Journal of Polymer Science.Polymer Physics》2015,53(17):1238-1246
Synthesis, molecular, and morphological characterization of two linear diblock copolymers consisting of two polydienes with specific geometric isomerisms and two triblock terpolymers with a combination of the same polydienes with polystyrene are investigated for both lower and very high molecular weights. This work is inspired from a previous research study which demonstrated that linear ABC terpolymers consisting of polystyrene, poly(butadiene), and poly(isoprene), with specific geometric isomerisms for the polydienes, lead to 3‐phase microphase separated systems. We report also the coexistence of the core‐shell double gyroid and the 3‐phase 4‐layer alternating lamellae morphologies with the majority fraction being the lamellar structure. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1238–1246 相似文献
863.
Full‐Spectrum Photonic Pigments with Non‐iridescent Structural Colors through Colloidal Assembly 下载免费PDF全文
Dr. Jin‐Gyu Park Prof. Shin‐Hyun Kim Sofia Magkiriadou Tae Min Choi Dr. Young‐Seok Kim Prof. Vinothan N. Manoharan 《Angewandte Chemie (International ed. in English)》2014,53(11):2899-2903
Structurally colored materials could potentially replace dyes and pigments in many applications, but it is challenging to fabricate structural colors that mimic the appearance of absorbing pigments. We demonstrate the microfluidic fabrication of “photonic pigments” consisting of microcapsules containing dense amorphous packings of core–shell colloidal particles. These microcapsules show non‐iridescent structural colors that are independent of viewing angle, a critical requirement for applications such as displays or coatings. We show that the design of the microcapsules facilitates the suppression of incoherent and multiple scattering, enabling the fabrication of photonic pigments with colors spanning the visible spectrum. Our findings should provide new insights into the design and synthesis of materials with structural colors. 相似文献
864.
Mattia Ghirardello Kim Öberg Samuele Staderini Olivier Renaudet Nathalie Berthet Pascal Dumy Yvonne Hed Alberto Marra Michael Malkoch Alessandro Dondoni 《Journal of polymer science. Part A, Polymer chemistry》2014,52(17):2422-2433
Alkene and alkyne functional polyester‐based dendrimers of generation 1 to 4 have been prepared and reacted under free‐radical conditions with 2‐acetamido‐2‐deoxy‐1‐thio‐β‐D ‐glucose (GlcNAc‐SH). As the alkene‐dendrimers underwent the addition of one thiyl radical per ene group whereas each yne group of alkyne‐dendrimers was saturated by two thiyl radicals, a collection of glycodendrimers with glycan density ranging from six to ninety‐six GlcNAc per dendrimer was obtained. The recognition properties of the prepared glycodendrimers toward the wheat germ agglutinin (WGA) were evaluated by enzyme‐linked lectin assay (ELLA). The eight glycodendrimers were excellent ligands showing IC50 values in the nanomolar range and relative potencies per sugar unit up to 2.27 e6 when compared to monosaccharidic GlcNAc used as monovalent reference. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2422–2433 相似文献
865.
Juliana Isabel Clodt Sofia Rangou Anne Schrder Kristian Buhr Janina Hahn Adina Jung Volkan Filiz Volker Abetz 《Macromolecular rapid communications》2013,34(2):190-194
Highly porous polystyrene‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP) diblock copolymer membranes are prepared using carbohydrates as additives. Therefore α‐cyclodextrine, α‐(D )‐glucose, and saccharose (cane sugar) are tested for the membrane formation of three different PS‐b‐P4VP polymers. The addition of the carbohydrates leads to an increasing viscosity of the membrane solutions due to hydrogen bonding between hydroxyl groups of the carbohydrates and pyridine units of the block copolymer. In all cases, the membranes made from solution with carbohydrates have higher porosity, an improved narrow pore distribution on the surface and a higher water flux as membranes made without carbohydrates with the same polymer, solvent ratio, and polymer concentration. 相似文献
866.
Alaa S. Abd-El-Aziz Sofia Tesfalidet Christine R. de Denus Krystyna Lezynska 《合成通讯》2013,43(10):1415-1426
A novel route to the synthesis of some 2-aryl alkanoic acid esters has been achieved. Aromatic nucleophilic substitution of various arene cyclopenta-dienyliron complexes with ethyl ethylacetoacetate and ethyl methylacetoacetate produced the complexed alkanoic acid esters. Photolysis of these complexes resulted in the liberation of the free esters in good yields. 相似文献
867.
Magnetic “Molecular Oligomers” Based on Decametallic Supertetrahedra: A Giant Mn49 Cuboctahedron and its Mn25Na4 Fragment 下载免费PDF全文
Dr. Maria Manoli Sofia Alexandrou Dr. Linh Pham Dr. Giulia Lorusso Dr. Wolfgang Wernsdorfer Dr. Marco Evangelisti Prof. George Christou Dr. Anastasios J. Tasiopoulos 《Angewandte Chemie (International ed. in English)》2016,55(2):679-684
Two nanosized Mn49 and Mn25Na4 clusters based on analogues of the high‐spin (S=22) [MnIII6MnII4(μ4‐O)4]18+ supertetrahedral core are reported. Mn49 and Mn25Na4 complexes consist of eight and four decametallic supertetrahedral subunits, respectively, display high virtual symmetry (Oh), and are unique examples of clusters based on a large number of tightly linked high nuclearity magnetic units. The complexes also have large spin ground‐state values (Mn49: S=61/2; Mn25Na4: S=51/2) with the Mn49 cluster displaying single‐molecule magnet (SMM) behavior and being the second largest reported homometallic SMM. 相似文献
868.
Jesus M. Rodilla Patricia P. Neves Sofia Pombal Vicente Rives Raquel Trujillano David Díez 《Natural product research》2016,30(7):834-840
The use of hydrotalcites for the synthesis of two chiral building blocks in a simple way is described as a new and green methodology. The synthesis of these compounds implies a regioselective Baeyer–Villiger reaction in a very selective way with ulterior opening and lactonisation. This methodology should be considered green for the use of hydrogen peroxide as the only oxidant and hydrotalcites as the catalyst, and because no residues are produced apart from water. The procedure is very adequate for using in gram scale, in order to increase the value of the obtained compounds. The conditions are excellent and can be applied for nonstable compounds, as they are very mild. The synthesised compounds are magnific starting materials for the synthesis of biologically active or natural compounds. The use of a cheap, commercial and chiral compound as carvone disposable in both enantiomeric forms adds an extra value to this methodology. 相似文献
869.
A. V. Sidel’nikov V. N. Maistrenko R. A. Zil’berg Yu. A. Yarkaeva E. M. Khamitov 《Journal of Analytical Chemistry》2017,72(5):575-581
An enantioselective voltammetric sensor for the recognition of propranolol stereoisomers is developed based on a carbon-paste electrode modified with uracil supramolecular structures and the use of chemometric methods. The conditions for the formation of an enantioselective selector on the surface of graphite (graphene) particles and the selective registration of voltammograms of enantiomers, as well as the possibility of the recognition thereof, are studied by methods of molecular dynamics simulation and voltammetry. 相似文献
870.
The small-angle X-ray data from a polydisperse solution of sodium silicate have been measured in the concentration range 3.6–169 mg/cm3 using aKratky camera. The following values of the particle parameters were obtained: the average radius of gyration =7.5 nm, the average particle weight =900 000, the average volume =671 nm3, and the average particle surface area =717 nm2.From the above parameters and the apparent specific volume, analysed to be 0.422 cm3/g, the water content of the silicate particles was determined to be 3% (by weight).From small-angle X-ray measurements, performed on solutions exposed to a hydrodynamic field, it is indicated that at least the larger particles in the solution have a relatively symmetric shape. Based on this observation it was assumed that the particles in solution are spherical, and particle size distribution functions were calculated using a least-squares program. It was found that the distribution cannot be described by a simple function, such as aGaussian function; instead, the distribution follows a histogram with three local maxima.Dedicated to Prof. Dr. Dr.Otto Kratky, Graz, on the occasion of his 80th birthday. 相似文献