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排序方式: 共有186条查询结果,搜索用时 15 毫秒
181.
Luminita Marin Vasile Cozan Maria Bruma Vasile Cristian Grigoras 《European Polymer Journal》2006,42(5):1173-1182
A new poly(azomethine-ether) was synthesized by the reaction of bisphenol A with a thermotropic azomethine monomer, namely 4,4′-oxy-bis(4-chlorobenzylideneimino phenylene). In order to understand the influence of the molecular weight on the thermal properties, four fractions were isolated from the initial polymer. They were investigated by elemental analysis and spectroscopic methods (IR, UV, 1H NMR) and their thermal behaviour was studied by differential scanning calorimetry, optical microscopy, thermogravimetrical analysis. An increase of the thermal transition temperatures and mesophase order with increasing molecular weight was noticed. 相似文献
182.
Marutoiu Constantin Gogoasa Ioan Oprean Ioan Marutoiu Olivia-Florena Moise Maria-Ioana Tigae Cristian Rada Maria 《平面色谱法杂志一现代薄层色谱法》2006,19(3):250-252
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
183.
Luminita Andronic Alexandru Enesca Cristina Cazan Maria Visa 《Journal of Sol-Gel Science and Technology》2014,71(3):396-405
Titanium oxide–active carbon composites (TiO2–AC) with photocatalytic activity were prepared by sol–gel method at low temperature. Titanium isopropoxide and active carbon were used as precursors, ethanol as solvent and HNO3 as catalyst. The composition of the studied composites was accomplished by means of X-ray diffraction, and Fourier Transform-Infrared spectrometry. The rutile crystalline phase was present in all samples. In scanning electron microscopy images the TiO2 aggregates existed either on the surface of the active carbon or heterogeneously dispersed over the whole catalyst matrix. The contact angle and point of zero charge measurements were applied to characterise the surface energy and surface charge. The photocatalytic activities of the TiO2–AC composites were evaluated in the bleaching of methyl orange and methylene blue solution from ternary mixture of methyl orange, methylene blue and Triton X100. The double divisor ratio spectra derivative method (as a multivariable calibration method) was developed to overcome the spectral overlapping, for the simultaneous analysis of ternary mixture. 相似文献
184.
Silvana Maione Georgina Fabregat Luis J. del Valle Anca‐Dana Bendrea Luminita Cianga Ioan Cianga Francesc Estrany Carlos Alemán 《Journal of Polymer Science.Polymer Physics》2015,53(4):239-252
Graft copolymers formed by anchoring poly(ethylene glycol) (PEG) chains to conjugated polythiophene have been prepared by copolymerizing two compounds: unsubstituted α‐terthiophene (Th3) and a thiophene‐derived macromonomer having an α‐terthiophene conjugated sequence and one Th3 bearing a PEG chain with molecular weight of 2000 as substitute at the 3‐position of the central heterocycle (Th3‐PEG2000). The grafting ratio of the resulting copolymers (PTh3*‐g‐PEG), which were obtained using 75:25 and 50:50 Th3‐PEG2000:Th3 weight ratios, is significantly smaller than that of copolymers derived from polymerization of macromonomers consisting of a α‐pentathiophene sequence in which the central ring bears a PEG chain of Mw = 2000 (PTh5‐g‐PEG). The electroactivity and electrochemical stability of PTh3*‐g‐PEG is not only higher than that of PTh5‐g‐PEG but also higher than that of PTh3, the latter presenting a very compact structure that makes difficult the access and escape of dopant ions into the polymeric matrix during the redox processes. Furthermore, the optical π‐π* lowest transition energy of PTh3*‐g‐PEG is lower than that of both PTh5‐g‐PEG and PTh3. These properties, combined with suitable wettability and roughness, result in an excellent behavior as bioactive platform of PTh3*‐g‐PEG copolymers, which are more biocompatible, in terms of cellular adhesion and proliferation, and electro‐compatible than PTh5‐g‐PEG. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 239–252 相似文献
185.
Molecularly Imprinted Polymer Coated Quantum Dots for Multiplexed Cell Targeting and Imaging 下载免费PDF全文
Maria Panagiotopoulou Dr. Yolanda Salinas Dr. Selim Beyazit Dr. Stephanie Kunath Dr. Luminita Duma Elise Prost Dr. Andrew G. Mayes Prof. Marina Resmini Dr. Bernadette Tse Sum Bui Prof. Karsten Haupt 《Angewandte Chemie (International ed. in English)》2016,55(29):8244-8248
Advanced tools for cell imaging are of great interest for the detection, localization, and quantification of molecular biomarkers of cancer or infection. We describe a novel photopolymerization method to coat quantum dots (QDs) with polymer shells, in particular, molecularly imprinted polymers (MIPs), by using the visible light emitted from QDs excited by UV light. Fluorescent core–shell particles specifically recognizing glucuronic acid (GlcA) or N‐acetylneuraminic acid (NANA) were prepared. Simultaneous multiplexed labeling of human keratinocytes with green QDs conjugated with MIP‐GlcA and red QDs conjugated with MIP‐NANA was demonstrated by fluorescence imaging. The specificity of binding was verified with a non‐imprinted control polymer and by enzymatic cleavage of the terminal GlcA and NANA moieties. The coating strategy is potentially a generic method for the functionalization of QDs to address a much wider range of biocompatibility and biorecognition issues. 相似文献
186.
Vlad Cozma Irina Rosca Luminita Radulescu Cristian Martu Valentin Nastasa Cristian-Dragos Varganici Elena-Laura Ursu Florica Doroftei Mariana Pinteala Carmen Racles 《Molecules (Basel, Switzerland)》2021,26(16)
Within this study, new materials were synthesized and characterized based on polysiloxane modified with different ratios of N-acetyl-l-cysteine (NAC) and crosslinked via UV-assisted thiol-ene addition, in order to obtain efficient membranes able to resist bacterial adherence and biofilm formation. These membranes were subjected to in vitro testing for microbial adherence against S. pneumoniae using standardized tests. WISTAR rats were implanted for 4 weeks with crosslinked siloxane samples without and with NAC. A set of physical characterization methods was employed to assess the chemical structure and morphological aspects of the new synthetized materials before and after contact with the microbiological medium. 相似文献