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211.
Hassan Ridaoui Ali Dirani Olivier Soppera Esma Ismailova Cyril Brochon Guy Schlatter Georges Hadziioannou Raluca Tiron Philippe Bandelier Claire Sourd 《Journal of polymer science. Part A, Polymer chemistry》2010,48(6):1271-1277
Next generations of microelectronic devices request further miniaturized systems. In this context, photolithography is a key step and many efforts have been paid to develop new irradiation setup and materials compatible with sub‐100 nm resolution. Among other resist platforms, chemically amplified photoresists (CAR) are widely used because of their excellent properties in terms of resolution, sensitivity, and etching resistance. However, low information on the impact of the polymer structure on the lithography performance is available. CAR with well‐controlled polymer structures were thus prepared and investigated. In particular, the impact of the polymer structure on the lithographic performance was evaluated. Linear and branched polymers with various molecular weights and polydispersities were compared. We focused on the dependency of the photosensitivity of the resist with the structural parameters. These results allow further understanding the fundamental phenomena involved by 193‐nm irradiation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1271–1277, 2010 相似文献
212.
Raluca Pop Mihai Medeleanu Mircea V. Diudea Beata Szefler Jerzy Cioslowski 《Central European Journal of Chemistry》2013,11(4):527-534
Stability measures, such as the total energy and the HOMO-LUMO gap, calculated at the Hartree-Fock and DFT levels of theory, and the aromatic character of five circulenes/flowers with a hexagonal core and petals consisting of 5-, 6- and 7-membered rings are investigated. Geometric (HOMA) and magnetic (NICS) criteria are used to estimate the local aromatic character of every ring of the investigated circulenes. The local aromaticity of the coronene and sumanene patches in two tetrahedrally spanned fullerenes were calculated and compared with the HOMA and NICS values of the corresponding isolated circulenes. 相似文献
213.
Raluca Nicoleta Darie Ruxandra Bodirlau Carmen Alice Teaca Joanna Macyszyn Marek Kozlowski Iuliana Spiridon 《International Journal of Polymer Analysis and Characterization》2013,18(4):315-327
In the view of producing environmentally friendly materials without compromising properties, new composites containing polypropylene as a matrix and eucalyptus wood, with or without 15% of polylactic acid, were melt processed. In order to improve compatibility between components, a chemical modification of wood with toluene-2,4-diisocyanate (TDI) was realized and evidenced by changes in FT-IR and XPS spectra. The morphological, mechanical, and thermal characterizations of the obtained composites were evaluated before and after accelerating weathering. The results showed that the material comprising 15% TDI-modified wood, PP, and 15% PLA exhibited the best properties. 相似文献
214.
The complex between protoporphyrin IX and zinc was immobilized on nanocarbon paste and on nanodiamond paste to design two stochastic microsensors. The microsensors were used for the recognition and analysis of antibiotics: amoxicillin, ampicillin, and biotin in water samples. Stochastic sensors provided different signatures for the three antibiotics making possible their simultaneous recognition and assay in water samples. Low limits of determination 0.3 pg/mL for amoxicillin and ampicillin, and 0.21 pg/mL for biotin were obtained when nanocarbon paste was used, and 0.03 pg/mL for amoxicillin, 0.30 pg/mL for ampicillin, and 2.14 fg/mL for biotin were obtained when nanodiamond paste was used. Recoveries higher than 99.32 % with RSD lower than 1.00 % were obtained for the assay of the antibiotics in water samples. 相似文献
215.
Guillaume Freychet Mireille Maret Marta Fernandez-Regulez Raluca Tiron Ahmed Gharbi Celia Nicolet Patrice Gergaud 《Journal of polymer science. Part A, Polymer chemistry》2020,58(15):2041-2050
The morphologies of poly(lactide)-block-poly(dimethylsiloxane)-block-polylactide (PLA-b-PDMS-b-PLA) triblock copolymer films were studied using a combination of grazing-incidence small-angle X-ray scattering, X-ray reflectivity and scanning electron microscopy. This block copolymer is characterized by a high Flory–Huggins interaction parameter which leads to the self-assembly of periodic high-resolution nanodomains. In this article, we performed a detailed analysis of GISAXS patterns, in the frame of the Distorted Wave Born Approximation, in order to determine the morphology of blocks and their spatial arrangement. For a low volume fraction of PLA (17%), a three-dimensional hexagonal lattice of PLA spherical blocks is revealed, while, for a PLA fraction twice larger, in-plane (parallel) PLA lying cylinders adopt a two-dimensional centered rectangular lattice. Moreover, the in-depth electron density profile of the polymer film for the cylindrical morphology was extracted from the XRR data, revealing the presence of interfacial layers at the top surface and at the interface with the Si substrate. 相似文献
216.
Pierre Charbonnaz Dr. Yingjie Zhao Dr. Raluca Turdean Santiago Lascano Dr. Naomi Sakai Prof. Stefan Matile 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(51):17143-17151
Simple stacks of perylenediimides (PDIs) grown directly on solid surfaces are an intriguing starting point for the construction of multicomponent architectures because their intrinsic activity is already very high. The ability of PDI stacks to efficiently generate photocurrent originates from the strong absorption of visible light and the efficient transport of both electrons and holes after generation with light. The objective of this study was to explore whether or not the excellent performance of these remarkably simple single‐channel photosystems could be further improved in more sophisticated multicomponent architectures. We report that the directional construction of strings of anions or cations along the PDI stacks does not significantly improve their activity; that is, the intrinsic activity of PDI stacks is too high to yield ion‐gated photosystems. The directional construction of electron‐ and hole‐transporting stacks of naphthalenediimides (NDIs) and oligothiophenes along the central PDI stack did not improve photocurrent generation under standard conditions either. However, the activity of double‐channel photosystems increased with increasing thickness, whereas increasing charge recombination with single‐channel PDI stacks resulted in decreasing activity with increasing length. Most efficient long‐distance charge transport was found with double‐channel photosystems composed of PDIs and NDIs. This finding suggests that over long distances, PDI stacks transport holes better than electrons, at least under the present conditions. Triple‐channel photosystems built around PDI stacks with oligothiophenes and triphenylamines were less active, presumably because hole mobility in the added channels was inferior to that in the original PDI stacks, thus promoting charge recombination. 相似文献
217.
218.
Raluca M. Albu Ecaterina Avram Valentina E. Musteata Silvia Ioan 《Journal of Solid State Electrochemistry》2014,18(3):785-794
The frequency-dependent dielectric properties and conductivity of partially quaternized polysulfones, quaternized polysulfones containing chelating groups, and chelated quaternized polysulfones with Cu2+ have been studied. The permittivity has low values and is dependent on the chemical characteristic of samples, in relation with the charge transfer complex and free volume and, consequently, with packing of the polymer chains and of the polarizable groups per volume units. At temperatures below 150 °C, all polysulfone films develop two relaxation processes, i.e., γ and β relaxation, involving different enthalpy and entropy contributions induced by their chemical structures. Frequency–temperature-dependent conductivity showed that conductivity increased with frequency, while the values of thermal activation energy of electrical conduction, lower that 1, suggest that a model based on energy bandgap representation could be suitable for explaining the temperature influence on AC conductivity for all samples. In addition, enhancement of mobility of the charge carrier upon complexation was observed for chelated quaternized polysulfones with Cu2+. All these typical semiconducting properties recommend the studied polymers as potential candidates for use in various applications in electrotechnical industry. 相似文献
219.
Adrian Muntean 《Journal of Mathematical Analysis and Applications》2010,371(2):705-718
A Galerkin approach for a class of multiscale reaction-diffusion systems with nonlinear coupling between the microscopic and macroscopic variables is presented. This type of models are obtained e.g. by upscaling of processes in chemical engineering (particularly in catalysis), biochemistry, or geochemistry. Exploiting the special structure of the models, the functions spaces used for the approximation of the solution are chosen as tensor products of spaces on the macroscopic domain and on the standard cell associated to the microstructure. Uniform estimates for the finite dimensional approximations are proven. Based on these estimates, the convergence of the approximating sequence is shown. This approach can be used as a basis for the numerical computation of the solution. 相似文献
220.
Alexandru V. Asimit Raluca Vernic Ricardas Zitikis 《Methodology and Computing in Applied Probability》2016,18(3):805-827
Assuming the multiplicative background risk model, which has been a popular model due to its practical applicability and technical tractability, we develop a general framework for analyzing portfolio performance based on its subportfolios. Since the performance of subportfolios is easier to assess, the herein developed stepwise portfolio construction (SPC) provides a powerful alternative to a number of traditional portfolio construction methods. Within this framework, we discuss a number of multivariate risk models that appear in the actuarial and financial literature. We provide numerical and graphical examples that illustrate the SPC technique and facilitate our understanding of the herein developed general results. 相似文献