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51.
Jasim Ahmed Sunil K. Varshney Florence Janvier 《Journal of Thermal Analysis and Calorimetry》2014,115(3):2053-2061
Poly(l-lactide) (PLLA) and Poly(d-lactide) (PDLA) blended films (PLLA/PDLA) were prepared (5/95; 25/75; 50/50, and 75/25) by solvent casting method. Blend of PLLA and PDLA of medium molecular mass led to the formation of stereocomplex which was evidenced by differential scanning calorimetry, rheological measurement and Fourier transform infrared spectroscopy. The stereocomplex had a higher melting temperature (T m) (more than 50 °C) and crystallized at higher temperature (T c) (more than 25 °C) from the melt compared to neat PLLA and PDLA. The T m and T c gradually decreased with increasing the number of thermal scans. The enthalpy of fusion (?Hm) for stereocomplex crystallites in 50/50 blend films was the highest than that of homo-crystallites. Rheological measurement at a temperature of 180–195 °C revealed that the neat PLA was predominantly liquid-like behavior (G″ > G′) which transformed to extreme solid-like behavior by incorporation of PDLA into PLLA. Among blends, 50/50 PDLA/PLLA showed the maximum mechanical strength (G′) followed by 25/75, 75/25, and 5/95 blends. The significant increase in mechanical strength is believed to be attributed by stereocomplex formation by blends. Thermal and rheological data supported higher mechanical strength and an increase in melting and crystallization temperature adequately. 相似文献
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Direct Electrochemical Capture and Release of Carbon Dioxide Using an Industrial Organic Pigment: Quinacridone 下载免费PDF全文
Dogukan Hazar Apaydin Dr. Eric Daniel Głowacki Dr. Engelbert Portenkirchner Prof. Niyazi Serdar Sariciftci 《Angewandte Chemie (International ed. in English)》2014,53(26):6819-6822
Limiting anthropogenic carbon dioxide emissions constitutes a major issue faced by scientists today. Herein we report an efficient way of controlled capture and release of carbon dioxide using nature inspired, cheap, abundant and non‐toxic, industrial pigment namely, quinacridone. An electrochemically reduced electrode consisting of a quinacridone thin film (ca. 100 nm thick)on an ITO support forms a quinacridone carbonate salt. The captured CO2 can be released by electrochemical oxidation. The amount of captured CO2 was quantified by FT‐IR. The uptake value for electrochemical release process was 4.61 mmol g?1. This value is among the highest reported uptake efficiencies for electrochemical CO2 capture. For comparison, the state‐of‐the‐art aqueous amine industrial capture process has an uptake efficiency of ca. 8 mmol g?1. 相似文献
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Anne Vessires Nathalie Fischer‐Durand Franck Le Bideau Pierre Janvier Jan‐Martin Heldt Samy Ben Rejeb Grard Jaouen 《应用有机金属化学》2002,16(11):669-674
We report a new, non‐isotopic, immunoassay (CMIA) for chlortoluron, a pesticide of the phenylurea family. The novel feature of this assay is the use of metal carbonyl complexes as tracers and Fourier‐transform infrared (FT‐IR) spectroscopy as the detection method. We describe the synthesis of three tracers, derivatives of chlortoluron with an attached cyclopentadienyl manganese tricarbonyl moiety. Quantitative analysis of these tracers, by FT‐IR spectroscopy was performed by simple measurement of the absorbance peak at 2033 cm?1, characteristic of the νCO of the metal‐carbonyl unit. Immunoassays were carried out using the IgG fraction of rabbit antiserum. Standard curves obtained by CMIA for the three tracers showed the feasibility of this technique for chlortoluron assay. However, the IC50 and IC90 values obtained with the three tracers varied widely, with the long‐chain tracer 12 giving the most sensitive assay for chlortoluron, with an IC50 value of 50 pmol (21 µg l?1) and an IC90 of 6.5 pmol (2.7 µg l?1). Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Consider a continuous local martingale X. We say that X satisfies the representation property if any martingale Y of X can be represented as stochastic ITÔ integral of X. On the basis of part I of the present paper, in section 4 several general examples of continuous local martingales X satisfying the representation property are given: Stochastic continuous GAUSSian martingales, processes with conditionally independent increments, stopped continuous local martingales, random time change of WIENER processes, weak solutions of stochastic differential equations. Theorem 7 states that every (homogeneous) continuous strong MARKOV local martingale has the representation property. In section 5, the results of part I are applied to n-dimensional continuous local martingales and analogous representation results are obtained. In section 6, we consider an application of section 5 to the n-dimensional time change for reducing every n-dimensional continuous local martingale with orthogonal components to the WIENER process. This improves a theorem of F. B. KNIGHT and simplifies its proof considerably. 相似文献
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Stable chromium, molybdenum and tungsten nanoparticles are obtained reproducibly by thermal or photolytic decomposition under argon from mononuclear metal carbonyl precursors M(CO)(6) (M=Cr, Mo, W) suspended in the ionic liquids BMim(+)BF(4)(-), BMim(+)OTf(-) and BtMA(+)Tf(2)N(-) (BMim(+)=n-butyl-methyl-imidazolium, BtMA(+)=n-butyl-trimethyl-ammonium, Tf(2)N=N(O(2)SCF(3))(2), OTf=O(3)SCF(3)) with a very small and uniform size of 1 to 1.5 nm in BMim(+)BF(4)(-) which increases with the molecular volume of the ionic liquid anion to approximately 100 nm in BtMA(+)Tf(2)N(-) [characterization by transmission electron microscopy (TEM), dynamic light scattering and transmission electron diffraction (TED) analysis]. 相似文献
60.
Photoinduced Charge‐Carrier Generation in Epitaxial MOF Thin Films: High Efficiency as a Result of an Indirect Electronic Band Gap? 下载免费PDF全文
Dr. Jinxuan Liu Wencai Zhou Jianxi Liu Dr. Ian Howard Dr. Goran Kilibarda Dr. Sabine Schlabach Damien Coupry Dr. Matthew Addicoat Satoru Yoneda Yusuke Tsutsui Dr. Tsuneaki Sakurai Prof. Dr. Shu Seki Dr. Zhengbang Wang Peter Lindemann Dr. Engelbert Redel Prof. Thomas Heine Prof. Dr. Christof Wöll 《Angewandte Chemie (International ed. in English)》2015,54(25):7441-7445
For inorganic semiconductors crystalline order leads to a band structure which gives rise to drastic differences to the disordered material. An example is the presence of an indirect band gap. For organic semiconductors such effects are typically not considered, since the bands are normally flat, and the band‐gap therefore is direct. Herein we show results from electronic structure calculations demonstrating that ordered arrays of porphyrins reveal a small dispersion of occupied and unoccupied bands leading to the formation of a small indirect band gap. We demonstrate herein that such ordered structures can be fabricated by liquid‐phase epitaxy and that the corresponding crystalline organic semiconductors exhibit superior photophysical properties, including large charge‐carrier mobility and an unusually large charge‐carrier generation efficiency. We have fabricated a prototype organic photovoltaic device based on this novel material exhibiting a remarkable efficiency. 相似文献