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41.
Kaname Kanai Takahiro Miyazaki Takanori Wakita Kouki Akaike Takayoshi Yokoya Yukio Ouchi Kazuhiko Seki 《Advanced functional materials》2010,20(13):2046-2052
How annealing influences the morphology of a highly regioregular poly(3‐hexylthiophene) (RR‐P3HT) film at the substrate interface as well as the lateral inhomogeneity in the electronic structure of the film are elucidated. Whereas previous studies have reported that high‐molecular‐weight (MW) RR‐P3HT films tend to show low crystallinity even after annealing, it is found that high‐MW RR‐P3HT does show high crystallinity after annealing at high temperature for a long time. Photoemission electron microscopy (PEEM), X‐ray photoemission spectroscopy, and ultraviolet photoemission spectroscopy results clearly resolve a considerable lateral inhomogeneity in the morphology of RR‐P3HT film, which results in a variation of the electronic structure depending on the local crystallinity. The PEEM results show how annealing facilitates crystal growth in a high‐MW RR‐P3HT film. 相似文献
42.
评价了热二氧化氯(DHT段)操作条件对桉木硫酸盐浆的无元素氯漂白的影响.DHT段比普通D段对减少卡伯值更有效,但延长DHT段在95℃的反应时间超过60~90 min,会引起纸浆变黑. 相似文献
43.
Juan Peragón Eva E. Rufino-Palomares Irene Mu?oz-Espada Fernando J. Reyes-Zurita José A. Lupiá?ez 《International journal of molecular sciences》2015,16(9):21681-21694
Maslinic acid (MA) and oleanolic acid (OA), the main triterpenic acids present in olive, have important properties for health and disease prevention. MA selectively inhibits cell proliferation of the HT29 human colon-cancer cell line by inducing selective apoptosis. For measuring the MA and OA concentration inside the cell and in the culture medium, a new HPLC-MS procedure has been developed. With this method, a determination of the amount of MA and OA incorporated into HT29 and HepG2 human cancer-cell lines incubated with different concentrations of MA corresponding to 50% growth inhibitory concentration (IC50), IC50/2, IC50/4, and IC50/8 has been made. The results demonstrate that this method is appropriate for determining the MA and OA concentration in different types of cultured cells and reveals the specific dynamics of entry of MA into HT29 and HepG2 cells. 相似文献
44.
Yi‐Kai Fang Cheng‐Liang Liu Chaoxu Li Chih‐Jung Lin Raffaele Mezzenga Wen‐Chang Chen 《Advanced functional materials》2010,20(18):3012-3024
Novel donor–acceptor rod–coil diblock copolymers of regioregular poly(3‐hexylthiophene) ( P3HT )‐block‐poly(2‐phenyl‐5‐(4‐vinylphenyl)‐1,3,4‐oxadiaz‐ole) ( POXD ) are successfully synthesized by the combination of a modified Grignard metathesis reaction ( GRIM ) and atom transfer radical polymerization ( ATRP ). The effects of the block ratios of the P3HT donor and POXD pendant acceptor blocks on the morphology, field effect transistor mobility, and memory device characteristics are explored. The TEM, SAXS, WAXS, and AFM results suggest that the coil block fraction significantly affects the chain packing of the P3HT block and depresses its crystallinity. The optical absorption spectra indicate that the intramolecular charge transfer between the main chain P3HT donor and the side chain POXD acceptor is relatively weak and the level of order of P3HT chains is reduced by the incorporation of the POXD acceptor. The field effect transistor (FET) hole mobility of the system exhibits a similar trend on the optical properties, which are also decreased with the reduced ordered P3HT crystallinity. The low‐lying highest occupied molecular orbital (HOMO) energy level (–6.08 eV) of POXD is employed as charge trap for the electrical switching memory devices. P3HT‐ b ‐POXD exhibits a non‐volatile bistable memory or insulator behavior depending on the P3HT / POXD block ratio and the resulting morphology. The ITO/ P3HT44 ‐b‐ POXD18 /Al memory device shows a non‐volatile switching characteristic with negative differential resistance (NDR) effect due to the charge trapped POXD block. These experimental results provide the new strategies for the design of donor‐acceptor rod‐coil block copolymers for controlling morphology and physical properties as well as advanced memory device applications. 相似文献
45.
Chin‐Yi Liu Zachary C. Holman Uwe R. Kortshagen 《Advanced functional materials》2010,20(13):2157-2164
Silicon nanocrystals (Si NCs) are shown to be an electron acceptor in hybrid solar cells combining Si NCs with poly(3‐hexylthiophene) (P3HT). The effects of annealing and different metal electrodes on Si NC/P3HT hybrid solar cells are studied in this paper. After annealing at 150 °C, Si NC/P3HT solar cells exhibit power conversion efficiencies as high as 1.47%. The hole mobility in the P3HT phase extracted from space‐charge‐limited current measurements of hole‐only devices increases from 2.48 × 10?10 to 1.11 × 10?9 m2 V?1 s?1 after annealing, resulting in better transport in the solar cells. A quenching of the open‐circuit voltage and short‐circuit current is observed when high work function metals are deposited as the cathode on Si NC/P3HT hybrid devices. 相似文献
46.
J. SEITER E. MÜLLER H. BLANK H. GEHRKE D. MARKO D. GERTHSEN 《Journal of microscopy》2014,254(2):75-83
Backscattered electron imaging of HT29 colon carcinoma cells in a scanning electron microscope was studied. Thin cell sections were placed on indium‐tin‐oxide‐coated glass slides, which is a promising substrate material for correlative light and electron microscopy. The ultrastructure of HT29 colon carcinoma cells was imaged without poststaining by exploiting the high chemical sensitivity of backscattered electrons. Optimum primary electron energies for backscattered electron imaging were determined which depend on the section thickness. Charging effects in the vicinity of the SiO2 nanoparticles contained in cell sections could be clarified by placing cell sections on different substrates. Moreover, a method is presented for information depth determination of backscattered electrons which is based on the imaging of subsurface nanoparticles embedded by the cells. 相似文献
47.
In this paper, single reduced graphene oxide (rGO) and rGO/Poly (3-hexylthiophene) (P3HT) composite films were prepared by the spray process, which were deposited on the interdigitated transducers for preparing the resistive ammonia (NH3) sensor. The morphology of sensitive films was characterized by scanning electron microscopy (SEM). The gas-sensing properties of GO/P3HT film sensor were tested and analyzed. The results showed that rGO/P3HT composite film sensor exhibited better sensing properties and restorability than that rGO film sensor, which maybe was ascribed to π-π interaction between rGO and P3HT and the superior surface morphology of composite films. 相似文献
48.
49.
针对Incoloy 800HT管线断裂,检查原始施工记录,并通过扫描电镜和金相,及其应力分析等手段.研究结果显示,断裂处的材料出现了沿晶界析出的σ相和蠕变空洞并导致材料脆化,接管悬挂过重加速了蠕变空洞的形成,是导致接管断裂的根本原因. 相似文献
50.
Avishek R. Aiyar Jung‐Il Hong Rakesh Nambiar David M. Collard Elsa Reichmanis 《Advanced functional materials》2011,21(14):2652-2659
The properties of poly(alkylthiophenes) in solution are found to have a profound impact on the self assembly process and thus the microstructural and electrical properties of the resultant thin films. Ordered supramolecular precursors can be formed in regioregular poly(3‐hexylthiophene) (P3HT) solutions through the application of low intensity ultrasound. These precursors survive the casting process, resulting in a dramatic increase in the degree of crystallinity of the thin films obtained by spin coating. The crystallinity of the films is tunable, with a continuous evolution of mesoscale structures observed as a function of ultrasonic irradiation time. The photophysical properties of P3HT in solution as well in the solid state suggest that the application of ultrasound leads to a π stacking induced molecular aggregation resulting in field effect mobilities as high as 0.03 cm2 V?1 s?1. A multiphase morphology, comprising short quasi‐ordered and larger, ordered nanofibrils embedded in a disordered amorphous phase is formed as a result of irradiation for at least 1 min. Two distinct regions of charge transport are identified, characterized by an initial sharp increase in the field effect mobility by two orders of magnitude due to an increase in crystallinity up to the percolation limit, followed by a gradual saturation where the mobility becomes independent of the thin film microstructure. 相似文献