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131.
Jun Huang Yongxiang Zhu Lianjie Zhang Ping Cai Xiaofeng Xu Junwu Chen Yong Cao 《Journal of polymer science. Part A, Polymer chemistry》2014,52(12):1652-1661
Two conjugated copolymers PADT‐DPP and PADT‐FDPP based on anthradithiophene and diketopyrrolopyrrole, with thiophene and furan as the π‐conjugated bridge, respectively, were successfully synthesized and characterized. The number‐averaged molecular weights of the two polymers are 38.7 and 30.2 kg/mol, respectively. Polymers PADT‐DPP and PADT‐FDPP exhibit broad absorption bands and their optical band gaps are 1.44 and 1.50 eV, respectively. The highest occupied molecular orbital energy level of PADT‐DPP is located at ?5.03 eV while that of PADT‐FDPP is at ?5.16 eV. In field‐effect transistors, PADT‐DPP and PADT‐FDPP displayed hole mobilities of 4.7 × 10?3 and 2.7 × 10?3 cm2/(V s), respectively. In polymer solar cells, PADT‐DPP and PADT‐FDPP showed power conversion efficiency (PCE) of 3.44% and 0.29%, respectively. Atomic force microscopy revealed that the poor efficiency of PADT‐FDPP should be related to the large two‐phase separation in its active layer. If 1,8‐diiodooctane (DIO) was used as the solvent additive, the PCE of PADT‐DPP remained almost unchanged due to very limited morphology variation. However, the addition of DIO could remarkably elevate the PCE of PADT‐FDPP to 2.62% because of the greatly improved morphology. Our results suggest that the anthradithiophene as an electron‐donating polycyclic system is useful to construct new D–A alternating copolymers for efficient polymer solar cells. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1652–1661 相似文献
132.
This review discusses the latest advances in electrodeposition of nanostructured catalysts for electrochemical energy conversion: fuel cells, water splitting, and carbon dioxide electroreduction. The method excels at preparing efficient and durable nanostructured materials, such as nanoparticles, single atom clusters, hierarchical bifunctional combinations of hydroxides, selenides, phosphides, and so on. Yet, in most cases, chemical composition cannot be decoupled from catalyst morphology. This compromises the rational design of electrodeposition procedures because performance indicators depend on both morphology and surface chemistry. We expect electrodeposition will keep unraveling its potential as the preferred method for electrocatalyst synthesis once a deeper understanding of the electrochemical growth process is combined with complex chemistries to have control of the morphology and the surface composition of complex (bifunctional) electrocatalysts. 相似文献
133.
134.
This paper studies an (n+4)-dimensional nonlinear virus dynamics model that characterizes the interactions of the viruses, susceptible host cells, n-stages of infected cells, B cells and cytotoxic T lymphocyte (CTL) cells. Both viral and cellular infections have been incorporated into the model. The infected-susceptible and virus-susceptible infection rates as well as the generation and removal rates of all compartments are described by general nonlinear functions. Five threshold parameters are computed, which insure the existence of the equilibria of the model under consideration. A set of conditions on the general functions has been established, which is sufficient to investigate the global dynamics of the model. The global asymptotic stability of all equilibria is proven by utilizing Lyapunov function and LaSalle's invariance principle. The theoretical results are illustrated by numerical simulations of the model with specific forms of the general functions. 相似文献
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136.
In this study, Fe3O4@TiO2 nanoparticles were synthesized as a new Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) hybrid imaging agent and radiolabeled with 89Zr. In addition, Fe3O4 nanoparticles were synthesized and radiolabeled with 89Zr. Df-Bz-NCS was used as bifunctional ligand. The nanoconjugates were characterized with transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. Radiolabeling yields were 100%. Breast and prostate cancer cell affinities and cytotoxicity were determined using in vitro cell culture assays. The results demonstrated that Fe3O4@TiO2 nanoparticles are promising for PET/MR imaging. Finally, unlike Fe3O4 nanoparticles, Fe3O4@TiO2 nanoparticles showed a fluorescence spectrum at an excitation wavelength of 250 nm and an emission wavelength of 314 nm. Therefore, in addition to bearing the magnetic properties of Fe3O4 nanoparticles, Fe3O4@TiO2 nanoparticles display fluorescence emission. This provides them with photodynamic therapy potential. Therefore multimodal treatment was performed with the combination of PDT and RT by using human prostate cancer cell line (PC3). The development of 89Zr-Df-Bz-NCS-Fe3O4@TiO2 nanoparticles as a new multifunctional PET/MRI agent with photodynamic therapy and hyperthermia therapeutic ability would be very useful. 相似文献
137.
Wei Zhang Lin Deng Guangchao Wang Xianrong Guo Qiujin Li Jianfei Zhang Niveen M. Khashab 《Particle & Particle Systems Characterization》2014,31(9):985-993
Multifunctional magnetic microcapsules (MMCs) for the combined cancer cells hyperthermia and chemotherapy in addition to MR imaging are successfully developed. A classical layer‐by‐layer technique of oppositely charged polyelectrolytes (poly(allylamine hydrochloride) (PAH) and poly(4‐styrene sulfonate sodium) (PSS)) is used as it affords great controllability over the preparation together with enhanced loading of the chemotherapeutic drug (doxorubicin, DOX) in the microcapsules. Superparamagnetic iron oxide (SPIOs) nanoparticles are layered in the system to afford MMC1 (one SPIOs layer) and MMC2 (two SPIOs layers). Most interestingly, MMC1 and MMC2 show efficient hyperthermia cell death and controlled DOX release although their magnetic saturation value falls below 2.5 emu g?1, which is lower than the 7–22 emu g?1 reported to be the minimum value needed for biomedical applications. Moreover, MMCs are pH responsive where a pH 5.5 (often reported for cancer cells) combined with hyperthermia increases DOX release predictably. Both systems prove viable when used as T2 contrast agents for MR imaging in HeLa cells with high biocompatibility. Thus, MMCs hold a great promise to be used commercially as a theranostic platform as they are controllably prepared, reproducibly enhanced, and serve as drug delivery, hyperthermia, and MRI contrast agents at the same time. 相似文献
138.
Dr. Aron J. Huckaba Dr. Aswani Yella Dr. Louis E. McNamara April E. Steen J. Scott Murphy Casey A. Carpenter George D. Puneky Prof. Nathan I. Hammer Prof. Mohammad Khaja Nazeeruddin Prof. Michael Grätzel Prof. Jared H. Delcamp 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15536-15542
Desirable components for dye‐sensitzed solar cell (DSC) sensitizers and fluorescent imaging dyes include strong donating building blocks coupled with well‐balanced acceptor functionalities for absorption beyond the visible range. We have evaluated the effects of increasing acceptor strengths and incorporation of dye morphology controlling groups on molar absorptivity and absorption breadth with indolizine donor‐based dyes. Indolizine‐based D –A and D –π–A sensitizers incorporating bis‐rhodanine, tricyanofuran (TCF), and cyanoacrylic acid functionalities were analyzed for performance in DSC devices. The TCF derivatives were also evaluated as near‐infrared (NIR)‐emissive materials with the AH25 emissions extending past 1000 nm. 相似文献
139.
Surya Prakash Singh CH Pavan Kumar G. D. Sharma J. A. Mikroyannidis Manjeet Singh Rajnish Kurchania 《Journal of Polymer Science.Polymer Physics》2012,50(23):1612-1618
Power conversion efficiency (PCE) of phenylenevinylene‐based copolymer with BF2 azopyrrole complex (PB)/modified PC70BM, that is, CN‐PC70BM bulk heterojunction solar cells improves from 2.16 to 4.90% using a processing additive and drying condition. The results demonstrate that a processing additive and drying condition provides an effective means to control both the surface roughness and finer interpenetrating networks to enhance the exciton dissociation into free charge carriers, charge transportation, and collection. Taking into the account of simple device fabrication process without thermal annealing, the PCE of the polymer solar cell can further improved by chloronapthalene (CN) additive under the fast drying condition. The average carrier lifetimes extracted from the impedance spectra and found to correlate with measured PCEs. At short circuit conditions and illumination, the average charge carrier lifetime was found vary from 16.8 to 32 μs with power conversion efficiencies ranging from 3.0 to 4.9%. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献