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991.
Parveen Saini Sachin Kaushik Rahul Sharma Disha Chakravarty Rishi Raj Jyotirmay Sharma 《The European Physical Journal B - Condensed Matter and Complex Systems》2016,89(6):137
Graphitic oxide (GO) was synthesized by oxidation of graphite powder using Hummer’s method and the formed GO is solution processed into paper-like macroscopic form. Subsequently, chemically reduced graphitic oxide paper (CRGOP) is prepared by hydrazine vapours induced reduction of formed GO precursor based paper. The formation of GO and its successful reduction to RGO phase is confirmed by FTIR, Raman Spectroscopy and X-ray diffraction. It has been observed that due to high electrical conductivity ~200 micron thick CRGOP display excellent EMI shielding performance at very high frequency of 101 GHz frequency with total shielding effectiveness (SE) value of ?35.49 dB (i.e. >99.97% blocking of incident EM radiation) which is much higher compared to pristine GO paper (?1.55 dB) or comparable to expanded graphite (EG) sheet (?35.61 dB). Due to their lightweight nature, these freestanding CRGOPs display average specific SE value of ?221.8 dB cm3/g. Besides, their excellent flexibility and makes them potential candidate for lightweight EMI gasketing material compared to other forms of flexible carbons like EG. 相似文献
992.
Five new ruthenium(III) complexes of the general formulas [RuCl(H2O)L2] (1–4) and [RuCl3(H2O)(HL)2] (5), where L = benzohydroximato (1), salicylhydroximato (2), acetohydroximato (3), hydroxyureato (4), LH = N-hydroxy-N-phenylbenzamide (5), were synthesized by reaction of RuCl3 · 3H2O with the corresponding hydroxamic acids at a molar ratio of 1: 2 molar. The complexes were characterized by elemental analyses and FT-IR, UV-Vis, 1H and 13C NMR, and mass spectra. The complexes showed higher antibacterial activity against ten pathogenic bacterial strains than the corresponding ligands. The anticancer activity of the complexes against IMR-32 (neuroblastoma) cancer and CHO (Chinese hamster ovary) normal cell lines was evaluated using MTT assay with respect to camptothecin as control. Complex 5 was found to exhibit an appreciable cytotoxicity against IMR-32 cell line with an IC50 value of 102.27 μM. 相似文献
993.
Enhanced Photocatalytic Degradation of 17α‐Ethinylestradiol Exhibited by Multifunctional ZnFe2O4–Ag/rGO Nanocomposite Under Visible Light
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Nirina Khadgi Yi Li Akhanda Raj Upreti Chi Zhang Wenlong Zhang Yuming Wang Dawei Wang 《Photochemistry and photobiology》2016,92(2):238-246
In this paper, ZnFe2O4, a visible light active photocatalyst, was comodified by graphene oxide (GO) and Ag nanoparticles (NPs) to form ZnFe2O4–Ag/rGO nanocomposite (NC) by facile one‐pot hydrothermal method. Reduction of GO and formation of ZnFe2O4 and Ag nanoparticles occurred simultaneously during hydrothermal reaction. The photocatalytic activity of the NC was investigated under visible light, for the degradation of 17α‐ethinylestradiol (EE2), a nondye compound, which also is an emerging pollutant with endocrine‐disrupting activity. The pseudo rate constant (k′) of as‐synthesized ZnFe2O4–Ag/rGO NC was higher by the factor of 14.6 and 5.6 times than the corresponding ZnFe2O4 and ZnFe2O4/rGO respectively. The synergistic interactions between ZnFe2O4, Ag and rGO leading to decreased aggregation of the NPs, increased surface area, better absorption in visible region, effective electron–hole generation transfer. However, in the presence of humic acid (HA), the photosensitization effect was predominated by competitive interaction resulting in only 80% removal of EE2 within the same time. Moreover, the composite can easily be magnetically separated for reuse. 相似文献
994.
A. S. Bhattacharyya S. K. Raj Parameshwar Kommu P. Prabhakar R. Praveen Kumar Neha Kumari Kumar Gaurav 《Surface and interface analysis : SIA》2016,48(12):1294-1298
Cu thin films were deposited on Si(111), glass, and quartz substrates by magnetron sputtering. X‐ray diffraction, SEM, and photoemission electron microscope studies were carried out to characterize the films. An influence of the nature of substrate on the Cu2O and CuO phases formed was observed. Copper silicide formation in case of silicon substrates aided in formation of Cu2O rather than CuO unlike glass and quartz substrates. Formation of nanocrystallites was observed by SEM and X‐ray diffraction. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
995.
996.
Jeyaraj Pandiyan Dhanalakshmi Mahendran Arunjunai Raj Chinnaswamy Thangavel Vijayakumar 《高分子科学》2016,34(3):253-267
Structurally diverse bispropargyl ethers using resorcinol,quinol,4,4¢-dihydroxy biphenyl,bisphenol-A,4,4¢-dihydroxy diphenyl ketone,4,4¢-dihydroxy diphenylsulphone,trimethyl indane bisphenol and tetramethyl spirobiindane bisphenol were prepared by using phase transfer catalyst.Synthesized materials were separately blended with 4,4¢-bismaleimido diphenyl methane(BMIM)in mole ratios(0.5:0.5).The materials were thermally cured and the structural characterisation and the thermal properties of these cross-linked materials are investigated using Fourier-transform infrared(FTIR)spectrophotometer and thermogravimetric analyzer(TGA).Among the different materials investigated poly MRPE,poly MBPEBPA and poly MSPE show higher onset degradation temperature of 300°C indicating higher thermal stability.The degradation kinetics is investigated using Flynn-Wall-Ozawa(FWO),Vyazovkin(VYZ)and Friedman(FRD)methods.Amongst the various cured materials investigated,the activation energy(Ea-D)values obtained for poly MRPE and poly MKPE were observed to increase continuously froma=0.2 to 0.8 and the values range from 199 kJ/mol to 245 k J/mol and 153 k J/mol to 295 k J/mol respectively.The crosslinked materials resulting from these bispropargyl monomers definitely need more energy for bond cleavage due to the presence of more aromatic units.The volatile products obtained during the thermal degradation of the polymers were analyzed using thermogravimetric-Fourier transform infrared analyses(TG-FTIR).The phenols,substituted phenols,carbon monoxide,carbon dioxide and small amount of aniline were found to be the major products during thermal degradation of these cured blends. 相似文献
997.
Synthesis of 10 nm β‐NaYF4:Yb,Er/NaYF4 Core/Shell Upconversion Nanocrystals with 5 nm Particle Cores
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Thorben Rinkel Athira Naduviledathu Raj Simon Dühnen Prof. Dr. Markus Haase 《Angewandte Chemie (International ed. in English)》2016,55(3):1164-1167
A new method is presented for preparing gram amounts of very small core/shell upconversion nanocrystals without additional codoping of the particles. First, ca. 5 nm β‐NaYF4:Yb,Er core particles are formed by the reaction of sodium oleate, rare‐earth oleate, and ammonium fluoride, thereby making use of the fact that a high ratio of sodium to rare‐earth ions promotes the nucleation of a large number of β‐phase seeds. Thereafter, a 2 nm thick NaYF4 shell is formed by using 3–4 nm particles of α‐NaYF4 as a single‐source precursor for the β‐phase shell material. In contrast to the core particles, however, these α‐phase particles are prepared with a low ratio of sodium to rare‐earth ions, which efficiently suppresses an undesired nucleation of β‐NaYF4 particles during shell growth. 相似文献
998.
999.
Engineered Upconversion Nanoparticles for Resolving Protein Interactions inside Living Cells
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Christoph Drees Athira Naduviledathu Raj Dr. Rainer Kurre Prof. Dr. Karin B. Busch Prof. Dr. Markus Haase Prof. Dr. Jacob Piehler 《Angewandte Chemie (International ed. in English)》2016,55(38):11668-11672
Upconversion nanoparticles (UCNPs) convert near‐infrared into visible light at much lower excitation densities than those used in classic two‐photon absorption microscopy. Here, we engineered <50 nm UCNPs for application as efficient lanthanide resonance energy transfer (LRET) donors inside living cells. By optimizing the dopant concentrations and the core–shell structure for higher excitation densities, we observed enhanced UCNP emission as well as strongly increased sensitized acceptor fluorescence. For the application of these UCNPs in complex biological environments, we developed a biocompatible surface coating functionalized with a nanobody recognizing green fluorescent protein (GFP). Thus, rapid and specific targeting to GFP‐tagged fusion proteins in the mitochondrial outer membrane and detection of protein interactions by LRET in living cells was achieved. 相似文献
1000.
A novel homologous series RO-C6H4-COO-C6H3-(NO2)-CO-CH?CH-C6H4OC18H37(n) para of chalconyl ester derivatives have been synthesized and studied with view to understanding the effect of an ortho substituted nitro group on thermotropic liquid crystal (LC) behavior. The novel homologous series consists of thirteen homologues (C1 to C18). The C1 to C4 homologues are nonliquid crystal (NLC) and the rest of the homologues (C5 to C18) homologues are enantiotropically nematogenic without exhibition of a smectic phase even in the monotropic condition. Transition temperatures were determined by an optical polarizing microscope (POM) equipped with a heating stage. Texture of nematic phase are threaded or Schlieren. Analytical, thermal and spectral data supported molecular structure of homologues. Thermal stability for nematic is 147.1°C whose mesophase lengths vary between 16.0 and 32.0°C the C7 and C18 homologues, respectively, and their mesogenic exhibition range between 96.0 and 166.0°C. Thus, the present novel series is middle ordered melting type, Group efficiency order is derived from comparative study of structurally similar series. The transition curves of a phase diagram behaved in normal manner except C10 and C16 homologues. Odd-even effect is observed for N-I transition curve. Group efficiency order derived is: -OC12H25 (n) > -OC18H37 (n) > -OC18H37 (n). 相似文献