@article { ISI:000230436500003, title = {Photoluminescent core-shell particles of organic dye in silica}, journal = {Journal of Luminescence}, volume = {114}, number = {1}, year = {2005}, month = {JUL}, pages = {15-23}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Using a single silica precursor, Rhodamine 6G organic dye molecules have been entrapped in silica particles resulting into core-shell particles of similar to 500 nm diameter. Energy dispersive X-ray analysis, X-ray photoelectron spectroscopy and transmission electron microscopy analysis reveals that dye molecules are trapped inside the silica particles. Photoluminescence investigations show that highly luminescent and photostable core-shell particles are formed. Such core-shell particles can be easily suspended in water and would be useful for a variety of applications. However, there is a blue shift in the photolumineseence wavelength in case of core-shell particles compared to bare dye powder sample. (c) 2004 Elsevier B.V. All rights reserved.

}, keywords = {core-shell, Luminescence, Nanoparticles, photoemission, RH06G dye, tetraethylorthosilicate (TEOS)}, issn = {0022-2313}, doi = {10.1016/j.jlumin.2004.11.005}, author = {Ethiraj, Anita S. and Hebalkar, Neha and Kharrazi, Sharmin and Urban, J. and Sainkar, S. R. and Kulkarni, S. K.} } @article { ISI:000249567000022, title = {Highly photostable dye entrapped core-shell particles}, journal = {Materials Letters}, volume = {61}, number = {25}, year = {2007}, month = {OCT}, pages = {4738-4742}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Organic dye namely Coumarin 7 has been entrapped in silica particles using a single silica precursor viz. tetraethylorthosilicate. Both bare Coumarin 7 dye and dye incorporated core-shell particles were studied. Investigations of these core-shell composites were carried out using different characterization techniques such as energy dispersive X-ray analysis, X-ray photoelectron spectroscopy and transmission electron microscopy. It has been shown that the photostability of dye molecules is improved along with an increase in photoluminescence. (c) 2007 Elsevier B.V. All rights reserved.

}, keywords = {core-shell, coumarin 7 dye, Luminescence, photostability, tetraethylorthosilicate}, issn = {0167-577X}, doi = {10.1016/j.matlet.2007.03.030}, author = {Ethiraj, Anita S. and Kharrazi, Sharmin and Hebalkar, Neha and Urban, J. and Sainkar, S. R. and Kulkarni, S. K.} } @article {2}, title = {Investigating organization of molecules that facilitates intermolecular acyl transfer in crystals: reactivity and x-ray structures of O-benzoyl-myo-inositol 1,3,5-orthoesters}, journal = {European Journal of Organic Chemsitry}, volume = {293}, number = {7}, year = {2007}, month = {FEB}, pages = {1153-1159}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

{Crystal structure analysis of racemic 2,6-di-O-benzoyl-myo-inositol 1,3,5-orthobenzoate reveals helical organization of the molecules, remarkably similar to that observed earlier in crystals of racemic 2,6-di-O-benzoyl-myo-inositol 1,3,5-orthoformate. Both these dibenzoates are isostructural despite the bulkier phenyl substituent in place of hydrogen. The latter compound shows highly facile intermolecular benzoyl transfer reactivity in its crystals and as anticipated from the crystal structure, the orthobenzoate indeed exhibits facile benzoyl transfer reactivity in its crystals. 2-O-Benzoyl-myo-inositol 1,3,5-orthoformate and the corresponding orthobenzoate also undergo transesterification in their crystals, but the specificity of acyl transfer is very low, and the reaction yields a mixture of products. The parameters of helical molecular assembly that facilitates acyl transfer in crystals have been investigated. A comparison of the molecular assemblies and lattice interactions in crystals of all the four compounds with the observed reactivity patterns show that facile acyl transfer reaction is brought about by a modular {\textquoteleft}{\textquoteleft}reaction tunnel{\textquoteright}{\textquoteright}

}, keywords = {AOT, CdS-Ag2S, core-shell, Nanoparticles, w/o microemulsion, XPS}, issn = {0927-7757}, author = {Murali, Chebrolu and Shashidhar, Mysore S. and Gonnade, Rajesh G. and Bhadbhade, Mohan M.} } @article { ISI:000266390000011, title = {Silver fused conducting fiber formation of Au-Ag core-shell nanoparticles mediated by ascorbic acid}, journal = {Plasmonics}, volume = {4}, number = {2}, year = {2009}, month = {JUN}, pages = {161-170}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

In this paper, we report the spontaneous formation of fibrous structures consisting of assemblies of Au-Ag core-shell nanoparticles (NPs) from a solution consisting of Au-Ag core-shell NPs and l-ascorbic acid (AA). AA acted both as the reducing agent for the generation of NPs and also as the mediator for the formation of fibers. The process of fiber formation involved three steps-reduction of HAuCl(4) to Au NPs by AA, subsequent formation of Au-Ag core-shell NPs after addition of AgNO(3), and spontaneous formation of fibers from the mixtures in water. It took typically about 30 days to form complete fibers that are of lengths of several hundred micrometers to millimeters, although nanofibers started forming from the first day of solution preparation. The width of each of these fibers was typically about 1-4 A mu m with length of each segment of fiber bundle, on the order of 40 A mu m. Formation of fibers was also observed in absence of AgNO(3). These fibers consisted of Au NPs and polymer of AA degradation products and were not electrically conducting. Also, low concentrations of AgNO(3) produced fibers with low electrical conductivity. However, it was observed that increase in the amount of AgNO(3) leads to the formation of fibers that were electrically conducting with conductivity values in the range of metallic conductivity. Spectroscopic and electron microscopic investigations were carried out to establish the formation of fibers. The details of fiber formation mechanism under different conditions and electrical conductivities of the fibers are discussed in the article.

}, keywords = {Ascorbic acid, core-shell, Fiber, Gold, Nanoparticles, Silver}, issn = {1557-1955}, doi = {10.1007/s11468-009-9091-5}, author = {Murugadoss, A. and Kar, Manoranjan and Pasricha, Renu and Chattopadhyay, Arun} } @article { ISI:000337521700013, title = {Large magnetocaloric effect, moment, and coercivity enhancement after coating Ni nanoparticles with Ag}, journal = {ChemPhysChem}, volume = {15}, number = {8}, year = {2014}, month = {JUN}, pages = {1619-1623}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

We observe a large magnetocaloric effect in monodisperse Ni and NicoreAgshell nanoparticles in the superparamagnetic region. The organically passivated Ni nanospheres show a large magnetic entropy change of 0.9 J kg(-1)K for a 3 T magnetic field change. In comparison to the surfactant-coated Ni nanoparticles, the NicoreAgshell nanoparticles show an enhanced coercivity, magnetization, and magnetocaloric effect (1.3 kgK for a 3 T magnetic field change). The coercivity at 10 K increases from 360 Oe for Ni nanoparticles to nearly 610 Oe for NicoreAgshell particles. This large enhancement is attributed to the enhanced inter-particle interaction, which is mediated by the metallic shell, over the relatively weaker dipolar interaction in the surfactant-coated Ni nanoparticles, and to modification of the surface spin structure.

}, keywords = {anisotropy, core-shell, magnetic properties, Nanoparticles, superparamagnetic}, issn = {1439-4235}, doi = {10.1002/cphc.201300886}, author = {Srinath, Sanyadanam and Poddar, Pankaj and Das, Raja and Sidhaye, Deepti and Bhagavatula L. V. Prasad and Gass, James and Srikanth, Hariharan} } @article {46143, title = {Surfactant free synthesis of Au@Ni core-shell nanochains in aqueous medium as efficient transfer hydrogenation catalyst}, journal = {Applied Catalysis A-General}, volume = {575}, year = {2019}, month = {APR }, pages = {93-100}, type = {Article}, abstract = {

A surfactant free aqueous phase synthesis method is reported for the generation of highly lattice mismatched Au@Ni core-shell nanochains without using any expensive and hazardous organic ligands. As synthesised Au@Ni nanochain structures showed high thermal stability and bulk oxidation resistance up to 300 degrees C. In situ near ambient pressure XPS (NAPXPS) analysis has been done for the bare Au@Ni nanochain surfaces under oxygen atmosphere and at different temperatures which showed evidence for the surface oxidation resistance of naked Au@Ni nanochains up to 200 degrees C. Ligand or capping agent free Au@Ni nanochain surfaces are found to be highly active for transfer hydrogenation of acetophenone to 1-phenyl ethanol an important commodity in perfumery industry.

}, keywords = {Au@Ni nanochains, core-shell, NAPXPS, Surfactant free, synergistic effects, transfer hydrogenation}, issn = {0926-860X}, doi = {10.1016/j.apcata.2019.01.017}, author = {Vysakh, A. B. and Shebin, K. J. and Jain, Ruchi and Sumanta, P. and Gopinath, Chinnakonda S. and Vinod, C. P.} } @article {48198, title = {High-alkaline water-splitting activity of mesoporous 3D heterostructures: an amorphous-shell@crystalline-core nano-assembly of Co-Ni-phosphate ultrathin-nanosheets and V- doped cobalt-nitride nanowires}, journal = {Advanced Science}, volume = {9}, year = {2022}, month = {AUG}, pages = {2201311}, type = {Article}, abstract = {

Introducing amorphous and ultrathin nanosheets of transition bimetal phosphate arrays that are highly active in the oxygen evolution reaction (OER) as shells over an electronically modulated crystalline core with low hydrogen absorption energy for an excellent hydrogen evolution reaction (HER) can boost the sluggish kinetics of the OER and HER in alkaline electrolytes. Therefore, in this study, ultrathin and amorphous cobalt-nickel-phosphate (CoNiPOx) nanosheet arrays are deposited over vanadium (V)-doped cobalt-nitride (V-3\%-Co4N) crystalline core nanowires to obtain amorphous-shell@crystalline-core mesoporous 3D-heterostructures (CoNiPOx@V-Co4N/NF) as bifunctional electrocatalysts. The optimized electrocatalyst shows extremely low HER and OER overpotentials of 53 and 270 mV at 10 mA cm(-2), respectively. The CoNiPOx@V-3\%-Co4N/NF (+/-) electrolyzer utilizing the electrocatalyst as both anode and cathode demonstrates remarkable overall water-splitting activity, requiring a cell potential of only 1.52 V at 10 mA cm(-2), 30 mV lower than that of the RuO2/NF (+)/20\%-Pt/C/NF (-) electrolyzer. Such impressive bifunctional activities can be attributed to abundant active sites, adjusted electronic structure, lower charge-transfer resistance, enhanced electrochemically active surface area (ECSA), and surface- and volume-confined electrocatalysis resulting from the synergistic effects of the crystalline V-3\%-Co4N core and amorphous CoNiPOx shells boosting water splitting in alkaline media.

}, keywords = {core-shell, hydrogen productions, metal nitrides, metal phosphates, synergistic effect, water-splitting}, doi = {10.1002/advs.202201311}, author = {Singh, Thangjam Ibomcha and Maibam, Ashakiran and Cha, Dun Chan and Yoo, Sunghoon and BabaRao, Ravichandar and Lee, Sang Uck and Lee, Seunghyun} } @article {47750, title = {Progress and potential of electrospinning-derived substrate-free and binder-free lithium-ion battery electrodes}, journal = {Chemical Engineering Journal}, volume = {430}, year = {2022}, month = {FEB }, pages = {132876}, type = {Review}, abstract = {Carbon nanofibers derived from electrospun precursors show great promise for electronic applications owing to their flexibility, conductivity, high surface area, and open structure. The integration of metal oxides and sulfides in carbon nanofibers, rather than using them with other binders, eliminates many problems caused by poor adhesion, nanomaterial agglomeration, excess mass contributed by inactive binders, and low conductivity of embedded active materials. The engineering of electrospun fibers with novel morphologies, such as core-shell, hollow, or porous structures, and the use of decorated carbon nanofibers (e.g., by electrodeposition or co precipitation) are discussed in this review. Representative schematic illustrations of the lithium-storage mechanism for these binder-free electrodes are presented. We describe how the electrospinning technique can offer a cost-effective strategy for fabrication of lightweight lithium-ion batteries with high capacity and excellent bendability. This review presents the fascinating morphologies of these specially designed carbon nanofiber electrodes, which enhance the electrochemical performance of metal oxides and sulfides, illustrating their enormous potential for use in wearable electronic devices and hybrid electric vehicles.}, keywords = {Carbon nanofibers, Co-axial, composites, core-shell, electrospinning, Flexible}, issn = {1385-8947}, doi = {10.1016/j.cej.2021.132876}, author = {Joshi, Bhavana and Samuel, Edmund and Kim, Yong-il and Yarin, Alexander L. and Swihart, Mark T. and Yoon, Sam S.} } @article {48226, title = {Review of recent progress in electrospinning-derived freestanding and binder-free electrodes for supercapacitors}, journal = {Coordination Chemistry Reviews}, volume = {460}, year = {2022}, month = {JUN }, pages = {214466}, type = {Review}, abstract = {

The versatile electrospinning technique is scalable and suitable to fabricate highly conducting freestanding carbon nanofiber composite electrodes for energy storage devices. Freestanding/flexible electrodes hold enormous potential for use in wearable electronic devices. Carbon-yielding polymers and the optimal use of sacrificial polymers, metal oxides, and sulfides retain the flexibility and enhance the surface area and pseudocapacitance of electrodes. Both as-prepared electrospun fibers and carbonized nanofibers are compatible with surface decoration via various chemical and electrochemical routes. Metal oxides/sulfides with various morphologies, such as nanocones and nanosheets, can be grown on the carbon nanofibers or on the as-prepared electrospun fibers using chemical synthesis methods such as electro-deposition, hydrothermal processes, and chemical impregnation to enhance the pseudocapacitance of the electrodes. Similarly, the deposition of metal organic frameworks on as-prepared electrospun fibers embellishes these fibers with nanostructures of specific morphologies such as dodecahedral and spindle-shaped structures. Under optimal conditions, these morphologies do not hamper the flexibility of the fibers, and binders are not required to retain them or maintain the electrode integrity. The engineering of electrodes with various morphologies and process parameters is presented systematically. Electrospinning-derived electrodes that have demonstrated significant electrochemical performance are highlighted and critically analyzed, and the energy storage mechanisms of these supercapacitors are described in detail. (C) 2022 Elsevier B.V. All rights reserved.

}, keywords = {Carbon nanofibers, Co-axial, composites, core-shell, electrospinning, Flexible, Porous, supercapacitor}, issn = {0010-8545}, doi = {10.1016/j.ccr.2022.214466}, author = {Joshi, Bhavana and Samuel, Edmund and Kim, Yong-il and Yarin, Alexander L. and Swihart, Mark T. and Yoon, Sam S.} }