@article { ISI:000258442800007, title = {Nanoreactors for nanostructured materials}, journal = {International Journal of Chemical Reactor Engineering}, volume = {6}, year = {2008}, month = {JAN}, pages = {A62}, publisher = {BERKELEY ELECTRONIC PRESS}, address = {2809 TELEGRAPH AVENUE, STE 202, BERKELEY, CA 94705 USA}, abstract = {

Organized systems such as micelles, reverse micelles, vesicles, polyelectrolyte capsules, liquid crystals, etc., formed through a self-assembling process represent nanoreactors that can be used for preparing nanostructured materials. Besides a fascinating academic subject, these nanoreactors provide a unique way to develop a special type of advanced material for a wide variety of applications in electronics, photonics, biomedical and other areas. The article examines the formation, functioning, properties and special attributes of these nanoreactors with a view towards their engineering analysis, design and possible integration in manufacturing technology.

}, keywords = {nanoreactors, Nanostructured materials, organized self-assemblies}, issn = {1542-6580}, author = {Khomane, Ramdas B. and Kulkarni, Bhaskar D.} } @article { ISI:000269638800052, title = {Magnetic characteristics of nanocrystalline multiferroic BiFeO3 at low temperatures}, journal = {Physical Review B}, volume = {80}, number = {6}, year = {2009}, month = {AUG}, pages = {064423}, publisher = {AMER PHYSICAL SOC}, address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}, abstract = {

The magnetic characteristics of nanocrystalline BiFeO3 with average crystallite sizes of similar to 50 and similar to 100 nm are evaluated by studying the temperature and field dependence of magnetization at low temperatures. Different properties such as magnetization, coercivity, and remanence show evidence for changes in the magnetic properties associated with the phase transitions at low temperatures, reported from Raman studies. Detailed field-cooled and zero-field-cooled magnetization measurements show that the likely origin of the changes in the magnetic characteristics is from the changes in the domain structure.

}, keywords = {bismuth compounds, coercive force, crystallites, magnetic domains, magnetic transitions, Multiferroics, Nanostructured materials, Raman spectra, remanence}, issn = {1098-0121}, doi = {10.1103/PhysRevB.80.064423}, author = {Vijayanand, S. and Mahajan, Mangesh B. and Potdar, H. S. and Joy, Pattayil Alias} } @article { ISI:000265933700042, title = {Origin of high room temperature ferromagnetic moment of nanocrystalline multiferroic BiFeO3}, journal = {Applied Physics Letters}, volume = {94}, number = {18}, year = {2009}, month = {MAY}, pages = {182507}, publisher = {AMER INST PHYSICS}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

Single phase nanocrystalline BiFeO3 of average crystallite size similar to 25 nm with very high magnetization at room temperature is synthesized by an autocombustion method. Magnetic measurements above room temperature show deviation between field cooled and zero field cooled magnetization below 645 K, the Neel temperature (T-N) of the bulk material, indicating intrinsic nature of ferromagnetism. However, observation of a broad magnetic transition above T-N of BiFeO3 and extended up to 800 K suggests the presence of Fe3O4 as a possible magnetic impurity phase. Evidence for the presence of Fe3O4 is obtained from detailed analysis of the powder x-ray diffraction pattern.

}, keywords = {bismuth compounds, Combustion synthesis, crystallites, ferromagnetic materials, high-temperature effects, magnetic impurities, Magnetic moments, Magnetisation, Multiferroics, Nanostructured materials, Neel temperature, X-ray diffraction}, issn = {0003-6951}, doi = {10.1063/1.3132586}, author = {Vijayanand, S. and Potdar, H. S. and Joy, Pattayil Alias} } @article { ISI:000279514400059, title = {Nanoscale modulation of electronic states across unit cell steps on the surface of an epitaxial colossal magnetoresistance manganite film}, journal = {Applied Physics Letters}, volume = {96}, number = {26}, year = {2010}, month = {JUN}, pages = {Article No. 263108}, publisher = {AMER INST PHYSICS}, type = {Article}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

The nature of electronic states near the edge of unit cell steps on the surface of epitaxial La(0.7)Sr(0.3)MnO(3) (LSMO) thin films grown by real-time reflection high energy electron diffraction monitored pulsed laser deposition is examined by scanning tunneling microscopy and scanning tunneling spectroscopy techniques. It is observed that the electronic states are strongly modulated near the step edge with considerably high gap at the edge and low gap on the terrace. This modulation weakens at low temperature. The temperature evolution of the density of states and the nature of gap in deep metallic state of LSMO are also discussed. (C) 2010 American Institute of Physics. [doi:10.1063/1.3455886]

}, keywords = {colossal magnetoresistance, electronic density of states, lanthanum compounds, magnetic epitaxial layers, Nanostructured materials, pulsed laser deposition, reflection high energy electron diffraction, scanning tunnelling microscopy, scanning tunnelling spectroscopy, strontium compounds}, issn = {0003-6951}, doi = {10.1063/1.3455886}, author = {Rana, Abhimanyu and Bogle, Kashinath A. and Game, Onkar S. and Patil, Shankar and Valanoor, Nagarajan and Ogale, Satishchandra B.} } @article { ISI:000288772300011, title = {Magnetic properties of thermal plasma synthesized nanocrystalline nickel ferrite (NiFe2O4)}, journal = {Journal of Alloys and Compounds}, volume = {509}, number = {12}, year = {2011}, month = {MAR}, pages = {4404-4413}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

A rapid synthesis method is reported for magnetic nanoparticles of nickel ferrite involving thermal plasma assisted vapor phase condensation process. The as-synthesized samples were characterized by X-ray Diffraction, Transmission Electron Microscopy, Vibrating Sample Magnetometer and X-ray Photoelectron Spectroscopy techniques. The average particle size was determined from the TEM micrographs and found to be around 30 nm. The effects of reactor parameters on the magnetic and structural properties have been evaluated, to find the optimized parameters so as to achieve the highest values of saturation magnetization and coercivity. Reasonably high saturation magnetization (48 emu/g) has been assigned to the high degree of crystallinity, achieved on account of high temperature during the growth, and the cation redistribution. The high value of coercivity (1150e) is explained on the basis of possible lattice defects arising from the cation redistribution. Detailed analysis of cation distribution using the XRD line intensity data leads to the conclusion that these samples are iron deficit and nickel rich. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {crystal structure, Magnetic measurements, Magnetization, Nanostructured materials, TEM}, issn = {0925-8388}, doi = {10.1016/j.jallcom.2011.01.057}, author = {Nawale, Ashok B. and Kanhe, Nilesh S. and Patil, K. R. and Bhoraskar, S. V. and Mathe, Vikas L. and Das, A. K.} } @article { ISI:000293826800006, title = {Structural, magnetic and mossbauer spectral studies of nanocrystalline Ni0.5Zn0.5Fe2O4 ferrite powders}, journal = {Journal of Alloys and Compounds}, volume = {509}, number = {37}, year = {2011}, month = {SEP}, pages = {8999-9004}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Nanocrystalline Ni0.5Zn0.5Fe2O4 powders, synthesized by a combustion method are investigated by X-ray diffraction, vibrating sample magnetometry and Mossbauer spectroscopic techniques. We adopt a strategy to systematically control the particle sizes between 4 and 45 nm simply by changing the elemental stoichiometric coefficient, Phi(e), of the combustion mixture. Curie temperature of the superparamagnetic particles of size 4 nm is higher than that of the bulk particles. Interestingly, bigger particles (45 nm) show a comparable room temperature saturation magnetization and exceptionally very high Curie temperature of 833 K, when compared to that of the bulk Ni0.5Zn0.5Fe2O4 material (563 K). (C) 2011 Elsevier B. V. All rights reserved.

}, keywords = {Chemical synthesis, Magnetisation, Mossbauer spectroscopy, Nanostructured materials}, issn = {0925-8388}, doi = {10.1016/j.jallcom.2011.06.047}, author = {Verma, Seema and Joy, Pattayil Alias and Kurian, Sajith} } @article { ISI:000291293600027, title = {Synthesis of cube-shaped gold nanostructures by electron irradiation}, journal = {Materials Letters}, volume = {65}, number = {11}, year = {2011}, month = {JUN}, pages = {1605-1607}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The needle-like gold nanostructures were synthesized by using chloroauric acid (HAuCl(4)) as a metal precursor and sodium borohydride (NaBH(4)) as the reducing agent. These needle-like nanostructures of gold were irradiated with high energy electrons (E-6 MeV, phi similar to 10(12) e cm(-2) s(-1)). The pre- and post-irradiated gold nanostructures were characterized by Scanning Electron Microscopy (SEM), UV-vis spectroscopy, X-ray Diffraction (XRD) and contact angle measurement (GBX-Model Digidrop) techniques. The results of the SEM revealed that after electron irradiation, the needle-like gold structures got fragmented into identical cube-shaped gold nanostructures, though of different sizes. The XRD analysis indicated that the average crystallite size of the gold nanostructures remained unchanged even after irradiation with high energy electrons. A glass surface showed hydrophilic behavior when coated with needle-like nanostructures and became ultra hydrophilic when coated with cube-shaped gold nanostructures. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {Gold nanostructures, High energy electron irradiation, Nanostructured materials, Radiation damage, Surfaces, Ultra hydrophilic surfaces}, issn = {0167-577X}, doi = {10.1016/j.matlet.2011.02.053}, author = {Dhumale, Vinayak A. and Gangwar, Rajesh K. and Shah, Preeti V. and Bhoraskar, Vasant N. and Mulla, Imtiaz S. and Sharma, Rishi B.} } @article { ISI:000369681000007, title = {Multifunctional nanocatalysts for tandem reactions: a leap toward sustainability}, journal = {Applied Catalysis A-General}, volume = {511}, year = {2016}, month = {FEB}, pages = {59-77}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Design of new multifunctional nanocatalysts is a hot area of research that aims to introduce multiple types of active sites on a single nanocatalyst. Multifunctional nanocatalysts are useful to carry out a multi-step reaction requiring same or different active sites in a single pot. Such catalysts must possess the active sites at spatially distinct locations to avoid neutralization but yet remain active independently or through cooperative actions. The necessity of nanostructuring the active sites have emerged as the key point in a successful design of the catalysts. The review covers the progress in this area of research done in the last five years. It includes the classification of catalysts based on active sites and structure of active sites at the nanoscale. The review covers exhaustively with 250+ references and ample examples to present the concept succinctly. The review covers the evolution of multifunctional catalysts from the perspective of materials chemistry. (C) 2015 Elsevier B.V. All rights reserved.

}, keywords = {Heterogeneous catalysts, Multifunctional nanocatalysts, Nanostructured materials, Tandem reactions}, issn = {0926-860X}, doi = {10.1016/j.apcata.2015.11.033}, author = {Jagadeesan, Dinesh} } @article {49073, title = {Investigation of structural and morphological insights of nanostructured layered double hydroxides: catalytic activity in aldol condensation}, journal = {Journal of Porous Materials }, volume = {31}, year = {2024}, month = {APR}, pages = {759-778}, type = {Article}, abstract = {

Layered double hydroxides (LDHs) materials finds extensive applications in numerous fields such as medical science, industrial sector, agriculture and food, catalysis, polymers, nanotechnology, etc. The LDHs properties (structural, textural, morphological, spectroscopic and theoretical insights) can be design for achieving required materials for particular application in scientific areas. In the current investigation, we have synthesized mesoporous nanostructured LDHs materials via microwave, sonication and stirring method. The nanostructured LDHs was scientifically characterized by various physico-chemical techniques like XRD, N2 sorption, TGA, solid state one-dimensional 27Al magic angle spinning NMR spectroscopy, XPS, Raman Spectroscopy, FT-IR, ICP-OES, Electron Microscopy (SEM, FE-SEM, TEM and HR-TEM), EDX, elemental analysis, etc. On the basis of experimental study, it can be evidently witnessed that nanostructured LDHs materials was formed with good crystalline mesoporous nature. Solid state 27Al NMR showed single and sharp 27Al NMR signal at chemical shift value of + 1.4 ppm, strongly suggesting the presence of octahedral (Oh) AlO6 coordination site in all as-synthesized LDHs. Microwave and sonication techniques furnishes regularly dispersed well-developed flower-shaped nanocrystals however, stirring method gives mostly agglomerated nano-sized platelets. The mechanistic insights for the fabrication of nanostructures LDHs via microwave, sonication and stirring process were also highlighted. The different LDHs materials were utilized in the aldol condensation reaction of furfural with acetone for understanding structure-activity correlation. Microwave and sonication methodologies can be further exploited for the synthesis of many other inorganic-organic nanocomposites materials with stable and good dispersion of nanocrystals in addition to desired morphology and catalytic activity.

}, keywords = {Aldol condensation, catalysis, Flower-shaped nanocrystals, layered double hydroxides, Microwave and sonication techniques, Nanostructured materials}, issn = {1380-2224}, doi = {10.1007/s10934-023-01545-w}, author = {Bhagat, Shailesh K. and Nagpure, Atul S. and Lanjewar, Mamata R. and Gode, Nilesh G. and Thakare, Sanjay R.} }