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Basudeb Karmakar - One of the best experts on this subject based on the ideXlab platform.
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effects of in situ generated coinage Nanometals on crystallization and microstructure of fluorophlogopite mica containing glass ceramics
Journal of Materials Science & Technology, 2015Co-Authors: Mrinmoy Garai, Nibedita Sasmal, Atiar Rahaman Molla, Anal Tarafder, Basudeb KarmakarAbstract:The effects of in-situ generated coinage Nanometals (Cu, Ag and Au) on crystallization behavior, microstructure, thermal and mechanical properties of SiO 2 –MgO–Al 2 O 3 –B 2 O 3 –K 2 O–MgF 2 (BMAPS) glass‒ceramics were systematically studied. On addition of coinage nanometal, the glass transition temperature ( T g ) is increased by 20–30 °C, crystallization temperature ( T c ) by 30–50 °C and dilatometric softening temperature ( T d ) by 10–25 °C. It was found that the density of Cu-containing glass was 2.59 g cm −3 and for other glasses it was in the range of 2.56–2.57 g cm −3 . From the non-isothermal differential scanning calorimetry study, the activation energy of crystallization for BMAPS base glass was calculated as 344 kJ/mol, and changed to 406, 334 and 274 kJ/mol on addition of Cu, Ag and Au-Nanometals, respectively. Crystals evolved in the opaque BMAPS glass‒ceramics derived by controlled heat treatment, were identified as fluorophlogopite mica (KMg 3 (AlSi 3 O 10 )F 2 ) by X-ray diffraction (XRD) technique and confirmed by Fourier transformed infrared spectroscopy. Presences of copper, silver and gold Nanometals were also identified by XRD technique. It is found from field emission scanning electron microscopy that the interlocked grain like microstructure developed in BMAPS glass‒ceramics (being heat-treated at 1050 °C for 4 h) changed to denser house-of-cards like microstructure (containing smaller sized mica crystals) on addition of coinage Nanometals. Density of BMAPS base glass‒ceramic was 2.60 g cm −3 and marginally changed to 2.61–2.62 g cm −3 on addition of Cu, Ag and Au-Nanometals. The change in microstructure resulted in the decrease of Vickers micro hardness value from 5.37 to 4.12, 4.20 and 4.58 GPa on addition of Cu, Ag and Au, respectively. Coinage nanometal doped mica glass‒ceramics containing interlocked microstructure with higher thermal expansion coefficient, hence, is suitable for high temperature sealing application (like solid oxide fuel cell).
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Effects of In-situ Generated Coinage Nanometals on Crystallization and Microstructure of Fluorophlogopite Mica Containing Glass?Ceramics
Journal of Materials Science & Technology, 2015Co-Authors: Mrinmoy Garai, Nibedita Sasmal, Atiar Rahaman Molla, Anal Tarafder, Basudeb KarmakarAbstract:The effects of in-situ generated coinage Nanometals (Cu, Ag and Au) on crystallization behavior, microstructure, thermal and mechanical properties of SiO 2 –MgO–Al 2 O 3 –B 2 O 3 –K 2 O–MgF 2 (BMAPS) glass‒ceramics were systematically studied. On addition of coinage nanometal, the glass transition temperature ( T g ) is increased by 20–30 °C, crystallization temperature ( T c ) by 30–50 °C and dilatometric softening temperature ( T d ) by 10–25 °C. It was found that the density of Cu-containing glass was 2.59 g cm −3 and for other glasses it was in the range of 2.56–2.57 g cm −3 . From the non-isothermal differential scanning calorimetry study, the activation energy of crystallization for BMAPS base glass was calculated as 344 kJ/mol, and changed to 406, 334 and 274 kJ/mol on addition of Cu, Ag and Au-Nanometals, respectively. Crystals evolved in the opaque BMAPS glass‒ceramics derived by controlled heat treatment, were identified as fluorophlogopite mica (KMg 3 (AlSi 3 O 10 )F 2 ) by X-ray diffraction (XRD) technique and confirmed by Fourier transformed infrared spectroscopy. Presences of copper, silver and gold Nanometals were also identified by XRD technique. It is found from field emission scanning electron microscopy that the interlocked grain like microstructure developed in BMAPS glass‒ceramics (being heat-treated at 1050 °C for 4 h) changed to denser house-of-cards like microstructure (containing smaller sized mica crystals) on addition of coinage Nanometals. Density of BMAPS base glass‒ceramic was 2.60 g cm −3 and marginally changed to 2.61–2.62 g cm −3 on addition of Cu, Ag and Au-Nanometals. The change in microstructure resulted in the decrease of Vickers micro hardness value from 5.37 to 4.12, 4.20 and 4.58 GPa on addition of Cu, Ag and Au, respectively. Coinage nanometal doped mica glass‒ceramics containing interlocked microstructure with higher thermal expansion coefficient, hence, is suitable for high temperature sealing application (like solid oxide fuel cell).
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Nanometal-Glass Hybrid Nanocomposites: Synthesis, Properties and Applications
Transactions of the Indian Ceramic Society, 2010Co-Authors: Basudeb Karmakar, Tirtha Som, Shiv Prakash Singh, Mithun NathAbstract:In recent past research on nanometal-glass hybrid composites has been the centre of attention across the globe particularly in the area of nanoscience and for the future nanotechnology. In this review, with a short historical background, its preparation by various multi-step techniques, properties and applications are briefly described. In addition, recently developed single-step in situ thermochemical reduction methodology by these authors for synthesis of various nanometal-glass hybrid nanocomposites are described in detail with their significant characteristic properties, relevant theories and applications. Here Au, Ag and Bi metals are considered and the synthesized glasses are mostly based on antimony, bismuth and phosphorus oxides. Some of them are dichroic in nature, that is, they exhibit blue to green colourations in transmitted light and brown to reddish brown colourations in reflected light. The appropriate reasons for their dichroic character are still remained unsolved. Nanometal-antimony oxid...
Geoffrey F. Strouse - One of the best experts on this subject based on the ideXlab platform.
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microwave enhancement of autocatalytic growth of Nanometals
ACS Nano, 2017Co-Authors: Bridgett Ashley, Parth N Vakil, Brian B Lynch, Christopher M Dyer, Joseph B Tracy, Jeffery R Owens, Geoffrey F. StrouseAbstract:The desire for designing efficient synthetic methods that lead to industrially important nanomaterials has led a desire to more fully understand the mechanism of growth and how modern synthetic techniques can be employed. Microwave (MW) synthesis is one such technique that has attracted attention as a green, sustainable method. The reports of enhancement of formation rates and improved quality for MW driven reactions are intriguing, but the lack of understanding of the reaction mechanism and how coupling to the MW field leads to these observations is concerning. In this manuscript, the growth of a metal nanoparticles (NPs) in a microwave cavity is spectroscopically analyzed and compared with the classical autocatalytic method of NP growth to elucidate the underpinnings for the observed enhanced growth behavior for metal NPs prepared in a MW field. The study illustrates that microwave synthesis of nickel and gold NPs below saturation conditions follows the Finke–Watzky mechanism of nucleation and growth. T...
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Nanometals and Quantum Dots as Optical Markers in Biophysics
Biophysical Journal, 2010Co-Authors: Geoffrey F. Strouse, Tim Logan, Steven M. HiraAbstract:Nanometals and Quantum Dots are finding wide ranging applications in molecular beacon based optical assays. Whether the application is for measuring distances by resonant energy transfer processes or tracking the fate of gene delivery by cellular transfection, nanomaterials are ideal markers for the optical probe. The presentation will probe the use of nanometal Hammerhead RNA, as well as investigate in-vitro release of a gene coding for fluorescent proteins and/or siRNA from a nanometal surface or fluorescent Quantum Dot by live optical microscopy imaging. The applicability of the results to biological, the perturbations arising from non-specific interactions between the nucleic acid and nanomaterial, and cellular cytotoxicity are investigated.
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nanometal surface energy transfer in optical rulers breaking the fret barrier
Journal of the American Chemical Society, 2005Co-Authors: C S Yun, Steven M. Hira, Artjay Javier, Travis L Jennings, M Fisher, Stacey N Peterson, B Hopkins, Norbert O Reich, Geoffrey F. StrouseAbstract:Optical-based distance measurements are essential for tracking biomolecular conformational changes, drug discovery, and cell biology. Traditional Forster resonance energy transfer (FRET) is efficient for separation distances up to 100 A. We report the first successful application of a dipole-surface type energy transfer from a molecular dipole to a nanometal surface that more than doubles the traditional Forster range (220 A) and follows a 1/R4 distance dependence. We appended a 1.4 nm Au cluster to the 5‘ end of one DNA strand as the energy acceptor and a fluorescein (FAM) to the 5‘ end of the complementary strand as the energy donor. Analysis of the energy transfer on DNA lengths (15, 20, 30, 60bp), complemented by protein-induced DNA bending, provides the basis for fully mapping the extent of this dipole surface type mechanism over its entire usable range (50−250 A). Further, protein function is fully compatible with these nanometal−DNA constructs. Significantly extending the range of optical based met...
Mrinmoy Garai - One of the best experts on this subject based on the ideXlab platform.
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effects of in situ generated coinage Nanometals on crystallization and microstructure of fluorophlogopite mica containing glass ceramics
Journal of Materials Science & Technology, 2015Co-Authors: Mrinmoy Garai, Nibedita Sasmal, Atiar Rahaman Molla, Anal Tarafder, Basudeb KarmakarAbstract:The effects of in-situ generated coinage Nanometals (Cu, Ag and Au) on crystallization behavior, microstructure, thermal and mechanical properties of SiO 2 –MgO–Al 2 O 3 –B 2 O 3 –K 2 O–MgF 2 (BMAPS) glass‒ceramics were systematically studied. On addition of coinage nanometal, the glass transition temperature ( T g ) is increased by 20–30 °C, crystallization temperature ( T c ) by 30–50 °C and dilatometric softening temperature ( T d ) by 10–25 °C. It was found that the density of Cu-containing glass was 2.59 g cm −3 and for other glasses it was in the range of 2.56–2.57 g cm −3 . From the non-isothermal differential scanning calorimetry study, the activation energy of crystallization for BMAPS base glass was calculated as 344 kJ/mol, and changed to 406, 334 and 274 kJ/mol on addition of Cu, Ag and Au-Nanometals, respectively. Crystals evolved in the opaque BMAPS glass‒ceramics derived by controlled heat treatment, were identified as fluorophlogopite mica (KMg 3 (AlSi 3 O 10 )F 2 ) by X-ray diffraction (XRD) technique and confirmed by Fourier transformed infrared spectroscopy. Presences of copper, silver and gold Nanometals were also identified by XRD technique. It is found from field emission scanning electron microscopy that the interlocked grain like microstructure developed in BMAPS glass‒ceramics (being heat-treated at 1050 °C for 4 h) changed to denser house-of-cards like microstructure (containing smaller sized mica crystals) on addition of coinage Nanometals. Density of BMAPS base glass‒ceramic was 2.60 g cm −3 and marginally changed to 2.61–2.62 g cm −3 on addition of Cu, Ag and Au-Nanometals. The change in microstructure resulted in the decrease of Vickers micro hardness value from 5.37 to 4.12, 4.20 and 4.58 GPa on addition of Cu, Ag and Au, respectively. Coinage nanometal doped mica glass‒ceramics containing interlocked microstructure with higher thermal expansion coefficient, hence, is suitable for high temperature sealing application (like solid oxide fuel cell).
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Effects of In-situ Generated Coinage Nanometals on Crystallization and Microstructure of Fluorophlogopite Mica Containing Glass?Ceramics
Journal of Materials Science & Technology, 2015Co-Authors: Mrinmoy Garai, Nibedita Sasmal, Atiar Rahaman Molla, Anal Tarafder, Basudeb KarmakarAbstract:The effects of in-situ generated coinage Nanometals (Cu, Ag and Au) on crystallization behavior, microstructure, thermal and mechanical properties of SiO 2 –MgO–Al 2 O 3 –B 2 O 3 –K 2 O–MgF 2 (BMAPS) glass‒ceramics were systematically studied. On addition of coinage nanometal, the glass transition temperature ( T g ) is increased by 20–30 °C, crystallization temperature ( T c ) by 30–50 °C and dilatometric softening temperature ( T d ) by 10–25 °C. It was found that the density of Cu-containing glass was 2.59 g cm −3 and for other glasses it was in the range of 2.56–2.57 g cm −3 . From the non-isothermal differential scanning calorimetry study, the activation energy of crystallization for BMAPS base glass was calculated as 344 kJ/mol, and changed to 406, 334 and 274 kJ/mol on addition of Cu, Ag and Au-Nanometals, respectively. Crystals evolved in the opaque BMAPS glass‒ceramics derived by controlled heat treatment, were identified as fluorophlogopite mica (KMg 3 (AlSi 3 O 10 )F 2 ) by X-ray diffraction (XRD) technique and confirmed by Fourier transformed infrared spectroscopy. Presences of copper, silver and gold Nanometals were also identified by XRD technique. It is found from field emission scanning electron microscopy that the interlocked grain like microstructure developed in BMAPS glass‒ceramics (being heat-treated at 1050 °C for 4 h) changed to denser house-of-cards like microstructure (containing smaller sized mica crystals) on addition of coinage Nanometals. Density of BMAPS base glass‒ceramic was 2.60 g cm −3 and marginally changed to 2.61–2.62 g cm −3 on addition of Cu, Ag and Au-Nanometals. The change in microstructure resulted in the decrease of Vickers micro hardness value from 5.37 to 4.12, 4.20 and 4.58 GPa on addition of Cu, Ag and Au, respectively. Coinage nanometal doped mica glass‒ceramics containing interlocked microstructure with higher thermal expansion coefficient, hence, is suitable for high temperature sealing application (like solid oxide fuel cell).
Subhash Chandra Bhattacharya - One of the best experts on this subject based on the ideXlab platform.
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Understanding the effect of size and shape of gold nanomaterials on nanometal surface energy transfer.
Journal of colloid and interface science, 2016Co-Authors: Soumyadipta Rakshit, Satya P. Moulik, Subhash Chandra BhattacharyaAbstract:Gold Nanomaterials (GNMs) interact with fluorophores via electromagnetic coupling under excitation. In this particular work we carried out (to the best of our knowledge for the first time) a comprehensive study of systematic quenching of a blue emitter 2-Anthracene Sulfonate (2-AS) in the presence of gold nanoparticles of different size and shape. We synthesized gold nanomaterials of four different dimensions [nanoparticle (0D), nanorod (1D), nanotriangle (2D) and nanobipyramids (3D)] and realized the underlying effect on the emitting dipole in terms of steady and time resolved fluorescence. Nanometal Surface Energy Transfer (NSET) has already been proved to be the best long range spectroscopic ruler so far. Many attempts have been made to understand the interaction between a fluorescent molecule and gold nanomaterials. But not a single model can interpret alone the interaction phenomena. We have opted three different models to compare the experimental and theoretical data. Due to the presence of size dependent absorptivity and dielectric function, modified CPS-Kuhn model was proved to be the worthiest to comprehend variance of behavior of an emitting dipole in close proximity to nanometal surface by coupling with the image dipole of gold nanomaterials.
Anal Tarafder - One of the best experts on this subject based on the ideXlab platform.
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effects of in situ generated coinage Nanometals on crystallization and microstructure of fluorophlogopite mica containing glass ceramics
Journal of Materials Science & Technology, 2015Co-Authors: Mrinmoy Garai, Nibedita Sasmal, Atiar Rahaman Molla, Anal Tarafder, Basudeb KarmakarAbstract:The effects of in-situ generated coinage Nanometals (Cu, Ag and Au) on crystallization behavior, microstructure, thermal and mechanical properties of SiO 2 –MgO–Al 2 O 3 –B 2 O 3 –K 2 O–MgF 2 (BMAPS) glass‒ceramics were systematically studied. On addition of coinage nanometal, the glass transition temperature ( T g ) is increased by 20–30 °C, crystallization temperature ( T c ) by 30–50 °C and dilatometric softening temperature ( T d ) by 10–25 °C. It was found that the density of Cu-containing glass was 2.59 g cm −3 and for other glasses it was in the range of 2.56–2.57 g cm −3 . From the non-isothermal differential scanning calorimetry study, the activation energy of crystallization for BMAPS base glass was calculated as 344 kJ/mol, and changed to 406, 334 and 274 kJ/mol on addition of Cu, Ag and Au-Nanometals, respectively. Crystals evolved in the opaque BMAPS glass‒ceramics derived by controlled heat treatment, were identified as fluorophlogopite mica (KMg 3 (AlSi 3 O 10 )F 2 ) by X-ray diffraction (XRD) technique and confirmed by Fourier transformed infrared spectroscopy. Presences of copper, silver and gold Nanometals were also identified by XRD technique. It is found from field emission scanning electron microscopy that the interlocked grain like microstructure developed in BMAPS glass‒ceramics (being heat-treated at 1050 °C for 4 h) changed to denser house-of-cards like microstructure (containing smaller sized mica crystals) on addition of coinage Nanometals. Density of BMAPS base glass‒ceramic was 2.60 g cm −3 and marginally changed to 2.61–2.62 g cm −3 on addition of Cu, Ag and Au-Nanometals. The change in microstructure resulted in the decrease of Vickers micro hardness value from 5.37 to 4.12, 4.20 and 4.58 GPa on addition of Cu, Ag and Au, respectively. Coinage nanometal doped mica glass‒ceramics containing interlocked microstructure with higher thermal expansion coefficient, hence, is suitable for high temperature sealing application (like solid oxide fuel cell).
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Effects of In-situ Generated Coinage Nanometals on Crystallization and Microstructure of Fluorophlogopite Mica Containing Glass?Ceramics
Journal of Materials Science & Technology, 2015Co-Authors: Mrinmoy Garai, Nibedita Sasmal, Atiar Rahaman Molla, Anal Tarafder, Basudeb KarmakarAbstract:The effects of in-situ generated coinage Nanometals (Cu, Ag and Au) on crystallization behavior, microstructure, thermal and mechanical properties of SiO 2 –MgO–Al 2 O 3 –B 2 O 3 –K 2 O–MgF 2 (BMAPS) glass‒ceramics were systematically studied. On addition of coinage nanometal, the glass transition temperature ( T g ) is increased by 20–30 °C, crystallization temperature ( T c ) by 30–50 °C and dilatometric softening temperature ( T d ) by 10–25 °C. It was found that the density of Cu-containing glass was 2.59 g cm −3 and for other glasses it was in the range of 2.56–2.57 g cm −3 . From the non-isothermal differential scanning calorimetry study, the activation energy of crystallization for BMAPS base glass was calculated as 344 kJ/mol, and changed to 406, 334 and 274 kJ/mol on addition of Cu, Ag and Au-Nanometals, respectively. Crystals evolved in the opaque BMAPS glass‒ceramics derived by controlled heat treatment, were identified as fluorophlogopite mica (KMg 3 (AlSi 3 O 10 )F 2 ) by X-ray diffraction (XRD) technique and confirmed by Fourier transformed infrared spectroscopy. Presences of copper, silver and gold Nanometals were also identified by XRD technique. It is found from field emission scanning electron microscopy that the interlocked grain like microstructure developed in BMAPS glass‒ceramics (being heat-treated at 1050 °C for 4 h) changed to denser house-of-cards like microstructure (containing smaller sized mica crystals) on addition of coinage Nanometals. Density of BMAPS base glass‒ceramic was 2.60 g cm −3 and marginally changed to 2.61–2.62 g cm −3 on addition of Cu, Ag and Au-Nanometals. The change in microstructure resulted in the decrease of Vickers micro hardness value from 5.37 to 4.12, 4.20 and 4.58 GPa on addition of Cu, Ag and Au, respectively. Coinage nanometal doped mica glass‒ceramics containing interlocked microstructure with higher thermal expansion coefficient, hence, is suitable for high temperature sealing application (like solid oxide fuel cell).
