Arul Murugesan; Robert M Gengan
Abstract
A simple and efficient procedure for the preparation of boron nitride bound N-propyl triethylenetetramine sulfonic acid (BN-BPTETSA) by the reaction of boron nitride bound N-propyl triethylenetetramine (3-TETANP BN) with chlorosulfonic acid in chloroform is described. The boron nitride (BN) ...
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A simple and efficient procedure for the preparation of boron nitride bound N-propyl triethylenetetramine sulfonic acid (BN-BPTETSA) by the reaction of boron nitride bound N-propyl triethylenetetramine (3-TETANP BN) with chlorosulfonic acid in chloroform is described. The boron nitride (BN) nanomaterial was prepared by first activating BN with nitric acid under reflux for 24h. Thereafter trimethoxy -3-mercaptopropylchloride was added, refluxed for 24 h then an excess of triethylenetetramine was added in anhydrous xylene and the system was refluxed. After filtration and washing of the filter cake with xylene, chlorosulfonic acid was added drop-wise at 0 °C over a period of 3 h. Further filtration yielded a solid cake which was washed with ethanol and air died. The morphological properties of catalyst was characterized by FT-IR, XRD, TEM, SEM, BET and Raman spectroscopy techniques. The preparation of the catalyst is safe and demonstrates high catalytic activity for the synthesis of piperazinyl quinolinyl carbaldehyde derivatives. Furthermore, a small amount of catalyst was used, demonstrated good reusability and may have potential for industrial applications in the future. Copyright © 2018 VBRI Press.
Rohit Sharma; Neha Khatri; Vinod Mishra; Harry Garg; Vinod Karar
Abstract
Subsurface Damage (SSD), which is introduced to optical materials by diamond turning processes, affects the performance in optical, laser and infrared applications. For optical applications, SSD can be the source of component instability (e.g., surface stress) and flaw. The objective of the present study ...
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Subsurface Damage (SSD), which is introduced to optical materials by diamond turning processes, affects the performance in optical, laser and infrared applications. For optical applications, SSD can be the source of component instability (e.g., surface stress) and flaw. The objective of the present study is to investigate the subsurface damage in silicon. Interferometry and Raman Spectroscopy are used to detect the surface finish and SSD. The surface roughness of 0.243 nm is achieved at best combination. A sharp Raman shift at 409 cm-1 is obtained, which reveals that a thin layer of Silicon has transformed to amorphous state resulting in subsurface damages. Copyright © 2017 VBRI Press.
Vipin Jain; Anil Kumar; Ajay Dhar
Abstract
Graphene possesses excellent properties such as, high Young’s modulus (1 TPa), high fracture strength (~125 GPa) and extreme thermal conductivity (~5000 W/m/K), therefore, can serve as an ideal reinforcement material for the metal based High Tech structural nanocomposites. In the present work, ...
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Graphene possesses excellent properties such as, high Young’s modulus (1 TPa), high fracture strength (~125 GPa) and extreme thermal conductivity (~5000 W/m/K), therefore, can serve as an ideal reinforcement material for the metal based High Tech structural nanocomposites. In the present work, a novel chemical synthesis method has been adopted for the in-situ synthesis of aluminium-graphene (Al-Gr) nanocomposite powders with varying compositions using graphene oxide (GO) as the precursor. The pure aluminium powder was initially cryomilled to refine the crystallite size. Subsequently, Al-reduced graphene (Al-Gr) nanocomposite powders were synthesized employing different volume proportions of GO (referred as 0.5, 2, 4, and 6 ml) dispersed in deionized water. The synthesized nanocomposite powders were ball milled followed by consolidation using spark plasma sintering under the optimized conditions. The nanocomposite powder as well as SPSed samples were characterized using X-ray diffraction (XRD), Raman Spectroscopy and electron microscopy. Scanning electron microscopy (SEM) studies of nanocomposite powders have depicted wrinkled structure typical of reduced graphene. Raman spectra have shown regular D, G, 2D and D+G bands and a modulated 2D peak having intensity significantly less than the G peak was observed for the nanocomposite powders confirming multilayered graphene is synthesized. The graphene wrinkles were determined in the size of 100 nm or more. Microhardness of SPS sintered nanocomposites is found progressively increased with the increasing content of reduced graphene with up to 58% improvement over pure Al was observed for the maximized GO content depicting potential for energy efficient high strength applications. The synthesized Al-graphene nanocomposites are novel in terms of an innovative, indigenously developed and scalable to bulk synthesis approach based on in-situ chemical synthesis route adopted. Copyright © 2017 VBRI Press.
M. Malligavathy; D. Pathinettam Padiyan
Abstract
Phase pure bismite nanoparticles were successfully prepared by means of hydrothermal method by varying the precursor solution pH from 10 to 13. The as-prepared nanoparticles were characterized by different techniques such as X-ray diffraction pattern (XRD), Raman spectroscopy, Scanning electron microscopy ...
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Phase pure bismite nanoparticles were successfully prepared by means of hydrothermal method by varying the precursor solution pH from 10 to 13. The as-prepared nanoparticles were characterized by different techniques such as X-ray diffraction pattern (XRD), Raman spectroscopy, Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX). The effects of pH on the structural properties of these nanoparticles were corroborated using XRD and Raman spectrum. From the XRD pattern it is found that all the samples are polycrystalline in nature and the Raman spectra are used to confirm the phase transformation of the Bi2O3 nanoparticles. At the low pH value, the SEM image reveals that as-prepared samples are homogeneous with particle size of ~ 25 nm and with the increase in the pH value spherical particle forms uniform blocks like morphology for both the samples prepared at the pH 12 and 13. Copyright © 2017 VBRI Press.
