Growth of dense CNT on the multilayer graphene film by the microwave plasma enhanced chemical vapor deposition technique and their field emission properties

Catalyst assisted carbon nanotubes (CNTs) were grown on multilayer graphene (MLG) on copper and silicon substrates by the microwave plasma enhanced chemical vapor deposition technique. The transmission of the MLG was found to vary between 82 to 91.8% with the increase of deposition time. Scanning electron microscopy depicted that the MLG film survived at the deposition condition of CNTs with the appearance of the damaged structure due to the plasma. Growth of CNTs was controlled by adjusting the flow rates of methane gas. The density of carbon nanotubes was observed to increase with a higher supply of methane gas. It was observed that the field emission properties were improved with the increased density of CNTs on MLG. The lowest turn-on field was found to be 1.6 V mu m(-1) 1 accompanied with the highest current density of 2.8 mA cm(-2) for the CNTs with the highest density. The findings suggested that the field emission properties can be tuned by changing the density of CNTs

Recent advances in additive manufacturing for current challenges, materials and their applications

Additive Manufacturing (AM) technology in 3-D printing has grown into a great field in today’s technological world, especially in manufacturing sectors. Various AM technologies have been developed presently and their advancement has beenprocessed worldwide is presented. Their advancement included usability and compatibility of the different types of material. Moreover, the applications of 3-D printing via different AM technologies in biomedical applications, dental implants, pharmaceutical industries, chemical processing equipment, structural components, automotive industries, marine sectors, aerospace sectors, sports equipment and food processing industries have been presented. However, suggested applications viadifferent AM technologies have also been reported. Further, the challenges in development of the 3D structure via different AM technologies have also been discussed. The remedial/treatment like pre and post processing operations, tool path planning, and slicing orientation have also been suggested in printing of the sound 3D complex structure

Enhancement of Germination on Abrus Precatorius L. Seeds by Specific Pre-sowing Treatments

Herbal medicines are in great demand for preliminary health care due to their wide medicinal value, with no side effects. Since many species are used in the system of traditional medicine, scientists have great opportunities to develop appropriate packages of practices for their multiplication and conservation. Abrus precatorius is the native plant of India and used in many ways in the Indian Ayurvedic system of medicine. This seeds of the species is dormant due to hard seed coat. So the aim of the study is to remove seed dormancy and enhance germination capacity within a short period. To overcome the problem of dormancy, seeds were scarified by seed scarifier and sand paper and also treated with acid (H2SO4) and hot water just before sowing. 60-95% germination was achieved under different treatment conditions while the seeds without any treatment fail to germinate. The highest (95%) germination was observed just 12 days after sowing in seeds treated with concentrated H2SO4 for 120 minutes. 70-75% germination was achieved when the seeds were treated with acid for 105 and 135 minutes. Seeds treated with con. H2SO4 for 150, 90 and 60 minutes and also scarified by sand paper showed similar results with 60-65% germination. The seeds scarified by a mechanical scarifier and treated with hot water did not show more than 32.5% germination

Structural, Field Emission and Ammonia Gas Sensing Properties of Multiwalled Carbon Nanotube-Graphene Like Hybrid Films Deposited by Microwave Plasma Enhanced Chemical Vapor Deposition Technique

This paper reports the direct deposition of multiwalled carbon nanotube (MWCNT)-graphene like hybrid films on nickel substrate using a 2.45 GHz microwave plasma enhanced chemical vapor deposition (MW PECVD) system in the temperature range of 500-700 degrees C at 20 Torr pressure. The films have been characterized by Raman spectra, high resolution transmission electron microscope (HRTEM), scanning electron microscope, high resolution X-ray diffraction and contact angle measurement. Raman spectroscopy and HRTEM reveal the formation of MWCNT and graphene like hybrid carbon sheet structures. The effect of processing temperature on the field emission properties of MWCNT-graphene like hybrid films has been investigated. Field emission measurement reveals that the turn-on field decrease and the emission current density increase with the increase of deposition temperature. The rambutan structure of MWCNT formed at 700 degrees C is responsible for the improvement in the field emission properties. The film deposited at 700 degrees C shows fast response and recovery time of 40 and 96 s, respectively, for ammonia gas sensing due to the high surface area of the film. It has also been found that the hydrophobic surface of the film helps to perform the gas sensing in the humid environment

Synthesis of vertical graphene by microwave plasma enhanced chemical vapor deposition technique

Vertical graphene was synthesized on nickel substrate using microwave plasma enhanced chemical vapor deposition technique by varying gas pressure from 5 to 30 Torr under various mixing ratios of argon, hydrogen and methane. The Raman spectra show two major fingerprints of graphene, 2D peak at 2700 cm(-1) and G peak 1580 cm(-1). Scanning electron microscopy microstructure revealed flower like graphene structure which could find applications in gas sensing and field emission due to high surface-to-volume ratio

Growth of dense CNT on the multilayer graphene film by the microwave plasma enhanced chemical vapor deposition technique and their field emission properties

Catalyst assisted carbon nanotubes (CNTs) were grown on multilayer graphene (MLG) on copper and silicon substrates by the microwave plasma enhanced chemical vapor deposition technique. The transmission of the MLG was found to vary between 82 to 91.8% with the increase of deposition time. Scanning electron microscopy depicted that the MLG film survived at the deposition condition of CNTs with the appearance of the damaged structure due to the plasma. Growth of CNTs was controlled by adjusting the flow rates of methane gas. The density of carbon nanotubes was observed to increase with a higher supply of methane gas. It was observed that the field emission properties were improved with the increased density of CNTs on MLG. The lowest turn-on field was found to be 1.6 V mu m(-1) 1 accompanied with the highest current density of 2.8 mA cm(-2) for the CNTs with the highest density. The findings suggested that the field emission properties can be tuned by changing the density of CNTs

Recent advances in additive manufacturing for current challenges, materials and their applications

331-344Additive Manufacturing (AM) technology in 3-D printing has grown into a great field in today’s technological world, especially in manufacturing sectors. Various AM technologies have been developed presently and their advancement has been processed worldwide is presented. Their advancement included usability and compatibility of the different types of material. Moreover, the applications of 3-D printing via different AM technologies in biomedical applications, dental implants, pharmaceutical industries, chemical processing equipment, structural components, automotive industries, marine sectors, aerospace sectors, sports equipment and food processing industries have been presented. However, suggested applications via different AM technologies have also been reported. Further, the challenges in development of the 3D structure via different AM technologies have also been discussed. The remedial/treatment like pre and post processing operations, tool path planning, and slicing orientation have also been suggested in printing of the sound 3D complex structure