Synthesis and Study of Nanostructures Via Microwave Heating
- PDF / 1,553,118 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 21 Downloads / 203 Views
P3.19.1
Synthesis and Study of Nanostructures Via Microwave Heating Oxana V. Kharissova 1, Eder Zavala 1, Ubaldo Ortíz 2, Jorge L. Hernández-Piñero 3, Stanislav Soloviev 4 1
Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Nuevo León, México [email protected] , [email protected] 2 Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, México [email protected] 3 Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, México 4 University of South Caroline, USA [email protected]
ABSTRACT This work is devoted to microwave heating of graphite, sucrose, calcined sucrose, and a mixture of graphite with sucrose to produce carbon nanotubes (CNT’s). The samples were submitted to microwave radiation (power 800W, frequency 2.45 GHz) in air and high vacuum (10-5 Torr) for 30 – 60 min. The oven temperature was approximately 1200°C. After vaporization the condensed material was collected on various fused silica targets (different morphologies were used). The samples were found to contain a significant proportion of nanotubes, nanoparticles and fibers (1-2.8 micrometers), which appeared to be highly graphitized and helical structured. After deposition, the morphology of carbon nanotubes was studied with SEM, TEM and AFM techniques. It was observed that multi-walled nanotubes (MWNT’s) were produced by this method. The morphology of fused silicon based substrates (SiO2, SiC) was studied as an important factor for the growth of carbon nanotubes. Many aspects as the size and shape of the obtained nanotubes on different substrates (porous and non-porous fused silicon substrates) were achieved, as well as the concentration of them across the substrate and other properties. INTRODUCTION The science of carbon nanotubes has received a big enhancement in last years, especially since the development of standardized methods for its production in laboratories. The most recent efforts have been focused mainly in the reaching of a way for producing carbon nanotubes at a bigger scale, i.e., quantities bigger enough for being able to experiment on them easily and consequently getting a better quality of results on researches about properties and technologic applications. Numerous potential applications, such as flat panel displays 1, chemical sensors 2, hydrogen storage 3, etc., had been proposed. A number of methods such as arc discharge 4, laser vaporization 5, gas-phase pyrolysis 6,7, plasma-enhanced 8,9 or thermal chemical vapor deposition (CVD) 10,11, had been developed for the production of CNT’s. The synthesis of CNT’s is often accompanied by the formation of other forms of carbon, such as fullerenes, polyhedral particles and amorphous forms of carbon. In many instances, purification of CNT’s is necessary 12. The microwave (MW) irradiation technique is widely applied in some areas of chemistry 13 and technology to produce or degrade various materials and chemical compounds 14, as well as in the study of chemical processes. A synthesis of fullerenes method using microwav
Data Loading...
