Growth Of Single-walled Carbon Nanotube Arrays And The Study Of Their Adhesion Force

Since their discovery in 1991, Carbon nanotubes have attracted considerable interest among scientists because of their unique physical properties, chemical properties, and electrical properties. In 1993,single walled carbon nanotubes (SWNT) was discovered and has even better application potentials. There are many techniques for nanotubes preparation. Such as: arc discharge,laser ablation and chemical vapour deposition(CVD). The CVD method appears to be a promising technique since it has the potential for a large-scale synthesis of high-quality SWCNTs at relatively low cost. The preparation of SWCNTs is the base to study the physical and chemical properties of single-walled carbon nanotubes,great progress has been made in this area. However,the difficulty of large-scale , and directional growth of carbon nanotube arrays on flat substrate has restrained the application of SWCNTs in many areas.The aligned single-walled carbon nanotubes arrays were synthesized on quartz substrate by chemical vapor deposition(CVD),using ferric chloride (FeCl3) ethanol solution as catalyst and methane as carbon source, polyvinylpyrrolidone (PVP) as dispersant. Experimental results show that using metal mask which engraved lines, spraying the catalyst on the quartz substrate to form neat, regular arrangement of the catalyst section, can improve the orientation of carbon nanotube arrays and control the growth of carbon nanotubes arrays. The sample's was characterized by scanning electron microscope,atom force microscope and Raman spectroscopy. The studies showed that the product is less structural defects, high purity, uniform diameter single-walled carbon nanotube arrays.Based on simple beam theory to deal with small deformation and the theoretical model to calculate the adhesion force between two parallel suspended carbon nanotube ropes through examining the geometry with scanning electron microscopy (SEM), we derive the formulas to calculate the adhesion force between two parallel suspended carbon nanotube ropes and the adhesion to the substrate. We estimate variation of the critical trench width with the nanotube ropes spacing and the relationship between the trench width and height when the carbon nanotube just glues to the substrate. We preliminarily explored the production process to make the suspended structure of carbon nanotubes.