Formation Of Carbon Nanotube Arrays By Using Solvent Evaporation Induced Self-assembly

Carbon nanotube arrays (CNAs) have many applications in many field involvedfield-effect devices, sensors and electrochemical sensor due to its unique structural,excellent mechanical, thermal and electrical properties. At present, CNAs are mainlyformed by chemical evaporate deposition (CVD), which require high temperaturetogether with pre-patterned catalysts, Hence, preparation of CNAs with relativelysimple method is necessary and important. In this study, we reported the preparationof CNAs through the solvent evaporation induced self-assembly, which is simple,easy and one-step to fabricate regular CNTs strip arrays with a characteristic ofgradient. This is valuable for the intensive study of CNTs properties and applications.The works in this paper mainly include the followings:Firstly, multi-walled carbon nanotubes (MWNTs) were dispersed in dichloroethane(DCE) under sonication, and then stable MWNTs/DCE dispersion was obtained aftercentrifugation. Regular stripe arrays of MWNTs were spontaneously formed at solid-liquid-air contact line by using the solvent evaporation induced self-assembly.Secondly, we systematically studied the effect of experiment parameters such as tiltangle of substrate, concentration of MWNTs/DCE dispersion, solvent evaporationtemperature and substrate type on structure of the formed arrays.Thirdly, we fabricated arrays of MWNTs stripe on Si/SiO2substrate and tested theoutput characteristics of the transistors based on these stripes.Lastly, the pristine arc-discharged single-walled carbon nanotubes (SWNTs) werepurified and then shortened into1~5μm by sonication for6hours in mixed acid. Astable SWNTs/water dispersion was received. After the SWNTs/water dispersionevaporated under80oC, regular and gradient SWNTs arrays were also formed. Thescan electronic microscope (SEM) indicated that SWNTs were in tendency ofalignment.