Synthesis And Surface Properties Of Carbon Nanotube Surface Composite

Within two decades, carbon nanotube (CNT) has attracted great attention due to itsoutstanding properties and attractive applications. By exploiting its unique surfaceproperties, CNTs are good absorber using as gas sensing, oil spoil clean up and removalheavy metallic ions in water. It is important for their applications in environmental pro-tection to assemble the CNT powders into macro-structure, so as to prevent them frominhaling into body or flow into environment.The carbon nanotube powder is conglutinated by adhesive surface of polyvinyl-pyrrolidone (PVP) nanowires which is produced by electrospinning method, and thenthey form the CNT/PVP surface composite which has macroscopic dimension and por-ous structure. The composite has high CNT load (99wt%), low density (~50mg/cm3),well extensibility (~92%) and conductivity. The composite well keeps the CNT surfaceproperties and it is one kind of porous materials with high porosity (>97%), large spe-cific surface area (~200m2/g) and vast pore diameter distribution (2nm~500μm). Theproductivity, component percentage and micro-structure can be modulated by feedspeed of polymer solution and ball mill treatment.The surface of the CNT/PVP surface composite is hydrophobic and oleophylic.The saturated adsorption capacity and volume are17~22g/g and0.8~1.1g/cm3respec-tively. The composite shows a more rapidly adsorption velocity to oil with higher vis-cosity, and shows a larger saturated adsorption capacity to one with larger density. Theoil adsorption kinetics model and the free energy change of oil slick adsorption in waterare analyzed.According to its sensibility to water molecular, the sensibility to gas flow of thecomposite film has been researched. In the range of200~800cc/min of nitrogen, thecomposite film shows well sensibility with a absolute precision of±9.6cc/min. Thesensibility has well repeatability. Since the nitrogen dioxide has interaction with carbonnanotube, the composite film shows stable sensibility to nitrogen dioxide concentrationin range of10~60ppm with an absolute precision of±1.3ppm. The sensibility has well repeatability.