Abstract
Buckypaper are thin membranes or films of preformed networks of well-dispersed carbon nanotubes. In literature, aligned buckypapers can deliver better characteristics than random buckypapers. Numerous applications are developed based on alignment buckypapers. However, existing manufacturing processes only align nanotubes in parallel direction. In this paper, we seek to align nanotubes in concentric pattern. In addition, most of the align methods need expensive equipment or special nanotube treatments. In this research, we proposed a cost effective way to achieve alignment. To manufacture concentric aligned buckypapers, a Direct-Current mixer (DC-mixer) is added in the existing buckypaper manufacturing process. The spinning of DC-mixer forms a swirl in suspension and by means of the swirling current, aligning nanotubes in a concentric pattern. Design of Experiments is used for choosing factor combinations. Analysis of Variance and paired t-tests are used to verify the effectiveness of the proposed method. Results show that DC-mixer significantly changes the resistivity of axial direction of nanotube. In addition, the electrical resistivity from the center to the circumference are ordered because of different degree of alignment.