Neat macroscopic membranes of aligned carbon nanotubes

Thick macroscopic membranes of magnetically aligned single-wall carbon nanotubes (SWNT) have been produced via high pressure filtration of aqueous surfactant-suspended SWNT in a magnetic field, resulting in membrane thicknesses of 10 μm and surface areas of 125 cm². Field strengths of 7 and 25 T were used. Polarized Raman spectroscopy shows an anisotropy of $\text{(2.5±0.5),}$ indicating good alignment. A similar degree of alignment was seen at both intensities of magnetic field. Furthermore, the degree of alignment is comparable to that achieved in previous work that produced smaller and thinner membranes at 25 T. The membranes also exhibit uniform anisotropy across their surface and throughout their thickness.