Abstract: The invention relates to carbon nanotube arrays and methods for the preparation and modification of carbon nanotube arrays. The method includes synthesizing a plurality of carbon nanotubes on a substrate such that the carbon nanotubes are substantially vertically aligned and exposing the array to a plasma to change the topography of the array, change the structure or chemical nature of the individual nanotubes, remove at least a portion of the carbon nanotubes, and/or removing nanotubes to expose monodispserse groupings of nanotubes.

Abstract: Opaque glitter particles that are uniform in size and shape are disclosed that have an optically variable color with a change in angle of incident light. The glitter particles have an organic substrate and an optical interference structure on one or both sides of the organic substrate. The optical interference design can be a Fabry-Perot structure or can be an optically variable ink.

Abstract: A rigid and brittle bright metal flake is formed of a central layer of a reflective material supported on both sides by dielectric layers. In a preferred embodiment, the metal layer is aluminum having a thickness of about 100 nm and the dielectrics are either silicon dioxide or magnesium fluoride, each having a thickness of about 100 nm. The result is a very thin three-layered metal flake about 300 nm thick that exhibits a uniaxial compressive strength of about 8 times a corresponding uniaxial tensile strength. As a result, the metal flake is then afforded the benefits of rigidity and brittle fracture during the manufacturing and applicational processes which ultimately provides favorable planar and specular reflectance characteristics in the visible wavelength range.