A method for the coating of silica spheres with an ultrathin layer of pristine single-walled carbon nanotubes

We describe a method to fabricate silica gel particles coated with a monolayer of pristine single-walled carbon nanotubes (SWCNTs). SWCNTs dissolved in 1-methyl-2-pyrrolidinone (NMP) are mixed with amino-functionalized silica gels having different diameters. Strong interaction between the amino group and the SWCNT surfaces induces the adsorption of the SWCNTs on the silica, while the stable solvation in NMP hampers further adsorption of the tubes. This approach enables the production of a homogeneous, nondestructive and high-yield coating of the SWCNTs onto the silica surfaces, especially for larger sphere with a diameter over 1 μm. The density and bundling degree of the SWCNTs on the silica gel surfaces are finely controlled by simply changing the ratios of the SWCNTs to the silica gels as well as the SWCNT concentrations. We also describe the coating of the silica gels with metallic SWCNTs. The SWCNT-coated silica gels are useful for a wide range of materials, such as the stationary phase for liquid chromatography and catalyst supporting materials.

Homogeneous coating technique of silica spheres using pristine single-walled carbon nanotubes (SWCNTs) was developed. Coating density and bundling degree of the SWCNTs on the silica spheres were finely controllable. Coating stability of the SWCNTs in organic and in aqueous solutions was very high due to the strong adsorption of the tubes onto the surfaces of the silica spheres.Figure optionsDownload as PowerPoint slideResearch highlights
► Homogeneous coating of silica spheres using pristine single-walled carbon nanotubes.
► Homogeneous coating of silica spheres using metallic single-walled carbon nanotubes.
► Fine density control of single-walled carbon nanotubes on silica spheres.
► Fine bundling degree control of single-walled carbon nanotubes on silica spheres.