Preparation of Single‐Handed Helical Carbon/Silica and Carbonaceous Nanotubes by Using 4,4′‐Biphenylene‐Bridged Polybissilsesquioxane

Abstract

Single-handed, helical, 4,4'-biphenylene-bridged polybissilsesquioxane nanotubes were prepared by using the self-assemblies of a pair of chiral low-molecular-weight gelators as templates. Single-handed, helical, carbon/silica nanotubes were obtained after carbonization of the self-assemblies, and single-handed helical carbonaceous nanotubes were then obtained by removal of silica with aqueous HF. Samples were characterized by using field-emission SEM, TEM, X-ray diffraction, thermogravimetric analysis, Raman spectroscopy, and circular dichroism. The polysilsesquioxane and carbonaceous structures exhibited optical activity. The walls of the carbon/silica and carbonaceous nanotubes were predominantly amorphous carbon. The surface area of the left-handed, helical, carbonaceous nanotubes was 1439 m(2) g(-1), and such materials have potential applications as catalyst supports, chirality sensors, supercapacitor electrodes, and adsorbents.

Single‐Handed Helical Carbonaceous Nanotubes: Preparation, Optical Activity, and Applications

“…The lipodipeptides LL-3, LD-3, DL-3, and DD-3 can self-assemble into twisted nanoribbons in deionized water. [9] The handedness of the nanoribbons is dominated by the chirality of the amino acid at the Cterminal. This "C-terminal domination" rule has been also found in other homogeneous lipodipeptides.…”

“…[5][6][7][8][9] The formation mechanism was a hard-templating mechanism, or a cooperation mechanism, depending on reaction conditions. When the anionic gelators L-2, D-2, LL-3, LD-3, DL-3, and DD-3 were used to prepare twisted or coiled polybissilsesquioxane tubular nanoribbons, APTMS was used as a costructure-directing agent.…”

“…For examples, helical LiTaO 3 and BaTiO 3 nanotubes were prepared using helical Ta 2 O 5 and TiO 2 nanotubes, respectively. [33,34] Recently, helical carbonaceous nanotubes were prepared via the carbonization of organopolymeric nanotubes, [7][8][9] organic-inorganic hybrid silica nanotubes, [21][22][23][24][25] or organic compounds within silica nanotubes. [26] The handedness of the carbonaceous nanotubes was consistent with that of their starting materials.…”

“…[15][16][17][18][19][20][21][22][23][24][25][26][27] Chiral carbon dots, [15,16] chiral single-walled carbon nanotubes (SWNTs), [17][18][19] helical carbon nanofibers, [20] and helical carbonaceous nanotubes [7][8][9][21][22][23][24][25][26] have been successfully prepared. The optical activity of chiral carbon dots is controlled by their chiral protecting groups, and they can be used as chirality inducers and sensors.…”

“…Helical organic-inorganic hybrid silica nanofibers and nanotubes have been prepared using self-and external templating approaches, respectively. [4][5][6][7][8][9] The handedness of such nanofibers and nanotubes is determined by that of the template. Helical organic selfassemblies have been built using chiral or achiral molecules, [10][11][12] and the handedness is determined by the chirality of the building blocks and the surrounding conditions.…”