Preparation of Helical Mesoporous Tantalum Oxide Nanotubes through a Sol–Gel Transcription Approach

Abstract

The TaO of nanotubes: Single‐handed helical Ta2O5 nanotubes with mesopores in the walls were prepared using the self‐assemblies of the low‐molecular‐weight gelators as the templates. The handedness of the Ta2O5 nanotubes was controlled by organic self‐assemblies.

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

“…(Figure 1). [13] Preparation of Single-Handed, Helical, 4,4'-Biphenylene-Bridged Polybissilsesquioxane Nanotubes LMWG l,l-(or d,d-)8Val11PyClO 4 (35 mg, 0.034 mmol) and BTSB (0.46 mmol) were dissolved in absolute ethanol (1.0 mL) under reflux in a test tube. After cooling to room temperature, an opaque gel was formed.…”

“…If reactions were carried out in alcohol with atmospheric moisture as the reactant, singlehanded, helical nanotubes were obtained. [13] The chirality at the ngstrom level has also been observed by means of CD spectroscopy. Herein, single-handed, helical, 4,4'-biphenylene-bridged polybissilsesquioxane nanotubes were prepared through a diffusion approach.…”

“…Although chiral SWNTs can be separated by chromatography and selective solubilization, obtaining enantiopure samples remains a challenge. [5][6][7] To control the handedness of these one-dimensional nanomaterials, external [8][9][10][11][12][13] and self-templated approaches [14,15] have been developed. Self-assemblies of chiral low-molecular-weight gelators (LMWGs) generally serve as templates.…”

Chiral defects on single-handed helical Ta2O5 nanotubes prepared using a supramolecular templating approach

“…The LMWGs for the preparation of Ta 2 O 5 nanotubes were shown in Fig. 27 Herein, although the LMWG concentration in the reaction mixtures was increased, single-handed helical Ta 2 O 5 nanotubes were also obtained. It has been reported that LL-and DD-8Val11PyClO 4 in ethanol at a concentration of 10 mg mL À1 can self-assemble into le-and right-handed twisted nanoribbons, respectively.…”

Preparation of single-handed helical carbonaceous nanotubes using 3-aminophenol-formaldehyde resin

“…4 Silicon microtubes have been prepared via the evaporation of sodium from NaSi disks. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] The optical chirality of these materials has been studied using circular dichroism (CD), and diffuse reectance circular dichroism (DRCD). 6 Although materials with helical morphologies can be obtained, it is difficult to obtain single-handed materials using these approaches.…”