Growth of Half-Meter Long Carbon Nanotubes Based on Schulz–Flory Distribution

Abstract

The Schulz-Flory distribution is a mathematical function that describes the relative ratios of polymers of different length after a polymerization process, based on their relative probabilities of occurrence. Carbon nanotubes (CNTs) are big carbon molecules which have a very high length-to-diameter ratio, somewhat similar to polymer molecules. Large amounts of ultralong CNTs have not been obtained although they are highly desired. Here, we report that the Schulz-Flory distribution can be applied to describe the relative ratios of CNTs of different lengths produced with a floating chemical vapor deposition process, based on catalyst activity/deactivation probability. With the optimized processing parameters, we successfully synthesized 550-mm-long CNTs, for which the catalyst deactivation probability of a single growth step was ultralow. Our finding bridges the Schulz-Flory distribution and the synthesis of one-dimensional nanomaterials for the first time, and sheds new light on the rational design of process toward controlled production of nanotubes/nanowires.

Carbon nanomaterials: production, impact on plant development, agricultural and environmental applications

“…Application of 14 C-labeled C60 to radish (Raphanus sativus) grown in sand and hydroponic culture, revealed plant uptake of 7 % of the applied fullerene dosage. In a study with wheat (T. aestivum) and rapeseed (B. napus) exposed to 14 C-radiolabeled MWCNTs (10-100 mg L −1 ) in a hydroponic culture medium [171] it was demonstrated that less than 0.005 ‰ (≈ 200 ng g −1 plant dry matter) of the total applied nanomaterial, was taken up and translocated within the plants without beneficial or detrimental effects. The high discrepancy between the externally applied amount of CNTs and the fraction really taken up by the plants, as well as typical features of carbon nanomaterials, such as agglomeration or sedimentation in suspensions and surface adsorption to solid substrates, which can vary considerably depending on the composition of the incubation media [152], demonstrate that the simple indication of application concentrations is easy to use but only of little informative value with respect to the real effective dosage.…”

“…Multi-walled CNTs have a diameter of 5-40 nm and a length around 10 μm. However, recently synthesis of CNTs with a length of even 550 mm has been reported [14]. The structure of CNTs leads to exceptional properties with a unique combination of rigidity, strength and elasticity compared with other fibrous materials.…”

Graphene Nanocomposites Studied by Raman Spectroscopy

“…A carbon nanotube can be defined as a tube-shaped material, entirely made from carbon, having the diameter measuring on the nanometer scale. A carbon nanotube can be as thin as a few nanometers but as long as hundreds of microns [8]. CNTs are at least 100 times stronger than steel, but only one sixth as heavy, so nanotube fibers could strengthen almost any material [9].…”

Carbon-Based Metal-Free Electrocatalysis for Energy Conversion, Energy Storage, and Environmental Protection

“…Nanotubes usually possess diameters ranging from a few angstroms to tens of nanometres and lengths of up to several centimeters and even submeters [45,46]. The peculiar hollow geometry, coupled with a conjugated all-carbon structure, allows CNTs to exhibit many intriguing electrical, mechanical, and thermal properties that are absent from other members of the carbon family.…”