The structure of carbon nanoscrolls is similar to that of a multi-walled
carbon nanotube
A scanning tunneling microscopy image of a single-walled carbon nanotube
Rotating single-walled zigzag carbon nanotube
A carbon nanotube (CNT) is a tube made of carbon with diameters typically measured in nanometers.
''Single-wall carbon na ...
, but with a spiral-like rolled-up geometry and open edges at the ends.
A number of methods have been reported to produce carbon nanoscrolls, including
arc discharge
An electric arc, or arc discharge, is an electrical breakdown of a gas that produces a prolonged electrical discharge. The electric current, current through a normally Electrical conductance, nonconductive medium such as air produces a plasma (p ...
, high-energy
ball milling
A ball mill is a type of grinder used to grind or blend materials for use in mineral dressing processes, paints, pyrotechnics, ceramics, and selective laser sintering. It works on the principle of impact and attrition: size reduction is done ...
, and
intercalation, among others.
Wedge based mechanical exfoliation
Wedge-based mechanical exfoliation is a method that involves the use of an ultra-sharp single crystal diamond wedge to penetrate inside a material and cleave a thin layer of material. It was proposed to produce few layers of graphene from a bulk ...
is also reported to form carbon nanoscrolls experimentally.
However, the real world applications of nanoscroll products are limited due to their difficult colloidal processing. Thermodynamically, the nanoscale surfaces are stacking each other via van der Waals force to lower the
energy barrier
In chemistry and physics, activation energy is the minimum amount of energy that must be provided for compounds to result in a chemical reaction. The activation energy (''E''a) of a reaction is measured in joules per mole (J/mol), kilojoules p ...
. To overcome this problem and obtain high quality nanoscrolls, a polymer-assisted liquid exfoliation technique has been recently demonstrated, allowing to manufacture high throughput and high quality CNS dispersions. Other material-based nanoscrolls, e.g. gold nanoscrolls, were also successfully attained by the exfoliation technique.
References
{{allotropes of carbon
Carbon nanoparticles