Magnetic nanocubes self-assemble into spirals


nanocube

© AAAS/Science

Scientists have been coaxing nano-sized cubes of magnetite (Fe3O4) into larger, more complex structures like helices without using a template by exposing them to a magnetic field.

A team led by Rafal Klajn at the Weizmann Institute of Science in Israel found that by varying the density of the cubes and the size and direction of the magnetic field they can control the kind of structure the cubes self-assemble into, which depends on the interplay between intermolecular forces and magnetic interactions. Under an increasing magnetic field the nanocubes line up to make a ‘belt’, while under a constant magnetic field at high density they curl round and form a helix. Single helices tend to clump together to make double helices (like the rope-like structure shown above) or even triple helices.

Although at the moment there is no obvious use for the structures, the team say they could have interesting magnetic properties. They are now exploring the effects of using other magnetic nanomaterials, such as nickel or iron nanoparticles, and decorating the nanocube surfaces with functional ligands to see what other shapes can be made.


Related Content

The golden helix

10 October 2012 Premium contentFeature

news image

Fifty years after the Nobel prize was awarded for the structure of DNA, Mike Sutton looks back at how it all came about

Keratin

26 September 2012 Podcast | Compounds

news image

This week's podcast is about keratin

Most Read

Antimicrobial resistance will kill 300 million by 2050 without action

16 December 2014 News and Analysis

news image

UK report says resistance will cost global economy $100 trillion

Cutting edge chemistry in 2014

10 December 2014 Research

news image

We take a look back at the year's most interesting chemical science stories

Most Commented

Smart skin for prosthetic limbs senses heat and touch

12 December 2014 Research

news image

Ultra-thin plastic skin can bend and flex without affecting the skin's ability to detect stimuli

Chemistry behind the ‘blue man’ unlocked

1 November 2012 Research

news image

Biochemical model suggests that silver ions, not nanoparticles, cause a rare skin complaint