Nano Dandelions: Bundles of cysteine-lead nanowires spread into highly oriented structures

Sep 03, 2007

Under an electron microscope they look like dandelions. In the journal Angewandte Chemie, Xiao-Fang Shen and Xiu-Ping Yan explain their nanoscopic bouquets: They consist of spread-out bundles of nanowires made of lead and the amino acid l-cysteine. The Chinese researchers have discovered a new, cost-effective method by which ordered nanostructures can be produced on a large scale, at room temperature, and under atmospheric pressure.

The properties of nanomaterials are not determined exclusively by their chemical composition; other characteristics such as structure and morphology, as well as the form, size, and spatial distribution of the individual particles, also play a role.

It is equally important for the construction of future nanocomponents that nanomaterials can be produced with controlled “architecture”. For example, one-dimensional nanoobjects, known as nanowires, are needed for the (opto)electronics of the future and for the construction of superordinate structures.

Thanks to their specific structures and fascinating penchant for self-assembly, biomaterials make particularly interesting “molds” for the production of defined inorganic nanostructures. In particular, the amino acid cysteine easily forms coordination compounds with inorganic cations and metals.

The research team at Nankai University started with an aqueous solution of cysteine and lead acetate. At room temperature and under certain conditions, spindly bundles of nanowires form. These bundles spread out to form dandelion-like structures with a highly oriented morphology.

When heated under hydrothermal conditions, these structures decompose. Depending on the reaction conditions, hierarchical lead sulfide microstructures are formed with various attractive shapes, including spherical, needle-like, and different flower-like structures. Lead sulfide is an important semiconductor.

“Our new process enables the simple, controlled synthesis of nanowires and three-dimensional lead sulfide microstructures,” summarizes Yan. “In addition, we expect to gain new insights into the fundamental processes involved in mineralization, the transformation of bioorganic nano- and microstructures into inorganic structures. This process also occurs in living organisms, in which it plays an important role.”

Citation: Xiu-Ping Yan, Facile Shape-Controlled Synthesis of Well-Aligned Nanowire Architectures in Binary Aqueous Solution, Angewandte Chemie International Edition, doi: 10.1002/anie.200702451

Source: Angewandte Chemie

Explore further: New insights on carbonic acid in water

add to favorites email to friend print save as pdf

Related Stories

Seeing clearly through a liquid

Sep 08, 2014

Accurately examining materials in liquids using electron microscopy is a difficult task for scientists, as electron beams perturb the sample and induce artifacts. This is especially true when using in situ ...

Chromium's bonding angles let oxygen move quickly

Sep 03, 2014

By taking advantage of the natural tendency of chromium atoms to avoid certain bonding environments, scientists at DOE's Pacific Northwest National Laboratory have generated a material that allows oxygen ...

Recommended for you

Researchers developing new thermal interface materials

35 minutes ago

In the microelectronics world, the military and private sectors alike need solutions to technologic challenges. Dr. Mustafa Akbulut, assistant professor of chemical engineering, and two students lead a project ...

New insights on carbonic acid in water

15 hours ago

Though it garners few public headlines, carbonic acid, the hydrated form of carbon dioxide, is critical to both the health of the atmosphere and the human body. However, because it exists for only a fraction ...

User comments : 0