2013 New's Items

3D Dynamic Imaging of Soft Materials

October 2, 2013

Autumn is usually not such a great time for big special effects movies as the summer blockbusters have faded and those for the holiday season have not yet opened. Fall is more often the time for thoughtful films about small subjects, which makes it perfect for the unveiling of a new movie produced by researchers at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab). Through a combination of transmission electron microscopy (TEM) and their own unique graphene liquid cell, the researchers have recorded the three-dimensional motion of DNA connected to...

Scientists Capture First-Ever Images of Molecules In Chemical Reaction

June 4, 2013

Dust off your chemistry knowledge, because a team of scientists from the University of California at Berkeley has stumbled upon a breakthrough that might influence what you remember from high school.

Using an atomic force microscope and a bit of luck, Berkeley Lab scientists captured the first-ever high-resolution images of a molecule breaking and reforming its bonds. The team was actually trying to create graphene nanostructures using a new, controlled approach to chemical reactions. (Graphene is an...

An Inside Look at a MOF in Action

November 22, 2013

A unique inside look at the electronic structure of a highly touted metal-organic framework (MOF) as it is adsorbing carbon dioxide gas should help in the design of new and improved MOFs for carbon capture and storage. Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have recorded the first in situ electronic structure observations of the adsorption of carbon dioxide inside Mg-MOF-74, an open metal site MOF that has emerged as one of the most promising strategies for capturing and storing greenhouse gases.

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Taking a New Look at Carbon Nanotubes

November 12, 2013

Despite their almost incomprehensibly small size – a diameter about one ten-thousandth the thickness of a human hair – single-walled carbon nanotubes come in a plethora of different “species,” each with its own structure and unique combination of electronic and optical properties. Characterizing the structure and properties of an individual carbon nanotube has involved a lot of guesswork – until now.

Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have developed a technique...

Quanta Magazine Q&A with Birgitta Whaley: In Pursuit of Quantum Biology

July 30, 2013

As an undergraduate at Oxford University in the mid-1970s, K. Birgitta Whaley struggled to choose between chemistry and physics. Now, as a professor at the University of California, Berkeley, and director of its Quantum Information and Computation Center, she doesn’t have to: Her research interests span all realms quantum, including both chemistry and physics, as well as computer science and her newest pursuit, quantum biology, where physics meets the life sciences.

Whaley turned her...

Researchers Discover Universal Law for Light Absorption in 2D Semiconductors

July 31, 2013

From solar cells to optoelectronic sensors to lasers and imaging devices, many of today’s semiconductor technologies hinge upon the absorption of light. Absorption is especially critical for nano-sized structures at the interface between two energy barriers called quantum wells, in which the movement of charge carriers is confined to two-dimensions. Now, for the first time, a simple law of light absorption for 2D semiconductors has been demonstrated.

Working with ultrathin membranes of the semiconductor indium arsenide, a team of researchers with the U.S. Department of Energy (DOE)’...

Introducing the Kavli Energy NanoSciences Institute

August 29, 2013

By tapping the latest advances in nanoscience, Kavli ENSI researchers plan to unravel the most intimate details of nature's energy secrets.

NATURE EXPENDS ENERGY LAVISHLY, but rarely squanders it. From photosynthesis and building proteins to virus replication and muscle contraction, her processes are efficient, some remarkably so. Yet they occur so quickly and at such infinitesimally small scales that until recently, researchers could discern only their barest outlines.

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Nucleotide and Partner-Protein Control of Bacterial Replicative Helicase Structure and Function

M. S. Strycharska
E. Arias-Palomo
A. Y. Lyubimov
J. P. Erzberger
V. L. O’Shea
C. J. Bustamante
J. M. Berger
2013

Cellular replication forks are powered by ring-shaped, hexameric helicases that encircle and unwind DNA. To better understand the molecular mechanisms and control of these enzymes, we used multiple methods to investigate the bacterial replicative helicase, DnaB. A 3.3 Å crystal structure of ...

Luminescent Solar Concentration with Semiconductor Nanorods and Transfer-Printed Micro-Silicon Solar Cells

N. D. Bronstein
L. Li
L. Xu
Y. Yao
V. E. Ferry
A. P. Alivisatos
R. G. Nuzzo
2013

We utilize CdSe/CdS seeded nanorods as a tunable lumophore for luminescent concentration. Transfer-printed, ultrathin crystalline Si solar cells are embedded directly into the luminescent concentrator, allowing the study of luminescent concentrators with an area over 5000 times the area of the solar cell. By increasing the size of the CdS rod with respect to the luminescent CdSe seed, the reabsorption of propagating photons is dramatically reduced. At long luminescence propagation distances, this reduced reabsorption can overcome the diminished quantum yield inherent to the larger...

Inorganic Micelles as Efficient and Recyclable Micellar Catalysts

Q. Zhang
X.-Z. Shu
J. M. Lucas
F. D. Toste
G. A. Somorjai
A. P. Alivisatos
2013

An “inorganic micelle” structure that has a hydrophilic cavity and hydrophobic surface has been synthesized. The inorganic micelles possess large surface area and controllable hydrophobic/hydrophilic interface. It shows high catalytic efficiency and great recyclability in the bromination of alcohols. This work suggests that inorganic micelles may be suitable for selective organic syntheses as well as industrial applications and demonstrates the value of translating nanostructure design from organic to inorganic.