Category Chemistry/Nanotechnology

Abiogenesis: blue-green algae in a hot spring, Yellowstone National Park

Earth’s oxygen-rich atmosphere emerged in whiffs from a kind of blue-green algae in shallow oceans around 2.5 billion years ago, according to new research from Canadian and US scientists. These whiffs of oxygen likely happened in the following 100 million years, changing the levels of oxygen in Earth’s atmosphere until enough accumulated to create a permanently oxygenated atmosphere around 2.4 billion years ago – a transition widely known as the Great Oxidation Event.

The team presents new isotopic data showing that a burst of oxygen production by photosynthetic cyanobacteria temporarily increased oxygen concentrations in Earth’s atmosphere...

QA_Cn incorporated in a composite resin system.

Material scientist Andreas Hermann, orthodontist Yijin Ren et al have made a 3D printing substrate which kills bacteria on contact. The first applications will be in dentistry, but other implants may follow.

‘The director of Kolff, who is head of the Orthodontics Department, asked me if I could come up with an antimicrobial dental glue’, Herrmann explains. Kids with braces have small metal blocks glued to their teeth, and these are an ideal breeding ground for the microbes that cause tooth decay. ‘So when I saw all sorts of 3D printed objects for use in dentistry in her office, I said: why not incorporate the antimicrobials in 3D prints?’ The results were published after 2.5 years of work.

In dentistry, it is standard practice to work with ma...

A hybrid 3-D optical microscope – mass spectrometry map showing optical brightness (height) and chemical distribution of poly(2vinylpyridine) (red) and poly(N-vinylcarbazole) (blue) signals of a 20 micron-by-20 micron area of a polymer blend. (ORNL/DOE)

The hybrid optical microscope/mass spectrometry-based imaging system developed at the Department of Energy’s Oak Ridge National Laboratory operates under ambient conditions and requires no pretreatment of samples to analyze chemical compounds with sub-micron resolution. One micron is equal to about 1/100th the width of a human hair.

“Knowing the chemical basis of material interactions that take place at interfaces is vital for designing and advancing new functional materials that are important for DOE missions such as organic photovoltaic...

An advance in the storage of concentrated solar thermal energy may reduce reduce its cost and make it more practical for wider use. Credit: Graphic by Kelvin Randhir, courtesy of the University of Florida

New approach for storage of concentrated solar thermal energy has been found, to reduce cost and make it more practical for wider use. The advance is based on thermochemical storage, in which chemical transformation is used in repeated cycles to hold heat, use it to drive turbines, and then be re-heated to continue the cycle. Most commonly this might be done over a 24 hour period, with variable levels of solar-powered electricity available at any time of day, as dictated by demand.

Conceptually, all of the energy produced could be stored indefinitely and used later when the electricity is...