Chemistry

Northwestern University graduate student Jonathan Barnes and colleagues are the first to permanently interlock two identical tetracationic rings that normally are repelled by each other.

Some experts had said it couldn't be done. 

On the surface, the rings hate each other because each carries four positive charges (making them tetracationic). But they discovered that by introducing radicals (unpaired electrons) onto the scene, the researchers could create a love-hate relationship in which love triumphs.

Unpaired electrons want to pair up and be stable, and it turns out the attraction of one ring's single electrons to the other ring's single electrons is stronger than the repelling forces.

Researchers in Spain have mixed paper industry waste with ceramic material used in the construction industry and created a brick that has low thermal conductivity and so is a good insulator. 

What's the catch? Its mechanical resistance still requires improvement. 

The scientists collected cellulous waste from a paper factory (recycled) along with sludge from the purification of its waste water. In their laboratory they then mixed this material with clay used in construction and passed the mixture through a pressure and extrusion machine to obtain bricks.

A research team has tested a popular zinc hypothesis in paleo-ocean chemistry and concluded it is false.

Rose madder, a natural plant dye once prized throughout the Old World to make fiery red textiles, might be cool once again. 

Chemists have developed a non-toxic and sustainable lithium-ion battery powered by purpurin, a dye extracted from the roots of the madder plant (Rubia species).

Over 3,500 years ago, civilizations in Asia and the Middle East first boiled madder roots to dye fabrics in orange, pink and red but the climbing herb might also lay the foundation for an eco-friendly alternative to traditional lithium-ion (Li-ion) batteries in the 21st century.  Lithium-ion batteries are great for consumers but costs to the environment for production, recycling and disposal are high.

One way to clean up hazardous heavy metals like arsenic, lead and mercury in contaminated materials could be to use waste from the processing and canning of onions (Allium cepa L.) and garlic (Allium sativum L.)

Biotechnologists Rahul Negi, Gouri Satpathy, Yogesh Tyagi and Rajinder Gupta of the GGS Indraprastha University in Delhi studied the influence of acidity or alkalinity, contact time, temperature and concentration of the different materials present to optimize conditions for making a biological heavy metal filter for industrial-scale decontamination.

Teflon is popular, used on everything from cooking pans to armor-piercing bullets, but it has a waste byproduct, fluoroform, which has to be stored by chemical companies because it has an estimated global warming potential 11,700 times higher than carbon dioxide. 

The world's smallest reaction chamber has a mixing volume that can be measured in femtoliters - that's a million billionths of a liter.

The reaction chamber actually consists of nothing more than a tiny spray of liquid, produced by a technique known as electrospray ionization, in which a liquid is converted into lots of charged droplets by exposing it to a high voltage as it exits the nozzle of a thin capillary.

Like water being sprayed out of a hose, these charged droplets form a cone shape, known as a Taylor cone, as they are emitted from the nozzle. Because the electrospray process transforms any chemical entities within the liquid into ions, it is a commonly used technique for ionizing a liquid sample prior to analysis by mass spectrometry.

Chemists have been using
the SPring-8 synchrotron at the Japan Synchrotron Radiation Research Institute
to get a detailed look at enzymes that could help power the green economy. 

One option for powering clean, environment friendly vehicles is to run them on hydrogen fuel rather than carbon-based fuels. Cheap catalysts to prepare hydrogen gas (H2) are a necessity if this future "hydrogen economy" is to become a reality.

Current man-made catalysts are based on platinum, a rare and precious metal. However, living cells contain enzymes called hydrogenases, based on the abundant metals nickel and iron, which can do the same job. Chemists are very interested in figuring out how these natural catalysts work and trying to mimic them.

The wetting model is a classical problem in surface and biomimetic science.  Wettability is determined by the balance between adhesive and cohesive forces, adhesive which is when a liquid tries to spread on a surface and cohesive when it forms into a ball.

The resultant between adhesive and cohesive forces is called the contact angle. As the tendency of a drop to spread out over a surface increases, the contact angle decreases, making the contact angle an inverse measure of wettability.

Researchers have unveiled a new way to use sunlight to produce steam and other vapors without heating an entire container of fluid to the boiling point. The research could lead to inexpensive, compact devices for purification of drinking water, sterilization of medical instruments and sanitizing sewage. 

Metallic nanoparticles - so small that 1,000 would fit across the width of a human hair - absorb large amounts of light, resulting in a dramatic rise in their temperature. That ability to generate heat has fostered interest among scientists in using nanoparticles in a range of applications. These include photothermal treatment of certain forms of cancer, laser-induced drug release and nanoparticle-enhanced bioimaging.