A repulsive material: New hydrogel dominated by electrostatic repulsion -- ScienceDaily

According to Yasuhiro Ishida, head of the Emergent Bioinspired Soft Matter Research Team, the work began from a surreptitious discovery, that when titanate nano-sheets are suspended in an aqueous colloidal dispersion, they align themselves face-to-face in a plane when subjected to a strong magnetic field. The field maximizes the electrostatic repulsion between them and entices them into a quasi-crystalline structure. They naturally orient themselves face to face, separated by the electrostatic forces between them.

To create the new material, the researchers used the newly discovered method to arrange layers of the sheets in a plane, and once the sheets were aligned in the plane, fixed the magnetically induced structural order by transforming the dispersion into a hydrogel using a procedure called light-triggered in-situ vinyl polymerization. Essentially, pulses of light are used to congeal the aqueous solution into a hydrogel, so that the sheets could no longer move.

By doing this, they created a material whose properties are dominated by electrostatic repulsion, the same force that makes our hair stand end when we touch a van generator.

A repulsive material: New hydrogel dominated by electrostatic repulsion 

Green meets Nano: Scientists create multifunctional nanotubes using nontoxic materials

A doctoral student in materials science at Technische Universität Darmstadt is making multifunctional nanotubes of gold -- with the help of vitamin C and other harmless substances.

Coffee, apple juice, and vitamin C: things that people ingest every day are experimental material for chemist Eva-Maria Felix. The doctoral student in the research group of Professor Wolfgang Ensinger in the Department of Material Analysis is working on making nanotubes of gold. She precipitates the precious metal from an aqueous solution onto a pretreated film with many tiny channels. The metal on the walls of the channels adopts the shape of nanotubes; the film is then dissolved. The technique itself is not new, but Felix has modified it: "The chemicals that are usually used for this were just too toxic for me." She preferred not to use cyanide, formaldehyde, arsenic and heavy metal salts. She was inspired by a journal article by researchers who achieved silver precipitation using coffee.

Felix also used coffee in her first experiments. She then tested apple juice, followed by vitamin C. This seemed to be the best suited to her because "you never know what's in coffee and apple juice." On the other hand, Vitamin C -- or ascorbic acid -- is available in pure form from chemical stores -- a requirement for reproducible studies. But what does the vitamin have to do with the precipitation of gold? In the human body, vitamin C makes free radicals harmless by transferring electrons to them. "Gold precipitation functions according to the same principle. The only difference is that the vitamin does not take on radicals, but rather gold ions," explains Falk Münch, a postdoctoral researcher and supervisor of Felix' PhD thesis. The gold ions that are dissolved in the precipitation bath are transformed into metallic gold after absorbing electrons.

Green meets Nano: Scientists create multifunctional nanotubes using nontoxic materials  

Green meets Nano: Scientists create multifunctional nanotubes using nontoxic materials

A doctoral student in materials science at Technische Universität Darmstadt is making multifunctional nanotubes of gold -- with the help of vitamin C and other harmless substances.

Coffee, apple juice, and vitamin C: things that people ingest every day are experimental material for chemist Eva-Maria Felix. The doctoral student in the research group of Professor Wolfgang Ensinger in the Department of Material Analysis is working on making nanotubes of gold. She precipitates the precious metal from an aqueous solution onto a pretreated film with many tiny channels. The metal on the walls of the channels adopts the shape of nanotubes; the film is then dissolved. The technique itself is not new, but Felix has modified it: "The chemicals that are usually used for this were just too toxic for me." She preferred not to use cyanide, formaldehyde, arsenic and heavy metal salts. She was inspired by a journal article by researchers who achieved silver precipitation using coffee.

Felix also used coffee in her first experiments. She then tested apple juice, followed by vitamin C. This seemed to be the best suited to her because "you never know what's in coffee and apple juice." On the other hand, Vitamin C -- or ascorbic acid -- is available in pure form from chemical stores -- a requirement for reproducible studies. But what does the vitamin have to do with the precipitation of gold? In the human body, vitamin C makes free radicals harmless by transferring electrons to them. "Gold precipitation functions according to the same principle. The only difference is that the vitamin does not take on radicals, but rather gold ions," explains Falk Münch, a postdoctoral researcher and supervisor of Felix' PhD thesis. The gold ions that are dissolved in the precipitation bath are transformed into metallic gold after absorbing electrons.

Green meets Nano: Scientists create multifunctional nanotubes using nontoxic materials  

Nanotubes may restore sight to blind retinas

Retinal degeneration is one of the most worrisome dangers in the aging process. Now researchers have made an important technological breakthrough towards a prosthetic retina that could help alleviate conditions that result from problems with this vital part of the eye.

New progress towards a prosthetic retina could help alleviate conditions that result from problems with this vital part of the eye. An encouraging new study published in Nano Letters describes a revolutionary novel device, tested on animal-derived retinal models, that has the potential to treat a number of eye diseases. The proof-of-concept artificial retina was developed by an international team led by Prof. Yael Hanein of Tel Aviv University's School of Electrical Engineering and head of TAU's Center for Nanoscience and Nanotechnology and including researchers from TAU, the Hebrew University of Jerusalem, and Newcastle University.

"Compared to the technologies tested in the past, this new device is more efficient, more flexible, and can stimulate neurons more effectively," said Prof. Hanein. "The new prosthetic is compact, unlike previous designs that used wires or metals while attempting to sense light. Additionally, the new material is capable of higher spatial resolution, whereas older designs struggled in this area."

A natural shape

The researchers combined semiconductor nanorods and carbon nanotubes to create a wireless, light-sensitive, flexible film that could potentially replace a damaged retina. The researchers tested the new device with chick retinas which were not yet light sensitive to prove that the artificial retina is able to induce neuronal activity in response to light.

Patients with age-related macular degeneration (AMD), which usually affects people age 60 or older who have damage to a specific part of the retina, will stand to benefit from the nanotube device if it is proved compatible in animals over the long term.

According to TAU doctoral student and research team member Dr. Lilach Bareket, there are already medical devices that attempt to treat visual impairment by sending sensory signals to the brain. While scientists are trying different approaches to develop an implant that can "see" light and send visual signals to a person's brain, to counter the effects of AMD and related vision disorders, many of these approaches require the use of metallic parts and cumbersome wiring or result in low resolution images. The researchers set out to make a more compact device.

Nanotubes may restore sight to blind retinas

Buckyballs enhance carbon capture

Amines bound by buckyballs can absorb carbon dioxide from emissions at industrial plants and at natural gas wells, according to new research. Tests from one to 50 atmospheric pressures showed the newly developed compound captured a fifth of its weight in carbon dioxide but no measurable amount of methane.

The Rice lab of chemist Andrew Barron revealed in a proof-of-concept study that amine-rich compounds are highly effective at capturing the greenhouse gas when combined with carbon-60 molecules.

The research is the subject of an open-access paper today in Nature's online journal Scientific Reports.

"We had two goals," Barron said. "One was to make the compound 100 percent selective between carbon dioxide and methane at any pressure and temperature. The other was to reduce the high temperature needed by other amine solutions to get the carbon dioxide back out again. We've been successful on both counts."

Tests from one to 50 atmospheric pressures showed the Rice compound captured a fifth of its weight in carbon dioxide but no measurable amount of methane, Barron said, and the material did not degrade over many absorption/desorption cycles.

Carbon-60, the soccer ball-shaped molecule also known as buckminsterfullerene (or the "buckyball") was discovered at Rice by Nobel Prize laureates Richard Smalley, Robert Curl and Harold Kroto in 1985. The ultimate curvature of buckyballs may make them the best possible way to bind amine molecules that capture carbon dioxide but allow desirable methane to pass through.

Bucky balls enhance carbon capture  

Atmospheric carbon dioxide used for energy storage products

Researchers have discovered a fascinating new way to take some of the atmospheric carbon dioxide that's causing the greenhouse effect and use it to make an advanced, high-value material for use in energy storage products.

Atmospheric carbon dioxide used for energy storage products  

Breakthrough in flexible electronics enabled by inorganic-based laser lift-off

A research team led by Prof. Keon Jae Lee of KAIST provides an easier methodology  to  realize  high  performance flexible electronics by using the  Inorganic-based Laser  Lift-off  (ILLO),  which  enables    nanoscale processes  for   high   density   flexible   devices and    high temperature processes that were previously difficult to achieve on plastic substrates.

Breakthrough in flexible electronics enabled by inorganic-based laser lift-off  

Engineers make sound loud enough to bend light on a computer chip: Device could improve wireless communications systems

University of Minnesota engineering researchers have developed a chip on which both sound wave and light wave are generated and confined together so that the sound can very efficiently control the light. The novel device platform could improve wireless communications systems using optical fibers and ultimately be used for computation using quantum physics.

The research was recently published in Nature Communications. 

The University of Minnesota chip is made with a silicon base coated with a layer of aluminum nitride that conducts an electric change. Applying alternating electrical signal to the material causes the material to deform periodically and generate sound waves that grow on its surface, similar to earthquake waves that grow from the center of the earthquake. The technology has been widely used in cell phones and other wireless devices as microwave filters.

"Our breakthrough is to integrate optical circuits in the same layer of material with acoustic devices in order to attain extreme strong interaction between light and sound waves," said Mo Li, assistant professor in the Department of Electrical and Computer Engineering and the lead researcher of the study.

The researchers used the state-of-the-art nanofabrication technology to make arrays of electrodes with a width of only 100 nanometers (0.00001 centimeters) to excite sound waves at an unprecedented high frequency that is higher than 10 GHz, the frequency used for satellite communications.

Engineers make sound loud enough to bend light on a computer chip: Device could improve wireless communications systems 

New method to determine surface properties at the nanoscale

Engineering researchers at Texas Tech University have developed a method for characterizing the surface properties of materials at different temperatures at the nanoscale.

Knowing properties of materials at different temperatures is important in engineering, said Gregory McKenna, a professor of chemical engineering and the John R. Bradford Endowed Chair in Engineering. For example, the rubber O-ring that failed during the 1986 space shuttle disaster serves at a tragic case study of what can go wrong when decision-makers don't take this into account.

The problem, he said, is known properties of a material can radically change at the nanoscale -- a tiny scale about 1/1000 of the diameter of a human hair at which scientists have begun building machines that do work. McKenna and graduate student Meiyu Zhai looked at several polymers and explosive materials to see how surface properties varied at the nanoscale and how the surface impacts the nanoscale properties.

Their first results on the "multi-curve method" appeared in the peer-reviewed journal, Journal of Polymer Science Part B: Polymer Physics and was highlighted in Advances in Engineering.

"The nanoscale is a funny range of sizes where materials have properties that are not what we expect, even at a step up at the microscale," he said. "We are developing methods to characterize surface properties and relate them to nanoscale behavior using a nanoindenter and other nano-mechanical measurement methods."

In nanoindentation, researchers can investigate both the elastic properties (how materials spring back when pushed) or the viscous properties (how the material flows). The group has found several surprising results: For example, in other work, the team found extremely thin polycarbonate films become liquid-like at the nanoscale, while they are glassy at the macroscopic size scale. Nanoindentation can be used to relate surface properties to this observation.

As machines get smaller and smaller, McKenna said, knowing this information can be invaluable to future engineers.

New method to determine surface properties at the nanoscale

Nanomolar chemistry enables 1500 experiments in a single day

Chemists at pharma giant Merck have conducted over 1500 chemistry experiments in under a day thanks to a miniaturised, high throughput automation platform they developed for identifying how synthetic molecules react under various conditions. The work could speed up drug discovery and provide chemists with a tool kit to explore new medicinal compounds.

The discovery of drug leads involves synthesising complex molecules and then screening them to identify how they react under various conditions including temperature and concentration. However, a typical screen might require 10mg of a compound to get just one data point, while state-of-the-art methods achieve the same with 1mg of material. Not only is this time consuming, but every milligram is precious in medicinal chemistry and the substrates needed to synthesise complex molecules are invariably in short supply.

Frustrated by these problems, which mean many molecules designed at Merck never get made or tested, Tim Cernak, Spencer Dreher and colleagues at Merck Research Laboratories in Rahway in the US, have found a solution. They combined the robotics used in biotechnology with high throughput mass spectrometry techniques to produce between 50 and 500 times more reaction data than existing methods. The team demonstrated their nanomole-scale method could execute 1536 chemistry experiments in less than a day with as little as 20µg of material per reaction.

'We are excited about how this technique could encourage the use of new chemistries in drug discovery,' says Dreher. 'Medicinal chemists tend to steer towards the reactions they can trust as there’s little time and material for reactions that might fail. We hope that, initially, the adoption of this approach can help medicinal chemists try out a new reaction on their complex substrate without burning up time and material.'

'You have to make the molecule to test your hypothesis of what it might do so you need a reaction that works – some reactions fail more than 50% of the time on drug-like substrates and that disconnect spurred 

Nanomolar chemistry enables 1500 experiments in a single day