#Bending helps to control nanomaterials A new remedy has been found to tackle the difficulty of controlling layered nanomaterials.
The mechanism was observed by Academy Research Fellow Pekka Koskinen from the Nanoscience Center of the University of Jyväskylä together with his colleagues from the University of Massachusetts Amherst in the US.
The group investigated the Van der waals nanomaterials which consist of stacked and loosely bound two-dimensional atomic layers.
According to Koskinen the observation advances research in nanoelectronics and optoelectronics because it markedly simplifies the interpretation and understanding of the electronic and optical properties of layered materials.
In nanoscience experimental and theoretical research advance side by side. This time the prediction came first and now we eagerly await for an experimental confirmation Koskinen says.
P. Koskinen I. Fampiou A. Ramasubramaniam Density-Functional Tight-Binding Simulations of Curvature-Controlled Layer Decoupling and Bandgap Tuning in Bilayer Mos2 Physical Review Letters
#Nanoparticles on track to distinguish tumour tissue Gold nanoparticles could be used to help detect the margins between tumours and normal tissue,
enabling surgeons to better determine which tissue to remove and which to leave. Research by Jeremy Duczynski from the University of WA's School of Chemistry and Biochemistry investigated
whether the nanoparticles would work as effective optical contrast agents to provide an estimate of the size and shape of tumour margins during surgery.
Optical coherence tomography (OCT) is developed a recently high-resolution imaging test but one of its limitations is an inability to distinguish between some types of healthy tissue and tumours.
Other imaging tests use dye administered to patients to distinguish between different tissue typeslthough to date, no such dyes exist for OCT. Mr Duczynski says OCT is analogous to ultrasound,
"Most research has been done with straight gold nanoparticles as contrast agents but the problem with them is they absorb light very strongly.
"Silica-gold nanoparticles provide greater contrast, visibility To get around this, Mr Duczynski used silica nanoparticles coated with a gold shell (silica-gold core-shell nanoparticles) in his research."
"There are some theoretical and experimental papers where it was observed that by varying the dimensions of either the silica core
or gold shell you could also vary the scattering ratio of the particles, "he says."
because the test requires a high scattering of light at about 850 nanometres for good image contrast."
"Ultraviolet spectroscopy was used on the silica-gold core-shell nanoparticles made by Mr Duczynski to better understand their optical properties, such as extinction, scattering and absorption.
The research also involved the development of iron oxide-gold core shell nanoparticles.""This particle system was attempted because
I was having difficulty with shelling the silica particles, "Mr Duczynski says.""I was able to see some scattering of the iron oxide-gold core-shell nanoparticles,
meaning they could possibly be pursued as another contrast agent for OCT."Iron oxide is also magnetic,
meaning these particles could be used as a multimodal contrast agent for imaging techniques such as MRI magnetic resonance imaging. g
When University of Illinois Associate professor of Chemical and Biomolecular engineering Hyunjoon Kong graduate student Cartney Smith and colleagues set out to improve MR imaging (MRI) they turned current contrast agent technology on its head
The new compound they designed in collaboration with Illinois'Roger Adams Professor of Chemistry Steven C. Zimmerman is not only more effective but also self-assembling.
Kong is also a member of the Regenerative Biology and Tissue Engineering research theme at the Institute for Genomic Biology.
When doctors perform an MRI they administer a contrast agent: a chemical that when injected into the bloodstream
and internal bleeding contains gadolinium a rare-earth metal. Recently biomedical researchers have found ways to increase the effectiveness of certain contrast agents by associating them with nanoparticles.
The contrast agent being used is packaged inside or bonded to the surface of microscopic particles which can be designed to target certain regions of the body
Researchers are now exploring the multipurpose use of nanoparticles. If particles could be loaded with several types of contrast agents
or dyes instead of one or a contrast agent along with another type of diagnostic aid or a medication doctors could more efficiently test for
and limit the number of injections received by patients. Just like toddlers sharing a new toy
though compounds packaged together into a nanoparticle cannot always play well together. For example contrast agents may bind to other chemicals reducing their effectiveness.
In addition when contrast agents are enclosed inside a nanoparticle they may not work as well. Attempts to attach agents to the outer surface of nanoparticles via covalent formation are also problematic as they can negatively affect the activity of the nanoparticles or the compounds that they carry.
Kong Smith and colleagues tackled these challenges by using interactions between naturally occurring biomolecules as a guide.
Many types of proteins are attached strongly to cell membranes not by covalent bonds but by the sum of multiple weaker forces the attraction of positive and negative charges and the tendency of nonpolar (oil-like) substances to seek each other
The group hypothesized that the same types of forces could be used to attach a contrast agent to the surface of a type of nanoparticle called a liposome
Gadolinium stably associated with the modified nanoparticles in solution and experiments in animal models showed that these nanoparticles produced clear diagnostic images.
The strategy works like Velcro on a molecular level to adhere functional units to the outer leaflet of a liposome said Smith who was first author on the study.
This work represents a new material design strategy that is scalable and easily implemented. The development of improved contrast agents has the potential to directly impact patients'lives by detecting damaged blood vessels.
One of the difficulties of working with liposomes is their tendency to degrade inside the body.
10.1021/la500412r) Kong and Smith developed a process for chemically cross-linking the components of the nanoparticle that prolonged the life of the nanoparticles in biological conditions.
Nanoparticle pinpoints blood vessel plaque e
#Liberating devices from their power cords: New structural'supercaps'take a lickin'keep on workin'Imagine a future in which our electrical gadgets are limited no longer by plugs and external power sources.
This intriguing prospect is one of the reasons for the current interest in building the capacity to store electrical energy directly into a wide range of products,
such as a laptop whose casing serves as its battery, or an electric car powered by energy stored in its chassis,
or a home where the dry wall and siding store the electricity that runs the lights and appliances.
It also makes the small dull grey wafers that graduate student Andrew Westover and Assistant professor of Mechanical engineering Cary Pint have made in Vanderbilt's Nanomaterials
and Energy Devices Laboratory far more important than their nondescript appearance suggests.""These devices demonstrate for the first time as far as we can tell that it is possible to create materials that can store
and discharge significant amounts of electricity while they are subject to realistic static loads and dynamic forces,
such as vibrations or impacts,"said Pint.""Andrew has managed to make our dream of structural energy storage materials into a reality."
"That is important because structural energy storage will change the way in which a wide variety of technologies are developed in the future."
"When you can integrate energy into the components used to build systems, it opens the door to a whole new world of technological possibilities.
The new device that Pint and Westover has developed is a supercapacitor that stores electricity by assembling electrically charged ions on the surface of a porous material,
instead of storing it in chemical reactions the way batteries do. As a result supercaps can charge
and discharge in minutes, instead of hours, and operate for millions of cycles, instead of thousands of cycles like batteries.
In a paper appearing online May 19 in the journal Nano Letters, Pint and Westover report that their new structural supercapacitor operates flawlessly in storing
and releasing electrical charge while subject to stresses or pressures up to 44 psi and vibrational accelerations over 80 g (significantly greater than those acting on turbine blades in a jet engine).
Furthermore, the mechanical robustness of the device doesn't compromise its energy storage capability.""In an unpackaged, structurally integrated state our supercapacitor can store more energy
and operate at higher voltages than a packaged, off-the-shelf commercial supercapacitor, even under intense dynamic and static forces,
"Pint said. One area where supercapacitors lag behind batteries is in electrical energy storage capability: Supercaps must be larger and heavier to store the same amount of energy as lithium-ion batteries.
However, the difference is not as important when considering multifunctional energy storage systems.""Battery performance metrics change when you're putting energy storage into heavy materials that are needed already for structural integrity,
"said Pint.""Supercapacitors store ten times less energy than current lithium-ion batteries, but they can last a thousand times longer.
That means they are suited better for structural applications. It doesn't make sense to develop materials to build a home, car chassis,
or aerospace vehicle if you have to replace them every few years because they go dead."
"Westover's wafers consist of electrodes made from silicon that have been treated chemically so they have nanoscale pores on their inner surfaces
and then coated with a protective ultrathin graphene-like layer of carbon. Sandwiched between the two electrodes is a polymer film that acts as a reservoir of charged ions, similar to the role of electrolyte paste in a battery.
When the electrodes are pressed together, the polymer oozes into the tiny pores in much the same way that melted cheese soaks into the nooks and crannies of artisan bread in a Panini.
When the polymer cools and solidifies it forms an extremely strong mechanical bond.""The biggest problem with designing load-bearing supercaps is preventing them from delaminating,
"said Westover.""Combining nanoporous material with the polymer electrolyte bonds the layers together tighter than superglue."
"The use of silicon in structural supercapacitors is suited best for consumer electronics and solar cells, but Pint and Westover are confident that the rules that govern the load-bearing character of their design will carry over to other materials, such as carbon nanotubes and lightweight porous metals like aluminum.
The intensity of interest in"multifunctional"devices of this sort is reflected by the fact that the U s. Department of energy's Advanced Research Project Agency for Energy is investing $8. 7 million in research projects that focus specifically on incorporating energy storage into structural materials.
There have also been recent press reports of several major efforts to develop multifunctional materials or structural batteries for use in electric vehicles and for military applications.
However Pint pointed out that there have not been any reports in the technical literature of tests performed on structural energy storage materials that show how they function under realistic mechanical loads l
#Ultra-sensitive nano-chip capable of detecting cancer at early stages developed Today the majority of cancers are detected on the macroscopic level
when the tumor is composed already of millions of cancer cells and the disease is starting to advance into a more mature phase.
But what if we could diagnose cancer before it took hold -while it was still only affecting a few localized cells?
It would be like putting a fire out while it was still just a few sparks
versus after having already caught on and spread to many areas of the house. An international team of researchers led by ICFO-Institute of Photonic Sciences in Castelldefels announce the successful development of a lab-on-a-chip platform capable of detecting protein cancer markers in the blood using the very latest advances
in plasmonics nanofabrication microfluids and surface chemistry. The device is able to detect very low concentrations of protein cancer markers in blood enabling diagnoses of the disease in its earliest stages.
The detection of cancer in its very early stages is seen as key to the successful diagnosis and treatment of this disease.
This cancer-tracking nanodevice shows great promise as a tool for future cancer treatments not only because of its reliability sensitivity and potential low cost but also because of its easy carry on portable properties which is foreseen to facilitate effective diagnosis and suitable
treatment procedures in remote places with difficult access to hospitals or medical clinics. Although very compact (only a few square centimeters) the lab-on-a-chip hosts various sensing sites distributed across a network of fluidic micro-channels that enables it to conduct multiple analyses.
Gold nanoparticles lie on the surface of the chip and are programed chemically with an antibody receptor in such a way that they are capable of specifically attracting the protein markers circulating in blood.
When a drop of blood is injected into the chip it circulates through the micro-channels
and if cancer markers are present in the blood they will stick to the nanoparticles located on the micro-channels as they pass by setting off changes in
what is known as the plasmonic resonance. The device monitors these changes the magnitude of which are directly related to the concentration/number of markers in the patient blood
thus providing a direct assessment of the risk for the patient to develop a cancer.
ICREA Professor at ICFO Romain Quidant coordinator of the project comments the most fascinating finding is that we are capable of detecting extremely low concentrations of this protein in a matter of minutes making this device an ultra-high sensitivity state-of-the-art
powerful instrument that will benefit early detection and treatment monitoring of cancer. In 2009 Prof.
Quidant's research group at ICFO in collaboration with several groups of oncologists joined the worldwide effort devoted to the ultra-sensitive detection of protein markers located on the surface of cancer cells and in peripheral blood
which had been determined to be a clear indicator of the development of cancer. In 2010 they successfully obtained funding for the project called SPEDOC (Surface Plasmon Early Detection of Circulating Heat shock proteins and Tumor Cells) under the 7th Framework Program (FP7) of the European commission.
The effort was boosted also by generous philanthropic support from Cellex Foundation Barcelona. Today's announcement is an important outcome of this project t
#Stronger black solar coating that retains original color and absorption properties Solar thermal panels developed at EPFL are are dressed up in unique and patented new materials.
Researchers created a stronger black coating that retains its original color and thereby its absorption properties much longer than traditional panels.
Like most elements of a building, the lifespan of a solar thermal panel is between 25 and 30 years.
To slow the aging process and maintain their performance, a team of researchers from EPFL have,
in rapid succession, improved the black coating used for thermal sensors and developed an original and patented method for depositing the coating.
The color black is at the key element of thermal panels because it can absorb up to 90%of the energy it receives.
However, over time, the effects of light and heat deteriorate the black, and the panel becomes less efficient.
Engineers have developed an innovative process that deposits thin layers of 3 different materials that are more resistant,
more selective and less toxic than the chromium used thus far. As such this new material provides high durability in the open air at temperatures of 300°C to 400°C,
thus avoiding the use of glass vacuum tubes, which are expensive. Martin Joly, of the Laboratory of Solar energy and Building Physics, researched a novel process for the conversion of solar thermal energy.
He developed a nano crystalline coating which shows exceptional resistance to high temperatures. It abandons the black chromium that was used for panels currently on the market in favor of a multilayer composite of cobalt for its corrosion resistance, manganese for black,
and copper for its thermal conductivity.""We wanted to develop selective layers that absorb light well
and that are less toxic than chromium. That's why we followed the trail of these materials."
"Layers deposited by a chemical process boast an exceptional heat resistance that was achieved never with traditional chromium coatings.
In fact, they can withstand temperatures of 360 degrees Celcius without deteriorating in contact with air.
For a flat sensor, the actual average temperature is about 80°C, and in summer the temperature can reach 200°C. Regularly exposed to air and moisture,
the sensor must last for 25 years on a building, which is not so easy.""The durability of our materials at temperatures exceeding 360°C could also be of interest to thermal power plants,
"says Andreas Schüler, who heads the research team. In order to cast the 3 different elements in thin and homogeneous layers,
the researchers did not hesitate to work in full scale:""When researching nanoparticles, you normally use samples.
For us, we set the challenge to coat 2 meters long stainless steel tubes, "explains the researcher.
To achieve this, the scientists had to build suitable machines for their project. Materials are deposited by successive dipping,
and each layer is heated by induction which evaporates the carbon and fixes the elements.""We started by buying simple resistors then tried induction
and obtained results that far exceeded our expectations, "says the researcher. This method has the advantage of being rapid, with impressive energy efficiency and an improved quality in the results.
And the layers are deposited perfectly and homogeneous. What's more, a patent has been filed on this new method.
The work conducted by Martin Joly has resulted in two publications. One in Solar energy, on the black chromium-free components and their optical properties, won the best paper award from 2012013
#Using light to identify chiral molecules for pharmaceuticals A combination of nanotechnology and a unique twisting property of light could lead to new methods for ensuring the purity and safety of pharmaceuticals.
A direct relationship between the way in which light is twisted by nanoscale structures and the nonlinear way in
which it interacts with matter could be used to ensure greater purity for pharmaceuticals, allowing for'evil twins'of drugs to be identified with much greater sensitivity.
Researchers from the University of Cambridge have used this relationship, in combination with powerful lasers and nanopatterned gold surfaces
to propose a sensing mechanism that could be used to identify the right-handed and left-handed versions of molecules.
Some molecules are symmetrical, so their mirror image is an exact copy. However, most molecules in nature have a mirror image that differs-try putting a left-handed glove on to your right hand
One chiral form of Thalidomide worked as an effective treatment for morning sickness in early pregnancy,
resulting in more than 10,000 children worldwide being born with serious birth defects, such as shortened or missing limbs.
Researchers from the University of Cambridge have designed a new type of sensing mechanism, combining a unique twisting property of light with frequency doubling to identify different chiral forms of molecules with extremely high sensitivity,
The sensing mechanism, designed by Dr Ventsislav Valev and Professor Jeremy Baumberg from the Cavendish Laboratory, in collaboration with colleagues from the UK and abroad, uses a nanopatterned gold surface in combination with powerful lasers.
The researchers also used tiny gold structures, known as plasmonic nanostructures, to focus the beams of light.
Just as a glass lens can be used to focus sunlight to a certain spot, these plasmonic nanostructures concentrate incoming light into hotspots on their surface,
"By using nanostructures, lasers and this unique twisting property of light, we could selectively destroy the unwanted form of the molecule,
#Silly Putty material inspires better batteries Using a material found in Silly Putty and surgical tubing, a group of researchers at the University of California,
Riverside Bourns College of Engineering have developed a new way to make lithium-ion batteries that will last three times longer between charges compared to the current industry standard.
The team created silicon dioxide (Sio2) nanotube anodes for lithium-ion batteries and found they had over three times as much energy storage capacity as the carbon-based anodes currently being used.
This has significant implications for industries including electronics and electric vehicles which are always trying to squeeze longer discharges out of batteries."
"We are taking the same material used in kids'toys and medical devices and even fast food and using it to create next generation battery materials,
"said Zachary Favors, the lead author of a just-published paper on the research. The paper,"Stable Cycling of Sio2 Nanotubes as High-performance Anodes for Lithium-Ion Batteries,"was published online in the journal Nature Scientific Reports.
It was authored co by Cengiz S. Ozkan, a mechanical engineering professor, Mihrimah Ozkan, an electrical engineering professor,
and several of their current and former graduate students: Wei Wang, Hamed Hosseinni Bay, Aaron George and Favors.
The team originally focused on silicon dioxide because it is an extremely abundant compound, environmentally friendly, nontoxic,
and found in many other products. Silicon dioxide has previously been used as an anode material in lithium ion batteries,
but the ability to synthesize the material into highly uniform exotic nanostructures with high energy density
and long cycle life has been limited. There key finding was that the silicon dioxide nanotubes are extremely stable in batteries,
which is important because it means a longer lifespan. Specifically, Sio2 nanotube anodes were cycled 100 times without any loss in energy storage capability
and the authors are highly confident that they could be cycled hundreds more times. The researchers are focused now on developed methods to scale up production of the Sio2 nanotubes in hopes they could become a commercially viable product t
#Researchers find definitive evidence of how zeolites grow Researchers have found the first definitive evidence of how silicalite-1 (MFI type) zeolites grow showing that growth is concerted a process involving both the attachment of nanoparticles and the addition of molecules.
Both processes appear to happen simultaneously said Jeffrey Rimer an engineering professor at the University of Houston
and lead author of a paper published Thursday in the journal Science. He said a second component to the research could have even more lasting impact.
He and researcher Alexandra I. Lupulescu used a new technique allowing them to view zeolite surface growth in real time a breakthrough Rimer said can be applied to other types of materials as well.
Typically researchers examine zeolite growth by removing crystals from the natural synthesis environment and analyzing changes in their physical properties said Rimer Ernest J. and Barbara M. Henley Assistant professor of Chemical and Biomolecular engineering at UH.
That has made understanding the fundamental mechanism of zeolite growth more challenging. Zeolites occur naturally but can also be manufactured.
This research involved silicalite-1 a synthetic aluminum-free zeolite that has served as a prototype in literature for studying zeolite growth.
For more than two decades researchers have theorized that nanoparticles which are known to be present in zeolite growth solutions played a role in the growth
but there was no direct evidence. And while most crystals grow through classical means the addition of atoms
or molecules to the crystal the presence and gradual consumption of nanoparticles suggested a nonclassical pathway for zeolite crystallization.
Rimer and Lupulescu found that both classical and nonclassical growth models were at work. We have shown that a complex set of dynamics takes place Rimer said.
In doing so we have revealed that there are multiple pathways in the growth mechanism which solves a problem that has been debated for nearly 25 years.
It solves a mystery in the world of crystal engineering but how they did it may have a more lasting impact.
Rimer and Lupulescu who did the project as part of her dissertation earning her Ph d. in chemical engineering from UH's Cullen College of Engineering in December worked with California-based Asylum Research.
along with software developed by Asylum Research and his lab made it possible to study the growth in situ or in place.
While his lab works at temperatures up to 100 degrees Celsius the instrumentation can handle temperatures as high as 300 C making it possible to use it for a number of materials that grow in solvothermal conditions he said.
Synthetic natural gas from excess electricity More information: In situ Imaging of Silicalite-1 Surface Growth Reveals the Mechanism of Crystallization Science 2014
#DNA double helix measurements Researchers at the National Physical Laboratory (NPL) and the London Centre for Nanotechnology (LCN) have determined the structure of DNA from measurements on a single molecule using atomic force microscopy (AFM),
The structure of these nanometre scale machines is at the heart of our understanding of health and disease,
and the DNA double helix has been the key to understanding how genetic information is stored and passed on.
and suppress the use of genetic information stored in their DNA A
#MEMS nanoinjector for genetic modification of cells The ability to transfer a gene or DNA sequence from one animal into the genome of another plays a critical role in a wide range of medical researchncluding cancer, Alzheimer's disease, and diabetes.
But the traditional method of transferring genetic material into a new cell, called"microinjection,"has a serious downside.
It involves using a small glass pipette to pump a solution containing DNA into the nucleus of an egg cell,
but the extra fluid can cause the cell to swell and destroy itesulting in a 25 to 40 percent cell death rate.
thanks to the work of researchers Brigham Young University, there's a way to avoid cell death
which was designed to inject DNA into mouse zygotes (single-cell embryos consisting of a fertilized egg)."
and repel DNALLOWING injections to occur with a tiny, electrically conductive lance,"explained Brian Jensen, associate professor in the Department of Mechanical engineering at Brigham Young University."
"DNA is attracted to the outside of the lance using positive voltage, and then the lance is inserted into a cell."
This ability to inject DNA into cells without causing cell death leads to"more efficient injections,
which in turn reduces the cost to create a transgenic animal,"according to Jensen. One of the team's most significant findings is that it's possible to use the electrical forces to get DNA into the nucleus of the cellithout having to carefully aim the lance into the pronucleus (the cellular structure containing the cell's DNA."
"This may enable future automation of the injections, without requiring manual injection, "Jensen says. It may also mean that injections can be performed in animals with cloudy or opaque embryos."
"Such animals, including many interesting larger ones like pigs, would be attractive for a variety of transgenic technologies,
"said Jensen.""We believe nanoinjection may open new fields of discovery in these animals.""As a next step, Jensen and colleagues are performing injections into cells in a cell culture using an array of lances that can inject hundreds of thousands of cells at once."
"We expect the lance array may enable gene therapy using a culture of a patient's own cells,
"he noted
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