14 Feb 2017
Creating a Life-Saving, Blood-Repellent Super Material – Revolutionizing Medical Implants: Colorado State University
Goodbye Rejection – Implanted medical devices like stents, catheters, and titanium rods are essential, life-saving tools for patients around the world. Still, having a foreign object in the human body does pose its own risks – chiefly, having the body reject the object or increasing the risk of dangerous blood clots. A new collaboration between two distinct scientific disciplines is working toward making those risks a concern of the past.
Biomedical engineers and materials scientists from Colorado State University (CSU) ….
Florida State University College of Engineering Assistant Professor Shangchao Lin has published a new paper in the journal ACS Nano that predicts how an organic-inorganic hybrid material called organometal halide perovskites could be more mechanically flexible than existing silicon and other inorganic materials used for solar cells, thermoelectric devices and light-emitting diodes.
What if every vehicle, home appliance, heating system and light switch were connected to the Internet? Today, that’s not such a stretch of the imagination.
Modern cars, for instance, already have hundreds of sensors and multiple computers connected over an internal network. And that’s just one example of the 6.4 billion connected “things” in use worldwide this year, according to research by Gartner Inc. DHL and Cisco Systems offer even higher estimates—their 2015 Trend Report sets the current number of connected devices at about 15 billion, amidst industry expectations that the tally will increase to 50 billion by 2020.
Read Today’s Top Stories in Nanotechnology and the ‘Business’ of Nanotechnology.
Stories about the Discoveries and Technologies that will reshape our world and drive New Economic Engines for the Future.
and much more …
Genesis Nanotechnology, Inc. ~ “Great Things from Small Things”
25 Jun 2016
Northwestern University: The Power of the “Gene Chip” Coming to Nanotechnology: Ability to Rapidly Test Millions/ Billions of Nanoparticles at ONE Time
Plus More …. Click on the Link Below To Read This Week’s Publication
Genesis Nanotechnology, Inc. ~ “Great Things from Small Things”
Large quantities of steel are used in architecture, bridge construction and ship-building. Structures of this type are intended to be long-lasting. Furthermore, even in the course of many years, they must not lose any of their qualities regarding strength and safety. For this reason, the steel plates and girders used must have extensive and durable protection against corrosion. In particular, the steel is attacked by oxygen in the air, water vapor and salts. Nowadays, various techniques are used to prevent the corrosive substances from penetrating into the material. One common method is to create an anti-corrosion coating by applying layers of zinc-phosphate. Now, research scientists at INM — Leibniz Institute for New Materials developed a special type of zinc-phosphate nanoparticles. In contrast to conventional, spheroidal zinc-phosphate nanoparticles, the new nanoparticles are flake-like. They are ten times as long as they are thick. As a result of this anisotropy, the penetration of gas molecules into the metal is slowed down.
The developers will be demonstrating their results and the possibilities they offer at stand B46 in hall 2 at this year’s Hanover Trade Fair as part of the leading trade show Research & Technology which takes place from 25th to 29th April.
“In first test coatings, we were able to demonstrate that the flake-type nanoparticles are deposited in layers on top of each other thus creating a wall-like structure,” explained Carsten Becker-Willinger, Head of Nanomers® at INM. “This means that the penetration of gas molecules through the protective coating is longer because they have to find their way through the ´cracks in the wall´.” The result, he said, was that the corrosion process was much slower than with coatings with spheroidal nanoparticles where the gas molecules can find their way through the protective coating to the metal much more quickly.
In further series of tests, the scientists were able to validate the effectiveness of the new nanoparticles. To do so, they immersed steel plates both in electrolyte solutions with spheroidal zinc-phosphate nanoparticles and with flake-type zinc-phosphate nanoparticles in each case. After just half a day, the steel plates in the electrolytes with spheroidal nanoparticles were showing signs of corrosion whereas the steel plates in the electrolytes with flake-type nanoparticles were still in perfect condition and shining, even after three days. The researchers created their particles using standard, commercially available zinc salts, phosphoric acid and an organic acid as a complexing agent. The more complexing agent they added, the more anisotropic the nanoparticles became.
INM conducts research and development to create new materials — for today, tomorrow and beyond. Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new, how can they be investigated and how can they be tailored for industrial applications in the future?
Four research thrusts determine the current developments at INM:
- New materials for energy application,
- New concepts for medical surfaces,
- New surface materials for tribological systems and
- Nano safety and nano bio.
Research at INM is performed in three fields: Nanocomposite Technology, Interface Materials, and Bio Interfaces. INM — Leibniz Institute for New Materials, situated in Saarbrücken, is an internationally leading center for materials research. It is an institute of the Leibniz Association and has about 220 employees.
15 Apr 2016
Researchers have demonstrated that transparent ink containing gold, silver, and magnetic nanoparticles can be easily screen-printed onto various types of paper, with the nanoparticles being so small that they seep into the paper’s pores. Although invisible to the naked eye, the nanoparticles can be detected by the unique ways that they scatter light and by their magnetic properties. Since the combination of optical and magnetic signatures is extremely difficult to replicate, the nanoparticles have the potential to be an ideal anti-counterfeiting technology.
The researchers, Carlos Campos-Cuerva, Maciej Zieba, and coauthors at the University of Zaragoza in Zaragoza, Spain, and CIBER-BBN in Madrid, Spain, have published a paper on the anti-counterfeiting nanoparticle ink in a recent issue of Nanotechnology.
“We believe that it would be interesting to sell to different manufacturers their own personalized ink providing a specific combination of signals,” coauthor Manuel Arruebo at the University of Zaragoza and CIBER-BBN told Phys.org. “The nanoparticle-containing ink could then be used to mark a wide variety of supports including paper (documents, labels of wine, or drug packaging), plastic (bank or identity cards), textiles (luxury clothing or bags), and so on.”
Whereas previous methods of using nanoparticles as an anti-counterfeiting measure often require expensive, sophisticated equipment, the new technique is much simpler. The researchers attached the nanoparticles to the paper by standard screen-printing of transparent ink, and then authenticated the samples using commercially available optical and magnetic sensors.
A paper with the word “Nanotechnology,” where different pairs of letters are printed with different combinations of overlapping nanoparticle inks. Credit: Campos-Cuerva, et al. ©2016 IOP Publishing
“We demonstrated that the combination of nanomaterials providing different optical and magnetic properties on the same printed support is possible, and the resulting combined signals can be used to obtain a user-configurable label, providing a high degree of security in anti-counterfeiting applications using simple commercially available sensors at a low cost,” Arruebo said.
Although the nanoparticle ink is easy for the researchers to fabricate, attempting to replicate these authentication signals would be extremely difficult for a forger because the signals arise from the highly specific physical and chemical characteristics of the nanoparticles. Replicating the exact type, size, shape, and surface coating requires highly precise fabrication methods and an understanding of the correlation between the signals and these characteristics.
Making replication even more complicated is the fact that the combined optical and magnetic nanoparticles are printed on top of each other in the same spot, and this overlap creates an even more complex signal. Another advantage of the new technique is that the nanoparticles are able to withstand extreme temperatures and humidity under accelerated weathering conditions.
One of the greatest applications of the technology may be to prevent forgery of pharmaceutical drugs. Counterfeit medicine—which includes drugs that have incorrect or no active ingredients, as well as drugs that are intentionally mislabeled—is a growing problem throughout the world. The researchers plan to pursue such applications as well as further increase the security of the technology in future work.
“We plan to add more physical signals to the same tag by combining nanoparticles which could provide optical, magnetic, and electrical signals, etc., on the same printed spot,” Arruebo said.
More information: Carlos Campos-Cuerva, et al. “Screen-printed nanoparticles as anti-counterfeiting tags.” Nanotechnology. DOI: 10.1088/0957-4484/27/9/095702
A Rice University laboratory has found a way to turn common carbon fiber into graphene quantum dots, tiny specks of matter with properties expected to prove useful in electronic, optical and biomedical applications.
The Rice lab of materials scientist Pulickel Ajayan, in collaboration with colleagues in China, India, Japan and the Texas Medical Center, discovered a one-step chemical process that is markedly simpler than established techniques for making graphene quantum dots. The results were published online this month in the American Chemical Society’s journal Nano Letters.
“There have been several attempts to make graphene-based quantum dots with specific electronic and luminescent properties using chemical breakdown or e-beam lithography of graphene layers,” said Ajayan, Rice’s Benjamin M. and Mary Greenwood Anderson Professor of Mechanical Engineering and Materials Science and of Chemistry. “We thought that as these nanodomains of graphitized carbons already exist in carbon fibers, which are cheap and plenty, why not use them as the precursor?”
Quantum dots, discovered in the 1980s, are semiconductors that contain a size- and shape-dependent band gap. These have been promising structures for applications that range from computers, LEDs, solar cells and lasers to medical imaging devices. The sub-5 nanometer carbon-based quantum dots produced in bulk through the wet chemical process discovered at Rice are highly soluble, and their size can be controlled via the temperature at which they’re created.
The Rice researchers were attempting another experiment when they came across the technique. “We tried to selectively oxidize carbon fiber, and we found that was really hard,” said Wei Gao, a Rice graduate student who worked on the project with lead author Juan Peng, a visiting student from Nanjing University who studied in Ajayan’s lab last year. “We ended up with a solution and decided to look at a few drops with a transmission electron microscope.”
The specks they saw were bits of graphene or, more precisely, oxidized nanodomains of graphene extracted via chemical treatment of carbon fiber. “That was a complete surprise,” Gao said. “We call them quantum dots, but they’re two-dimensional, so what we really have here are graphene quantum discs.” Gao said other techniques are expensive and take weeks to make small batches of graphene quantum dots. “Our starting material is cheap, commercially available carbon fiber. In a one-step treatment, we get a large amount of quantum dots. I think that’s the biggest advantage of our work,” she said.
Further experimentation revealed interesting bits of information: The size of the dots, and thus their photoluminescent properties, could be controlled through processing at relatively low temperatures, from 80 to 120 degrees Celsius. “At 120, 100 and 80 degrees, we got blue, green and yellow luminescing dots,” she said.
They also found the dots’ edges tended to prefer the form known as zigzag. The edge of a sheet of graphene — the single-atom-thick form of carbon — determines its electrical characteristics, and zigzags are semiconducting.
Their luminescent properties give graphene quantum dots potential for imaging, protein analysis, cell tracking and other biomedical applications, Gao said. Tests at Houston’s MD Anderson Cancer Center and Baylor College of Medicine on two human breast cancer lines showed the dots easily found their way into the cells’ cytoplasm and did not interfere with their proliferation.
“The green quantum dots yielded a very good image,” said co-author Rebeca Romero Aburto, a graduate student in the Ajayan Lab who also studies at MD Anderson. “The advantage of graphene dots over fluorophores is that their fluorescence is more stable and they don’t photobleach. They don’t lose their fluorescence as easily. They have a depth limit, so they may be good for in vitro and in vivo (small animal) studies, but perhaps not optimal for deep tissues in humans.
“But everything has to start in the lab, and these could be an interesting approach to further explore for bioimaging,” Romero Alburto said. “In the future, these graphene quantum dotscould have high impact because they can be conjugated with other entities for sensing applications, too.”
Explore further: Single Atom Quantum Dots Bring Real Devices Closer (Video)
More information: Nano Lett., Article ASAP DOI: 10.1021/nl2038979
Ciphers and invisible ink – many of us experimented with these when we were children. A team of Chinese scientists has now developed a clever, high-tech version of “invisible ink”. As reported in the journal Angewandte Chemie, the ink is based on carbon nitride quantum dots. Information written with this ink is not visible under ambient or UV light; however, it can be seen with a fluorescence microplate reader. The writing can be further encrypted or decrypted by quenching or recovering the fluorescence with different reagents.
Fluorescing security inks are primarily used to ensure the authenticity of products or documents, such as certificates, stock certificates, transport documents, currency notes, or identity cards. Counterfeits may cost affected companies lost profits, and the poor quality of the false products may damage their reputations. In the case of sensitive products like pharmaceuticals and parts for airplanes and cars, human lives and health may be endangered. Counterfeiters have discovered how to imitate UV tags but it is significantly harder to copy security inks that are invisible under UV light.
Researchers working with Xinchen Wang and Liangqia Guo at Fuzhou University have now introduced an inexpensive “invisible” ink that increases the security of encoded data while also making it possible to encrypt and decrypt secure information.
The new ink is based on water-soluble quantum dots, nanoscopic “heaps” of a semiconducting material. Quantum dots have special optoelectronic properties that can be controlled by changing the size of the dots.
The scientists used quantum dots made from graphitic carbon nitride. This material consists of ring systems made of carbon and nitrogen atoms linked into two-dimensional molecular layers. The structure is similar to that of graphite (or graphene), one of the forms of pure carbon, but also has semiconductor properties.
Information written with this new ink is invisible under ambient and UV light because it is almost transparent in the visible light range and emits fluorescence with a peak in the UV range. The writing only becomes visible under a microplate reader like those used in biological fluorescence tests. In addition, the writing can be further encrypted and decrypted: treatment with oxalic acid renders it invisible to the microplate reader. Treatment with sodium bicarbonate reverses this process, making the writing visible to the reader once more.
Explore further: Luminescent ink from eggs
More information: Zhiping Song et al. Invisible Security Ink Based on Water-Soluble Graphitic Carbon Nitride Quantum Dots, Angewandte Chemie International Edition (2016). DOI: 10.1002/anie.201510945
Journal reference: Angewandte Chemie Angewandte Chemie International Edition
Provided by: Angewandte Chemie
A spot of sunshine is all it could take to get your washing done, thanks to pioneering nano research into self-cleaning textiles.
Researchers at RMIT University in Melbourne, Australia, have developed a cheap and efficient new way to grow special nanostructures—which can degrade organic matter when exposed to light—directly onto textiles.
The work paves the way towards nano-enhanced textiles that can spontaneously clean themselves of stains and grime simply by being put under a light bulb or worn out in the sun.
Dr Rajesh Ramanathan said the process developed by the team had a variety of applications for catalysis-based industries such as agrochemicals, pharmaceuticals and natural products, and could be easily scaled up to industrial levels.
“The advantage of textiles is they already have a 3D structure so they are great at absorbing light, which in turn speeds up the process of degrading organic matter,” he said.
“There’s more work to do to before we can start throwing out our washing machines, but this advance lays a strong foundation for the future development of fully self-cleaning textiles.”
The researchers from the Ian Potter NanoBioSensing Facility and NanoBiotechnology Research Lab at RMIT worked with copper and silver-based nanostructures, which are known for their ability to absorb visible light.
When the nanostructures are exposed to light, they receive an energy boost that creates “hot electrons“. These “hot electrons” release a burst of energy that enables the nanostructures to degrade organic matter.
The challenge for researchers has been to bring the concept out of the lab by working out how to build these nanostructures on an industrial scale and permanently attach them to textiles.
The RMIT team’s novel approach was to grow the nanostructures directly onto the textiles by dipping them into a few solutions, resulting in the development of stable nanostructures within 30 minutes.
When exposed to light, it took less than six minutes for some of the nano-enhanced textiles to spontaneously clean themselves.
“Our next step will be to test our nano-enhanced textiles with organic compounds that could be more relevant to consumers, to see how quickly they can handle common stains like tomato sauce or wine,” Ramanathan said.
The research is published on March 23, 2016 in the high-impact journal Advanced Materials Interfaces.
More information: Samuel R. Anderson et al. Robust Nanostructured Silver and Copper Fabrics with Localized Surface Plasmon Resonance Property for Effective Visible Light Induced Reductive Catalysis, Advanced Materials Interfaces (2016). DOI: 10.1002/admi.201500632
22 Mar 2016
Groundbreaking research at Griffith University is leading the way in clean energy, with the use of carbon as a way to deliver energy using hydrogen.
Professor Xiangdong Yao and his team from Griffith’s Queensland Micro- and Nanotechnology Centre have successfully managed to use the element to produce hydrogen from water as a replacement for the much more costly platinum.
“Hydrogen production through an electrochemical process is at the heart of key renewable energy technologies including water splitting and hydrogen fuel cells,” says Professor Yao.
“Despite tremendous efforts, exploring cheap, efficient and durable electrocatalysts for hydrogen evolution still remains a great challenge.
“Platinum is the most active and stable electrocatalyst for this purpose, however its low abundance and consequent high cost severely limits its large-scale commercial applications.
“We have now developed this carbon-based catalyst, which only contains a very small amount of nickel and can completely replace the platinum for efficient and cost-effective hydrogen production from water.
“In our research, we synthesize a nickel-carbon-based catalyst, from carbonization of metal-organic frameworks, to replace currently best-known platinum-based materials for electrocatalytic hydrogen evolution.
“This nickel-carbon-based catalyst can be activated to obtain isolated nickel atoms on the graphitic carbon support when applying electrochemical potential, exhibiting highly efficient hydrogen evolution performance and impressive durability.”
Proponents of a hydrogen economy advocate hydrogen as a potential fuel for motive power including cars and boats and on-board auxiliary power, stationary power generation (e.g., for the energy needs of buildings), and as an energy storage medium (e.g., for interconversion from excess electric power generated off-peak).
Professor Yao says that this work may enable new opportunities for designing and tuning properties of electrocatalysts at atomic scale for large-scale water electrolysis.
- Lili Fan, Peng Fei Liu, Xuecheng Yan, Lin Gu, Zhen Zhong Yang, Hua Gui Yang, Shilun Qiu, Xiangdong Yao.Atomically isolated nickel species anchored on graphitized carbon for efficient hydrogen evolution electrocatalysis. Nature Communications, 2016; 7: 10667 DOI: 10.1038/ncomms10667
Printing has come a long way since the days of Johannes Gutenberg. Now, researchers have developed a new method that uses plasma to print nanomaterials onto a 3-D object or flexible surface, such as paper or cloth. The technique could make it easier and cheaper to build devices like wearable chemical and biological sensors, flexible memory devices and batteries, and integrated circuits.
One of the most common methods to deposit nanomaterials—such as a layer of nanoparticles or nanotubes—onto a surface is with an inkjet printer similar to an ordinary printer found in an office. Although they use well-established technology and are relatively cheap, inkjet printers have limitations. They can’t print on textiles or other flexible materials, let alone 3-D objects. They also must print liquid ink, and not all materials are easily made into a liquid.
Some nanomaterials can be printed using aerosol printing techniques. But the material must be heated several hundreds of degrees to consolidate into a thin and smooth film. The extra step is impossible for printing on cloth or other materials that can burn, and means higher cost for the materials that can take the heat.
The nozzle firing a jet of carbon nanotubes with helium plasma off and on. When the plasma is off, the density of carbon nanotubes is small. The plasma focuses the nanotubes onto the substrate with high density and good adhesion. Credit: …more
The plasma method skips this heating step and works at temperatures not much warmer than 40 degrees Celsius. “You can use it to deposit things on paper, plastic, cotton, or any kind of textile,” said Meyya Meyyappan of NASA Ames Research Center. “It’s ideal for soft substrates.” It also doesn’t require the printing material to be liquid.
The researchers, from NASA Ames and Stanford Linear Accelerator Center, describe their work in the American Institute of Physics journal Applied Physics Letters.
They demonstrated their technique by printing a layer of carbon nanotubes on paper. They mixed the nanotubes into a plasma of helium ions, which they then blasted through a nozzle and onto paper. The plasma focuses the nanoparticles onto the paper surface, forming a consolidated layer without any need for additional heating.
The team printed two simple chemical and biological sensors. The presence of certain molecules can change the electrical resistance of the carbon nanotubes. By measuring this change, the device can identify and determine the concentration of the molecule. The researchers made a chemical sensor that detects ammonia gas and a biological sensor that detects dopamine, a molecule linked to disorders like Parkinson’s disease and epilepsy.
But these were just simple proofs-of-principle, Meyyappan said. “There’s a wide range of biosensing applications.” For example, you can make sensors that monitor health biomarkers like cholesterol, or food-borne pathogens like E. coli and Salmonella.
Because the method uses a simple nozzle, it’s versatile and can be easily scaled up. For example, a system could have many nozzles like a showerhead, allowing it to print on large areas. Or, the nozzle could act like a hose, free to spray nanomaterials on the surfaces of 3-D objects.
“It can do things inkjet printing cannot do,” Meyyappan said. “But anything inkjet printing can do, it can be pretty competitive.”
The method is ready for commercialization, Meyyappan said, and should be relatively inexpensive and straightforward to develop. Right now, the researchers are designing the technique to print other kinds of materials such as copper. They can then print materials used for batteries onto thin sheets of metal such as aluminum. The sheet can then be rolled into tiny batteries for cellphones or other devices.
Explore further: Ink with tin nanoparticles could print future circuit boards
More information: “Plasma jet printing for flexible substrates,” R. Gandhiraman, E. Singh, D. Diaz-Cartagena, D. Nordlund, J. Koehne and M. Meyyappan,Applied Physics Letters , March 22, 2016. DOI: 10.1063/1.4943792