Category Archives: coatings

Nanopollution of marine life

Concerns are being raised about nanosunscreens and nanotechnology-enabled marine paints and their effect on marine life, specifically, sea urchins. From a May 13, 2015 news item on Nanowerk (Note: A link has been removed),

Nanomaterials commonly used in sunscreens and boat-bottom paints are making sea urchin embryos more vulnerable to toxins, according to a study from the University of California, Davis [UC Davis]. The authors said this could pose a risk to coastal, marine and freshwater environments.

The study, published in the journal Environmental Science and Technology (“Copper Oxide and Zinc Oxide Nanomaterials Act as Inhibitors of Multidrug Resistance Transport in Sea Urchin Embryos: Their Role as Chemosensitizers”), is the first to show that the nanomaterials work as chemosensitizers. In cancer treatments, a chemosensitizer makes tumor cells more sensitive to the effects of chemotherapy.

Similarly, nanozinc and nanocopper made developing sea urchin embryos more sensitive to other chemicals, blocking transporters that would otherwise defend them by pumping toxins out of cells.

A May 12, 2015 UC Davis news release, which originated the news item, includes some cautions,

Nanozinc oxide is used as an additive in cosmetics such as sunscreens, toothpastes and beauty products. Nanocopper oxide is often used for electronics and technology, but also for antifouling paints, which prevent things like barnacles and mussels from attaching to boats.

“At low levels, both of these nanomaterials are nontoxic,” said co-author Gary Cherr, professor and interim director of the UC Davis Bodega Marine Laboratory, and an affiliate of the UC Davis Coastal Marine Sciences Institute. “However, for sea urchins in sensitive life stages, they disrupt the main defense mechanism that would otherwise protect them from environmental toxins.”

Science for safe design

Nanomaterials are tiny chemical substances measured in nanometers, which are about 100,000 times smaller than the diameter of a human hair. Nano-sized particles can enter the body through the skin, ingestion, or inhalation. They are being rapidly introduced across the fields of electronics, medicine and technology, where they are being used to make energy efficient batteries, clean up oil spills, and fight cancer, among many other uses. However, relatively little is known about nanomaterials with respect to the environment and health.

Here’s a link to and a citation for the paper,

Copper Oxide and Zinc Oxide Nanomaterials Act as Inhibitors of Multidrug Resistance Transport in Sea Urchin Embryos: Their Role as Chemosensitizers by Bing Wu, Cristina Torres-Duarte, Bryan J. Cole, and Gary N. Cherr. Environ. Sci. Technol., 2015, 49 (9), pp 5760–5770 DOI: 10.1021/acs.est.5b00345 Publication Date (Web): April 7, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

While this research into nanoparticles as chemosensitizers is, according to UC Davis, the first of its kind, the concern over nanosunscreens and marine waters has been gaining traction over the last few years. For example, there’s  research featured in a June 10, 2013 article by Roberta Kwok for the University of Washington’s ‘Conservation This Week’ magazine,

Sunscreen offers protection from UV rays, reduces the risk of skin cancer, and even slows down signs of aging. Unfortunately, researchers have found that sunscreen also pollutes the ocean.

Although people have been using these products for decades, “the effect of sunscreens, as a source of introduced chemicals to the coastal marine system, has not yet been addressed,” a research team writes in PLOS ONE. Sunscreens contain chemicals not only for UV protection, but also for coloring, fragrance, and texture. And beaches are becoming ever-more-popular vacation spots; for example, nearly 10 million tourists visited Majorca Island in the Mediterranean Sea in 2010.

Here’s a link to the 2013 PLOS ONE paper,

Sunscreen Products as Emerging Pollutants to Coastal Waters by Antonio Tovar-Sánchez, David Sánchez-Quiles, Gotzon Basterretxea, Juan L. Benedé, Alberto Chisvert, Amparo Salvador, Ignacio Moreno-Garrido, and Julián Blasco. PLOS ONE DOI: 10.1371/journal.pone.0065451 Published: June 5, 2013

This is an open access journal.

Netting oil spills the nano way

Given current local events (April 8, 2015 oil spill in English Bay of 2700 litres (or more) of fuel in Vancouver, Canada), this news item about a mesh useful for oil cleanups seems quite timely. From an April 15, 2015 news item on ScienceDaily,

The unassuming piece of stainless steel mesh in a lab at The Ohio State University doesn’t look like a very big deal, but it could make a big difference for future environmental cleanups.

Water passes through the mesh but oil doesn’t, thanks to a nearly invisible oil-repelling coating on its surface.

In tests, researchers mixed water with oil and poured the mixture onto the mesh. The water filtered through the mesh to land in a beaker below. The oil collected on top of the mesh, and rolled off easily into a separate beaker when the mesh was tilted.

The mesh coating is among a suite of nature-inspired nanotechnologies under development at Ohio State and described in two papers in the journal Nature Scientific Reports. Potential applications range from cleaning oil spills to tracking oil deposits underground.

An April 15, 2015 Ohio State University news release (also on EurekAlert*) by Pam Frost Gorder, which originated the news item, expands on the theme (unusually I’ve left the links undisturbed),

“If you scale this up, you could potentially catch an oil spill with a net,” said Bharat Bhushan, Ohio Eminent Scholar and Howard D. Winbigler Professor of mechanical engineering at Ohio State.

The work was partly inspired by lotus leaves, whose bumpy surfaces naturally repel water but not oil. To create a coating that did the opposite, Bhushan and postdoctoral researcher Philip Brown chose to cover a bumpy surface with a polymer embedded with molecules of surfactant—the stuff that gives cleaning power to soap and detergent.

They sprayed a fine dusting of silica nanoparticles onto the stainless steel mesh to create a randomly bumpy surface and layered the polymer and surfactant on top.

The silica, surfactant, polymer, and stainless steel are all non-toxic and relatively inexpensive, said Brown. He estimated that a larger mesh net could be created for less than a dollar per square foot.

Because the coating is only a few hundred nanometers (billionths of a meter) thick, it is mostly undetectable. To the touch, the coated mesh doesn’t feel any bumpier than uncoated mesh. The coated mesh is a little less shiny, though, because the coating is only 70 percent transparent.

The researchers chose silica in part because it is an ingredient in glass, and they wanted to explore this technology’s potential for creating smudge-free glass coatings. At 70 percent transparency, the coating could work for certain automotive glass applications, such as mirrors, but not most windows or smartphone surfaces.

“Our goal is to reach a transparency in the 90-percent range,” Bhushan said. “In all our coatings, different combinations of ingredients in the layers yield different properties. The trick is to select the right layers.”

He explains that combinations of layers yield nanoparticles that bind to oil instead of repelling it. Such particles could be used to detect oil underground or aid removal in the case of oil spills.

The shape of the nanostructures plays a role, as well. In another project, research assistant Dave Maharaj is investigating what happens when a surface is made of nanotubes. Rather than silica, he experiments with molybdenum disulfide nanotubes, which mix well with oil. The nanotubes are approximately a thousand times smaller than a human hair.

Maharaj measured the friction on the surface of the nanotubes, and compressed them to test how they would hold up under pressure.

“There are natural defects in the structure of the nanotubes,” he said. “And under high loads, the defects cause the layers of the tubes to peel apart and create a slippery surface, which greatly reduces friction.”

Bhushan envisions that the molybdenum compound’s compatibility with oil, coupled with its ability to reduce friction, would make it a good additive for liquid lubricants. In addition, for micro- and nanoscale devices, commercial oils may be too sticky to allow for their efficient operation. Here, he suspects that the molybdenum nanotubes alone could be used to reduce friction.

This work began more than 10 years ago, when Bhushan began building and patenting nano-structured coatings that mimic the texture of the lotus leaf. From there, he and his team have worked to amplify the effect and tailor it for different situations.

“We’ve studied so many natural surfaces, from leaves to butterfly wings and shark skin, to understand how nature solves certain problems,” Bhushan said. “Now we want to go beyond what nature does, in order to solve new problems.”

“Nature reaches a limit of what it can do,” agreed Brown. “To repel synthetic materials like oils, we need to bring in another level of chemistry that nature doesn’t have access to.”

This work was partly funded by the American Chemical Society Petroleum Research Fund, the National Science Foundation, and Dexerials Corporation (formerly a chemical division of Sony Corp.) in Japan.

Here are links to and citations for the papers,

Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation by Philip S. Brow & Bharat Bhushan. Scientific Reports 5, Article number: 8701 doi:10.1038/srep08701 Published 03 March 2015

Nanomechanical behavior of MoS2 and WS2 multi-walled nanotubes and Carbon nanohorns by Dave Maharaj, & Bharat Bhushan. Scientific Reports 5, Article number: 8539 doi:10.1038/srep08539 Published 23 February 2015

Both papers are open access.

* EurekAlert link added Apr.16, 2015 at 1300 PST.

Improving firearm performance with Duralar, a diamond-based coating

A metal and diamond-based coating, Duralar,used to give metal better hardness and durability is also good for guns. I checked a few times and the April 1, 2015 news item on Azonano does not appear to be an April Fool’s joke,

ProtoTactical, a Tucson-area manufacturer of firearms and firearm components has discovered a new way to significantly improve their firearm performance — by applying a special nanotechnology coating called Duralar™. Duralar is an advanced, diamond-based coating that is being used in a variety of industries to enhance metal hardness and durability — and to provide other qualities as well.

Confirming the unlikelihood of this news being a joke is a March 31, 2015 Duralar Coatings news release about the coating and guns,

“Our use of Duralar coatings began as an experiment,” said Gary Palese, president of ProTactical. “I coated a few standard AR-15 trigger parts, mainly to check out the increased durability and wear resistance. But I got a nice surprise and an interesting bonus…”

“As soon as we installed a Duralar-coated trigger and dry-fired the weapon we immediately discovered that the trigger action was significantly smoother. Customers who tried it were amazed at the difference between the coated and uncoated triggers. They were certain that we must have changed the springs or reground the edges, or something! But the only difference was Duralar.”

“Because Duralar is a carbon-based material it has a natural, dry lubricity,” explained Andrew Tudhope, president of Duralar North America. “In firearm applications this means smoother action, less friction and no need for liquid lubricants, which can collect dirt and cause jamming. So, when you combine the intrinsic lubricity with Duralar’s hardness and increased wear and scratch resistance, it gives gun manufacturers a very useful suite of performance features.”

Sex appeal

Gary Palese is also pleased with another Duralar feature, which he calls “sex appeal!”  “Duralar coating gives metals a unique pearlescent gray-black surface that is very tactical and ‘stealthy’ looking — which many of our customers find very sexy! So, because of its hardness and attractive appearance, I’m going to start using Duralar to coat our line of custom knife blades, as well.”

Introduced by Duralar Technologies in 2012, Duralar is an advanced, uniquely structured nanocomposite coating that blends metal and diamond-based components to achieve exceptional hardness, toughness, strength and a spectrum of performance qualities. It is comprised of multiple layers that can be configured in multiple ways to address different applications. Because of its many features Duralar is finding use in an ever-widening range of metal-coating applications. In addition to hardness, durability and lubricity the coatings also provide excellent corrosion and erosion resistance, and they are environmentally friendly, as well.

About Duralar Technologies

Duralar Technologies is a global nanotechnology company and developer of the state-of-the-art Duralar family of ultra-hard coatings. The diamond-based next-generation products are designed to replace hard chrome plating, thermal spray and other previous generations of hard coatings in a broad range of industries including oil & gas, automotive, pulp & paper and aerospace. The company sells and supports Duralar’s coating technology as well as the systems, precursors and materials used in the Duralar coating process. In addition, Duralar Technologies provides Duralar coating services for selected customers. The company’s U.S. headquarters are located in Marana, AZ. European headquarters are in Bedizzole, Italy. The company has additional facilities and offices in Brazil, Mexico and the U.S. For more information, visit www.duralar.com.

About ProtoTactical

ProtoTactical LLC, based in Marana, AZ, is a precision machine shop and manufacturer of AR-style firearms and accessories under its own name as well as for other firearms companies across the U.S. and around the world. The company specializes in reliability at an affordable price, delivering unique product solutions as well as tried-and-true designs. With its rapid prototyping, design and manufacturing capabilities ProtoTactical is able to supply virtually any firearm or component in-house and respond quickly to customer needs. ProtoTactical is a division of ProtoTech, a full-service product development and high-precision machine shop. Established in 1995, ProtoTech is a respected member of Tucson’s advanced technology industry, supplying quality precision parts worldwide. For more information, visit www.prototactical.com.

I found this about the coating technology on Duralar Coatings’ Advanced Technology webpage (Note: Links have been removed),

Duralar is a proprietary and uniquely structured new nanocomposite coating that blends metal and diamond-based components to achieve exceptional hardness, toughness, strength and a broad range of performance qualities. It is comprised of multiple layers that can be configured in different ways to address different applications. The multiple layers are also effective for eliminating microcracks in the coating and blocking other problems like corrosion.

Because Duralar is not a sprayed coating it does not have the limitations that are usually associated with line-of-sight application. Instead, Duralar is highly conformal and uniform, which makes it well suited to coating three-dimensional features. It gives very consistent coverage, even on screw threads and intricately shaped features which can be challenging for other coating methods.

Also, Duralar does not require extremely high deposition temperatures, so it does not alter the morphology of substrates and works well on a broad range of substrate materials. At present Duralar technology is primarily designed to coat conductive substrates; in the future it may also be used on plastics and other materials.

Duralar offers this image of diamonds to illustrate their point,

Duralar is a nanocomposite blend of metal and diamond components.

Duralar is a nanocomposite blend of metal and diamond components.

Nano-Clear® makes lifeboats glossy for Carnival Cruise Lines

A Feb. 9, 2015 news item on Azonano profiles Carnival Cruise Lines and a deal the company has struck with Nanovere Technologies,

Carnival Cruise Lines implementing Nano-Clear® Coatings to restore their entire fleet of lifeboats.

Ship owners and operators spend a great deal of money and time maintaining their vessels and lifeboats to the highest quality standards, but are often let down by poor appearance. Conventional marine paints and gel coatings are highly susceptible to UV damage, causing the surface to oxidize and loose color over time. Lifeboats are designed to have a bright and glossy appearance for improved safety and visibility, but become dull and less visible over time due to UV damage.

 

A Feb. 7, 2015 Nanovere Technologies press release, which originated the news item, provides more details,

In late 2014, Nanotech Marine Services, based in the UK conducted a field application trial aboard the Queen Elizabeth Ship using Nano-Clear® Coatings manufactured by Nanovere Technologies in Brighton, MI USA. The purpose of the trial was to provide a long-term solution to the gel-coat oxidation issue on the ships lifeboats and tenders, as the orange gel-coat on these vessels are continually exposed to high levels of UV and fade rapidly. This paint oxidation issue has proven to be difficult to overcome including continuous polishing of the surface or a costly new paint job.

Nano-Clear® Coating was applied to the gel-coat surface and left to weather for several months aboard the Queen Elizabeth while operating in the Mediterranean. The field trial represented real world conditions and proved that a polished surface using the traditional cut-and-polish approach, fails surprisingly fast when exposed to harmful UV rays. The test patches coated with Nano-Clear® Coating showed “no” deterioration in gloss or color; as compared with the surrounding area showing a dull surface that will continue to oxidize over time.

Due to the outstanding success of the Nano-Clear® trials on the Queen Elizabeth, Nanotech Marine secured the restoration of 18 lifeboats aboard Queen Victoria. Carnival Cruise Lines is also implementing Nano-Clear® Coatings to restore their entire fleet of lifeboats starting with 26 aboard the Cruise Ship Azura in 2015. Nano-Clear® Coatings provide ship operators, maintenance yards and super yacht owners with a tested and practical solution to restore and maintain high value assets to the highest gloss level for many years.

Nano Clear is the only marine coating in the global market place to enhance, restore and extend the service life of newly painted or highly oxidized painted surfaces by 10 years. Nano-Clear® penetrates deep into the smallest pores of paint, enhancing the underlying color, dramatically improving gloss, scratch resistance, corrosion resistance and extending UV resistance, while reducing surface cleaning by 50%. Nano-Clear® eliminates the need to re-paint, color match or polish gel-coatings, thereby reducing material, labor and maintenance costs.

Nano-Clear® Coatings have been validated by leading global organizations including the US Army, Carnival Cruise Lines, Princimar Chemical Carriers, Toshiba Industrial Products and leading tank car manufactures. To learn more about Nano-Clear® Coatings, please email [email protected], visit www.nanocoatings.com or call (810) 227-0077.

Here’s an image illustrating the pre-NanoClear- and post-NanoClear-coated lifeboats,

Courtesy: Nanovere Technologies

Courtesy: Nanovere Technologies

I last wrote about Nanovere Technologies in a Jan. 2, 2013 post about automotive plastics.

Philippe Starck’s luggage goes nano

For anyone unfamiliar with Philippe Starck, there’s this from his Wikipedia entry (Note: Links have been removed),

Philippe Starck is a French designer[1] who has become widely known since the start of his career in the 1980s[2] for his interior, product, industrial and architectural design work.

A minimalist, Starck’s work is ‘stark’. In an interesting publicity campaign, his latest collection of travel gear is mentioned in a Feb. 4, 2015 news item on Nanotechnology Now,

In association with Philippe Starck, renowned French creator, designer and architect, DELSEY is reinventing the world of travel with the launch of STARCKTRIP, a new collection of luggage conceived on a single concept: intelligence in motion. Bold, original and innovative, leaving the fickle constraints of fashion behind to embrace timelessness.

The launch for this line was originally announced in an Oct. 9, 2014 Starck press release which includes a bit about the nanotechnology-enabled features of this luggage,

HIGH TECH DISCRETION
The materials used take advantage of the latest technological innovations but manage to be discrete about it. Nanotechnology is used to protect the bags and
cases, inside and out, from dirt and bacteria; fabric screens also protect against data theft; gentle plastic moulded material provides unparalleled rolling comfort, smoothness and silence. In addition, anti-rain treatment of the surfaces ensures that you, the business traveller, keep your belongings dry at all times. [emphases mine]

I’m not sure about the dirt but the protection from bacteria makes it sound like they’ve added nanoscale silver to the luggage and the anti-rain treatment sounds like a nanotechnology-enabled superhydrophobic coating of some kind. Unfortunately there are no details to be had on either Philippe Starck’s website or on the Delsey website. BTW, the middle-aged male model in the Starck press release, is M. Philippe Starck himself.

India’s S. R. Vadera and Narendra Kumar (Defence Laboratory, Jodhpur) review stealth and camouflage technology

Much of the military nanotechnology information I stumble across is from the US, Canada, and/or Europe and while S. R. Vadera and Narendra Kumar (of India’s Defence Laboratory, Jodhpur [DLJ]) do offer some information about India’s military nanotechnology situation, they focus largely on the US, Canada, and Europe. Happily, their Jan. 30, 2014 Nanowerk Spotlight 6 pp. article titled, Nanotechnology and nanomaterials for camouflage and stealth applications offers a comprehensive review of the field,

This article briefly describes how nanomaterials and nanotechnology can be useful in the strategic area of camouflage and stealth technology. …

The word camouflage has its origin in the French word camoufler which means to disguise. In English dictionary, the word meaning was initially referred to concealment or disguise of military objects in order to prevent detection by the enemy. In earlier days, specifically before 20th century, the only sensor available to detect was human eye and so camouflage was confined to the visible light only. The rapid development of sensor technology outside the visible range has forced to use new definition and terminologies for camouflage.

Modern definition of camouflage may be given as “delay or deny detection of a military target by detectors operating over multispectral wavelength region of electromagnetic spectrum or non-electromagnetic radiation e.g., acoustic, magnetic, etc. Multispectral camouflage, low-observability, countermeasures, signature management, and stealth technology are some of the new terminologies used now instead of camouflage.

In modern warfare, stealth technology is applied mostly to aircrafts and combat weapons. Stealth technology can improve the survivability and performance of aircrafts and weapons to gain the upper hand. Stealth technology involves the minimization of acoustic, optical, infra-red, and electromagnetic signatures. Among them, the minimization of electromagnetic signature, particularly in microwave region, is the most important. It can be realized in several ways which include stealth shaping design, radar absorbing material (RAM), and radar absorbing structures (RAS)1.

Unexpectedly, there are multiple reference to Canadian stealth and camouflage technology all of them courtesy of one company, HyperStealth Biotechnology Corp. based in Maple Ridge, BC, Canada. mentioned in my Jan. 7, 2013 post about an invisibility cloak.

Getting back to the article, the authors have this to say about the international ‘stealth scene’,

Today virtually every nation and many non-state military organizations have access to advanced tactical sensors for target acquisition (radar and thermal imagers) and intelligence gathering surveillance systems (ground and air reconnaissance). Precision-guided munitions exist that can be delivered by artillery, missiles, and aircraft and that can operate in the IR [infra red] region of the electromagnetic spectrum. These advanced imaging sights and sensors allow enemies to acquire and engage targets through visual smoke, at night, and under adverse weather conditions.

To combat these new sensing and detection technologies, camouflage paint, paint additives, tarps, nets and foams have been developed for visual camouflage and thermal and radar signature suppression. …

One comment, thermal and radar signature suppression sounds like another way of saying ‘invisibility cloak’.

The authors also had something to say about the application of nanomaterials/nanotechnology,

Nanotechnology has significant influence over a set of many interrelated core skills of land forces like protection, engagement, detection, movements, communications and information collection together with interrelated warfare strategies. Additionally, nanotechnology also has its role in the development of sensor for warfare agents, tagging and tracking and destruction of CBRN [chemical, biological, radiological and nuclear] warfare agents, besides many other possible applications.

There’s a very interesting passage on ‘stealth coatings’ which includes this,

These new coatings can be attached to a wide range of surfaces and are the first step towards developing ‘shape shifting clothing’ capable of adapting to the environment around it. …

In another example, an Israeli company, Nanoflight has claimed to develop a new nano paint, which can make it near impossible to detect objects painted with the material. The company is continuing their efforts to extend the camouflage action of these paints in infrared region as well. BASF, Germany (uses polyisocynate dendrimer nanoparticles) and Isotronic Corporation, USA are among the very few agencies coming up with chemical agent resistant and innovative camouflage (CARC) coatings using nanomaterials. In India, paints developed by Defence Laboratory, Jodhpur (DLJ) using polymeric nanocomposites, nanometals and nanometal complexes are perhaps the first examples of multispectral camouflage paints tested in VIS-NIR and thermal infrared regions of the electromagnetic spectrum at system level. The nanocomposites developed by DLJ provide excellent scope for the tuning of reflectance properties both in visible and near infrared region6 of electromagnetic spectrum leading to their applications on military targets (Fig. 4).

For anyone interested in this topic, I recommend reading the article in its entirety.

One final note, I found this Wikipedia entry about the DLJ, (Note: A link has been removed)

Defence Laboratory (DLJ) is westernmost located, an strategically important laboratory of the Defence Research and Development Organisation (DRDO).

Its mission is development of Radio Communication Systems, Data links, Satellite Communication Systems, Millimeter Wave Communication systems. There are two divisions in laboratory

NRMA (Nuclear Radiation’s Management and Applications) Division
Camouflage Division

That’s all folks!

A hedgehog particle for safer paints and coatings?

The researchers did not extract particles from hedgehogs for this work but they are attempting to provide a description for a class of particles, which could make paints and coatings more environmentally friendly. From a Jan. 28, 2015 news item on phys.org,

A new process that can sprout microscopic spikes on nearly any type of particle may lead to more environmentally friendly paints and a variety of other innovations. Made by a team of University of Michigan engineers, the “hedgehog particles” are named for their bushy appearance under the microscope. …

A Jan. 28, 2015 University of Michigan news release (also EurekAlert), which originated the news item, describes the research,

The new process modifies oily, or hydrophobic, particles, enabling them to disperse easily in water. It can also modify water-soluble, or hydrophilic, particles, enabling them to dissolve in oil or other oily chemicals.

The unusual behavior of the hedgehog particles came as something of a surprise to the research team, says Nicholas Kotov, the Joseph B. and Florence V. Cejka Professor of Engineering.

“We thought we’d made a mistake,” Kotov said. “We saw these particles that are supposed to hate water dispersing in it and we thought maybe the particles weren’t hydrophobic, or maybe there was a chemical layer that was enabling them to disperse. But we double-checked everything and found that, in fact, these particles defy the conventional chemical wisdom that we all learned in high school.”

The team found that the tiny spikes made the particles repel each other more and attract each other less. The spikes also dramatically reduce the particles’ surface area, helping them to diffuse more easily.

One of the first applications for the particles is likely to be in paints and coatings, where toxic volatile organic compounds (VOCs) like toluene are now used to dissolve pigment. Pigments made from hedgehog particles could potentially be dissolved in nontoxic carriers like water, the researchers say.

This would result in fewer VOC emissions from paints and coatings, which the EPA [US Environmental Protection Agency] estimates at over eight million tons per year in the United States alone. VOCs can cause a variety of respiratory and other ailments and also contribute to smog and climate change. Reducing their use has become a priority for the Environmental Protection Agency and other regulatory bodies worldwide.

“VOC solvents are toxic, they’re flammable, they’re expensive to handle and dispose of safely,” Kotov said. “So if you can avoid using them, there’s a significant cost savings in addition to environmental benefits.”

While some low- and no-VOC coatings are already available, Kotov says hedgehog particles could provide a simpler, more versatile and less expensive way to manufacture them.

For the study, the team created hedgehog particles by growing zinc oxide spikes on polystyrene microbeads. The researchers say that a key advantage of the process is its flexibility; it can be performed on virtually any type of particle, and makers can vary the number and size of the spikes by adjusting the amount of time the particles sit in various solutions while the protrusions are growing. They can also make the spikes out of materials other than zinc oxide.

“I think one thing that’s really exciting about this is that we’re able to make such a wide variety of hedgehog particles,” said Joong Hwan Bahng, a chemical engineering doctoral student. “It’s very controllable and very versatile.”

The researchers say the process is also easily scalable, enabling hedgehog particles to be created “by the bucketful,” according to Kotov. Further down the road, Kotov envisions a variety of other applications, including better oil dispersants that could aid in the cleanup of oil spills and better ways to deliver non-water-soluble prescription medications.

As is becoming more common in news releases, there’s a reference to commercial partners, suggesting (to me) they might be open to offers,

“Anytime you need to dissolve an oily particle in water, there’s a potential application for hedgehog particles,” he said. “It’s really just a matter of finding the right commercial partners. We’re only just beginning to explore the uses for these particles, and I think we’re going to see a lot of applications in the future.”

Here’s a link to and a citation for the paper,

Anomalous dispersions of ‘hedgehog’ particles by Joong Hwan Bahng, Bongjun Yeom, Yichun Wang, Siu On Tung, J. Damon Hoff, & Nicholas Kotov. Nature 517, 596–599 (29 January 2015) doi:10.1038/nature14092 Published online 28 January 2015

This paper is behind a paywall.

Get dirty with a LEAF car, the world’s cleanest car (according to Nissan)

In a bid to advertise and create excitement about a self-cleaning version of Nissan’s zero-emissions LEAF car, the company kicked off a contest a few days ago with this video,


A Dec. 3, 2014 news item on Azonano describes the car and the campaign,

The “world’s cleanest car” is daring its fans to get it dirty. Starting today, Nissan will launch a social media campaign that will include a series of online videos to showcase a zero-emissions Nissan LEAF with self-cleaning nano-paint technology. Created to demonstrate its potential use in future production vehicles, this LEAF is armed with Ultra-Ever Dry® paint to help repel almost any liquid that may come its way. Nissan first introduced the one-of-a-kind LEAF this past April [2014].

“The LEAF is already one of the cleanest vehicles around even without this incredibly innovative paint technology; that said, we’re not afraid to get our hands dirty to take this to the next level,” said Pierre Loing, vice president, Product Planning, Nissan North America, Inc. “Getting fans involved via this social media campaign is a fun, creative way to show how the LEAF can stay clean no matter how dirty the world around it may be. A marriage with the Ultra-Ever Dry® exterior coating truly puts this LEAF in a league of its own, and we’re excited to see where this technology can take us.”

A Dec. 2, 2014 news item on Yahoo News provides details about the campaign to ‘dirty up the LEAF’,

First in the series of planned activations, “The Nissan Paint Prank” will launch on YouTube today [Dec. 2, 2014]. A “Three Stooges” style calamity, the video catches expressions of innocent bystanders shocked to see what happens as a crew of painters “accidentally” spills buckets of paint on the Nissan LEAF. As bystanders are playfully made aware of the prank, viewers online will be encouraged to visit Nissan’s Instagram channel to participate in a related series of videos, which also launch today.

First up on Instagram, “Guess the Mess” challenges fans to guess the liquid being poured on the self-cleaning LEAF. After guessing the mess, it’s the fans’ turn to decide what gets poured on the LEAF in the final set of videos entitled “Will it Stick?” Fans will be called upon on Instagram to suggest things they’d like to see dumped on the LEAF – ketchup, honey, eggs… anything is in play. Starting next week, Nissan will decide “if it sticks” by sharing videos on Instagram that will include the liquids suggested by selected fans. To encourage suggestions for liquids to pour on the LEAF from Instagram users, all participants will be entered for a chance to win a gift card toward a car wash.

To conclude the series, a compilation video featuring all “Guess the Mess” and “Will It Stick?” videos will be posted to Nissan’s YouTube channel and shared across Nissan’s social media platforms. Social media users can follow along on Instagram using #WorldsCleanestCar.

While there are currently no plans for this unique paint coating technology to be applied to Nissan vehicles as standard equipment, Nissan continues to consider the technology as a future aftermarket option.

Well, self-cleaning is always very appealing feature for me but I wonder if there are enthusiasts out there who take satisfaction in cleaning their cars and might mourn the loss of satisfaction?

SLIPS (Slippery Liquid-Infused Porous Surfaces) technology repels blood and bacteria from medical devices

Researchers at Harvard University’s Wyss Institute for Biologically Inspired Engineering have developed a coating for medical devices that helps to address some of these devices’ most  troublesome aspects. From an Oct. 12, 2014 news item on ScienceDaily,

From joint replacements to cardiac implants and dialysis machines, medical devices enhance or save lives on a daily basis. However, any device implanted in the body or in contact with flowing blood faces two critical challenges that can threaten the life of the patient the device is meant to help: blood clotting and bacterial infection.

A team of Harvard scientists and engineers may have a solution. They developed a new surface coating for medical devices using materials already approved by the Food and Drug Administration (FDA). The coating repelled blood from more than 20 medically relevant substrates the team tested — made of plastic to glass and metal — and also suppressed biofilm formation in a study reported in Nature Biotechnology. But that’s not all.

The team implanted medical-grade tubing and catheters coated with the material in large blood vessels in pigs, and it prevented blood from clotting for at least eight hours without the use of blood thinners such as heparin. Heparin is notorious for causing potentially lethal side-effects like excessive bleeding but is often a necessary evil in medical treatments where clotting is a risk.

“Devising a way to prevent blood clotting without using anticoagulants is one of the holy grails in medicine,” said Don Ingber, M.D., Ph.D., Founding Director of Harvard’s Wyss Institute for Biologically Inspired Engineering and senior author of the study. Ingber is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children’s Hospital, as well as professor of bioengineering at Harvard School of Engineering and Applied Sciences (SEAS).

An Oct. 12, 2014 Wyss Institute news release (also on EurekAlert), which originated the news item, describes the inspiration for this work,

The idea for the coating evolved from SLIPS, a pioneering surface technology developed by coauthor Joanna Aizenberg, Ph.D., who is a Wyss Institute Core Faculty member and the Amy Smith Berylson Professor of Materials Science at Harvard SEAS. SLIPS stands for Slippery Liquid-Infused Porous Surfaces. Inspired by the slippery surface of the carnivorous pitcher plant, which enables the plant to capture insects, SLIPS repels nearly any material it contacts. The liquid layer on the surface provides a barrier to everything from ice to crude oil and blood.

“Traditional SLIPS uses porous, textured surface substrates to immobilize the liquid layer whereas medical surfaces are mostly flat and smooth – so we further adapted our approach by capitalizing on the natural roughness of chemically modified surfaces of medical devices,” said Aizenberg, who leads the Wyss Institute’s Adaptive Materials platform. “This is yet another incarnation of the highly customizable SLIPS platform that can be designed to create slippery, non-adhesive surfaces on any material.”

The Wyss team developed a super-repellent coating that can be adhered to existing, approved medical devices. In a two-step surface-coating process, they chemically attached a monolayer of perfluorocarbon, which is similar to Teflon. Then they added a layer of liquid perfluorocarbon, which is widely used in medicine for applications such as liquid ventilation for infants with breathing challenges, blood substitution, eye surgery, and more. The team calls the tethered perfluorocarbon plus the liquid layer a Tethered-Liquid Perfluorocarbon surface, or TLP for short.

In addition to working seamlessly when coated on more than 20 different medical surfaces and lasting for more than eight hours to prevent clots in a pig under relatively high blood flow rates without the use of heparin, the TLP coating achieved the following results:

  • TLP-treated medical tubing was stored for more than a year under normal temperature and humidity conditions and still prevented clot formation
  • The TLP surface remained stable under the full range of clinically relevant physiological shear stresses, or rates of blood flow seen in catheters and central lines, all the way up to dialysis machines
  • It repelled the components of blood that cause clotting (fibrin and platelets)
  • When bacteria called Pseudomonas aeruginosa were grown in TLP-coated medical tubing for more than six weeks, less than one in a billion bacteria were able to adhere. Central lines coated with TLP significantly reduce sepsis from Central-Line Mediated Bloodstream Infections (CLABSI). (Sepsis is a life-threatening blood infection caused by bacteria, and a significant risk for patients with implanted medical devices.)

Out of sheer curiosity, the researchers even tested a TLP-coated surface with a gecko – the superstar of sticking whose footpads contain many thousands of hairlike structures with tremendous adhesive strength. The gecko was unable to hold on.

“We were wonderfully surprised by how well the TLP coating worked, particularly in vivo without heparin,” said one of the co-lead authors, Anna Waterhouse, Ph.D., a Wyss Institute Postdoctoral Fellow. “Usually the blood will start to clot within an hour in the extracorporeal circuit, so our experiments really demonstrate the clinical relevance of this new coating.”

While most of the team’s demonstrations were performed on medical devices such as catheters and perfusion tubing using relatively simple setups, they say there is a lot more on the horizon.

“We feel this is just the beginning of how we might test this for use in the clinic,” said co-lead author Daniel Leslie, Ph.D., a Wyss Institute Staff Scientist, who aims to test it on more complex systems such as dialysis machines and ECMO, a machine used in the intensive care unit to help critically ill patients breathe.

I first featured SLIPS technology in a Jan. 15, 2014 post about its possible use for stain-free, self-cleaning clothing. This Wyss Institute video about the latest work featuring the use of  SLIPS technology in medical devices also describes its possible use in pipelines and airplanes,

You can find research paper with this link,

A bioinspired omniphobic surface coating on medical devices prevents thrombosis and biofouling by Daniel C Leslie, Anna Waterhouse, Julia B Berthet, Thomas M Valentin, Alexander L Watters, Abhishek Jain, Philseok Kim, Benjamin D Hatton, Arthur Nedder, Kathryn Donovan, Elana H Super, Caitlin Howell, Christopher P Johnson, Thy L Vu, Dana E Bolgen, Sami Rifai, Anne R Hansen, Michael Aizenberg, Michael Super, Joanna Aizenberg, & Donald E Ingber. Nature Biotechnology (2014) doi:10.1038/nbt.3020 Published online 12 October 2014

This paper is behind a paywall but there is a free preview available via ReadCube Access.

Female triathlete from Iran and a nanotechnology solution to water repellent gear

The style is a bit breathless, i.e., a high level of hype with very little about the technology, but it features an interesting partnership in the world of sport and a nanotechnology-enabled product (from an Oct. 7, 2014 news item on Azonano; Note: A link has been removed),

Shirin Gerami’s story is one which will go down in history. Shirin is the first Iranian female to represent her country in a triathlon and is paving the way for setting gender equality both in Iran and across the world.

In order to race for Iran, it was essential that Shirin respected the rules of her country, and raced in clothes that covered her body and hair. It was necessary to design clothes those both adhered to these conditions, whilst ensuring her performance was not affected.

An Oct. 7, 2014 P2i press release, which originated the news item, goes on to describe it role in Shirin Gerami athletic career,

Previously, waterproof fabrics Shirin had tried were uncomfortable, lacked breathability and slowed down her performance. Shirin contacted P2i upon hearing of the liquid repellent qualities of our patented nano-technology. Our nano-technology, a thousand times thinner than a human hair, has no effect on the look or feel of a product. This means we can achieve the highest levels of water repellency without affecting the quality of a fabric. A P2i coating on the kit meant it was water repellent whilst remaining highly breathable and light – essential when trying to remain as streamlined as possible!

Here’s a picture of Gerami wearing her new gear at a recently held triathlete event held in Edmonton, Alberta, Canada,

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The press release describes her first experience with her P2i-enabled running gear (Note: A link has been removed),

Shirin only received approval for her race kit from the Iranian government days before the race, so it was quite literally a race to the starting line. Consequently, Shirin did not have time to test the P2i coated kit before she began the World Triathlon Grand Final in Edmonton, Canada. Shirin explains, ‘I cannot tell you how relieved and happy I am that the coating worked exactly as I hoped it would. It was bone dry when I took my wetsuit off!’

I believe Gerami is using the term ‘wetsuit’ as a way of identifying the kit’s skintight properties similar to the ‘wetsuits’ that divers wear.

The press release concludes (Note: A link has been removed),

You can find out more about UK-based P2i on its website. I was not able to find more information about its products designed for use in sports gear but was able to find a May 11, 2012 press release about its partnership with UK Sport.

As for the Aug. 25 – Sept. 1, 2014 TransCanada Corp. World Triathlon Grand Final where Gerami tested her suit, you can find out more about the event here (scroll down).