Tag Archives: nanocomposites

Plantains and carbon nanotubes to improve cars

I always enjoy the unexpected in a story and this one has to do with plantains and luxury cars, from a July 29, 2020 news item on phys.org (Note: A link has been removed),

A luxury automobile is not really a place to look for something like sisal, hemp, or wood. Yet automakers have been using natural fibers for decades. Some high-end sedans and coupes use these in composite materials for interior door panels, for engine, interior and noise insulation, and internal engine covers, among other uses.

Unlike steel or aluminum, natural fiber composites do not rust or corrode. They can also be durable and easily molded. The biggest advantages of fiber reinforced polymer composites for cars are light weight, good crash properties, and noise- and vibration-reducing characteristics. But making more parts of a vehicle from renewable sources is a challenge. Natural fiber polymer composites can crack, break and bend. The reasons include low tensile, flexural and impact strength in the composite material.

Researchers from the University of Johannesburg [South Africe] have now demonstrated that plantain, a starchy type of banana, is a promising source for an emerging type of composite material for the automotive industry. The natural plantain fibers are combined with carbon nanotubes and epoxy resin to form a natural fiber-reinforced polymer hybrid nanocomposite material. Plantain is a year-round staple food crop in tropical regions of Africa, Asia and South America. Many types of plantain are eaten cooked.

A July 29, 2020 University of Johannesburg press release, which originated the news item, delves into plantains and how their fibers enhance nanocomposites destined for integration into luxury cars,

Plantain is a year-round staple food crop in tropical regions of Africa, Asia and South America. Many types of plantain are eaten cooked.

The researchers moulded a composite material from epoxy resin, treated plantain fibers and carbon nanotubes. The optimum amount of nanotubes was 1% by weight of the plantain-epoxy resin combined.

The resulting plantain nanocomposite was much stronger and stiffer than epoxy resin on its own.

The composite had 31% more tensile and 34% more flexural strength than the epoxy resin alone. The nanocomposite also had 52% higher tensile modulus and 29% higher flexural modulus than the epoxy resin alone.

“The hybridization of plantain with multi-walled carbon nanotubes increases the mechanical and thermal strength of the composite. These increases make the hybrid composite a competitive and alternative material for certain car parts,” says Prof Tien-Chien Jen.

Prof Jen is the lead researcher in the study and the Head of the Department of Mechanical Engineering Science at the University of Johannesburg.

Natural fibres vs metals

Producing car parts from renewable sources have several benefits, says Dr Patrick Ehi Imoisili. Dr Imoisili is a postdoctoral researcher in the Department of Mechanical Engineering Science at the University of Johannesburg.

“There is a trend of using natural fibre in vehicles. The reason is that natural fibres composites are renewable, low cost and low density. They have high specific strength and stiffness. The manufacturing processes are relatively safe,” says Imoisili.

“Using car parts made from these composites, can reduce the mass of a vehicle. That can result in better fuel-efficiency and safety. These components will not rust or corrode like metals. Also, they can be stiff, durable and easily molded,” he adds.

However, some natural fibre reinforced polymer composites currently have disadvantages such as water absorption, low impact strength and low heat resistance. Car owners can notice effects such as cracking, bending or warping of a car part, says Imoisili.

Standardised tests

The researchers subjected the plantain nanocomposite to a series of standardised industrial tests. These included ASTM Test Methods D638 and D790; impact testing according to the ASTM A-370 standard; and ASTM D-2240.

The tests showed that a composite with 1% nanotubes had the best strength and stiffness, compared to epoxy resin alone.

The plantain nanocomposite also showed marked improvement in micro hardness, impact strength and thermal conductivity compared to epoxy resin alone.

Moulding a nanocomposite from natural fibres

The researchers compression-moulded a ‘stress test object’. They used 1 part inedible plantain fibres, 4 parts epoxy resin and multi-walled carbon nanotubes. The epoxy resin and nanotubes came from commercial suppliers. The epoxy was similar to resins that auto manufacturers use in certain car parts.

The plantain fibres came from the ‘trunks’ or pseudo-stems, of plantain plants in the south-western region of Nigeria. The pseudo-stems consist of tightly-overlapping leaves.

The researchers treated the plantain fibers with several processes. The first process is an ancient method to separate plant fibres from stems, called water-retting.

In the second process, the fibres were soaked in a 3% caustic soda solution for 4 hours. After drying, the fibres were treated with high-frequency microwave radiation of 2.45GHz at 550W for 2 minutes.

The caustic soda and microwave treatments improved the bonding between the plantain fibers and the epoxy resin in the nanocomposite.

Next, the researchers dispersed the nanotubes in ethanol to prevent ‘bunching’ of the tubes in the composite. After that, the plantain fibres, nanotubes and epoxy resin were combined inside a mold. The mold was then compressed with a load for 24 hours at room temperature.

Food crop vs industrial raw material

Plantain is grown in tropical regions worldwide. This includes Mexico, Florida and Texas in North America; Brazil, Honduras, Guatemala in South and Central America; India, China, and Southeast Asia.

In West and Central Africa, farmers grow plantain in Cameroon, Ghana, Uganda, Rwanda, Nigeria, Cote d’Ivoire and Benin.

Using biomass from major staple food crops can create problems in food security for people with low incomes. In addition, the automobile industry will need access to reliable sources of natural fibres to increase use of natural fibre composites.

In the case of plantains, potential tensions between food security and industrial uses for composite materials are low. This is because plantain farmers discard the pseudo-stems as agro-waste after harvest.

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

Physical, mechanical and thermal properties of high frequency microwave treated plantain (Musa Paradisiaca) fibre/MWCNT hybrid epoxy nanocomposites by Patrick Ehi Imoisili, Kingsley Ukoba, Tien-Chien Jen. Journal of Materials Research and Technology Volume 9, Issue 3, May–June 2020, Pages 4933-4939 DOI: https://doi.org/10.1016/j.jmrt.2020.03.012

This paper is open access.

I’ve got my eye on you (tissue paper sensors from the University of Washington [state])

University of Washington graduate student, Jinyuan Zhang, demonstrates how wearable sensors can track eye movement. Dennis R. Wise/University of Washington

A February 13, 2018 news item on phys.org announces a technology that can transform tissue paper into a sensor,

University of Washington engineers have turned tissue paper – similar to toilet tissue – into a new kind of wearable sensor that can detect a pulse, a blink of an eye and other human movement. The sensor is light, flexible and inexpensive, with potential applications in health care, entertainment and robotics.

A February 12, 2018 University of Washington news release (also on EurekAlert) by Jackson Holtz, which originated the news item, provides more detail (Note: Links have been removed),

The technology, described in a paper published in January in the journal Advanced Materials Technologies, shows that by tearing tissue paper that’s loaded with nanocomposites and breaking the paper’s fibers, the paper acts as a sensor. It can detect a heartbeat, finger force, finger movement, eyeball movement and more, said Jae-Hyun Chung, a UW associate professor of mechanical engineering and senior author of the research.

Finger sensor

University of Washington graduate student, Jinyuan Zhang, demonstrates how a wearable sensor can measure finger pressure.Dennis R. Wise/University of Washington

“The major innovation is a disposable wearable sensor made with cheap tissue paper,” said Chung. “When we break the specimen, it will work as a sensor.”

These small, Band Aid-sized sensors could have a variety of applications in various fields. For example, monitoring a person’s gait or the movement of their eyes can be used to inspect brain function or a game player’s actions. The sensor could track how a special-needs child walks in a home test, sparing the child the need for hospital visits. Or the sensors could be used in occupational therapy for seniors.

“They can use these sensors and after one-time use, they can be thrown away,” said Chung.

In their research, the scientists used paper similar to toilet tissue. The paper – nothing more than conventional paper towels – is then doused with carbon nanotube-laced water. Carbon nanotubes are tiny materials that create electrical conductivity. Each piece of tissue paper has both horizontal and vertical fibers, so when the paper is torn, the direction of the tear informs the sensor of what’s happened. To trace eye movement, they’re attached to a person’s reading glasses.

For now, the work has been contained to a laboratory, and researchers are hoping to find a suitable commercial use. A provisional patent was filed in December 2017.

The study was funded partially by Samsung Research America through the Think Tank Team Award.

Foot sensor

University of Washington mechanical engineering undergraduate, Yared Shella, demonstrates how foot pressure is measured with a wearable sensor.Dennis R. Wise/University of Washington

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

Fracture-Induced Mechanoelectrical Sensitivities of Paper-Based Nanocomposites by Jinyuan Zhang, Gil-Yong Lee, Chiew Cerwyn, Jinkyu Yang, Fabrice Fondjo, Jong-Hoon Kim, Minoru Taya, Dayong Gao, and Jae-Hyun Chung. Advanced Materials Technologies Vol. 3 Issue 1 DOI: 10.1002/admt.201700266 Version of Record online: 26 JAN 2018

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Open access to nanoparticles and nanocomposites

One of the major issues for developing nanotechnology-enabled products is access to nanoparticles and nanocomposites. For example, I’ve had a number of requests from entrepreneurs for suggestions as to how to access cellulose nanocrystals (CNC) so they can develop a product idea. (It’s been a few years since the last request and I hope that means it’s easier to get access to CNC.)

Regardless, access remains a problem and the European Union has devised a solution which allows open access to nanoparticles and nanocomposites through project Co-Pilot. The announcement was made in a May 10, 2016 news item on Nanowerk (Note: A link has been removed),

“What opportunities does the nanotechnology provide in general, provide nanoparticles for my products and processes?” So far, this question cannot be answered easily. Preparation and modification of nanoparticles and the further processing require special technical infrastructure and complex knowledge. For small and medium businesses the construction of this infrastructure “just on luck” is often not worth it. Even large companies shy away from the risks. As a result many good ideas just stay in the drawer.

A simple and open access to high-class infrastructure for the reliable production of small batches of functionalized nanoparticles and nanocomposites for testing could ease the way towards new nano-based products for chemical and pharmaceutical companies. The European Union has allocated funds for the construction of a number of pilot lines and open-access infrastructure within the framework of the EU project CoPilot.

A May 9, 2016 Fraunhofer-Institut für Silicatforschung press release, which originated the news item, offers greater description,

A simple and open access to high-class infrastructure for the reliable production of small batches of functionalized nanoparticles and nanocomposites for testing could ease the way towards new nano-based products for chemical and pharmaceutical companies. The European Union has allocated funds for the construction of a number of pilot lines and open-access infrastructure within the framework of the EU project CoPilot. A consortium of 13 partners from research and industry, including nanotechnology specialist TNO from the Netherlands and the Fraunhofer Institute for Silicate Research ISC from Wuerzburg, Germany as well as seven nanomaterial manufacturers, is currently setting up the pilot line in Wuerzburg. First, they establish the particle production, modification and compounding on pilot scale based on four different model systems. The approach enables maximum variability and flexibility for the pilot production of various particle systems and composites. Two further open access lines will be established at TNO in Eindhoven and at the Sueddeutsche Kunststoffzentrum SKZ in Selb.

The “nanoparticle kitchen”

Essential elements of the pilot line in Wuerzburg are the particle synthesis in batches up to 100 liters, modification and separation methods such as semi-continuous operating centrifuge and in-line analysis and techniques for the uniform and agglomeration free incorporation of nanoparticles into composites. Dr. Karl Mandel, head of Particle Technology of Fraunhofer ISC, compares the pilot line with a high-tech kitchen: “We provide the top-notch equipment and the star chefs to synthesize a nano menu à la carte as well as nanoparticles according to individual requests. Thus, companies can test their own receipts – or our existing receipts – before they practice their own cooking or set up their nano kitchen.”

In the future, the EU project offers companies a contact point if they want to try their nano idea and require enough material for sampling and estimation of future production costs. This can, on the one hand, minimize the development risk, on the other hand, it maximizes the flexibility and production safety. To give lots of companies the opportunity to influence direction and structure/formation/setup of the nanoparticle kitchen, the project partners will offer open meetings on a regular basis.

I gather Co-Pilot has been offering workshops. The next is in July 2016 according to the press release,

The next workshop in this context takes place at Fraunhofer ISC in Wuerzburg, 7h July 2016. The partners present the pilot line and the first results of the four model systems – double layered hydroxide nanoparticle polymer composites for flame inhibiting fillers, titanium dioxide nanoparticles for high refractive index composites, magnetic particles for innovative catalysts and hollow silica composites for anti-glare coatings. Interested companies can find more information about the upcoming workshop on the website of the project www.h2020copilot.eu and on the website of Fraunhofer ISC www.isc.fraunhofer.de that hosts the event.

I tracked down a tiny bit more information about the July 2016 workshop in a May 2, 2016 Co-Pilot press release,

On July 7 2016, the CoPilot project partners give an insight view of the many new functionalization and applications of tailored nanoparticles in the workshop “The Nanoparticle Kitchen – particles und functions à la carte”, taking place in Wuerzburg, Germany. Join the Fraunhofer ISC’s lab tour of the “Nanoparticle Kitchen”, listen to the presentations of research institutes and industry and discuss your ideas with experts. Nanoparticles offer many options for today’s and tomorrow’s products.

More about program and registration soon on this [CoPilot] website!

I wonder if they’re considering this open access to nanoparticles and nanocomposites approach elsewhere?

Abakan makes good on Alberta (Canada) promise (coating for better pipeline transport of oil)

It took three years but it seems that US company Abakan Inc.’s announcement of a joint research development centre at the Northern Alberta Institute of Technology (NAIT), (mentioned here in a May 7, 2012 post [US company, Abakan, wants to get in on the Canadian oils sands market]), has borne fruit. A June 8, 2015 news item on Azonano describes the latest developments,

Abakan Inc., an emerging leader in the advanced coatings and metal formulations markets, today announced that it has begun operations at its joint-development facility in Edmonton, Alberta.

Abakan’s subsidiary, MesoCoat Inc., along with the lead project partner, Northern Alberta Institute of Technology (NAIT) will embark on an 18-month collaborative effort to establish a prototype demonstration facility for developing, testing and commercializing wear-resistant clad pipe and components. Western Economic Diversification Canada is also supporting this initiative through a $1.5 million investment toward NAIT. Improvements in wear resistance are expected to make a significant impact in reducing maintenance and downtime costs while increasing productivity in oil sands and other mining applications.

A June 4, 2015 Abakan news release, which originated the news item, provides more detail about the proposed facility, the difficulties encountered during the setup, and some interesting information about pipes,

Abakan shipped its CermaClad high-speed large-area cladding system for installation at the Northern Alberta Institute of Technology’s (NAIT) campus in Edmonton, Alberta in early 2015. Despite delays associated with the installation of some interrelated equipment and machinery, the CermaClad system and other ancillary equipment are now installed at the Edmonton facility. The Edmonton facility is intended to serve as a pilot-scale wear-resistant clad pipe manufacturing facility for the development and qualification of wear-resistant clad pipes, and as a stepping stone for setting-up a full-scale wear-resistant clad pipe manufacturing facility in Alberta. The new facility will also serve as a platform for Abakan’s introduction to the Alberta oil sands market, which, with proven reserves estimated at more than 169 billion barrels, is one of the largest oil resources in the world and a major source of oil for Canada, the United States and Asia. Since Alberta oil sands production is expected to increase significantly over the next decade, producers want to extend the life of the carbon steel pipes used for the hydro-transportation of tailings with harder, tougher coatings that protect pipes from the abrasiveness of tar-like bituminous oil sands.

“Our aim is to fast-track market entry of our wear-resistant clad pipe products for the transportation of oil sands and mining slurries. We have received commitments from oil sands producers in Canada and mining companies in Mexico and Brazil to field-test CermaClad wear-resistant clad pipe products as soon as our system is ready for testing. Apart from our work with conventional less expensive chrome carbide and the more expensive tungsten carbide wear-resistant cladding on pipes, Abakan also expects to introduce new iron-based structurally amorphous metal (SAM) alloy cladding that in testing has exhibited better performance than tungsten carbide cladding, but at a fraction of the cost.” Robert Miller stated further that “although more expensive than the more widely used chrome carbide cladding, our new alloy cladding is expected to be a significantly better value proposition when you consider an estimated life of three times that of chrome carbide cladding and those cost efficiencies that correspond to less downtime revenue losses, and lower maintenance and replacement costs.”

The costs associated with downtime and maintenance in the Alberta oil sands industry estimated at more than $10 billion a year are expected to grow as production expands, according to the Materials and Reliability in Oil Sands (MARIOS) consortium in Alberta. The development of Alberta’s oil sands has been held up by the lack of materials for transport lines and components that are resistant to the highly abrasive slurry. Due to high abrasion, the pipelines have to be rotated every three to four months and replaced every 12 to 15 months. [emphasis mine] The costs involved just in rotating and replacing the pipes is approximately $2 billion annually. The same is true of large components, for example the steel teeth on the giant electric shovels used to recover oil sands, must be replaced approximately every two days.

Abakan’s combination of high productivity coating processes and groundbreaking materials are expected to facilitate significant efficiencies associated with the extraction of these oil resources. Our proprietary materials combined with CermaClad large-area based fusion cladding technology, have demonstrated in laboratory tests a three to eight times improvement in wear and corrosion resistance when compared with traditional weld overlays at costs comparable to rubber and metal matrix composite alternatives. Abakan intends to complete development and initiate field-testing by end of year 2016 and begin the construction of a full-scale wear-resistant clad pipe manufacturing facility in Alberta in early-2017.

Given that there is extensive talk about expanding oil pipelines from Alberta to British Columbia (where I live), the information about the wear and tear is fascinating and disturbing. Emotions are high with regard to the proposed increase in oil flow to the coast as can be seen in a May 27, 2015 article by Mike Howell for the Vancouver Courier about a city hall report on the matter,

A major oil spill in Vancouver waters could potentially expose up to one million people to unsafe levels of a toxic vapour released from diluted bitumen, city council heard Wednesday in a damning city staff report on Kinder Morgan’s proposal to build a pipeline from Alberta to Burnaby [British Columbia].

In presenting the report, deputy city manager Sadhu Johnston outlined scenarios where exposure to the chemical benzene could lead to adverse health effects for residents and visitors, ranging from dizziness to nausea to possible death.

“For folks that are on the seawall, they could be actually struck with this wave of toxic gases that could render them unable to evacuate,” said Johnston, noting 25,000 residents live within 300 metres of the city’s waterfront. “These are serious health impacts. So this is not just about oil hitting shorelines, this is about our residents being exposed to very serious health effects.

  • Kinder Morgan’s own estimate is that pipeline leaks under 75 litres per hour may not be detected.

While I find the presentation’s hysteria a little off-putting, it did alert me to one or two new issues, benzene gas and when spillage from the pipes raises an alarm. For anyone curious about benzene gas and other chemical aspects of an oil spill, there’s a US National Oceanic and Atmospheric Administration (NOAA) webpage titled, Chemistry of an Oil Spill.

Getting back to the pipes, that figure of 75 litres per hour puts a new perspective on the proposed Abakan solution and it suggests that whether or not more and bigger pipes are in our future, we should do a better of job of protecting our environment now. That means better cladding for the pipes and better dispersants and remediation for water, earth, air when there’s a spill.

A coating for airplane windshields that mitigates laser intensity

Whether it’s done accidentally or with malice, blinding airplane pilots with lasers pointed at the windows of cockpits has become a serious problem. From the Lasers and aviation safety Wikipedia entry,

Pointing a laser at an aircraft can be hazardous to pilots[1] and has resulted in arrests, trials and jail sentences. It also results in calls to license or ban laser pointers.

A June 3, 2015 news item on Nanowerk describes a Lewis University technology that could help minimize this problem. (Lewis University is a private university located in the state of Illinois, US; Note: A link has been removed),

A recently published Journal of Aviation Technology and Engineering article (“Measuring the Effectiveness of Photoresponsive Nanocomposite Coatings on Aircraft Windshields to Mitigate Laser Intensity”) shows Lewis University researchers have created a coating for aircraft that reduces pilot distraction from laser attacks.

In [sic] 2013 study, Lewis University proved these laser attacks, which average around 3,750 incidents a year, can be a distraction to pilots and a potential safety hazard during critical phases of flight. As part of continued research on the matter, Lewis University recently developed a practical and economical solution through the use of photoresponsive nanocomposite coatings on aircraft windscreens.

The most recent study determined the application of the engineered films resulted in a reduction in laser intensity from 36-88 percent.

A June 2, 2015 Lewis University news release, which originated the news item, provides a bit more detail about the research (Note: Links have been removed),

The study was completed through collaboration of the Aviation, Physics and Chemistry departments at Lewis University. The Chemistry Department developed the photoselective coatings, and the Physics Department developed the apparatus to efficiently test the coatings while allowing safe viewings of laser illumination. The coatings were bench-tested in a laboratory prior to conducting field tests at the 200- and 500-foot distances.

I was unfamiliar with Lewis University so was happy to see the news release fill in a few blanks (Note: Links have been removed),

This research was sponsored, in part, by a grant from the Colonel Stephan S. and Lyla Doherty Center for Aviation and Health Research. The Doherty Center funds research and scholarly initiatives and provides opportunities for research experiences for students with faculty mentors. Investigators supported by the Doherty Center have focused on several areas, such as cardiac therapy, wound management, flight deck laser illumination, the environment, diabetes, MRSA, and alternative fuels for aviation.

Since 1932, Lewis University has led the field of aviation education by preparing students from around the world to succeed in the aviation industries. An on-site airport, experienced and industry-leading faculty, personalized learning, degree programs that provide you with specialized experience and a well-rounded business, management and liberal arts education have made Lewis University’s aviation program one of the most respected in Illinois.

Lewis University is a Catholic university in the Lasallian tradition offering distinctive undergraduate and graduate programs to more than 6,700 traditional and adult students. Lewis offers multiple campus locations, online degree programs, and a variety of formats that provide accessibility and convenience to a growing student population. Sponsored by the De La Salle Christian Brothers, Lewis prepares intellectually engaged, ethically grounded, globally connected, and socially responsible graduates. The seventh largest private not-for-profit university in Illinois, Lewis has been nationally recognized by The Princeton Review and U.S. News & World Report. Visit www.lewisu.edu for further information.

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

Measuring the Effectiveness of Photoresponsive Nanocompsite Coatings on Aircraft Windshields to Mitigate Laser Intensity by Ryan S. Phillips, Hubert K. Bilan, Zachary X. Widel, Randal J. DeMik, Samantha J. Brain, Matthew Moy, Charles Crowder, Stanley L. Harriman, James T. O’Malley III, Joseph E. Burlas, Steven F. Emmert, & Jason J. Keleher. Journal of Aviation Technology and Engineering (2015): Vol. 4: Iss. 2, Article 5. http://dx.doi.org/10.7771/2159-6670.1105

This paper is open access.

Taking the baking out of aircraft manufacture

It seems that ovens are an essential piece of equipment when manufacturing aircraft parts but that may change if research from MIT (Massachusetts Institute of Technology) proves successful. An April 14, 2015 news item on ScienceDaily describes the current process and the MIT research,

Composite materials used in aircraft wings and fuselages are typically manufactured in large, industrial-sized ovens: Multiple polymer layers are blasted with temperatures up to 750 degrees Fahrenheit, and solidified to form a solid, resilient material. Using this approach, considerable energy is required first to heat the oven, then the gas around it, and finally the actual composite.

Aerospace engineers at MIT have now developed a carbon nanotube (CNT) film that can heat and solidify a composite without the need for massive ovens. When connected to an electrical power source, and wrapped over a multilayer polymer composite, the heated film stimulates the polymer to solidify.

The group tested the film on a common carbon-fiber material used in aircraft components, and found that the film created a composite as strong as that manufactured in conventional ovens — while using only 1 percent of the energy.

The new “out-of-oven” approach may offer a more direct, energy-saving method for manufacturing virtually any industrial composite, says Brian L. Wardle, an associate professor of aeronautics and astronautics at MIT.

“Typically, if you’re going to cook a fuselage for an Airbus A350 or Boeing 787, you’ve got about a four-story oven that’s tens of millions of dollars in infrastructure that you don’t need,” Wardle says. “Our technique puts the heat where it is needed, in direct contact with the part being assembled. Think of it as a self-heating pizza. … Instead of an oven, you just plug the pizza into the wall and it cooks itself.”

Wardle says the carbon nanotube film is also incredibly lightweight: After it has fused the underlying polymer layers, the film itself — a fraction of a human hair’s diameter — meshes with the composite, adding negligible weight.

An April 14, 2015 MIT news release, which originated the news item, describes the origins of the team’s latest research, the findings, and the implications,

Carbon nanotube deicers

Wardle and his colleagues have experimented with CNT films in recent years, mainly for deicing airplane wings. The team recognized that in addition to their negligible weight, carbon nanotubes heat efficiently when exposed to an electric current.

The group first developed a technique to create a film of aligned carbon nanotubes composed of tiny tubes of crystalline carbon, standing upright like trees in a forest. The researchers used a rod to roll the “forest” flat, creating a dense film of aligned carbon nanotubes.

In experiments, Wardle and his team integrated the film into airplane wings via conventional, oven-based curing methods, showing that when voltage was applied, the film generated heat, preventing ice from forming.

The deicing tests inspired a question: If the CNT film could generate heat, why not use it to make the composite itself?

How hot can you go?

In initial experiments, the researchers investigated the film’s potential to fuse two types of aerospace-grade composite typically used in aircraft wings and fuselages. Normally the material, composed of about 16 layers, is solidified, or cross-linked, in a high-temperature industrial oven.

The researchers manufactured a CNT film about the size of a Post-It note, and placed the film over a square of Cycom 5320-1. They connected electrodes to the film, then applied a current to heat both the film and the underlying polymer in the Cycom composite layers.

The team measured the energy required to solidify, or cross-link, the polymer and carbon fiber layers, finding that the CNT film used one-hundredth the electricity required for traditional oven-based methods to cure the composite. Both methods generated composites with similar properties, such as cross-linking density.

Wardle says the results pushed the group to test the CNT film further: As different composites require different temperatures in order to fuse, the researchers looked to see whether the CNT film could, quite literally, take the heat.

“At some point, heaters fry out,” Wardle says. “They oxidize, or have different ways in which they fail. What we wanted to see was how hot could this material go.”

To do this, the group tested the film’s ability to generate higher and higher temperatures, and found it topped out at over 1,000 F. In comparison, some of the highest-temperature aerospace polymers require temperatures up to 750 F in order to solidify.

“We can process at those temperatures, which means there’s no composite we can’t process,” Wardle says. “This really opens up all polymeric materials to this technology.”

The team is working with industrial partners to find ways to scale up the technology to manufacture composites large enough to make airplane fuselages and wings.

“There needs to be some thought given to electroding, and how you’re going to actually make the electrical contact efficiently over very large areas,” Wardle says. “You’d need much less power than you are currently putting into your oven. I don’t think it’s a challenge, but it has to be done.”

Gregory Odegard, a professor of computational mechanics at Michigan Technological University, says the group’s carbon nanotube film may go toward improving the quality and efficiency of fabrication processes for large composites, such as wings on commercial aircraft. The new technique may also open the door to smaller firms that lack access to large industrial ovens.

“Smaller companies that want to fabricate composite parts may be able to do so without investing in large ovens or outsourcing,” says Odegard, who was not involved in the research. “This could lead to more innovation in the composites sector, and perhaps improvements in the performance and usage of composite materials.”

It can be interesting to find out who funds the research (from the news release),

This research was funded in part by Airbus Group, Boeing, Embraer, Lockheed Martin, Saab AB, TohoTenax, ANSYS Inc., the Air Force Research Laboratory at Wright-Patterson Air Force Base, and the U.S. Army Research Office.

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

Impact of carbon nanotube length on electron transport in aligned carbon nanotube networks by Jeonyoon Lee, Itai Y. Stein, Mackenzie E. Devoe, Diana J. Lewis, Noa Lachman, Seth S. Kessler, Samuel T. Buschhorn, and Brian L. Wardle. Appl. Phys. Lett. 106, 053110 (2015); http://dx.doi.org/10.1063/1.4907608

This paper is behind a paywall.

Let’s make our turbine blades really big (greater than 75 metres) with new nanocomposite

The is a story about balsa wood, wind farms, turbine blades, and nanocomposites according to a June 25, 2014 news item on ScienceDaily,

In wind farms across North America and Europe, sleek turbines equipped with state-of-the-art technology convert wind energy into electric power. But tucked inside the blades of these feats of modern engineering is a decidedly low-tech core material: balsa wood.

Like other manufactured products that use sandwich panel construction to achieve a combination of light weight and strength, turbine blades contain carefully arrayed strips of balsa wood from Ecuador, which provides 95 percent of the world’s supply.

For centuries, the fast-growing balsa tree has been prized for its light weight and stiffness relative to density. But balsa wood is expensive and natural variations in the grain can be an impediment to achieving the increasingly precise performance requirements of turbine blades and other sophisticated applications.

As turbine makers produce ever-larger blades — the longest now measure 75 meters, almost matching the wingspan of an Airbus A380 jetliner — they must be engineered to operate virtually maintenance-free for decades. In order to meet more demanding specifications for precision, weight, and quality consistency, manufacturers are searching for new sandwich construction material options.

Now, using a cocktail of fiber-reinforced epoxy-based thermosetting resins and 3D extrusion printing techniques, materials scientists at the Harvard School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering have developed cellular composite materials of unprecedented light weight and stiffness.

A June 25, 2014 Harvard University news release (also on EurekAlert), which originated the news item, goes on to describe the new technology in more detail while throwing 3D printing into the mix,

Until now, 3D printing has been developed for thermo plastics and UV-curable resins—materials that are not typically considered as engineering solutions for structural applications. “By moving into new classes of materials like epoxies, we open up new avenues for using 3D printing to construct lightweight architectures,” says principal investigator Jennifer A. Lewis, the Hansjörg Wyss Professor of Biologically Inspired Engineering at Harvard SEAS. “Essentially, we are broadening the materials palate for 3D printing.”

“Balsa wood has a cellular architecture that minimizes its weight since most of the space is empty and only the cell walls carry the load. It therefore has a high specific stiffness and strength,” explains Lewis, who in addition to her role at Harvard SEAS is also a Core Faculty Member at the Wyss Institute. “We’ve borrowed this design concept and mimicked it in an engineered composite.”

Lewis and Brett G. Compton, a former postdoctoral fellow in her group, developed inks of epoxy resins, spiked with viscosity-enhancing nanoclay platelets and a compound called dimethyl methylphosphonate, and then added two types of fillers: tiny silicon carbide “whiskers” and discrete carbon fibers. Key to the versatility of the resulting fiber-filled inks is the ability to control the orientation of the fillers.

The direction that the fillers are deposited controls the strength of the materials (think of the ease of splitting a piece of firewood lengthwise versus the relative difficulty of chopping on the perpendicular against the grain).

Lewis and Compton have shown that their technique yields cellular composites that are as stiff as wood, 10 to 20 times stiffer than commercial 3D-printed polymers, and twice as strong as the best printed polymer composites. The ability to control the alignment of the fillers means that fabricators can digitally integrate the composition, stiffness, and toughness of an object with its design.

“This paper demonstrates, for the first time, 3D printing of honeycombs with fiber-reinforced cell walls,” said Lorna Gibson, a professor of materials science and mechanical engineering at the Massachusetts Institute of Technology and one of world’s leading experts in cellular composites, who was not involved in this research. “Of particular significance is the way that the fibers can be aligned, through control of the fiber aspect ratio—the length relative to the diameter—and the nozzle diameter. This marks an important step forward in designing engineering materials that mimic wood, long known for its remarkable mechanical properties for its weight.”

“As we gain additional levels of control in filler alignment and learn how to better integrate that orientation into component design, we can further optimize component design and improve materials efficiency,” adds Compton, who is now a staff scientist in additive manufacturing at Oak Ridge National Laboratory. “Eventually, we will be able to use 3D printing technology to change the degree of fiber filler alignment and local composition on the fly.”

The work could have applications in many fields, including the automotive industry where lighter materials hold the key to achieving aggressive government-mandated fuel economy standards. According to one estimate, shedding 110 pounds from each of the 1 billion cars on the road worldwide could produce $40 billion in annual fuel savings.

3D printing has the potential to radically change manufacturing in other ways too. Lewis says the next step will be to test the use of thermosetting resins to create different kinds of architectures, especially by exploiting the technique of blending fillers and precisely aligning them. This could lead to advances not only in structural materials, but also in conductive composites.

Previously, Lewis has conducted groundbreaking research in the 3D printing of tissue constructs with vasculature and lithium-ion microbatteries.

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

3D-Printing of Lightweight Cellular Composites by Brett G. Compton and Jennifer A. Lewis. Advanced Materials DOI: 10.1002/adma.201401804 Article first published online: 18 JUN 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

The long road to commercializing nanotechnology-enabled products in Europe: the IP Nanoker Project

IP Nanoker, a nanotechnology commercialization project, was a European Union 7th Framework Programme-funded project from 2005 – 2009. So, how does IP Nanoker end up in a June 11, 2014 news item on Nanowerk? The road to commercialization is not only long, it is also winding as this news item points out in an illuminating fashion,

Superior hip, knee and dental implants, a new generation of transparent airplane windows and more durable coatings for automotive engines are just some of the products made possible – and cheaper – by the EU-funded IP NANOKER project. Many of these materials are now heading to market, boosting Europe’s competitiveness and creating jobs.

Launched back in 2005, the four-year project set out to build upon Europe’s expertise and knowledge in nanoceramics and nanocomposites.

Nanocomposites entirely made up of ceramic and metallic nanoscale particles – particles that are usually between 1 and 100 nanometres in size – are a broad new class of engineered materials that combine excellent mechanical performance with critical functionalities such as transparency, biocompatibility, and wear resistance.

These materials offer improvements over conventional materials. For some advanced optical applications – such as windows for aircraft – glass is too brittle. Nanoceramics offer both transparency and toughness, and thanks to IP NANOKER, can now be manufactured at a significantly reduced cost.
Indeed, one of the most important outcomes of IP NANOKER has been the development of new dense nanostructured materials as hard as diamond. The fabrication of these super hard materials require extreme conditions of high temperature and pressure, which is why IP NANOKER project partners developed a customised Spark Plasma Sintering machine.

“This new equipment is the largest in the world (12 metres high, 6 metres wide and 5 metres deep), and features a pressing force up to 400 tonnes and will allow the fabrication of near-net shaped products up to 400mm in diameter”, explains project coordinator Ramon Torrecillas from Spain’s Council for Scientific Research (CSIC).

This is obviously a distilled and simplified version of what occurred but, first, they developed the technology, then they developed a machine that would allow them to manufacture their nanotechnology-enabled materials. It’s unclear as to whether or not the machine was developed during the project years of 2005 – 2009 but the project can trace its impact in other ways (from the March 27, 2014 European Union news release), which originated the news item,

The project promises to have a long-lasting impact. In 2013, some former IP NANOKER partners launched a public-private initiative with the objective of bridging the gap between research and industry and boosting the industrial application of Spark Plasma Sintering in the development of nanostructured multifunctional materials.

Potential new nanomaterial-based products hitting the market soon include ultra-hard cutting and mining tools, tough ceramic armour and mirrors for space telescopes.

“Another positive result arising from IP NANOKER was the launch in 2011 of Nanoker Research, a Spanish spin-off company,” says Prof Torrecillas. “This company was formed by researchers from two of the project partners, CSIC and Cerámica Industrial Montgatina, and currently employs 19 people.”
IP NANOKER was also instrumental in creating the Nanomaterials and Nanotechnology Research Centre (CINN) in Spain, a joint initiative of the CSIC, the University of Oviedo and the Regional Government of Asturias.

As a result of its economic and societal impact, IP NANOKER was selected as project finalist in two European project competitions: Industrial Technologies 2012 and Euronanoforum 2013.
Some three years after its completion, the positive effects of the project are still being felt. Prof Torrecillas is delighted with the results, and argues that only a pan-European project could have achieved such ambitious goals.

“As an industry-led project, IP NANOKER provided a suitable framework for research on top-end applications that require not only costly technologies but also very specific know-how,” he says. “Thus, bringing together the best European experts in materials science, chemistry, physics and engineering and focusing the work of these multidisciplinary teams on specific applications, was the only way to face the project challenges.”

The technology for producing these materials/coatings has yet to be truly commercialized. They face a somewhat tumultuous future as they develop markets for their products and build up manufacturing capabilities almost simultaneously.

They will definitely use ‘push’ strategies, i.e., try to convince car manufacturers, hip implant manufacturers,etc. their materials are a necessity for improved sales of the product (car, hip implant, etc.).

They could also use ‘pull’ strategies with retailers (convince them their sales will improve) and or the general public (this will make your life easier, better, more exciting, safer, etc.). The hope with a pull strategy is that retailers and/or the general public will start demanding these improved products (car, hip implants, etc.) and the manufacturers will be clamouring for your nanotechnology-enabled materials.

Of course, if you manage to create a big demand, then you have the problem of delivering your product, which brings this post back to manufacturing and having to address capacity issues. You will also have competitors, which likely means the technology and/or  the buyers’ ideas about the technology, will evolve, at least in the short term, while the market (as they say) shakes out.

If you want to read more about some of the issues associated with commercializing nanotechnology-enabled products, there’s this Feb. 10, 2014 post titled, ‘Valley of Death’, ‘Manufacturing Middle’, and other concerns in new government report about the future of nanomanufacturing in the US‘ about a report from the US Government Accountability Office (GAO) and a May 23, 2014 post titled, ‘Competition, collaboration, and a smaller budget: the US nano community responds‘, which touches on some commercialization issues, albeit, within a very different context.

One final note, it’s interesting to note that the March 2014 news release about IP Nanoker is on a Horizon 2020 (this replaces the European Union’s 7th Framework Programme) news website. I expect officials want to emphasize the reach and impact these funded projects have over time.

Atlantic Canada’s Lamda Guard signs deal to test nanocomposite windshield film with Airbus

This story comes from Nova Scotia although you wouldn’t know it if you’d only read the June 5, 2014 news item on Azonano,

Lamda Guard, a company based in Atlantic Canada, has signed an agreement with leading aircraft manufacturer Airbus to test a breakthrough innovation designed to deflect unwanted bright light or laser sources from impacting jetliner flight paths, and causing pilot disorientation or injury.

A June 4, 2014 news release (either from Lamda Guard.com or MTI [metamaterial.com]; Note: More about the multiple webspaces later] and there’s a PDF version here), which originated the news item, provides a little more information about the technology and the perspectives from various stakeholders

Lamda Guard’s innovative thin films utilize metamaterial technology on cockpit windscreens to selectively block and control light coming from any angle even at the highest power levels. “Today marks a milestone in optical applications of nano-composites,” said George Palikaras, President and CEO of Lamda Guard. “Through our collaboration with Airbus we are working to introduce our metamaterial technology, for the first time, as a solution to laser interference in the aviation industry.” The announcement today comes within weeks of the release of an FBI [US Federal Bureau of Investigation] report citing 3,960 aircraft laser strikes in the US in 2013 according to the Federal Aviation Authority (FAA).

Senior Vice President of Innovation Yann Barbaux stated: “At Airbus, we are always on the lookout for new ideas coming from innovative SMEs [small to medium enterprises], such as Lamda Guard. We are very pleased to explore together the potential application of this solution to our aircraft, for the benefit of our customers.”

Over the past year Lamda Guard has been working with the research community at the University of Moncton and the University of New Brunswick, as well as stakeholders, investors and funders to highlight the benefits of nano-composites. The Atlantic Canada Opportunities Agency (ACOA) in particular has played an important role in Lamda Guard’s research and development efforts. In 2012, ACOA assisted Lamda Guard with technology commercialization and recently upgraded its contribution to $500,000 to further assist the company in developing and manufacturing its products for the aviation industry.

The Lamda Guard Airbus partnership marks the first time an optical metamaterial nano-composite has been applied on a large-scale surface.

I tried to find more information about the technology and tracked down this tiny bit, from the What are MetaMaterials? webpage on the MTI website,

A metamaterial typically consists of a multitude of structured unit cells that are comprised of multiple individual elements, which are referred to as meta-atoms. The individual elements are assembled from conventional microscopic materials such as metals and/or plastics, which are arranged in periodic patterns.

MTI’s precisely designed structures are developed with proprietary algorithms, producing a new generation of optical products that are built in state-of-the-art thin film nano-fabrication labs. MTI’s proprietary software accurately predicts the desired design pattern to generate a unique material that meets customer specifications. MTI’s sleek designs mean manufacturers can reduce their cost of materials significantly while increasing performance, e.g. by increasing the light output of an LED bulb or increasing the absorption of light in a solar panel.

Multiple webspaces and presences

While Lamda Guard has a .com presence, you will find yourself on the metamaterial.com website in the Lamda Guard webspace (I suppose you could also call it a subsite) once you start clicking for more information.  In fact, MTI owns three Lamda companies as per this description from the Our Company webpage on the MTI (metamaterial.com) website (Note: Links have been removed),

MTI is an advanced materials and systems engineering company developing and commercializing innovative optical solutions. The company’s core team has over 200 years of combined experience at the forefront of the design and implementation of metamaterials, making MTI a pioneer in bridging the gap between the theoretical and the possible.

MTI specializes in metamaterials, nanotechnology, theoretical and computational electromagnetics. The company’s in-house expertise enables the rapid development of a wide array of metamaterial applications, covering a diverse range of markets.

MTI’s technologies are adaptable and can be custom-designed to suit an industry manufacturer’s specifications allowing for scalability and rapid prototyping with minimum overheads. MTI provides access to world class nano-composite research and development, including specialty, as well as customized, products and licensing of its proprietary solutions to customers ranging from government to private companies.

MTI has three wholly owned subsidiaries:

Lamda Guard Inc. which develops advanced filters to block out selected parts of the light spectrum, protecting the eyes from lasers or other sources of hazardous light.

Lamda Solar Inc. products increase the efficiency of solar panel cells by absorbing more light.

Lamda Lux Inc. technology increases the delivered lumens and reduces the cost of thermal management of LED lighting.

Interestingly, the Lamda Guard Management team‘s (in the Lamda Guard webspace) Chief Science Officer, Dr. Themos Kallos, and Chief Intellectual Property Officer, Dr. Quinton Fivelman, both appear to reside in the UK (assuming I looked at the correct LinkedIn profiles).  Coincidentally, MTI’s contact page lists the company’s headquarters as being in Nova Scotia but Sales, Research and Development would seem to be located in the UK.

Presumably, this company is maximizing its access to government grants and tax incentives in both the UK and Canada. The deal with the Airbus suggests that this has been a successful strategy possibly leading to commercialized technology and, hopefully, jobs.

Mixing and matching your nanoparticles

An Oct. 20, 2013 Brookhaven National Laboratory (BNL; US Dept. of Energy) news release (also on EurekAlert) describes a technique for combining different kinds of nanoparticles into a single nanocomposite,

Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have developed a general approach for combining different types of nanoparticles to produce large-scale composite materials. The technique, described in a paper published online by Nature Nanotechnology on October 20, 2013, opens many opportunities for mixing and matching particles with different magnetic, optical, or chemical properties to form new, multifunctional materials or materials with enhanced performance for a wide range of potential applications.

The approach takes advantage of the attractive pairing of complementary strands of synthetic DNA—based on the molecule that carries the genetic code in its sequence of matched bases known by the letters A, T, G, and C. After coating the nanoparticles with a chemically standardized “construction platform” and adding extender molecules to which DNA can easily bind, the scientists attach complementary lab-designed DNA strands to the two different kinds of nanoparticles they want to link up. The natural pairing of the matching strands then “self-assembles” the particles into a three-dimensional array consisting of billions of particles. Varying the length of the DNA linkers, their surface density on particles, and other factors gives scientists the ability to control and optimize different types of newly formed materials and their properties.

The news release details some of the challenges the researchers faced,

… the scientists explored the effect of particle shape. “In principle, differently shaped particles don’t want to coexist in one lattice,” said Gang [Brookhaven physicist Oleg Gang]. “They either tend to separate into different phases like oil and water refusing to mix or form disordered structures.” The scientists discovered that DNA not only helps the particles mix, but it can also improve order for such systems when a thicker DNA shell around the particles is used.

They also investigated how the DNA-pairing mechanism and other intrinsic physical forces, such as magnetic attraction among particles, might compete during the assembly process. For example, magnetic particles tend to clump to form aggregates that can hinder the binding of DNA from another type of particle. “We show that shorter DNA strands are more effective at competing against magnetic attraction,” Gang said.

For the particular composite of gold and magnetic nanoparticles they created, the scientists discovered that applying an external magnetic field could “switch” the material’s phase and affect the ordering of the particles. “This was just a demonstration that it can be done, but it could have an application—perhaps magnetic switches, or materials that might be able to change shape on demand,” said Zhang [[Yugang Zhang, first author of the paper].

The third fundamental factor the scientists explored was how the particles were ordered in the superlattice arrays: Does one type of particle always occupy the same position relative to the other type—like boys and girls sitting in alternating seats in a movie theater—or are they interspersed more randomly? “This is what we call a compositional order, which is important for example for quantum dots because their optical properties—e.g., their ability to glow—depend on how many gold nanoparticles are in the surrounding environment,” said Gang. “If you have compositional disorder, the optical properties would be different.” In the experiments, increasing the thickness of the soft DNA shells around the particles increased compositional disorder.

These fundamental principles give scientists a framework for designing new materials. The specific conditions required for a particular application will be dependent on the particles being used, Zhang emphasized, but the general assembly approach would be the same.

Said Gang, “We can vary the lengths of the DNA strands to change the distance between particles from about 10 nanometers to under 100 nanometers—which is important for applications because many optical, magnetic, and other properties of nanoparticles depend on the positioning at this scale. We are excited by the avenues this research opens up in terms of future directions for engineering novel classes of materials that exploit collective effects and multifunctionality.”

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

A general strategy for the DNA-mediated self-assembly of functional nanoparticles into heterogeneous systems by Yugang Zhang, Fang Lu, Kevin G. Yager, Daniel van der Lelie, & Oleg Gang. Nature Nanotechnology (2013) doi:10.1038/nnano.2013.209 Published online 20 October 2013.

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