GE Creates Superhydrophobic Nano-Coatings to Prevent Icing on Wind Turbines and Jet Aircraft

 Joseph Vinciquerra, a project leader in the Mechanical Integration & Operability Laboratory at GE’s Global Research Center in Niskayuna, New York,  and his team have for the past several years been working with nanotechnology to understand and exploit superhydrophobic materials in an attempt to make surfaces resistant to atmospheric icing, or ice that forms at certain altitudes or on the ground in cold weather climates.

By superhydrophobic,  GE means creating materials that are super water repellent. It’s similar to “nano pants” that are spill or stain resistant. It’s amazing… you can spill coffee or juice and the liquid just rolls off the clothing without causing a stain. At GE interests are much different. GE products like wind turbines and aircraft engines come into contact with water all the time, often in the form of ice.

For a wind blade that’s 200 feet up in the air, ice buildup can cause significant drag on the blade and reduce the turbine’s energy production. For aircraft engines flying at 30,000 feet, engineering solutions are used to prevent icing, but they typically cost significant engine efficiency. But what if we could place special nano-coatings on a wind blade or on aircraft engine parts that could repel water? And what if these coatings also could repel ice? If we could eliminate the need for expensive, energy intensive systems to prevent icing, we could realize a big improvement in efficiency. In the case of the wind turbines, for example, this would enable much higher energy production says Vinciquerra.

What GE has essentially done is re-create how atmospheric icing occurs in a lab environment to test its superhydrophobic materials.  GE created a test facility that simulates these specific conditions within novel wind tunnels, which allow them to conduct experiments on new materials in the icing conditions of interest. GE also has numerous facilities and test methods that allow us to simulate a vast array of harsh environments – like high-speed sand erosion and artificial UV exposure – to make sure the materials they’re developing are robust enough for the real world. With these tools at its disposal, and a multi-faceted team of chemists, material scientists, aerospace and mechanical engineers (to name a few), GE has made substantial progress toward new coatings that not only dramatically reduce the adhesion strength of atmospherically-formed ice, but also hold up to rigors of real-world operating conditions.

In the video shown here, GE shows two generic airfoils side-by-side in one of its icing wind tunnels. The specimen on the left-hand side is made of titanium, and the specimen on the right-hand side is made of aluminum coated with a thin layer of one of our coatings. At the start of the video, you can see ice forming on the upper-most edge of both specimens as the air flows over each airfoil from the top of the screen toward the bottom. As the ice accumulates, you’ll see both airfoils rotating toward you as the air is allowed to act against the ice that has formed. As you can see, our coating technology greatly affects the way ice tries to adhere to the surface!

In this example, GE relies on the aerodynamic forces of the wind acting against the ice to release the ice from the structure. Thus, we have developed a true “de-icing” material that does not require any additional power or heat from the system. While this already offers exciting possibilities for some of the world’s toughest icing challenges, our team continues to refine these materials for a multitude of potential applications, while also working to create new “anti-icing” surfaces (those where ice does not form at all!) based on similar principles.

Modumetal Wins NSF Award to Develop Nanolaminated Thick Thermal Barrier Coatings for Insulation of Critical Engine Components

Modumetal Inc (Seattle, WA) received a National Science Foundation (NSF) award in December for a cutting-edge new coating that is expected to improve the operating performance of diesel engines. Modumetal’s coating technology will provide for greater operating temperatures to be achieved in diesel engines, thus improving fuel efficiency and reducing emissions. There is an ever increasing demand in the marketplace and in the regulatory environment for improvements in the fuel efficiency of transportation vehicles.

A major limiting factor in meeting these needs is the availability of advanced materials that can survive the requisite operating temperatures. Modumetal’s Thick Thermal Barrier Coatings (T-TBC), which will be developed under the subject contract, is such a material that will provide the basis for high-temperature, high-efficiency automobile and truck diesel engines by reducing the apparent temperature at the engine’s base metal and protecting against abrasion and high temperature-accelerated degradation.

The project, which will be lead by Modumetal’s Dr. John Whitaker, will involve specific application of a novel, nanolaminated T-TBC for insulation of critical engine components such as piston crowns, valve faces, and cylinder heads, and lower the heat rejected to the cooling system, which in turn increases the amount of the combustion energy converted to useful work.

From an environment protection standpoint, the additional advantages afforded by higher diesel operating temperatures include reductions in both carbon emissions (unburned hydrocarbons, particulates, and CO2) and noise.

According to TBC Vice President, Todd Wallen, “Modumetal’s TBCs are not only reducing the emission of carbon into the environment, but are also eliminating the creation of additional waste of natural resources by ensuring longer life and efficiency in equipment and operations. So that as this NSF Award elevates further the performance advancements made possible by Modumetal’s unique coating technology, the recognition also punctuates the growing economic and positive environmental impact of this broad nanotechnology field."

“The NSF Award further validates the progress we’ve made both as a company, and as a solutions provider in a key U.S. industry which needs such innovative technologies as this one in order to secure a position in the forefront of a competitive and demanding international marketplace,” said Modumetal CEO, Christina Lomasney.

The manufacturing process, Modumetal by Design (MbD), is a low-cost, scalable, and net-shape descendant of electrochemical manufacturing. MbD is a non-line-of-site, ambient-temperature process that supports the production of a wide range of fully dense metals, alloys and net-shape parts. MbD differs from conventional electrochemical plating and forming in its precise, time-varying control of plating conditions at the workpiece surface, producing laminated structures with wavelengths approaching several nanometers. The Modumetal technology is the subject of several issued and pending patents.

Cytonix Durable, Weatherable, Extremely Hydrophobic Coating for Signal Transmitters Features Nano Compositions

Cytonix Corporation (Beltsville, MD) inventor James F. Brown reveals compositions for extremely hydrophobic coatings which are durable, weatherable, scratch- and erosion-resistant in U.S. Patent 7,579,056. The coatings can be used on a signal transmitter or receiver such as a microwave, infra-red, light, radar, electromagnetic emitter or receiver such as a radome. The coatings do not adversely affect signal reception or transmission and help maintain the signal during rainy and stormy weather.  The coating helps prevent satellite television interruption due to heavy rains.

The compositions consists of a fluorinated component and an adhesion promoter compound. The adhesion promoter compound can include an alkoxy group, a furfuryl-containing ring structure, and a reactive group.

The composition includes a hardenable resin, hydrophobic microparticles having an average particle size diameter of from about 1 nanometer to about 100 microns, and a substantially nonvolatile mobile fluorinated compound that is a liquid in a temperature range from about -30.degree. C. to about 30.degree. C. The fluorinated compound is a perfluorinated compound, for example, a perfluoroether or a fluoro-chloro compound.. The fluorinated compounds are resistant to degradation by sunlight.  The fluorinated compound produces a surface comprising at least fifteen percent trifluoromethyl groups.

Hydrophobic coatings are used on antennas and radomes. Microwave signals are significantly, and in some cases about equally, attenuated by atmospheric precipitation and by water films on antennas and radomes. Higher microwave frequencies have resulted in greater communication bandwidth, but the shorter wavelengths are even more susceptible to rain attenuation. Airports report losses of vital satellite links during heavy precipitation, and most home viewers of satellite TV are familiar with programming disruption during even light rain. As bandwidths expand commercial and private use of microwave links, the problem of rain attenuation will become even more critical.

Numerous companies have addressed the problem of water filming on microwave radomes and dishes by using hydrophobic coatings to shed water as small, microwave-transparent beads. The smooth silicones and fluoropolymer coatings allow formation of large beads that can form rivulets and films during moderate to heavy rain. As these coatings degrade over time due to sunlight and pollution, they become less hydrophobic and their effectiveness is diminished.

Several companies, notably Vellox (Salisbury, Mass.) and Boyd (Hudson, Mass.), have addressed the problem of rain fade using hydrophobic coatings that comprise micropowders of Teflon.TM. or fumed silica dispersed in a hardenable resin, such as an alkyd or diisocyanate. These composite coatings have good performance initially but begin to form water films in an hour or less of moderate to heavy rain. After months or just weeks of exposure to mid-latitude summer sunlight these types of coatings wet out even more quickly.

Mid-latitude summer sunlight is defined as average mid-day uv radiation during the summer months in regions of the United States from a latitude of 25.degree. to a latitude of 40.degree., and moderate to heavy rain is defined as 1 to 6 inches per hour. Drying fully after being swamped, the Boyd Teflon.TM. dispersion coating CRC6040 recovers most of its previous performance, but the hydrophobic performance of the Vellox LC-410 fumed silicate coating is permanently lost. Both coatings must be reapplied every year or two.

It is believed that sunlight damages at least the surfaces of all solid polymers to some degree. Generally, unsaturated materials degrade faster than aliphatics, and aliphatics degrade faster than some fluoropolymers. But all hydrocarbon resins suffer at least superficial changes that render them more wettable; and this is also true for most fluoropolymers.

The fluoropolymer exceptions are those that degrade to hydrophobic by-products, such as PTFE; but even the exceptions can be rendered somewhat more hydrophilic and receptive to adhesives by ionizing radiation treatment. Once surface damage has taken place, the new surface is a permanent feature of the solid. Tests of all common fluorinated and non-fluorinated plastics show increases in surface wettability after exposure to the equivalent of months in mid-latitude summer sunlight.

The Cytonix coating fills the need for extremely hydrophobic coatings that are durable, for coatings for articles such as windshields, rainshields, and satellite and/or radar dishes, other signal receivers and transmitters, and radomes that does not interfere with signal transmission or reception.

The  composition that forms a hydrophobic surface is useful as a surface for other articles which could benefit from hydrophobic properties such as radomes and antennas, vehicular surfaces, architectural surfaces, outdoor furniture, household goods, and kitchen and bath articles.

Other applications of the coating compositions include their use on ink-jet ink print heads to form hydrophobic surfaces surrounding ink jet nozzle orifices. Hydrophobic properties in such regions of an ink jet print head are particularly beneficial in the use of organic solvent based ink jet inks which have even a greater tendency to wet-out on the print head than do aqueous based ink jet inks. The hydrophobic nature of such a print head design prevents nozzle clogging and cross-contamination between individual orifices of the print head. The entire print head surface containing the ink jet nozzle orifices can be coated with the hydrophobic coating composition or only in areas surrounding the individual orifices.

TAU Nanosized "Forest of Peptides" Coating Means Self-Cleaning Windows and More Efficient Batteries

TAU's nanosized "forest of peptides" can be used as the basis for self-cleaning windows and more efficient batteries. (Credit: Image courtesy of American Friends of Tel Aviv University)

A coating on windows or solar panels that repels grime and dirt? Expanded battery storage capacities for the next electric car? New Tel Aviv University research, just published in Nature Nanotechnology, details a breakthrough in assembling peptides at the nano-scale level that could make these futuristic visions come true in just a few years.

Operating in the range of 100 nanometers (roughly one-billionth of a meter) and even smaller, graduate student Lihi Adler-Abramovich and a team working under Prof. Ehud Gazit in TAU's Department of Molecular Microbiology and Biotechnology have found a novel way to control the atoms and molecules of peptides so that they "grow" to resemble small forests of grass. These "peptide forests" repel dust and water — a perfect self-cleaning coating for windows or solar panels which, when dirty, become far less efficient.

"This is beautiful and protean research," says Adler-Abramovich, a Ph.D. candidate. "It began as an attempt to find a new cure for Alzheimer's disease. To our surprise, it also had implications for electric cars, solar energy and construction."

As cheap as the sweetener in your soda

A world leader in nanotechnology research, Prof. Gazit has been developing arrays of self-assembling peptides made from proteins for the past six years. His lab, in collaboration with a group led by Prof. Gil Rosenman of TAU's Faculty of Engineering, has been working on new applications for this basic science for the last two years.

Using a variety of peptides, which are as simple and inexpensive to produce as the artificial sweetener aspartame, the researchers create their "self-assembled nano-tubules" in a vacuum under high temperatures. These nano-tubules can withstand extreme heat and are resistant to water.

"We are not manufacturing the actual material but developing a basic-science technology that could lead to self-cleaning windows and more efficient energy storage devices in just a few years," says Adler-Abramovich. "As scientists, we focus on pure research. Thanks to Prof. Gazit's work on beta amyloid proteins, we were able to develop a technique that enables short peptides to 'self-assemble,' forming an entirely new kind of coating which is also a super-capacitor."

As a capacitor with unusually high energy density, the nano-tech material could give existing electric batteries a boost — necessary to start an electric car, go up a hill, or pass other cars and trucks on the highway. One of the limitations of the electric car is thrust, and the team thinks their research could lead to a solution to this difficult problem.

"Our technology may lead to a storage material with a high density," says Adler-Abramovich. "This is important when you need to generate a lot of energy in a short period of time. It could also be incorporated into today's lithium batteries," she adds.

Windex a thing of the past?

Coated with the new material, the sealed outer windows of skyscrapers may never need to be washed again — the TAU lab's material can repel rainwater, as well as the dust and dirt it carries. The efficiency of solar energy panels could be improved as well, as a rain shower would pull away any dust that might have accumulated on the panels. It means saving money on maintenance and cleaning, which is especially a problem in dusty deserts, where most solar farms are installed today.

The lab has already been approached to develop its coating technology commercially. And Prof. Gazit has a contract with drug mega-developer Merck to continue his work on short peptides for the treatment of Alzheimer's disease — as he had originally foreseen.

Novel Fouling Repellent Metallic Microsieves Offer Hope for Clean Water in Developing Countries and Conflict Zones

Advanced nano-engineered membranes for water purification have been developed at Fraunhofer UMSICHT, Process Technology (Oberhausen, Germany) by researchers Ilka Gehrke and Volkmar Keuter.

In 2030, 47% of world population will be living in areas of high water stress (UN World Water Development Report 3, 2009). From the global water shortage a growing need for novel, more efficient and cost saving water purification methods is emerging. In both developing and industrialized countries a growing number of contaminants like micropollutants (e. g. endocrine substances) are entering water supplies. Conventional water decontamination processes based on oxidizing chemicals like ozone or chlorine consume a high amount of chemical agents and, furthermore, can produce toxic by-products. A more promising water cleaning method is represented by membrane technology which uses few chemical substances and prevents contaminants from passing through the membrane with water molecules. However, membrane processes are characterized by a high tendency to fouling resulting in drastically flux decrease.

The adaption of highly advanced nanotechnology to traditional process engineering offers new opportunities for the intensification of water processes. In Kreuter and Gehrke’s approach the focus is on the application of nanocoating procedures to membrane processes in order to reduce the fouling potential of membranes and increase the filtration capacity.

Nanocoating methods based on biocide and photocatalytic substances like titanium dioxide and silver are applied in order to functionalize membranes. For producing suitable membranes novel molding processes were utilized. Specific experimental set-ups at laboratory scale for measuring permeate flux, pressure loss and photocatalytic as well as biocide effects were mounted.

Novel metallic microsieves at (critical dimension) CD-scale, including a homogeneous pore size distribution and higher robustness, have been developed and tested. They feature an enormous permeate flux. In order to maintain the high permeate capacity, currently, fouling repellent nanocoatings consisting of photocatalytic titanium dioxide are applied to the membrane surface. The coatings are characterized by a high adhesion to the metallic membrane material. The coating process can be exactly controlled, so the very precise pore geometry is preserved and the holes are kept unblocked from coating material.

The novel fouling repellent metallic microsieves are to be implemented in compact and flexibly adjustable membrane modules particularly for producing potable water but also for the post-treatment of waste water. Due to their high robustness and easily handling among others decentralized plants, e.g. for conflict areas and developing countries are possible.

Results were reported in the proceedings of  "EuroNanoForum 2009, Nanotechnology for Sustainable Economy: European and International Forum on Nanotechnology." 

Iran Showcases Nanocoating to Protect Antique Buildings and Nanotechnologhy for Cars

Iranian researchers at P.I.M (Jazika) Co. have developed NanoSeal, a new product which helps to preserve historical relics and monuments against deteriorating weather conditions by applying a nanotechnology coating.

NanoSeal is now offered at Iranian market and is capable of protecting any surfaces like plaster walls, bentonite structures, and bricks against humidity, according to the Iran Nanotechnology Initiative Council (INIC).

According to P.I.M (Jazika), the product benefits include a number of advantages like, resistance against sunlight, corrosion, erosion and other deteriorating effect, making it economical to preserve buildings and historical constructions. Depending on the type of the surface, the dosage of the mentioned product should be about 200 to 400 milliliters per one square meter.

Another product by the company is named NanoCX800 which is useful in sealing concrete tanks. It can completely seal any concrete tank or vessel and it doesn't block concrete breathing. The products along with four concrete samples were presented by Jazika at the International Iran Nano2009 Exhibition held on November 4-8 in Tehran.

Researchers at Iran Khodro Company (IKCO) in collaboration with their colleagues at SAPCO, two of the largest car producers in Iran, pursue replacing ordinary auto parts with nanotechnology-based ones in order to improve the qualities and reduce costs.

Their nominated parts for modification include windscreen, body paint, interior composite parts, various plastic parts, seat covers, dashboard, and gas tank. It has been proven that such modifications would provide easier and better health for the internal parts of the car.

IKCO presented its first nano-modified prototype car named Samand Soren at 'Iran Nano 2009' exhibition held in Tehran. According to IKCO's experts, the car takes advantage of anti-scratch paint, nanocomposite structures in its interior parts and inter-engine units, nano-diamond contained lubricating oil, hydrophobic glasses, antibacterial seats, anti-stain dashboard and nanocatalytic exhaust converter.

"When integrated in paints, nano-coatings improve lifetime and resistance to erosion/scratch and UV greatly. This will help producers lengthen guarantee periods for automobile paints," Ali Farshidi, head of Engineering and Materials Research Center at SAPCO explained to INIC.

The researchers at Institute for Color Science and Technology (ICPC) of Iran presented ZNO:CO nano-pigments synthesized by combustion method in Iran Nano 2009 Exhibition held on November 4-8 in Tehran.

Institute for Color Science and Technology was founded in 1997 to create a scientific base in the field of paint science and industry to train professional experts and to develop practical and developing research projects in different fields of science and technology.

The nano group of the institute started up its activities related to science and nanotechnology since 2004. It joined the laboratory network of nanotechnology in 2007 and achieved the third place among the members of laboratory network.

Three major fields of activities are nano-pigments, their synthesis, retrofits, and the application of nanoparticles, self cleaning nano-coatings, anti scratch and anti corrosion materials; and thin layers which could be polymeric, metallic, hybrid, or ceramic.

Preparation of raw materials based on nanotechnology for the manufacturing of screen displays, the synthesis of magnetic nanoparticles and nanocomposites used in special coatings, the synthesis of nanopowders for production of resistant parts, and optimization of chemical synthesis methods like combustion synthesis for the production of nanomaterials are examples of the current projects in this research institute.

The institute provides facilities for post graduate and under graduate students and accepts students in nanopaint technology at master level.

Nanomaterials are produced by all mechanical, chemical, and solid methods. The equipment available at the institute include nanostructured materials testers like SEM, electronic microscope, PSA (Particle Size Analysis), freeze dryer, thermal analysis, and FT-IR.

Titanium Dioxide Nanocoating Market in Japan Pegged at $1.1 Billion

Two-thirds of Tokyo’s buildings, as well as other high -profile constructions around the world, now incorporate ‘self-cleaning’ window glass coated with a 10 -20 nm layer of titanium dioxide (TiO2), noted Akira Fijishime (Kanagawa Academy of Science and Technology, Japan) at “Nanotechnology for Sustainable Economy European and International Forum on Nanotechnology” (Prague, Czech Republic, June 2-5, 2009). TiO2 promotes the decomposition of pollutants such as NOx, and acts as a wetting agent to facilitate the washing action of rainfall. Other applications of this versatile material are in fog -resistant mirrors and self –disinfecting coatings on tiles used in hospitals, as well as in air - and water-purification. In Japan alone, the market size is estimated at around $1.1 billion (€750 million), according to conference proceedings.

The market in Europe for TiO2 coatings remains slow due to delays in the introduction of relevant international standards, according to a conference report. Self-cleaning glass coatings are available from a number of manufacturers in the U.S. Titanium dioxide is a safe substance, which is harmless to humans. It has been approved by the food-testing laboratory of the United States Food and Drug Administration (FDA).

Photocatalytic materials have massive commercial potential, e.g. in the construction and environmental sectors. Studies over many years have focused mainly on titanium dioxide (TiO2) because of its stability, commercial availability and ecological safety. When the photo-catalyst, TiO2, captures ultraviolet light it forms activated oxygen from water or oxygen in the air. Because of its catalytic nature photo-catalyst properties are not consumed during this chemical reaction. The treated surface regenerates its photo-catalytic effect by reacting with oxygen in the air. TiO2 actively decompose bacteria, biological and chemical pollutants, toxins, bad odors, mold and other fungi.