Tag Archives: paint

Barnacle footprints could be useful

An Aug. 18, 2016 news item on Nanowerk describes efforts by scientists at the University of Twente (The Netherlands) and A*STAR (Singapore) to trace a barnacle’s footprints (Note: A link has been removed),

Barnacle’s larvae leave behind tiny protein traces on a ship hull: but what is the type of protein and what is the protein-surface interaction? Conventional techniques can only identify dissolved proteins, and in large quantities. Using a modified type of an Atomic Force Microscope, scientists of the University of Twente in The Netherlands and A*STAR in Singapore, can now measure protein characteristics of even very small traces on a surface. They present the new technique in Nature Nanotechnology (“Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample”).

An Aug. 16, 2016 University of Twente press release, which originated the news item, explains how the ‘footprints’ could lead to new applications for ships and boats and briefly describes the technical aspects of the research,

In infection diseases, membrane fouling, interaction with bacteria, as well as in rapid healing of wounds for example, the way proteins interact with a surface plays an important role. On a surface, they function in a different way than in solution. On a ship hull, the larvae of the barnacle will leave tiny traces of protein to test if the surface is attractive for long-term attachment. If we get to know more about this interaction, it will be possible to develop surface conditions that are less attractive for the barnacle. Large amounts of barnacles on a ship will have a destructive effect on flow resistance and will lead to more fuel consumption. The new measuring method makes use of a modified Atomic Force Microscope: a tiny ball glued to the cantilever of the microscope will attract protein molecules.

Modified AFM tip with a tiny ball that can attract protein molecules

FORCE MEASUREMENTS

An amount of just hundreds of protein molecules will be sufficient to determine a crucial value, called the iso-electric point (pI): this is the pH-value at which the protein has net zero electric charge. The pI value says a lot about the surroundings a protein will ‘feel comfortable’ in, and to which it preferably moves. Using the AFM microscope, of which the modified tip has collected protein molecules, it is possible to perform force measurements for different pH values. The tip will be attracted or repelled, or show no movement when the pI point is reached. For these measurement, the researchers made a special reference material consisting of several layers. Using this, the effect of a number of pH-values can be tested until the pI value is found.

The traces the larve leaves behind (left) and force measurements (right)

PAINT CHANGE

The tests have been successfully performed for a number of known proteins like fibrinogen, myoglobine and bovine albumin. And returning to the barnacle: the tiny protein footprint will contain enough molecules to determine the pI value. This quantifies the ideal surface conditions, and using this knowledge, new choices can be made for e.g. the paint that is used on a ship hull.

The research has been done within the group Materials Science and Technology of Polymers of Professor Julius Vancso, in close collaboration with colleagues of A*STAR in Singapore – Prof Vancso is a Visiting Professor there as well. His group is part of UT’s MESA+ Institute for Nanotechnology.

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

Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample by Shifeng Gu, Xiaoying Zhu, Dominik Jańczewski, Serina Siew Chen Lee, Tao He, Serena Lay Ming Teo, & G. Julius Vancso.  Nature Nanotechnology (2016) doi:10.1038/nnano.2016.118 Published online 25 July 2016

This paper is behind a paywall.

Watching paint dry at the nanoscale

When paint dries it separates itself into two layers and according to scientists this may have implications for improving performance in products ranging from paints to beauty and cosmetics. From a March 18, 2016 news item on ScienceDaily,

New research published today in the journal Physical Review Letters has described a new physical mechanism that separates particles according to their size during the drying of wet coatings. The discovery could help improve the performance of a wide variety of everyday goods, from paint to sunscreen.

A March 18, 2016 University of Surrey (England) press release (also on EurekAlert), which originated the news item, provides more details,

Researchers from the University of Surrey [England, UK] in collaboration with the Université Claude Bernard, Lyon [France] used computer simulation and materials experiments to show how when coatings with different sized particles, such as paints dry, the coating spontaneously forms two layers.

This mechanism can be used to control the properties at the top and bottom of coatings independently, which could help increase performance of coatings across industries as diverse as beauty and pharmaceuticals.

Dr Andrea Fortini, of the University of Surrey and lead author explained:

“When coatings such as paint, ink or even outer layers on tablets are made, they work by spreading a liquid containing solid particles onto a surface, and allowing the liquid to evaporate. This is nothing new, but what is exciting is that we’ve shown that during evaporation, the small particles push away the larger ones, remaining at the top surface whilst the larger are pushed to bottom. This happens naturally.”

Dr Fortini continued, “This type of ‘self-layering’ in a coating could be very useful. For example, in a sun screen, most of the sunlight-blocking particles could be designed to push their way to the top, leaving particles that can adhere to the skin near the bottom of the coating. Typically the particles used in coatings have sizes that are 1000 times smaller than the width of a human hair so engineering these coatings takes place at a microscopic level. ”

The team is continuing to work on such research to understand how to control the width of the layer by changing the type and amount of small particles in the coating and explore their use in industrial products such as paints, inks, and adhesives

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

Dynamic Stratification in Drying Films of Colloidal Mixtures by Andrea Fortini, Ignacio Martín-Fabiani, Jennifer Lesage De La Haye, Pierre-Yves Dugas, Muriel Lansalot, Franck D’Agosto, Elodie Bourgeat-Lami, Joseph L. Keddie, and Richard P. Sear. Phys. Rev. Lett. 116, 118301 – Published 18 March 2016 DOI:http://dx.doi.org/10.1103/PhysRevLett.116.118301

© 2016 American Physical Society

This article is behind a paywall.

A warning for when it’s “too hot to handle”

Who hasn’t picked up something that was hotter than you thought although you probably don’t have an example as extreme as this in a July 8, 2014 news item on Azonano,

… during the war in Iraq, for example, where soldiers reported temperatures near munitions that had sometimes exceeded 190 degrees F, far in excess of the shells’ design limits.

“It would have been helpful to have had some sort of a calibrated temperature-triggered signal warning, ‘Don’t go near or pick up this shell!’ “said Zafar Iqbal, a research professor in the Department of Chemistry and Environmental Science, who led the joint NJIT/ARDEC [New Jersey Institute of Technology/U.S. Army Armament Research Development and Engineering Center] research team. Referred to as a “thermal-indicating composition” and applied as a coating or a mark on packaging, the material turns different shades of color from blue to red in response to a range of temperatures, beginning at about 95 degrees F. It was awarded a U.S. patent in May of this year.

A July 3, 2014 NJIT news release, which originated the news item, describes the research and the researcher,

“We essentially modified commercial paints and introduced nanotechnology-based concepts to tailor the trigger temperatures,” Iqbal explained, adding that his laboratory is starting to develop inks related to the paints that can be applied by inkjet printers.

His current research came out of earlier work at Honeywell, then Allied Corp., leading to a “smart coating” embedded with color-sensitive materials that indicated how long a substance had been exposed to temperatures high enough to compromise its functionality. The time-temperature device has been widely used by the World Health Organization, for example, on vaccine packaging labels.

Time-temperature coding is also important for munitions, which can be stored for many years and transported long distances. Until now, there has been no cost-effective means for identifying when munitions have experienced critical exposures, including over a period of several days. Thermal stabilizers incorporated in weapon containers can be depleted by extended exposure to high temperatures. Iqbal said the coding will be included in the thermal-indicating paints as an element of the final product for the Army.

The technology has potentially wider applications as well, including as a temperature indicator for factory machines and household appliances and tools signaling they have become dangerously hot, or as a warning to firefighters of the intensity of a fire on the other side of a door coated with the thermal paint. Several large corporations expressed preliminary interest in it at a recent expo. The patent is jointly owned by NJIT and the U.S. Army; NJIT plans to commercialize the technology.

Iqbal, who is currently working on a book entitled “Nanomaterials Science and Technology” to be published by Cambridge University Press, has been awarded 22 U.S. patents on a wide range of technologies.

He has collaborated with the U.S. Army over the years since joining the Feltman Research Laboratory at Picatinny Arsenal in New Jersey in 1969, two years after earning his Ph.D. at Cambridge University, where he conducted research at the renowned Cavendish Lab, the site of such major scientific advances as the discovery of the electron and the double-helix structure of DNA. He was a research scientist for the Army until 1977, before he returned to teaching and research for several years and then served as a senior principal scientist and project manager for nearly 20 years at Honeywell and its predecessor companies, Allied and Allied Signal, before joining NJIT.

Iqbal is currently developing a related technology that would signal whether a product has been damaged by force, shock or exposure to dangerous chemicals, such as carcinogens, or to radiation.

“A smart coded coating is like a smart skin – it will provide a visual or sensing signal to tell you if there is a problem,” he says, noting that sports helmets used in American football would be one potential application, helping coaches to determine whether a player has received a damaging blow to the head.

There is at least one sensing project for helmets and the detection of serious injury as per my Nov. 7, 2013 posting: Nanotechnology-enabled football helmets could help to determine if players have a concussion as per Iqbal’s last suggestion for a potential application of his sensing technology.

Nanomaterial use in construction, in coatings, in site remediation, and on invisible planes

Next to biomedical and electronics industries, the construction industry is expected to be the most affected by nanotechnology according to a study in ACS (American Chemical Society) Nano (journal). From the news item on Azonano,

Pedro Alvarez and colleagues note that nanomaterials likely will have a greater impact on the construction industry than any other sector of the economy, except biomedical and electronics applications. Certain nanomaterials can improve the strength of concrete, serve as self-cleaning and self-sanitizing coatings, and provide many other construction benefits. Concerns exist, however, about the potential adverse health and environmental effects of construction nanomaterials.

The scientists analyzed more than 140 studies on the benefits and risks of nanomaterials. …

The article in ACS Nano is titled, “Nanomaterials in the Construction Industry: A Review of Their Applications and Environmental Health and Safety Considerations.

Still on the construction theme but this time more focused on site remediation, here’s a story about sulfur-rich drywall which corrodes pipes and wiring while possibly causing respiratory illness. From the news item on Nanowerk,

A nanomaterial originally developed to fight toxic waste is now helping reduce debilitating fumes in homes with corrosive drywall.

Developed by Kenneth Klabunde of Kansas State University, and improved over three decades with support from the National Science Foundation, the FAST-ACT material has been a tool of first responders since 2003.

Now, NanoScale Corporation of Manhattan, Kansas–the company Klabunde co-founded to market the technology–has incorporated FAST-ACT into a cartridge that breaks down the corrosive drywall chemicals.

Homeowners have reported that the chemicals–particularly sulfur compounds such as hydrogen sulfide and sulfur dioxide–have caused respiratory illnesses, wiring corrosion and pipe damage in thousands of U.S. homes with sulfur-rich, imported drywall.

“It is devastating to see what has happened to so many homeowners because of the corrosive drywall problem, but I am glad the technology is available to help,” said Klabunde. “We’ve now adapted the technology we developed through years of research for FAST-ACT for new uses by homeowners, contractors and remediators.”

The company has already tested its new product and found that corrosion was reduced and odor levels dropped to almost imperceptible. There are plans to use the company’s technology in the Gulf Coast and elsewhere there are airborne toxic substances.

In Europe, Germany has plans to introduce new concrete paving slabs that reduce the quantity of nitrogen oxide in the air. From the news item on Nanowerk,

In Germany, ambient air quality is not always as good as it might be – data from the federal environment ministry makes this all too clear. In 2009, the amounts of toxic nitrogen oxide in the atmosphere exceeded the maximum permitted levels at no fewer than 55 percent of air monitoring stations in urban areas. The ministry reports that road traffic is one of the primary sources of these emissions.

In light of this fact, the Baroque city of Fulda is currently embarking on new ways to combat air pollution. Special paving slabs that will clean the air are to be laid the length of Petersberger Strasse, where recorded pollution levels topped the annual mean limit of 40 micrograms per cubic meter (µg/m3) last year. These paving slabs are coated with titanium dioxide (TiO2), which converts harmful substances such as nitrogen oxides into nitrates. Titanium dioxide is a photocatalyst; it uses sunlight to accelerate a naturallyoccurring chemical reaction, the speed of which changes with exposure to light.

They’ve already had success with this approach in Italy but Germany has fewer hours of sunshine and lower intensities of light so the product had to be optimized and tested in Germany. Testing has shown that the effect for Germany’s optimized paving slabs does not wear off quickly (it was tested again at 14 months and 23 months). Finally, there don’t seem to be any environmentally unpleasant consequences. If you’re curious about the details, do click on the link.

One last item, this time it’s about a nano-enabled coating that’s a paint. An Israeli company has developed a paint for airplanes that can make them invisible to radar. From Dexter Johnson’s July 14, 2010 posting on Nanoclast,

No, we’re not talking about a Wonder Woman-type of invisible plane, but rather one that becomes very difficult to detect with radar.

The Israel-based Ynetnews is reporting that an Israeli company called Nanoflight has successfully run a test on dummy missiles that were painted with the nano-enabled coating and have shown that radar could not pick them up as missiles.

The YnetNews article rather brutally points out that painting an aircraft with this nanocoating is far cheaper than buying a $5 billion US-made stealth aircraft. Of course, it should also be noted that one sale of a $5 billion aircraft employs a large number of aeronautical engineers, and the high price tag also makes it far more difficult for others to purchase the technology and possess the ability to sneak up on an enemy as well.

You can read more and see a picture of Wonder Woman’s invisible plane by following the link to Dexter’s posting.