Tag Archives: water repelling

Better and greener oil recovery

A June 27, 2016 news item on phys.org describes research on achieving better oil recovery,

As oil producers struggle to adapt to lower prices, getting as much oil as possible out of every well has become even more important, despite concerns from nearby residents that some chemicals used to boost production may pollute underground water resources.

Researchers from the University of Houston have reported the discovery of a nanotechnology-based solution that could address both issues – achieving 15 percent tertiary oil recovery at low cost, without the large volume of chemicals used in most commercial fluids.

A June 27, 2016 University of Houston news release (also on EurekAlert) by Jeannie Kever, which originated the news item, provides more detail,

The solution – graphene-based Janus amphiphilic nanosheets – is effective at a concentration of just 0.01 percent, meeting or exceeding the performance of both conventional and other nanotechnology-based fluids, said Zhifeng Ren, MD Anderson Chair professor of physics. Janus nanoparticles have at least two physical properties, allowing different chemical reactions on the same particle.

The low concentration and the high efficiency in boosting tertiary oil recovery make the nanofluid both more environmentally friendly and less expensive than options now on the market, said Ren, who also is a principal investigator at the Texas Center for Superconductivity at UH. He is lead author on a paper describing the work, published June 27 [2016] in the Proceedings of the National Academy of Sciences.

“Our results provide a novel nanofluid flooding method for tertiary oil recovery that is comparable to the sophisticated chemical methods,” they wrote. “We anticipate that this work will bring simple nanofluid flooding at low concentration to the stage of oilfield practice, which could result in oil being recovered in a more environmentally friendly and cost-effective manner.”

In addition to Ren, researchers involved with the project include Ching-Wu “Paul” Chu, chief scientist at the Texas Center for Superconductivity at UH; graduate students Dan Luo and Yuan Liu; researchers Feng Wang and Feng Cao; Richard C. Willson, professor of chemical and biomolecular engineering; and Jingyi Zhu, Xiaogang Li and Zhaozhong Yang, all of Southwest Petroleum University in Chengdu, China.

The U.S. Department of Energy estimates as much as 75 percent of recoverable reserves may be left after producers capture hydrocarbons that naturally rise to the surface or are pumped out mechanically, followed by a secondary recovery process using water or gas injection.

Traditional “tertiary” recovery involves injecting a chemical mix into the well and can recover between 10 percent and 20 percent, according to the authors.

But the large volume of chemicals used in tertiary oil recovery has raised concerns about potential environmental damage.

“Obviously simple nanofluid flooding (containing only nanoparticles) at low concentration (0.01 wt% or less) shows the greatest potential from the environmental and economic perspective,” the researchers wrote.

Previously developed simple nanofluids recover less than 5 percent of the oil when used at a 0.01 percent concentration, they reported. That forces oil producers to choose between a higher nanoparticle concentration – adding to the cost – or mixing with polymers or surfactants.

In contrast, they describe recovering 15.2 percent of the oil using their new and simple nanofluid at that concentration – comparable to chemical methods and about three times more efficient than other nanofluids.

Dan Luo, a UH graduate student and first author on the paper, said when the graphene-based fluid meets with the brine/oil mixture in the reservoir, the nanosheets in the fluid spontaneously go to the interface, reducing interfacial tension and helping the oil flow toward the production well.

Ren said the solution works in a completely new way.

“When it is injected, the solution helps detach the oil from the rock surface,” he said. Under certain hydrodynamic conditions, the graphene-based fluid forms a strong elastic and recoverable film at the oil and water interface, instead of forming an emulsion, he said.

Researchers said the difference is due to the asymmetric property of the 2-dimensional material. Nanoparticles are usually either hydrophobic – water-repelling, like oil – or hydrophilic, water-like, said Feng Wang, a post-doctoral researcher who shared first author-duties with Luo.

“Ours is both,” he said. “Ours is Janus and also strictly amphiphilic.”

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

Nanofluid of graphene-based amphiphilic Janus nanosheets for tertiary or enhanced oil recovery: High performance at low concentration by Dan Luo, Feng Wang, Jingyi Zhu, Feng Cao, Yuan Liu, Xiaogang Li, Richard C. Willson, Zhaozhong Yang, Ching-Wu Chu, and Zhifeng Ren. PNAS 2016 doi: 10.1073/pnas.1608135113 published ahead of print June 27, 2016,

This paper is behind a paywall.

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

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

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

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

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

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

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

[downloaded from http://www.p2i.com/news/articles/P2i_and_Shirin_Gerami_A_partnership_changing_history]

[downloaded from http://www.p2i.com/news/articles/P2i_and_Shirin_Gerami_A_partnership_changing_history]

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

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

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

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

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

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

Nanex Canada (?) opens office in United States

Earlier this month in a Sept. 5, 2014 posting I noted that a Belgian company was opening a Canadian subsidiary in Montréal, Québec, called Nanex Canada. Not unexpectedly, the company has now announced a new office in the US. From a Sept. 23, 2014 Nanex Canada news release on Digital Journal,

Nanex Canada appoints Patrick Tuttle, of Havre de Grace, Maryland as the new USA National Sales Director. Tuttle will be in charge of all operations for the USA marketing and distribution for the Nanex Super hydrophobic Water Repellent Nanotechnology products.

… Nanex Canada is proud to announce a new partnership with Patrick Tuttle to develop the market within the Unites States for Its new line of super hydrophobic products. “We feel this is a very strategic alliance with Mr. Tuttle and his international marketing staff,” said Boyd Soussana, National Marketing Director for the parent company, Nanex Canada.

The products Mr. Tuttle will be responsible for in developing a market for include:

1) Aqua Shield Marine

2) Aqua Shield Leather and Textile

3) Aqua Shield Exterior: Wood, Masonry, Concrete

4) Aqua Shield Sport: Skiing, Snowboarding, Clothing

5) Aqua Shield Clear: Home Glass and Windshield Coating

6) Dryve Shield: For all Auto Cleaning and Shine

Soussana went on to say “the tests we have done in Canada on high dollar vehicles and the feedback from the Marine industry have been excellent. We are hearing from boat owners that they are seeing instant results in cleaning and protection from the Aqua Shield Marine products from the teak, to the rails and the fiberglass as well”

Boyd Soussana told me they did a private test on some very high end vehicles and the owners were very impressed, according to him.

So what is a Super hydrophobic Water Repellent Nanotechnology Product and how does it work?

A superhydrophobic coating is a nanoscopic surface layer that repels water and also can reduce dirt and friction against the surface to achieve better fuel economies for the auto and maritime industries according to Wikipedia.

About Nanex Company

Nanex is a developer of commercialized nanotechnology solutions headquartered in Belgium operating in North America through its Canadian subsidiary Nanex Canada Incorporated. At the start of 2012 it launched its first product, an advanced super hydrophobic formula called Always Dry. By 2014 Nanex had distributors around the world from Korea, Malaysia, and Singapore, to England and Eastern Europe, and had expanded its products into three lines and several formulas.

Given the remarkably short time span between opening a Canadian subsidiary and opening an office in the US, it’s safe to assume that obtaining a toehold in the US market was Nanex’s true objective.

Canadian nano business news: international subsidiary (Nanex) opens in Québec and NanoStruck’s latest results on recovering silver from mine tailings

The Canadian nano business sector is showing some signs of life. Following on my Sept. 3, 2014 posting about Nanotech Security Corp.’s plans to buy a subsidiary business, Fortress Optical Features, there’s an international subsidiary of Nanex (a Belgium-based business) planning to open in the province of Québec and NanoStruck (an Ontario-based company) has announced the results of its latest tests on cyanide-free recovery techniques.

In the order in which I stumbled across these items, I’m starting with the Nanex news item in a Sept. 3, 2014 posting on the Techvibes blog,

Nanex, a Belgian-based innovator and manufacturer of superhydrophobic nanotechnology products, announced last week the creation of its first international subsidiary.

Nanex Canada will be headquartered in Montreal.

For those unfamiliar with the term superhydrophobic, it means water repellent to a ‘super’ degree. For more information the properties of superhydrophobic coatings, the Techvibes post is hosting a video which demonstrates the coating’s properties (there’s a car which may never need washing again).

An Aug. 1, 2014 Nanex press release, which originated the news item, provides more details,

… Nanex Canada Incorporated will be starting operations on October 1st, 2014 and will be headquartered in Montreal, Quebec.

“Nanex’s expansion into Canada is a tremendous leap forward in our international operations, creating not only more efficient and direct channels into all of North America, but also providing access to a new top-notch intellectual pool for our R&D efforts,” Said Boyd Soussana, National Marketing Director at Nanex Canada. “We feel that Quebec and Canada have a great reputation as leaders in the field of advanced technologies, and we are proud to contribute to this scientific landscape.”

Upon launch, Nanex Canada Inc. will begin with retail and sales of its nanotechnology products, which have a wide range of consumer applications. Formal partnerships in B2B [business-to-business] further expanding these applications have been in place throughout Canada beginning in August of 2014. Through its Quebec laboratories Nanex Canada Inc. will also be pursuing R&D initiatives, in order to further develop safe and effective nano-polymers for consumer use, focusing entirely on ease of application and cost efficiency for the end consumer. In addition application of nano-coatings in green technologies will be a priority for North American R&D efforts.

Nanex Company currently manufactures three lines of products: Always Dry, Clean & Coat, and a self-cleaning coating for automotive bodies. These products contain proprietary nano-polymers that when sprayed upon a surface provide advanced abilities including super hydrophobic (extremely water-repellent), oleophobic (extremely oil repellent), and scratch resistance as well as self-cleaning properties.

 

The second piece of news is featured in a Sept. 5, 2014 news item on Azonano,

NanoStruck Technologies Inc. is pleased to announce positive results from test work carried out on silver mine tailings utilizing proprietary cyanide free recovery technologies that returned up to 87.6% of silver from samples grading 56 grams of silver per metric ton (g/t).

A Sept. 4, 2014 NanoStruck news release, which originated the news item, provides more details,

Three leach tests were conducted using the proprietary mixed acid leach process. Roasting was conducted on the sample for two of the leach tests, producing higher recoveries, although the un-roasted sample still produced a 71% recovery rate.

87.6% silver recoveries resulted from a 4 hour leach time at 95 degrees Celsius, with the standard feed grind size of D80 175 micron of roasted material.
84.3% recoveries resulted from a 4 hour leach at 95 degrees Celsius with the standard feed grind size of D80 175 micron with roasted material at a lower acid concentration.
71% recoveries resulted from a 4 hour leach at 95 degrees Celsius from received material, with the standard feed grind size of D80 175 micron with an altered acid mix concentration.

The average recovery for the roasted samples was 86% across the two leach tests performed using the proprietary process.

Bundeep Singh Rangar, Interim CEO and Chairman of the Board, said: “These results further underpin the effectiveness of our processing technology. With our patented process we are achieving excellent recoveries in not only silver tailings, but also gold tailings as well, both of which have vast global markets for us.”

The proprietary process combines a novel mixed acid leach with a solvent extraction stage, utilizing specific organic compounds. No cyanide is used in this environmentally friendly process. The flow sheet design is for a closed loop, sealed unit in which all chemicals are then recycled.

Previous test work undertaken on other gold mine tailings utilizing the proprietary process resulted in a maximum 96.1% recovery of gold. Previous test work undertaken on other silver tailings resulted in a maximum 86.4% recovery of silver.

The technical information contained in this news release has been verified and approved by Ernie Burga, a qualified person for the purpose of National Instrument 43-101, Standards of Disclosure for Mineral Projects, of the Canadian securities administrators.

Should you choose to read the news release in its entirety, you will find that no one is responsible for the information should anything turn out to be incorrect or just plain wrong but, like Nanotech Security Corp., (as I noted in my Sept. 4, 2014 posting), the company is very hopeful.

I have mentioned NanoStruck several times here:

March 14, 2014 posting

Feb. 19, 2014 posting

Feb. 10, 2014 posting

Dec. 27, 2013 posting

Affordable desktop nanocoating system makes devices water repellent

I like the idea of having a waterproof smartphone, unfortunately, that day has not yet arrived but this Feb. 24, 2014 news item on Azonano hints at an acceptable alternative in the shorter term,

DryWired™ announced today that it is expanding its customized surface modification product portfolio to include the DryWired™ Nebula and the Nebula Junior. These revolutionary patent- pending desktop nanocoating systems are low cost, compact, and ideal for electronic retailers looking to offer invisible water repellent nanocoatings directly to their customers.

There’s more about the Nebula and Nebula Junior (which are being introduced at the World Mobile Congress in Barcelona from Feb. 24 – 27, 2014,) from their product page on the DryWired website,

The DryWired™ Nebula and Nebula Junior are revolutionary patent pending bench top nanocoating systems that are affordable, compact and ideal for electronic retailers looking to offer invisible water repellent nanocoatings directly to their customers.The Nebula systems are a perfect solution for consumer facing mobile phone retailers, repair/service centers, mobile phone accessory providers and other small businesses due to their small footprint and performance reliability.The award-winning Nebula systems are designed and manufactured in California.

Nebula systems can be used to Nanocoat:

•Mobile phones
•iPads and other tablets
•Gaming consoles
•Headsets, headphones and ear buds
•Hearing Aids
•Cameras
•Electronic assemblies

•Other high value items

Nebula Features:

• Two tiered configuration in the chamber allowing flexibility for multiple applications.
• Larger chamber size
• Can accommodate approximately 28 smartphones per cycle at full capacity.

• Process time cycles under 95 minutes at full capacity, including vacuum pump down.

Nebula Jr. Features:

• Single tier configuration.
• Smaller chamber size
• Can accommodate approximately 5 smartphones per cycle at full capacity.
• Process time cycles under 45 minutes including vacuum pump down.

The Nebula and Nebula Jr.Advantage:

• Repeatability: within-batch, and batch-to–batch uniformity.
• Lowest Cost-of-Ownership systems in the industry.
• Efficient and minimal chemical usage featuring single-use or multiple dose cartridges.
• Compact design with no restrictive ancillary requirements.
• Safe and user friendly with programmable settings.
• Ideal for retailers, repair/service centers, mobile ventures, and kiosks.
• Our chemical cartridges are non-hazardous, non-toxic and can be shipped worldwide without restrictions.
• Optional self-contained customized cart for consumer facing operations

Getting back to the news item, which notes some opportunities to see the products,

DryWired™ will present the Nebula systems to the public this week in Barcelona, Spain at the 2014 Mobile World Congress. The systems will be available for viewing and live demonstration by appointment only at the DryWired meeting room from Monday February 24th through Thursday February 27th, and thereafter at DryWired’s Los Angeles & Miami showrooms. DryWired is now taking pre-orders on its Nebula systems for shipment beginning March 1st. To schedule a meeting or place a pre-order on either system, please contact Alex Nesic at alex@drywired.com.

NBD Nano startup company and the Namib desert beetle

In 2001, Andrew Parker and Chris Lawrence published an article in Nature magazine about work which has inspired a US startup company in 2012 to develop a water bottle that fills itself up with water by drawing moisture from the air. Parker’s and Lawrence’s article was titled Water capture by a desert beetle. Here’s the abstract (over 10 years later the article is still behind a paywall),

Some beetles in the Namib Desert collect drinking water from fog-laden wind on their backs1. We show here that these large droplets form by virtue of the insect’s bumpy surface, which consists of alternating hydrophobic, wax-coated and hydrophilic, non-waxy regions. The design of this fog-collecting structure can be reproduced cheaply on a commercial scale and may find application in water-trapping tent and building coverings, for example, or in water condensers and engines.

Some five years later, there was a June 15, 2006 news item on phys.org about the development of a new material based on the Namib desert beetle,

When that fog rolls in, the Namib Desert beetle is ready with a moisture-collection system exquisitely adapted to its desert habitat. Inspired by this dime-sized beetle, MIT [Massachusetts Institute of Technology] researchers have produced a new material that can capture and control tiny amounts of water.

The material combines a superhydrophobic (water-repelling) surface with superhydrophilic (water-attracting) bumps that trap water droplets and control water flow. The work was published in the online version of Nano Letters on Tuesday, May 2 [2006] {behind a paywall}.

Potential applications for the new material include harvesting water, making a lab on a chip (for diagnostics and DNA screening) and creating microfluidic devices and cooling devices, according to lead researchers Robert Cohen, the St. Laurent Professor of Chemical Engineering, and Michael Rubner, the TDK Professor of Polymer Materials Science and Engineering.

The MIT June 14, 2006 news release by Anne Trafton, which originated the news item about the new material, indicates there was some military interest,

The U.S. military has also expressed interest in using the material as a self-decontaminating surface that could channel and collect harmful substances.

The researchers got their inspiration after reading a 2001 article in Nature describing the Namib Desert beetle’s moisture-collection strategy. Scientists had already learned to copy the water-repellent lotus leaf, and the desert beetle shell seemed like another good candidate for “bio-mimicry.”

When fog blows horizontally across the surface of the beetle’s back, tiny water droplets, 15 to 20 microns, or millionths of a meter, in diameter, start to accumulate on top of bumps on its back.

The bumps, which attract water, are surrounded by waxy water-repelling channels. “That allows small amounts of moisture in the air to start to collect on the tops of the hydrophilic bumps, and it grows into bigger and bigger droplets,” Rubner said. “When it gets large, it overcomes the pinning force that holds it and rolls down into the beetle’s mouth for a fresh drink of water.”

To create a material with the same abilities, the researchers manipulated two characteristics — roughness and nanoporosity (spongelike capability on a nanometer, or billionths of a meter, scale).

By repeatedly dipping glass or plastic substrates into solutions of charged polymer chains dissolved in water, the researchers can control the surface texture of the material. Each time the substrate is dipped into solution, another layer of charged polymer coats the surface, adding texture and making the material more porous. Silica nanoparticles are then added to create an even rougher texture that helps trap water droplets.

The material is then coated with a Teflon-like substance, making it superhydrophobic. Once that water-repellent layer is laid down, layers of charged polymers and nanoparticles can be added in certain areas, using a properly formulated water/alcohol solvent mixture, thereby creating a superhydrophilic pattern. The researchers can manipulate the technique to create any kind of pattern they want.

The research is funded by the Defense Advanced Research Projects Agency and the National Science Foundation.

I’m not sure what happened with the military interest or the group working out of MIT in 2006 but on Nov. 23, 2012, BBC News online featured an article about a US startup company, NBD Nano, which aims to bring a self-filling water bottle based on Namib desert beetle to market,

NBD Nano, which consists of four recent university graduates and was formed in May, looked at the Namib Desert beetle that lives in a region that gets about half an inch of rainfall per year.

Using a similar approach, the firm wants to cover the surface of a bottle with hydrophilic (water-attracting) and hydrophobic (water-repellent) materials.

The work is still in its early stages, but it is the latest example of researchers looking at nature to find inspiration for sustainable technology.

“It was important to apply [biomimicry] to our design and we have developed a proof of concept and [are] currently creating our first fully-functional prototype,” Miguel Galvez, a co-founder, told the BBC.

“We think our initial prototype will collect anywhere from half a litre of water to three litres per hour, depending on local environments.”

According to the Nov. 25, 2012 article by Nancy Owano for phys.org, the company is at the prototype stage now,

NBD Nano plans to enter the worldwide marketplace between 2014 and 2015.

You can find out more about NBD Nano here.

University of Twente (Holland) researchers love their metaphors: ‘bed of nails’ and ‘soccer balls’

In the last week there have been a couple of news releases from Dutch researchers at the University of Twente’s MESA+ Institute for Nanotechnology which feature some metaphors. The first was a Sept. 20, 2012 news item on Nanowerk (Note: I have removed a link),

Nanotechnology researchers develop ‘bed of nails’ material for clean surfaces

Scientists at the University of Twente’s MESA+ Institute for Nanotechnology have developed a new material that is not only extremely water-repellent but also extremely oil-repellent. It contains minuscule pillars which retain droplets. What makes the material unique is that the droplets stay on top even when they evaporate (slowly getting smaller). This opens the way to such things as smartphone screens that really cannot get dirty. The study appears today in the scientific journal Soft Matter (“Absence of an evaporation-driven wetting transition on omniphobic surfaces”).

The University of Twente Sept. 12, 2012 news release, which originated the news item explores the metaphor and the technology,

Water-repellent surfaces can be used as a coating for windows, obviating the need to clean them ever again. These surfaces have an orderly arrangement of tiny pillars less than one-hundredth of a millimetre high (similar to a bed of nails but on an extremely small scale). Water droplets stay on the tips of the pillars, retaining the shape of perfectly round tiny pearls. As a result they can roll off the surface like marbles, taking all the dirt with them.

Nanotechnologists at the University of Twente have now managed to create a silicon surface that retains not only water droplets but also oil droplets like tiny pearls …. What makes the material unique is that the droplets remain in place even when they evaporate (get smaller).

With existing materials, evaporating droplets drop down between the pillars onto the surface after a while, changing in shape to hemispheres which can no longer simply roll off the surface. The surface can therefore still get dirty. By modifying the edges and the roughness of the minuscule pillars the UT scientists have managed to create a surface on which the droplets do not drop down even when they evaporate but stay neatly on top.

The Sept. 27, 2012 news item on Nanowerk features another metaphor, one which is well known amongst followers of the nanotechnology scene,

Nanotechnologists create miniscule soccer balls

Nanotechnologists at the University of Twente’s MESA+ research institute have developed a method whereby minuscule polystyrene spheres, automatically and under controlled conditions, form an almost perfect ball that looks suspiciously like a football, but about a thousand times smaller. The spheres organize themselves in such a way that they approach the densest arrangement possible, known as ‘closest packing of spheres’. The method provides nanotechnologists with a new way of creating minuscule 3D structures.

Soccer balls usually reference buckminster fullerenes (bucky balls). The news item explains this new use further,

The method developed by the University of Twente scientists involves placing a drop of water containing thousands of polystyrene spheres one micrometre in size (a thousand times smaller than a millimetre) on a superhydrophobic surface. As the drop is allowed to evaporate very slowly under controlled conditions the distances between the spheres become smaller and smaller and surprisingly they form a highly organized 3D structure. The spheres were found to organize themselves of their own accord in such a way that the ball they form approaches the most compact arrangement possible (‘closest packing of spheres’), with 74% of the space filled by the spheres. Like a football, the structures that form are almost perfectly spherical, consisting of a large number of planes. The researchers have therefore dubbed their material ‘microscopic soccer balls’. The minuscule footballs are a hundred to a thousand micrometres in size, containing from ten thousand to as much as a billion of the tiny polystyrene spheres.

There’s more on the University of Twente’s MESA+ Institute for Nanotechnology website but you will need to have Dutch language skills.

It’s always good to see metaphors and I like when scientists (or whoever’s writing the news releases) get create that way.

Hands off the bubbles in my boiling water!

The discovery that boiling water bubbled was important to me. I’ve never really thought about it until now when researchers at Northwestern University have threatened to take my bubbles away, metaphorically speaking. From the Sept. 13, 2012 news item on ScienceDaily,

Every cook knows that boiling water bubbles, right? New research from Northwestern University turns that notion on its head.

“We manipulated what has been known for a long, long time by using the right kind of texture and chemistry to prevent bubbling during boiling,” said Neelesh A. Patankar, professor of mechanical engineering at Northwestern’s McCormick School of Engineering and Applied Science and co-author of the study.

This discovery could help reduce damage to surfaces, prevent bubbling explosions and may someday be used to enhance heat transfer equipment, reduce drag on ships and lead to anti-frost technologies.

The Sept. 13, 2012 news release from McCormick University (which originated the news item) provides details,

This phenomenon is based on the Leidenfrost effect. In 1756 the German scientist Johann Leidenfrost observed that water drops skittered on a sufficiently hot skillet, bouncing across the surface of the skillet on a vapor cushion or film of steam. The vapor film collapses as the surface falls below the Leidenfrost temperature. When the water droplet hits the surface of the skillet, at 100 degrees Celsius, boiling temperature, it bubbles.

To stabilize a Leidenfrost vapor film and prevent bubbling during boiling, Patankar collaborated with Ivan U. Vakarelski of King Abdullah University of Science and Technology, Saudi Arabia. Vakarelski led the experiments and Patankar provided the theory. The collaboration also included Derek Chan, professor of mathematics and statistics from the University of Melbourne in Australia.

In their experiments, the stabilization of the Leidenfrost vapor film was achieved by making the surface of tiny steel spheres very water-repellant. The spheres were sprayed with a commercially available hydrophobic coating — essentially self-assembled nanoparticles — combined with other water-hating chemicals to achieve the right amount of roughness and water repellency. At the correct length scale this coating created a surface texture full of tiny peaks and valleys.

When the steel spheres were heated to 400 degrees Celsius and dropped into room temperature water, water vapors formed in the valleys of the textured surface, creating a stable Leidenfrost vapor film that did not collapse once the spheres cooled to the temperature of boiling water. In the experiments, researchers completely avoided the bubbly phase of boiling.

To contrast, the team also coated tiny steel spheres with a water-loving coating, heated the objects to 700 degrees Celsius, dropped them into room temperature water and observed that the Leidenfrost vapor collapsed with a vigorous release of bubbles.

The scientists have provided a video illustrating their work,

This movie shows the cooling of 20 mm hydrophilic (left) and superhydrophobic (right) steel spheres in 100 C water. The spheres’ initial temperature is about 380 C. The bubbling phase of boiling is completely eliminated for steel spheres with superhydrophobic coating. (from Vimeo, http://vimeo.com/49391913)

I understand there are advantages to not having bubbles in hot water but it somehow seems wrong. I’ve given up a lot over the years: gravity, boundaries between living and non-living (that was a very big thing to give up), and other distinctions that I have made based on traditional science but, today, this is one step too far.

It may seem silly but that memory of my mother explaining that you identify boiling water by its bubbles is important to me. It was one of my first science lessons. I imagine I will recover from this moment but it does remind me of how challenging it can be when your notions of reality/normalcy are challenged by various scientific endeavours. The process can get quite exhausting as you keep recalibrating everything you ‘know’ all the time.