Tag Archives: oil spills

Clean up oil spills (on water and/or land) with oil-eating bacterium

Quebec’s Institut national de la recherche scientifique (INRS) announced an environmentally friendly way of cleaning up oil spills in an April 9, 2018 news item on ScienceDaily,

From pipelines to tankers, oil spills and their impact on the environment are a source of concern. These disasters occur on a regular basis, leading to messy decontamination challenges that require massive investments of time and resources. But however widespread and serious the damage may be, the solution could be microscopic — Alcanivorax borkumensis — a bacterium that feeds on hydrocarbons. Professor Satinder Kaur Brar and her team at INRS have conducted laboratory tests that show the effectiveness of enzymes produced by the bacterium in degrading petroleum products in soil and water. Their results offer hope for a simple, effective, and eco-friendly method of decontaminating water and soil at oil sites.

An April 8, 2018 INRS news release by Stephanie Thibaut, which originated the news item, expands on the theme,

In recent years, researchers have sequenced the genomes of thousands of bacteria from various sources. Research associate Dr.Tarek Rouissi poured over “technical data sheets” for many bacterial strains with the aim of finding the perfect candidate for a dirty job: cleaning up oil spills. He focused on the enzymes they produce and the conditions in which they evolve.

A. borkumensis, a non-pathogenic marine bacterium piqued his curiosity. The microorganism’s genome contains the codes of a number of interesting enzymes and it is classified as “hydrocarbonoclastic”—i.e., as a bacterium that uses hydrocarbons as a source of energy. A. borkumensis is present in all oceans and drifts with the current, multiplying rapidly in areas where the concentration of oil compounds is high, which partly explains the natural degradation observed after some spills. But its remedial potential had not been assessed.

“I had a hunch,” Rouissi said, “and the characterization of the enzymes produced by the bacterium seems to have proven me right!” A. borkumensis boasts an impressive set of tools: during its evolution, it has accumulated a range of very specific enzymes that degrade almost everything found in oil. Among these enzymes, the bacteria’shydroxylases stand out from the ones found in other species: they are far more effective, in addition to being more versatile and resistant to chemical conditions, as tested in coordination by a Ph.D. student, Ms. Tayssir Kadri.

To test the microscopic cleaner, the research team purified a few of the enzymes and used them to treat samples of contaminated soil. “The degradation of hydrocarbons using the crude enzyme extract is really encouraging and reached over 80% for various compounds,” said Brar. The process is effective in removing benzene, toluene, and xylene, and has been tested under a number of different conditions to show that it is a powerful way to clean up polluted land and marine environments.”

The next steps for Brar’s team are to find out more about how these bacteria metabolize hydrocarbons and explore their potential for decontaminating sites. One of the advantages of the approach developed at INRS is its application in difficult-to-access environments, which present a major challenge during oil spill cleanup efforts.

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

Ex-situ biodegradation of petroleum hydrocarbons using Alcanivorax borkumensis enzymes by Tayssir Kadri, Sara Magdouli, Tarek Rouissi, Satinder Kaur Brar. Biochemical Engineering Journal Volume 132, 15 April 2018, Pages 279-287 DOI: https://doi.org/10.1016/j.bej.2018.01.014

This paper is behind a paywall.

In light of this research, it seems remiss not to mention the recent setback for Canada’s Trans Mountain pipeline expansion. Canada’s Federal Court of Appeal quashed the approval as per this August 30, 2018 news item on canadanews.org. There were two reasons for the quashing (1) a failure to properly consult with indigenous people and (2) a failure to adequately assess environmental impacts on marine life. Interestingly, no one ever mentions environmental cleanups and remediation, which could be very important if my current suspicions regarding the outcome for the next federal election are correct.

Regardless of which party forms the Canadian government after the 2019 federal election, I believe that either Liberals or Conservatives would be equally dedicated to bringing this pipeline to the West Coast. The only possibility I can see of a change lies in a potential minority government is formed by a coalition including the NDP (New Democratic Party) and/or the Green Party; an outcome that seems improbable at this juncture.

Given what I believe to be the political will regarding the Trans Mountain pipeline, I would dearly love to see more support for better cleanup and remediation measures.

Oil spill cleanup nanotechnology-enabled solution from A*STAR

A*STAR (Singapore’s Agency for Science Technology and Research) has developed a new technology for cleaning up oil spills according to an Oct. 11, 2016 news item on Nanowerk,

Oceanic oil spills are tough to clean up. They dye feathers a syrupy sepia and tan fish eggs a toxic tint. The more turbulent the waters, the farther the slick spreads, with inky droplets descending into the briny deep.

Now technology may be able to succeed where hard-working volunteers have failed in the past. Researchers at the A*STAR Institute of Bioengineering and Nanotechnology (IBN) are using nanotechnology to turn an oil spill into a floating mass of brown jelly that can be scooped up before it can make its way into the food chain.

“Nanoscience makes it possible to tailor the essential structures of materials at the nanometer scale to achieve specific properties,” says chemist Yugen Zhang at IBN, who is developing some of the technologies. “Structures and materials in the nanometer size range often take on distinctive properties that are not seen in other size ranges,” adds Huaqiang Zeng, another chemist at IBN.

An Oct. 11, 2016 A*STAR press release, which originated the news item, describes some of problematic solutions before describing the new technology,

There are many approaches to cleaning an oil spill, and none are completely effective. Fresh, thick grease can be set ablaze or contained by floating barriers for skimmers to scoop out. The slick can also be inefficiently hardened, messily absorbed, hazardously dispersed, or slowly consumed by oil-grazing bacteria. All of these are deficient on a large scale, especially in rough waters.

Organic molecules with special gelling abilities offer a cheap, simple and environmentally friendly alternative for cleaning up the mess. Zeng has developed several such molecules that turn crude oil into jelly within minutes.

To create his ‘supergelators’, Zeng designed the molecules to associate with each other without forming physical bonds. When sprayed on contaminated seawater, the molecules immediately bundle into long fibers between 40 and 800 nanometers wide. These threads create a web that traps the interspersed oil in a giant blob that floats on the water’s surface. The gunk can then be swiftly sieved out of the ocean. Valuable crude oil can later be reclaimed using a common technique employed by petroleum refineries called fractional distillation.

Zeng tested the supergelators on four types of crude oil with different densities, viscosities and sulfur levels in a small round dish. The results were impressive. “The supergelators solidified both freshly spilled crude oil and highly weathered crude oil 37 to 60 times their own weight,” says Zeng. The materials used to produce these organic molecules are cheap and non toxic, which make them a commercially viable solution for managing accidents out at sea. Zeng hopes to work with industrial partners to test the nanomolecules on a much larger scale.

Zeng and his colleagues have developed other other ‘water’ applications as well,

Unsalty water

Scientists at IBN are also using nanoscience to remove salt from seawater and heavy metals from contaminated water.

With dwindling global fresh and ground water reserves, many countries are looking to desalination as a viable source of drinking water. Desalination is expected to meet 30 per cent of the water demand of Singapore by 2060, which will mean tripling the country’s current desalination capacity. But desalination demands huge energy consumption and reverse osmosis, the mainstream technology it depends on, has a relatively high cost. Reverse osmosis works by using extreme pressures to squeeze water molecules through tightly knit membranes.

An emerging alternative solution mimics the way proteins embedded in cell membranes, known as aquaporins, channel water in and out. Some research groups have even created membranes made of fatty lipid molecules that can accommodate natural aquaporins. Zeng has developed a cheaper and more resilient replacement.

His building blocks consist of helical noodles with sticky ends that connect to form long spirals. Water molecules can flow through the 0.3 nanometer openings at the center of the spirals, but all the other positively and negatively charged ions that make up saltwater are too bulky to pass. These include sodium, potassium, calcium, magnesium, chlorine and sulfur oxide. “In water, all of these ions are highly hydrated, attached to lots of water molecules, which makes them too large to go through the channels,” says Zeng.

The technology could lead to global savings of up to US$5 billion a year, says Zeng, but only after several more years of testing and tweaking the lipid membrane’s compatibility and stability with the nanospirals. “This is a major focus in my group right now,” he says. “We want to get this done, so that we can reduce the cost of water desalination to an acceptable level.”

Stick and non-stick

Nanomaterials also offer a low-cost, effective and sustainable way to filter out toxic metals from drinking water.

Heavy metal levels in drinking water are stringently regulated due to the severe damage the substances can cause to health, even at very low concentrations. The World Health Organization requires that levels of lead, for example, remain below ten parts per billion (ppb). Treating water to these standards is expensive and extremely difficult.

Zhang has developed an organic substance filled with pores that can trap and remove toxic metals from water to less than one ppb. Each pore is ten to twenty nanometers wide and packed with compounds, known as amines that stick to the metals.

Exploiting the fact that amines lose their grip over the metals in acidic conditions, the valuable and limited resource can be recovered by industry, and the polymers reused.

The secret behind the success of Zhang’s polymers is the large surface area covered by the pores, which translates into more opportunities to interact with and trap the metals. “Other materials have a surface area of about 100 square meters per gram, but ours is 1,000 square meters per gram,” says Zhang. “It is 10 times higher.”

Zhang tested his nanoporous polymers on water contaminated with lead. He sprinkled a powdered version of the polymer into a slightly alkaline liquid containing close to 100 ppb of lead. Within seconds, lead levels reduced to below 0.2 ppb. Similar results were observed for cadmium, copper and palladium. Washing the polymers in acid released up to 93 per cent of the lead.

With many companies keen to scale these technologies for real-world applications, it won’t be long before nanoscience treats the Earth for its many maladies.

I wonder if the researchers have found industrial partners (who could be named) to bring these solutions for oil spill cleanups, desalination, and water purification to the market.

Canada’s Ingenuity Lab receives a $1.7M grant to develop oil recovery system for oil spills

A Sept. 15, 2016 news item on Benzinga.com describes the reasons for the $1.7M grant for Alberta’s (Canada) Ingenuity Lab to develop an oil spill recovery system,

Since 2010’s tragic events, which saw BP’s Deepwater Horizon disaster desecrate the Gulf of Mexico, oil safety has been on the forefront of the environmental debate and media outrage. In line with the mounting concerns continuing to pique public attention, at the end of this month [Sept. 2016], Hollywood will release its own biopic of the event. As can be expected, more questions will be raised about what exactly went wrong, in addition to fresh criticism aimed at the entire industry.

One question that is likely to emerge is how do we prevent such a calamity from ever happening again? Fortunately, some of the brightest minds in science have been preparing for such an answer.

One team that has been focusing on this dilemma is Alberta-based, multi-disciplinary research initiative Ingenuity Lab. The institution has just secured $1.7m in project funding for developing a highly advanced system for recovering oil from oil spills. This injection of capital will enable Ingenuity Lab to conduct new research and develop commercial production processes for recovering heavy oil spills in marine environments. The technology is centred on cutting edge nanowire-based stimuli-responsive membranes and devices that are capable for recovering oil.

A Sept. 15, 2016 Ingenuity Lab news release on MarketWired, which originated the news item, provides more insight into the oil spill situation,

Oil is a common pollutant in our oceans; more than three million metric tonnes contaminate the sea each year. When crude oil is accidentally released into a body of water by an oil tanker, refinery, storage facility, underwater pipeline or offshore oil-drilling rig, it is an environmental emergency of the most urgent kind.

Depending on the location, oil spills can be highly hazardous, as well as environmentally destructive. Consequently, a timely clean up is absolutely crucial in order to protect the integrity of the water, the shoreline and the numerous creatures that depend on these habitats.

Due to increased scrutiny of the oil industry with regard to its unseemly environmental track record, attention must be focused on the development of new materials and technologies for removing organic contaminants from waterways. Simply put, existing methods are not sufficiently robust.

Fortuitously, however, nanotechnology has opened the door for the development of sophisticated new tools that use specifically designed materials with properties that are ideally suited to enable complex separations, including the separation of crude oil from water.

Ingenuity Lab’s project focuses on the efficient recovery of oil through the development of this novel technology using a variety of stimuli-responsive nanomaterials. When the time comes for scale up production for this technology, Ingenuity Lab will work closely with industry trendsetters, Tortech Nanofibers.

This project forms a strong element of the Oil Spill Response Science (OSRS), which is part of Canada’s world-class tanker safety system for Responsible Resource Development. Through this programme, the Canadian Government ensures that the country’s resource wealth can be safely developed and transported to market, thus creating new jobs and economic growth for all Canadians.

From a communications standpoint, the news release is well written and well strategized to underline the seriousness of the situation and to take advantage of renewed interest in the devastating (people’s lives were lost and environmental damage is still being assessed) 2010 BP oil spill in the Gulf of Mexico due to the upcoming movie titled, Deepwater Horizon. A little more information about the team (how many people, who’s leading the research, are there international and/or interprovincial collaborators?), plans for the research (have they already started? what work, if any, are they building on? what challenges are they facing?) and some technical details would have been welcome.

Regardless, it’s good to hear about this initiative and I wish them great success with it.

You can find our more about Ingenuity Lab here and Tortech Nanofibers here. Interestingly, Tortech is a joint venture between Israel’s Plasan Sasa and the UK’s Q-Flo. (Q-Flo is a spinoff from Cambridge University.) One more thing, Tortech Nanofibers produces materials made of carbon nanotubes (CNTs). Presumably Ingenuity’s “nanowire-based stimuli-responsive membranes” include carbon nanotubes.

Oil spill cleanups with supergelators

Researchers in Singapore have proposed a new technology for cleaning up oil spills, according to a June 17, 2016 news item on Nanowerk,

Large-scale oil spills, where hundreds of tons of petroleum products are accidentally released into the oceans, not only have devastating effects on the environment, but have significant socio-economic impact as well [1].

Current techniques of cleaning up oil spills are not very efficient and may even cause further pollution or damage to the environment. These methods, which include the use of toxic detergent-like compounds called dispersants or burning of the oil slick, result in incomplete removal of the oil. The oil molecules remain in the water over long periods and may even be spread over a larger area as they are carried by wind and waves. Further, burning can only be applied to fresh oil slicks of at least 3 millimeters thick, and this process would also cause secondary environmental pollution.

In a bid to improve the technology utilized by cleanup crews to manage and contain such large spills, researchers from the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR [located in Singapore] have invented a smart oil-scavenging material or supergelators that could help clean up oil spills efficiently and rapidly to prevent secondary pollution.

These supergelators are derived from highly soluble small organic molecules, which instantly self-assemble into nanofibers to form a 3D net that traps the oil molecules so that they can be removed easily from the surface of the water.

A June 17, 2016 IBN A*STAR media release, which originated the news item, provides more detail,

“Marine oil spills have a disastrous impact on the environment and marine life, and result in an enormous economic burden on society. Our rapid-acting supergelators offer an effective cleanup solution that can help to contain the severe environmental damage and impact of such incidents in the future,” said IBN Executive Director Professor Jackie Y. Ying.

Motivated by the urgent need for a more effective oil spill control solution, the IBN researchers developed new compounds that dissolve easily in environmentally friendly solvents and gel rapidly upon contact with oil. The supergelator molecules arrange themselves into a 3D network, entangling the oil molecules into clumps that can then be easily skimmed off the water’s surface.

“The most interesting and useful characteristic of our molecules is their ability to stack themselves on top of each other. These stacked columns allow our researchers to create and test different molecular constructions, while finding the best structure that will yield the desired properties,” said IBN Team Leader and Principal Research Scientist Dr Huaqiang Zeng. (Animation: Click to see how the supergelators stack themselves into columns.)

IBN’s supergelators have been tested on various types of weathered and unweathered crude oil in seawater, and have been found to be effective in solidifying all of them. The supergelators take only minutes to solidify the oil at room temperature for easy removal from water. In addition, tests carried out by the research team showed that the supergelator was not toxic to human cells, as well as zebrafish embryos and larvae. The researchers believe that these qualities would make the supergelators suitable for use in large oil spill areas.

The Institute is looking for industrial partners to further develop its technology for commercial use. [emphasis mine]

Video: Click to watch the supergelators in action

  1. The well documented BP Gulf of Mexico oil well accident in 2010 was a catastrophe on an unprecedented scale, with damages amounting to hundreds of billions of dollars. Its wide-ranging effects on the marine ecosystem, as well as the fishing and tourism industries, can still be felt six years on.

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

Instant Room-Temperature Gelation of Crude Oil by Chiral Organogelators by Changliang Ren, Grace Hwee Boon Ng, Hong Wu, Kiat-Hwa Chan, Jie Shen, Cathleen Teh, Jackie Y. Ying, and Huaqiang Zeng. Chem. Mater., 2016, 28 (11), pp 4001–4008 DOI: 10.1021/acs.chemmater.6b01367 Publication Date (Web): May 10, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

I have featured other nanotechnology-enabled oil spill cleanup solutions here. One of the more recent pieces is my Dec. 7, 2015 post about boron nitride sponges. The search terms: ‘oil spill’ and ‘oil spill cleanup’ will help you unearth more.

There have been some promising possibilities and I hope one day these clean up technologies will be brought to market.

Directa Plus unleashes graphene-based mobile decontamination units

I’ve been covering Directa Plus stories for a little over a year now (my Dec. 17, 2014 posting titled: Water purification, Italy, Romania, and graphene and my May 25, 2015 posting titled: A GEnIuS approach to oil spill remediation at 18th European Forum on Eco-innovation. The product that most interests me is the graphene-based environmental decontamination unit, Grafysorber. Happily it is now being offered commercially according to a Dec. 18, 2015 Directa Plus press release found on Business Wire (and a PDF news release, you will need to download, can be found on the company’s website here),

Directa Plus (“Directa or “the Company”), one of the largest producers and suppliers of graphene for use in consumer and industrial products, is pleased to announce the global commercial launch of the Grafysorber™ Decontamination Unit, the world’s first graphene-based system for tackling environmental emergencies such as oil spills. The launch follows successful industrial remediation activities conducted in Italy and Romania.

The Company is also pleased to announce that Biocart S.r.l., an Italian company engaged in the research, development and industrialisation of next-generation materials and solutions for the mitigation of natural disasters and environmental remediation, has purchased the first three mobile units.

Giulio Cesareo, Chief Executive Officer of Directa, said: “We are pleased to launch the Grafysorber™ Decontamination Unit that will enable a prompt and effective response to a potential catastrophe such as an oil spill – and so help avoid a major environmental disaster. Due to the mobile nature of the unit, it can be stored nearer to an area where an event may occur, thereby reducing the time and costs ordinarily associated with the transportation of a solution.”

The Grafysorber™ Decontamination Unit contains a proprietary and patented plasma machine that is able to produce on site all the Grafysorber™ needed to clean up water contaminated with the harmful hydrocarbons contained in oil spills. As it is a mobile unit, it can be quickly deployed to the site of the spill.

During 2015, two industrial remediation activities have been carried out with GrafysorberTM, treating approximately 35,000m3 of water contaminated with petroleum hydrocarbons. Less than 5g/m3 of GrafysorberTM were able to remove the hydrocarbon contaminants, reducing the concentration from 550mg/l to a safe level of approximately 0.5mg/l, with a significant cost reduction of 50-60% compared with traditional technologies.

Grafysorber™ is a sustainable product as it enables the recovery and recycling of the adsorbed oils; it is recyclable; and it does not contain any toxic substances. The ability to produce the graphene on site and in the right quantity renders it a very cost-effective solution compared with conventional solutions. Grafysorber™ has received approval from the Ministry of Environment in Italy and in Romania.

“This is an important step for Directa Plus as we unveil another significant application for graphene-based solutions. It has been achieved due to our technical strength and proprietary process for producing graphene in various forms in a cost effective manner. The ability of the Grafysorber™ Decontamination Unit to produce all the graphene necessary to purify the contaminated water directly at the site of use can be easily replicated and applied to other emergency scenarios. The initial demand that we have already received for this product provides further evidence that graphene has left the laboratory and is ready for mass adoption,” added Giulio Cesareo.

I look forward to hearing more about this product as it is put into use.

Boron nitride sponges for oil spill cleanups

The best part of the news is that the scientists are ready to test these sponges in industrial trials but first here’s why the Australians are so excited about the work from a Dec. 1, 2015 news item on Azonano,

Deakin University scientists have manufactured a revolutionary material that can clean up oil spills, which could save the earth from potential future disasters such as any repeat of the 2010 Gulf Coast BP disaster that wreaked environmental havoc and cost a reported $40 billion.

The major breakthrough material, which literally absorbs the oil like a sponge, is the result of support from the Australian Research Council and is now ready to be trialled by industry after two years of refinement in the laboratory at Deakin’s Institute for Frontier Materials (IFM).

Alfred Deakin Professor Ying (Ian) Chen, the lead author on a paper which outlines the team’s breakthrough in today’s edition of Nature Communications, said the material was the most exciting advancement in oil spill clean-up technology in decades.

Oil spills are a global problem and wreak havoc on our aquatic ecosystems, not to mention cost billions of dollars in damage.

“Everyone remembers the Gulf Coast disaster, but here in Australia they are a regular problem, and not just in our waters. Oil spills from trucks and other vehicles can close freeways for an entire day, again amounting to large economic losses. Professor Chen

But current methods of cleaning up oil spills are inefficient and unsophisticated, taking too long, causing ongoing and expensive damage, which is why the development of our technology was supported by the Australian Research Council.

“We are so excited to have finally got to this stage after two years of trying to work out how to turn what we knew was a good material into something that could be practically used.

A Nov. 30, 2015 Deakin University media release, which originated the news item, provides some technical details,

“In 2013 we developed the first stage of the material, but it was simply a powder. This powder had absorption capabilities, but you cannot simply throw powder onto oil – you need to be able to bind that powder into a sponge so that we can soak the oil up, and also separate it from water.”

The lead author on the paper, IFM scientist Dr Weiwei Lei,) an Australian Research Council Discovery Early Career Research Awardee, said turning the powder into a sponge was a big challenge.

“But we have finally done it by developing a new production technique,” Dr Lei said.

“The ground-breaking material is called a boron nitride nanosheet, which is made up of flakes which are just several nanometers (one billionth of a meter) in thickness with tiny holes which can increase its surface area per gram to effectively the size of 5.5 tennis courts.”

The research team, which included scientists from Drexel University, Philadelphia, and Missouri University of Science and Technology, started with boron nitride powder known as “white graphite” and broke it into atomically thin sheets that were used to make a sponge.

“The pores in the nanosheets provide the surface area to absorb oils and organic solvents up to 33 times its own weight,” Dr Lei said.

Professor Yury Gogotsi from Drexel University said boron nitride nanosheets did not burn, could withstand flame, and be used in flexible and transparent electrical and heat insulation, as well as many other applications.

“We are delighted that support from the Australian Research Council allowed us to participate in this interesting study and we could help our IFM colleagues to model and better understand this wonderful material, ” Professor Gogotsi said.

Professor Vadym Mochalin from Missouri University of Science and Technology said the mechanochemical technique developed meant it was possible to produce high-concentration stable aqueous colloidal solutions of boron nitride sheets, which could then be transformed into the ultralight porous aerogels and membranes for oil clean-up.

“The use of computational modelling helped us to understand the intimate details of this novel mechanochemical exfoliation process. It is a nice illustration of the power, which combined experimental plus modelling approach offers researchers nowadays.”

The research team is now ready to have their “sponge” trialled by industry. [emphasis mine]

The nanotechnology team at IFM has been working on boron nitride nanomaterials for two decades and is an internationally recognised leader in boron nitride nanotubes and nanosheets.

There was at least one other team working on  sponges, all these are composed of carbon nanotubes, for oil spills (mentioned in my April 17, 2012 posting) but they don’t seem to have been able to get their work out of the laboratory.

Here’s a link to and a citation for boron nitride sponges,

Boron nitride colloidal solutions, ultralight aerogels and freestanding membranes through one-step exfoliation and functionalization by Weiwei Lei, Vadym N. Mochalin, Dan Liu, Si Qin, Yury Gogotsi, & Ying Chen. Nature Communications 6, Article number: 8849 doi:10.1038/ncomms9849 Published 27 November 2015

This is an open access paper.

Netting oil spills the nano way

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Here are links to and citations for the papers,

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

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

Both papers are open access.

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

Cleaning up oil* spills with cellulose nanofibril aerogels

Given the ever-expanding scope of oil and gas production as previously impossible to reach sources are breached and previously unusable contaminated sources are purified for use while major pipelines and mega tankers are being built to transport all this product, it’s good to see that research into cleaning up oil spills is taking place. A Feb. 26, 2014 news item on Azonano features a project at the University of Wisconsin–Madison,

Cleaning up oil spills and metal contaminates in a low-impact, sustainable and inexpensive manner remains a challenge for companies and governments globally.

But a group of researchers at the University of Wisconsin–Madison is examining alternative materials that can be modified to absorb oil and chemicals without absorbing water. If further developed, the technology may offer a cheaper and “greener” method to absorb oil and heavy metals from water and other surfaces.

Shaoqin “Sarah” Gong, a researcher at the Wisconsin Institute for Discovery (WID) and associate professor of biomedical engineering, graduate student Qifeng Zheng, and Zhiyong Cai, a project leader at the USDA Forest Products Laboratory in Madison, have recently created and patented the new aerogel technology.

The Feb. 25, 2014 University of Wisconsin–Madison news release, which originated the news item, explains a little bit about aergels and about what makes these cellulose nanofibril-based aerogels special,

Aerogels, which are highly porous materials and the lightest solids in existence, are already used in a variety of applications, ranging from insulation and aerospace materials to thickening agents in paints. The aerogel prepared in Gong’s lab is made of cellulose nanofibrils (sustainable wood-based materials) and an environmentally friendly polymer. Furthermore, these cellulose-based aerogels are made using an environmentally friendly freeze-drying process without the use of organic solvents.

It’s the combination of this “greener” material and its high performance that got Gong’s attention.

“For this material, one unique property is that it has superior absorbing ability for organic solvents — up to nearly 100 times its own weight,” she says. “It also has strong absorbing ability for metal ions.”

Treating the cellulose-based aerogel with specific types of silane after it is made through the freeze-drying process is a key step that gives the aerogel its water-repelling and oil-absorbing properties.

The researchers have produced a video showing their aerogel in operation,

For those who don’t have the time for a video, the news release describes some of the action taking place,

“So if you had an oil spill, for example, the idea is you could throw this aerogel sheet in the water and it would start to absorb the oil very quickly and efficiently,” she says. “Once it’s fully saturated, you can take it out and squeeze out all the oil. Although its absorbing capacity reduces after each use, it can be reused for a couple of cycles.”

In addition, this cellulose-based aerogel exhibits excellent flexibility as demonstrated by compression mechanical testing.

Though much work needs to be done before the aerogel can be mass-produced, Gong says she’s eager to share the technology’s potential benefits beyond the scientific community.

“We are living in a time where pollution is a serious problem — especially for human health and for animals in the ocean,” she says. “We are passionate to develop technology to make a positive societal impact.”

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

Green synthesis of polyvinyl alcohol (PVA)–cellulose nanofibril (CNF) hybrid aerogels and their use as superabsorbents by Qifeng Zheng, Zhiyong Cai, and Shaoqin Gong.  J. Mater. Chem. A, 2014,2, 3110-3118 DOI: 10.1039/C3TA14642A First published online 16 Dec 2013

This paper is behind a paywall. I last wrote about oil-absorbing nanosponges in an April 17, 2012 posting. Those sponges were based on carbon nanotubes (CNTs).

* ‘oils’ in headline changed to ‘oil’ on May 6, 2014.

Mop up the oil spills with nanosheets from Deakin University and The Conversation

Researchers from Deakin University (Australia) have developed a new material, boron-based nanosheets, which can mop up oil spills more efficiently than current methods and are recyclable. From the May 1, 2013 news item on Nanowerk, (Note: A link has been removed)

In Nature Communications today (“Porous boron nitride nanosheets for effective water cleaning”), we showed how we produced, probably for the first time, nanosheets that could revolutionise oil spill clean ups and water purification.

Not only do our nanosheets absorb 33 times their weight in oil, they’re also recyclable.

Ordinarily there’d be a news release from Deakin University but these researchers appear to have taken a different approach posting on a website called The Conversation. This is a very interesting science communicaton initiative from Australia and I will be digressing for a moment. Here’s a description of the initiative from their Who We Are page,

The Conversation is an independent source of news and views, sourced from the academic and research community and delivered direct to the public.

Our team of professional editors work with university, CSIRO and research institute experts to unlock their knowledge for use by the wider public.

Access to independent, high-quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to allow for better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversations.

We have introduced new protocols and controls to help rebuild trust in journalism. All authors and editors sign up to our Editorial Charter and Code of Ethics. And all contributors must abide by our Community Standards policy. We only allow authors to write on a subject on which they have proven expertise, which they must disclose alongside their article. Authors’ funding and potential conflicts of interest must be disclosed. Failure to do so carries a risk of being banned from contributing to the site.

Since our launch in March 2011, we’ve grown to become one of Australia’s largest independent news and commentary sites. Around 35% of our readers are from outside Australia.

We believe in open access and the free-flow of information. The Conversation is a free resource: free to read (we’ll never go behind a paywall), and free to share or republish under Creative Commons. All you need to do is follow our simple guidelines. We have also become an indispensable media resource: providing free content, ideas and talent to follow up for press, web, radio or TV.

They believe in open access and the free-flow of information as long as you don’t edit the article, etc. Here are five of the guidelines (from the Republishing guidelines page),

Republishing guidelines, for print and online

  1. Unless you have express permission from the author, you can’t edit our material, except to reflect relative changes in time, location and editorial style. (For example, “yesterday” can be changed to “last week,” and “Canberra, ACT.” to “Canberra” or “here”). If you need to materially edit our content, please contact our External Relations Manager.
  2. You have to credit our authors and partner institutions — ideally in the byline. We prefer “Author Name, Institution” (for example, Qing Wang, Warwick Business School).
  3. You have to credit The Conversation — ideally at the top of the article and include our logo — with a link back to either our home page, The Conversation, or (preferably) the specific article URL on The Conversation website.
  4. If space is tight, you can run the first few lines of the article and then say: “Read the full article at The Conversation” with a link back to the article page on our site.
  5. If you’re republishing online, you must use our page view counter, link to us, and include links from our story. Our page view counter is a small pixel-ping image (invisible to the eye) that allows us to know when our content is republished, and gives our authors sense of the size of audience and which publications they’re reaching. It is a condition of our guidelines that you include our counter. If you use the “republish” button that accompanies each article then you’ll capture our page counter.
  6. ….

Since I usually cut and paste parts of articles and news releases and often intersperse with my own comments and I don’t have the technical skills to use their page view counter, I won’t be using anything directly from The Conversation. I view my role as a curator (bringing together pieces of information from disparate sources) and a ‘connector’. To encourage connections, I don’t usually include a full news release or article as I suggest my readers look at the original or seek out the other sources I’ve included if they want more information.

Back to the boron nitride nanosheets and the news item on Nanowerk,

We found that porous boron nitride nanosheets have a couple of properties that make them particularly suitable for absorbing organic (carbon-based) contaminants, such as oil or dyes.

The nanosheets are made of a few layers of boron nitride atomic planes, and these sheets have a large number of holes.

It’s these holes that increase the surface area of the nanosheets to a huge 1,425m2 a gram.
This means one gram of porous boron nitride nanosheets has the same surface area as nearly 5.5 tennis courts – so plenty of surface for absorption.

Another advantage is that the saturated boron nitride nanosheets can be cleaned for reuse by simply heating in air for two hours.

The absorbed oil is burned off, leaving the nanosheets clean and free to absorb again.

To make our porous nanosheets, boron oxide powder and guanidine hydrochloride are mixed in methane and heated at 1,100C for several hours in nitrogen gas.

The news item on Nanowerk is illustrated with images and provides more detail as does the May 1, 2013 article (Don’t cry over spilled oil – use nanosheets) on The Conversation.

For those who’d like to read the published research, here’s a link to and a citation for it,

Porous boron nitride nanosheets for effective water cleaning by Weiwei Lei, David Portehault, Dan Liu, Si Qin, & Ying Chen. Nature Communications 4, Article number: 1777 doi:10.1038/ncomms2818 Published 30 April 2013

The article is behind a paywall.

Interestingly scientists in China have developed an entirely different material with similar properties for mopping up oil spills as per my Feb. 27, 2013 posting titled, Bacterial cellulose could suck up pollutants from oil spills.

ETA May 6, 2013: Dexter Johnson has commented on an outstanding issue with the Deakin University research and other such initiatives: a lack of commercialization efforts. From his May 4, 2013 posting on his Nanoclast blog (found on the IEEE [Institute of Electrical and Electronics Engineers] website), Note: A link has been removed,

In fact, there are a variety of nanomaterials for these applications [oil spill remediation and water purification]—so many of them that there are catalogues to guide you through them.  But not so fast. As yet, no one is bothering to commercialize them so that they are available for the next oil spill.

Dexter provides worthwhile context and some provocative comments on how to ‘encourage’ commercialization of nanotechnology-enabled oil spill remediation/water purification  products.

Bacterial cellulose could suck up pollutants from oil spills

Who doesn’t love a cellulose story, especially when it could involve cleaning up oil spills? The Feb. 26, 2013 news item on phys.org titled, Airy but thirsty: Ultralight, flexible, fire-resistant carbon nanotube aerogels from bacterial cellulose, highlights some work being done in China,

They can absorb vast amounts of oil or organic compounds, yet they are nearly as light as air: highly porous solids made of a three-dimensional network of carbon nanotubes. In the journal Angewandte Chemie, Chinese scientists have now introduced a simple technique for the production of these ultralight, flexible, fire-resistant aerogels. Their method begins with bacterial cellulose as an inexpensive starting material. Their fibrous lightweights can “suck” organic contaminants from polluted water and could possibly be used as pressure sensors.

The researchers [led by Shu-Hong Yu at the Hefei National Laboratory for Physical Sciences at Micrscale (HFNL), Univeristy of Science and Technology of China] trimmed off small pieces of the tangled cellulose nanofibers. These were freeze-dried and then pyrolyzed at 1300 °C under argon. This converts the cellulose into graphitic carbon. The density decreases but the network structure remains intact. The result is a black, ultralight, mechanically stable aerogel. Because it is porous and highly hydrophobic, it can adsorb organic solvents and oils—up to 106 to 312 times its own weight. It draws oil out of an oil/water mixture with high efficiency and selectivity, leaving behind pure water. This makes the new aerogel an ideal candidate for cleaning up oil spills or sucking up nonpolar industrial pollutants. The absorbed substances can easily be removed from the gel through distillation or combustion, allowing the gel to be used again.

There’s more about the work and its possible applications at physorg.com or, if you have access behind the paywall, here’s a citation and a link to the research article,

Ultralight, Flexible, and Fire-Resistant Carbon Nanofiber Aerogels from Bacterial Cellulose by Zhen-Yu Wu, Chao Li, Dr. Hai-Wei Liang, Prof. Dr. Jia-Fu Chen, Prof. Dr. Shu-Hong Yu. Angewandte Chemie International Edition, Volume 52, Issue 10, pages 2925–2929, March 4, 2013.

Here’s an image which illustrates the aerogels’ ability to suck up an organic solvent and explains some of the excitement,

Thirsty fibers: The aerogels described in the title can be fabricated in large scale by using a low-cost biomass, bacterial cellulose, as a precursor, which can be produced at industrial level in a microbial fermentation process. The carbon nanofiber aerogels (black pieces in picture) exhibit superior absorption capacity for organic solvents (red solution) and high potential for pressure sensing. [downloaded from http://onlinelibrary.wiley.com/doi/10.1002/anie.201209676/abstract;jsessionid=3EFB4241C0083135A6E657808F5410E5.d03t04]

Thirsty fibers: The aerogels described in the title can be fabricated in large scale by using a low-cost biomass, bacterial cellulose, as a precursor, which can be produced at industrial level in a microbial fermentation process. The carbon nanofiber aerogels (black pieces in picture) exhibit superior absorption capacity for organic solvents (red solution) and high potential for pressure sensing. [downloaded from http://onlinelibrary.wiley.com/doi/10.1002/anie.201209676/abstract;jsessionid=3EFB4241C0083135A6E657808F5410E5.d03t04]