Tag Archives: hemp

Drip dry housing

This piece on new construction materials does have a nanotechnology aspect although it’s not made clear exactly how nanotechnology plays a role.

From a Dec. 28, 2016 news item on phys.org (Note: A link has been removed),

The construction industry is preparing to use textiles from the clothing and footwear industries. Gore-Tex-like membranes, which are usually found in weather-proof jackets and trekking shoes, are now being studied to build breathable, water-resistant walls. Tyvek is one such synthetic textile being used as a “raincoat” for homes.

You can find out more about Tyvek here.on the Dupont website.

A Dec. 21, 2016 press release by Chiara Cecchi for Youris ((European Research Media Center), which originated the news item, proceeds with more about textile-type construction materials,

Camping tents, which have been used for ages to protect against wind, ultra-violet rays and rain, have also inspired the modern construction industry, or “buildtech sector”. This new field of research focuses on the different fibres (animal-based such as wool or silk, plant-based such as linen and cotton and synthetic such as polyester and rayon) in order to develop technical or high-performance materials, thus improving the quality of construction, especially for buildings, dams, bridges, tunnels and roads. This is due to the fibres’ mechanical properties, such as lightness, strength, and also resistance to many factors like creep, deterioration by chemicals and pollutants in the air or rain.

“Textiles play an important role in the modernisation of infrastructure and in sustainable buildings”, explains Andrea Bassi, professor at the Department of Civil and Environmental Engineering (DICA), Politecnico of Milan, “Nylon and fiberglass are mixed with traditional fibres to control thermal and acoustic insulation in walls, façades and roofs. Technological innovation in materials, which includes nanotechnologies [emphasis mine] combined with traditional textiles used in clothes, enables buildings and other constructions to be designed using textiles containing steel polyvinyl chloride (PVC) or ethylene tetrafluoroethylene (ETFE). This gives the materials new antibacterial, antifungal and antimycotic properties in addition to being antistatic, sound-absorbing and water-resistant”.

Rooflys is another example. In this case, coated black woven textiles are placed under the roof to protect roof insulation from mould. These building textiles have also been tested for fire resistance, nail sealability, water and vapour impermeability, wind and UV resistance.

Photo: Production line at the co-operative enterprise CAVAC Biomatériaux, France. Natural fibres processed into a continuous mat (biofib) – Martin Ansell, BRE CICM, University of Bath, UK

In Spain three researchers from the Technical University of Madrid (UPM) have developed a new panel made with textile waste. They claim that it can significantly enhance both the thermal and acoustic conditions of buildings, while reducing greenhouse gas emissions and the energy impact associated with the development of construction materials.

Besides textiles, innovative natural fibre composite materials are a parallel field of the research on insulators that can preserve indoor air quality. These bio-based materials, such as straw and hemp, can reduce the incidence of mould growth because they breathe. The breathability of materials refers to their ability to absorb and desorb moisture naturally”, says expert Finlay White from Modcell, who contributed to the construction of what they claim are the world’s first commercially available straw houses, “For example, highly insulated buildings with poor ventilation can build-up high levels of moisture in the air. If the moisture meets a cool surface it will condensate and producing mould, unless it is managed. Bio-based materials have the means to absorb moisture so that the risk of condensation is reduced, preventing the potential for mould growth”.

The Bristol-based green technology firm [Modcell] is collaborating with the European Isobio project, which is testing bio-based insulators which perform 20% better than conventional materials. “This would lead to a 5% total energy reduction over the lifecycle of a building”, explains Martin Ansell, from BRE Centre for Innovative Construction Materials (BRE CICM), University of Bath, UK, another partner of the project.

“Costs would also be reduced. We are evaluating the thermal and hygroscopic properties of a range of plant-derived by-products including hemp, jute, rape and straw fibres plus corn cob residues. Advanced sol-gel coatings are being deposited on these fibres to optimise these properties in order to produce highly insulating and breathable construction materials”, Ansell concludes.

You can find Modcell here.

Here’s another image, which I believe is a closeup of the processed fibre shown in the above,

Production line at the co-operative enterprise CAVAC Biomatériaux, France. Natural fibres processed into a continuous mat (biofib) – Martin Ansell, BRE CICM, University of Bath, UK [Note: This caption appears to be a copy of the caption for the previous image]

Hemp as a substitute for graphene in supercapacitors

As a member of the Cannabis plant family, hemp has an undeserved reputation due to its cousin’s (marijuana) notoriety and consciousness-altering properties. Hemp is, by contrast, the Puritan in the family, associated by the knowledgeable with virtues of thrift and hard work.

An Aug. 12, 2014 news item on Nanowerk highlights a hemp/supercapacitor presentation at the 248th meeting of the American Chemical Society (ACS),

As hemp makes a comeback in the U.S. after a decades-long ban on its cultivation, scientists are reporting that fibers from the plant can pack as much energy and power as graphene, long-touted as the model material for supercapacitors. They’re presenting their research, which a Canadian start-up company is working on scaling up, at the 248th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society.

David Mitlin, Ph.D., explains that supercapacitors are energy storage devices that have huge potential to transform the way future electronics are powered. Unlike today’s rechargeable batteries, which sip up energy over several hours, supercapacitors can charge and discharge within seconds. But they normally can’t store nearly as much energy as batteries, an important property known as energy density. One approach researchers are taking to boost supercapacitors’ energy density is to design better electrodes. Mitlin’s team has figured out how to make them from certain hemp fibers — and they can hold as much energy as the current top contender: graphene.

An Aug. 12, 2014 ACS news release features David Mitlin, formerly of the University of Alberta (Canada) where this research took place,, Mitlin is now with now with Clarkson University in New York,

“Our device’s electrochemical performance is on par with or better than graphene-based devices,” Mitlin says. “The key advantage is that our electrodes are made from biowaste using a simple process, and therefore, are much cheaper than graphene.”

The race toward the ideal supercapacitor has largely focused on graphene — a strong, light material made of atom-thick layers of carbon, which when stacked, can be made into electrodes. Scientists are investigating how they can take advantage of graphene’s unique properties to build better solar cells, water filtration systems, touch-screen technology, as well as batteries and supercapacitors. The problem is it’s expensive.

Mitlin’s group decided to see if they could make graphene-like carbons from hemp bast fibers. The fibers come from the inner bark of the plant and often are discarded from Canada’s fast-growing industries that use hemp for clothing, construction materials and other products. …

His team found that if they heated the fibers for 24 hours at a little over 350 degrees Fahrenheit, and then blasted the resulting material with more intense heat, it would exfoliate into carbon nanosheets.

Mitlin’s team built their supercapacitors using the hemp-derived carbons as electrodes and an ionic liquid as the electrolyte. Fully assembled, the devices performed far better than commercial supercapacitors in both energy density and the range of temperatures over which they can work. The hemp-based devices yielded energy densities as high as 12 Watt-hours per kilogram, two to three times higher than commercial counterparts. They also operate over an impressive temperature range, from freezing to more than 200 degrees Fahrenheit.

“We’re past the proof-of-principle stage for the fully functional supercapacitor,” he says. “Now we’re gearing up for small-scale manufacturing.”

I have not been able to confirm the name for Mitlin’s startup but I think it’s called Alta Supercaps (Alta being an abbreviation for Alberta,, amongst other things, and supercaps for supercapacitors) as per the information about a new startup on the Mitlin Group webspace (scroll down to the July 2, 2013 news item) which can still be found on the University of Alberta website (as of Aug. 12, 2014).

For those who would like more technical details, there is this July 2013 article by Mark Crawford for the ASME (American Society of Mechanical Engineers); Note: A link has been removed.

Activated carbons, templated carbons, carbon nanofibers, carbon nanotubes, and graphene have all been intensively studied as materials for supercapacitor electrodes. High manufacturing costs is one issue—another is that the power characteristics of many of these carbons are limited. This is a result of high microporosity, which increases ion transport limitations.

“It is becoming well understood that the key to achieving high power in porous electrodes is to reduce the ion transport limitations” says Mitlin. “Nanomaterials based on graphene and their hybrids have emerged as a new class of promising high-rate electrode candidates—they are, however, too expensive to manufacture compared to activated carbons derived from pyrolysis of agricultural wastes, or from the coking operations.”

Biomass, which mainly contains cellulose and lignin by-products, is widely utilized as a feedstock for producing activated carbons. Mitlin decided to test hemp bast fiber’s unique cellular structure to see if it could produce graphene-like carbon nanosheets.

Hemp fiber waste was pressure-cooked (hydrothermal synthesis) at 180 °C for 24 hours. The resulting carbonized material was treated with potassium hydroxide and then heated to temperatures as high as 800 °C, resulting in the formation of uniquely structured nanosheets. Testing of this material revealed that it discharged 49 kW of power per kg of material—nearly triple what standard commercial electrodes supply, 17 kW/kg.

Mitlin and his team successfully synthesized two-dimensional, yet interconnected, carbon nanosheets with superior electrochemical storage properties comparable to those of state-of-the-art graphene-based electrodes. “We were able to achieve this by employing a biomass precursor with a unique structure—hemp bast fiber,” says Mitlin. “The resultant graphene-like nanosheets possess fundamentally different properties—such as pore size distribution, physical interconnectedness, and electrical conductivity—as compared to conventional biomass-derived activated carbons.”

This image from Wikimedia was used to illustrate the Crawford article,

Hemp bast fiber is a low-cost graphene-like nanomaterial. Image: Wikimedia Commons

Hemp bast fiber is a low-cost graphene-like nanomaterial. Image: Wikimedia Commons

It seems to me that over the last few months there have been more than the usual number of supercapacitor stories, which makes the race to create the one that will break through in the marketplace fascinating to observe.

Alberta gave its cellulose nanocrystal (or nanocrystalline cellolose) production plant a soft launch in September 2013

It’s been a little over two years since Alberta’s proposed cellulose nanocrystal (CNC), then called nanocrystalline cellulose (NCC), pilot plant was first announced (my July 5, 2011 posting). I gather that the plant was quietly opened in Sept. 2013. Finding a news release about the event has proved to be a challenge. The Alberta Innovates website does not list it in its Newsroom while the Alberta Innovates Technology Futures website does list a news release (September 12, 2013Alberta’s one-of-a-kind CNC pilot plant commissioned: Cellulose-based ‘wonder material’ now available to researchers, industry partnersf), despite numerous efforts on my part (try it yourself), I’m unable to access it. Happily, I was able to track down some information elsewhere.

First (in the order in which I found the information), there’s an Oct. 2, 2013 news item on the WorkingForest.com website submitted by Pulp and Paper Canada),

Alberta’s cellulose nanocrystals (CNC) pilot plant, which produces up to 100 kilograms of CNC per week, was commissioned in early September at Alberta Innovates-Technology Futures’ (AITF) Mill Woods facility before a crowd of researchers, industry leaders and government representatives.

The $5.5-million pilot plant, created through a collaboration of the governments of Canada and Alberta in partnership with industry under the Western Economic Partnership Agreement (WEPA), uses wood and straw pulp from plants such as flax and hemp to create CNC for testing in commercial applications that will lead to production.

“Alberta Innovates-Technology Futures is proud to host and operate Western Canada’s only CNC pilot plant,” said Stephen Lougheed, AITF’s president and CEO. “We’re able to provide researchers with more CNC than ever before, thereby accelerating the development of commercial applications.”

The grand opening of the CNC pilot plant’s is planned for 2014.

Then, there was more information about the plant and the event in Catherine Griwkowsky’s Sept. 12, 2013 article for the Edmonton Sun,

A new cellulose nanocrystals (CNCs) pilot plant will take wood and agricultural fires and turn it into a form that can make products stronger, give them sunlight-absorbing properties, add a negative electromagnetic charge and more.

The $5.5-million project in Mill Woods will churn out up to 100 kilograms of the crystals each week.

Technical Lead Frank Tosto said researchers will study various properties of the crystals, and work with an internal team as well as external industry and other researchers to transform knowledge of the properties into ideas for applications. Later, the team may experiment with unconventional sources of cellulose.

The CNCs can be used for drilling fluids, paints, industrial coatings, automotive components, building materials, plastics and packaging.

The process [of refining hemp, etc.] breaks down cellulose into smaller building blocks using a chemical process of acid hydrolysis, that separates crystal formations in cellulose from other structures. The width is between five to 10 nanometres with a length of 150 to 200 nanometers. To scale, cellulose fibre would be the size of a hockey rink and the nano crystal would be like a pen or pencil, he explained.

Ultimately, Tosto hopes they will find commercial applications for the CNCs. The pilot should last five to seven years. He said it’s hard to think outside the box when they don’t know where all the boxes are.

I’d love to know if any of the entrepreneurs who contacted me privately about accessing CNC so they could develop new applications are now able to purchase product from the Alberta plant or from the one in Quebec (CelluForce), which had a stockpile last I heard (my Oct. 3, 2013 posting). It seems odd to be building another plant when the country’s first such plant has stopped production. Meanwhile, there’s some action on the international scene. An Israeli startup company, Melodea has developed its own CNC/NCC extraction process and has received money to develop applications, from my Oct. 31, 2013 posting),

Melodea Ltd. is developing an economic ally viable industrial process for the extraction of NCC from the sludge of the paper industry, a waste stream produced at millions of tons around the world. The core of the novel technology was developed by the lab of Professor Oded Shoseyov from the Hebrew University of Jerusalem and was licensed exclusively to Melodea.

Moreover, the company develops unique technologies to self-assemble the NCC into ecologically friendly foams for industrial applications.

Melodea Ltd. announced today that it has been awarded above 1,000,000 Euro in 3 projects of the European Union Seventh Framework Program (FP7).

You’ll note Melodea’s process extracts CNC from the paper industry’s sludge which leads me to this question: will there be any discussion of this extracting CNC from sludge technique at the 2014 TAPPI (Technical Association for the Pulp, Paper, Packaging and Converting Industries) nanotechnology conference being held in Vancouver (Canada), June 23-26, 2014 (mentioned in my Nov. 14, 2013 posting about the conference’s submission deadline, Nov. 22, 2013)?