Tag Archives: packaging

Cellulose- and chitin-based biomaterial to replace plastics?

Although the term is not actually used in the news release, one of the materials used to create a new biomaterial could safely be described as nanocellulose. From a Sept. 20, 2017 Pennsylvania State University (Penn State) news release (also on EurekAlert) by Jeff Mulhollem,

An inexpensive biomaterial that can be used to sustainably replace plastic barrier coatings in packaging and many other applications has been developed by Penn State researchers, who predict its adoption would greatly reduce pollution.

Completely compostable, the material — a polysaccharide polyelectrolyte complex — is comprised of nearly equal parts of treated cellulose pulp from wood or cotton, and chitosan, which is derived from chitin — the primary ingredient in the exoskeletons of arthropods and crustaceans. The main source of chitin is the mountains of leftover shells from lobsters, crabs and shrimp consumed by humans.

These environmentally friendly barrier coatings have numerous applications ranging from water-resistant paper, to coatings for ceiling tiles and wallboard, to food coatings to seal in freshness, according to lead researcher Jeffrey Catchmark, professor of agricultural and biological engineering, College of Agricultural Sciences.

“The material’s unexpected strong, insoluble adhesive properties are useful for packaging as well as other applications, such as better performing, fully natural wood-fiber composites for construction and even flooring,” he said. “And the technology has the potential to be incorporated into foods to reduce fat uptake during frying and maintain crispness. Since the coating is essentially fiber-based, it is a means of adding fiber to diets.”

The amazingly sturdy and durable bond between carboxymethyl cellulose and chitosan is the key, he explained. The two very inexpensive polysaccharides — already used in the food industry and in other industrial sectors — have different molecular charges and lock together in a complex that provides the foundation for impervious films, coatings, adhesives and more.

The potential reduction of pollution is immense if these barrier coatings replace millions of tons of petroleum-based plastic associated with food packaging used every year in the United States — and much more globally, Catchmark noted.

He pointed out that the global production of plastic is approaching 300 million tons per year. In a recent year, more than 29 million tons of plastic became municipal solid waste in the U.S. and almost half was plastic packaging. It is anticipated that 10 percent of all plastic produced globally will become ocean debris, representing a significant ecological and human health threat.

crab shells

The material is comprised of cellulose pulp from wood or cotton, and chitosan, derived from chitin, the primary ingredient in the exoskeletons of arthropods and crustaceans. The main source of chitin is shells from lobsters, crabs and shrimp. Image: © iStock Photo OKRAD

The polysaccharide polyelectrolyte complex coatings performed well in research, the findings of which were published recently in Green Chemistry. Paperboard coated with the biomaterial, comprised of nanostructured fibrous particles of carboxymethyl cellulose and chitosan, exhibited strong oil and water barrier properties. The coating also resisted toluene, heptane and salt solutions and exhibited improved wet and dry mechanical and water vapor barrier properties.

“These results show that polysaccharide polyelectrolyte complex-based materials may be competitive barrier alternatives to synthetic polymers for many commercial applications,” said Catchmark, who, in concert with Penn State, has applied for a patent on the coatings.

“In addition, this work demonstrates that new, unexpected properties emerge from multi-polysaccharide systems engaged in electrostatic complexation, enabling new high-performance applications.”

Catchmark began experimenting with biomaterials that might be used instead of plastics a decade or so ago out of concerns for sustainability. He became interested in cellulose, the main component in wood, because it is the largest volume sustainable, renewable material on earth. Catchmark studied its nanostructure — how it is assembled at the nanoscale.

He believed he could develop natural materials that are more robust and improve their properties, so that they could compete with synthetic materials that are not sustainable and generate pollution — such as the low-density polyethylene laminate applied to paper board, Styrofoam and solid plastic used in cups and bottles.

“The challenge is, to do that you’ve got to be able to do it in a way that is manufacturable, and it has to be less expensive than plastic,” Catchmark explained. “Because when you make a change to something that is greener or sustainable, you really have to pay for the switch. So it has to be less expensive in order for companies to actually gain something from it. This creates a problem for sustainable materials — an inertia that has to be overcome with a lower cost.”

lab vials

The amazingly sturdy and durable bond between carboxymethyl cellulose and chitosan is the key. The two very inexpensive polysaccharides, already used in the food industry and in other industrial sectors, have different molecular charges and lock together in a complex that provides the foundation for impervious films, coatings, adhesives and more. Image: Penn State

Funded by a Research Applications for Innovation grant from the College of Agricultural Sciences, Catchmark currently is working to develop commercialization partners in different industry sectors for a wide variety of products.

“We are trying to take the last step now and make a real impact on the world, and get industry people to stop using plastics and instead use these natural materials,” he said. “So they (consumers) have a choice — after the biomaterials are used, they can be recycled, buried in the ground or composted, and they will decompose. Or they can continue to use plastics that will end up in the oceans, where they will persist for thousands of years.”

Also involved in the research were Snehasish Basu, post-doctoral scholar, and Adam Plucinski, master’s degree student, now instructor of engineering at Penn State Altoona. Staff in Penn State’s Material Research Institute provided assistance with the project.

The U.S. Department of Agriculture supported this work. Southern Champion Tray, of Chattanooga, Tennessee, provided paperboard and information on its production for experiments.

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

Sustainable barrier materials based on polysaccharide polyelectrolyte complexes by
Snehasish Basu, Adam Plucinski, and Jeffrey M. Catchmark. Green Chemistry 2017, 19, 4080-4092 DOI: 10.1039/C7GC00991G

This paper is behind a paywall. One comment, I found an anomaly on the page when I visited. At the top of the citation page, it states that this is issue 17 of Green Chemistry but the citation in the column on the right is “2017, 19 … “, which would be issue 19.

More mangoes thanks to an Indian-Sri Lankan-Canadian nanotechnologyresearch project

I’ve been wondering what happened since I posted about this ‘mango’ project some years ago (my June 21, 2012 posting and my Nov. 1, 2012 posting) so, it’s nice to get an update from this Fresh Fruit Portal Feb. 4, 2015 posting,

Developed by Canadian, Indian and Sri Lankan researchers in a collaborative project funded by the International Development Research Centre (IDRC), the nanotech mango boxes are said to improve the fruit’s resilience and therefore boost quality over long shipping distances.

The project – which also includes the Tamil Nadu Agricultural University, India and the Industrial Technical Institute, Sri Lanka – has tested the use of the bio-compound hexanal, an artificially synthesized version of a natural substance produced by injured plants to reduce post-harvest losses.

The nanotech boxes could be particularly significant for India as a world leader in mango production, as well as Sri Lanka where approximately 90,000 metric tons (MT) are produced annually.

The IDRC report says although South Asian fruit production is globally competitive, the region only meets around half of its demand due to poor processing and preservation facilities. Waste can be as high as 35% and amounts to billions of dollars in annual losses.

Historically, the Indian mango sector has suffered severe post-harvest loses due to the lack of cold chain supply infrastructure across the country, and developing a smart packing system like nanotech boxes could therefore be one way to address such challenges.

“Special boxes have been designed to reduce losses during transport. The boxes are sturdy, and can be stacked without risking damage to the fruit, and this alone can reduce post-harvest losses by 10-15%,” the IDRC report continues.

“In order to further improve the storage life of fruits during transport, the project has made a pioneering attempt to develop ‘nano-matrices’ using banana fibers to regulate the release of hexanal.

I wasn’t able to find much more about the project which ended in August 2014 but there is new work being funded as per a Jan. 23, 2015 IDRC news release,

Canada’s International Development Research Centre (IDRC) and Foreign Affairs, Trade and Development Canada (DFATD) today announced three new projects to be supported under the Canadian International Food Security Research Fund (CIFSRF). The projects will help prevent livestock diseases and post-harvest fruit losses that affect millions of farmers around the world, and build on the successful research carried out during CIFSRF’s first phase. [emphasis mine]

  • Researchers from the University of Guelph, Canada, Tamil Nadu Agricultural University, India, and the Industrial Technical Institute, Sri Lanka, have shown that a natural compound known as hexanal delays the ripening of mangos. Using nanotechnology, the team will continue to develop hexanal-impregnated packaging and biowax coatings to improve the fruit’s resilience during handling and shipping for use in Asia, Africa, and the Caribbean. It will also expand its research to include other fruit and look at ways to commercialize the technologies.

New funding will allow the research teams to further develop the new technologies and involve partners who can bring them to market to reach greater numbers of small-holder farmers.

It seems this new round of funding will help bring these nanotechnology-enabled products to market.

The Code; a preview of the BBC documentary being released in Canada and the US

The three episodes (Numbers, Shapes, and Prediction)  of The Code, a BBC (British Broadcasting Corporation) documentary featuring Professor Marcus du Sautoy, focus on a ‘code’ that according to du Sautoy unlocks the secrets to the laws governing the universe.

During the weekend (June 16 & 17, 2012) I had the pleasure of viewing the two-disc DVD set which is to be released tomorrow, June 19, 2012, in the US and Canada.  It’s a beautiful and, in its way, exuberant exploration of patterns that recur throughout nature and throughout human endeavours. In the first episode, Numbers, du Sautoy relates the architecture of the Chartres Cathedral (France) , St. Augustine‘s (a Roman Catholic theologian born in an area we now call Algeria) sacred numbers, the life cycle of the periodic cicada in Alabama, US and more to number patterns. Here’s an excerpt of du Sautoy in Alabama with Dr. John Cooley discussing the cicadas’ qualities as pets and their remarkable 13 year life cycle,

In the second episode, Shapes,  du Sautoy covers beehive construction (engineering marvels), bird migrations and their distinct shapes (anyone who’s ever seen a big flock of birds move as one has likely marveled at the shapes the flock takes as it moves from area to another), computer animation, soap bubbles and more, explaining how these shapes can be derived from the principle of simplicity or as du Sautoy notes, ‘nature is lazy’. The question being, how do you make the most efficient structure to achieve your ends, i.e., structure a bird flock so it moves efficiently when thousands and thousands are migrating huge distances, build the best beehive while conserving your worker bees’ energies and extracting the most honey possible, create stunning animated movies with tiny algorithms, etc.?

Here’s du Sautoy with ‘soap bubbleologist’ Tom Noddy who’s demonstrating geometry in action,

For the final episode, Prediction, du Sautoy brings the numbers and geometry together demonstrating repeating patterns such as fractals which dominate our landscape, our biology, and our universe. du Sautoy visits a Rock Paper Scissors tournament in New York City trying to discern why some folks can ‘win’ while others cannot (individuals who can read other people’s patterns while breaking their own are more successful), discusses geographic profiling with criminal geographic profiler Prof. Kim Rossmo, Jackson Pollock’s paintings and his fractals, amongst other intriguing patterns.

I paid special to the Rossmo segment as he created and developed his geographic profiling techniques when he worked for the Vancouver (Canada) Police Department (VPD) and studied at a nearby university. As this groundbreaking work was done in my neck of the woods and Rossmo was treated badly by the VPD, I felt a special interest. There’s more about Rossmo’s work and the VPD issues in the Wikipedia essay (Note: I have removed links from the excerpt.),

D. Kim Rossmo is a Canadian criminologist specializing in geographic profiling. He joined the Vancouver Police Department as a civilian employee in 1978 and became a sworn officer in 1980. In 1987 he received a Master’s degree in criminology from Simon Fraser University and in 1995 became the first police officer in Canada to obtain a doctorate in criminology. His dissertation research resulted in a new criminal investigative methodology called geographic profiling, based on Rossmo’s formula.

In 1995, he was promoted to detective inspector and founded a geographic profiling section within the Vancouver Police Department. In 1998, his analysis of cases of missing sex trade workers determined that a serial killer was at work, a conclusion ultimately vindicated by the arrest and conviction of Robert Pickton in 2002. A retired Vancouver police staff sergeant has claimed that animosity toward Rossmo delayed the arrest of Pickton, leaving him free to carry out additional murders. His analytic results were not accepted at the time and after a falling out with senior members of the department he left in 2001. His unsuccessful lawsuit against the Vancouver Police Board for wrongful dismissal exposed considerable apparent dysfunction within that department.

… he moved to Texas State University where he currently holds the Endowed Chair in Criminology and is director of the Center for Geospatial Intelligence and Investigation. …

Within what appeared to be chaos, Rossmo found order. Somehow Jackson Pollock did the same thing to achieve entirely different ends, a new form of art. Here’s a video clip of du Sautoy with artist and physicist, Richard Taylor,

Intuitively, Pollock dripped paint onto his canvases creating fractals decades before mathematician, Benoit Mandelbrot, coined the phrase and established the theory.  (I wrote previously about Jackson Pollock [and fluid dynamics] in my June 30, 2011 posting.)

I gather that du Sautoy’s ‘code’ will offer a unified theory drawing together numbers, patterns, and shapes as they are found throughout the universe in nature  and in our technologies and sciences.

The DVDs offer three extras (4 mins. each): Phi’s the Limit (beauty and the golden ratio or Phi), Go Forth and Multiply (a base 2 system developed by Ethiopian traders predating binary computer codes by millenia) and Imagining the Impossible: The Mathematical Art of M. C. Escher  (Dutch artist’s [Escher] experiments with tessellation/tiling).

I quite enjoyed the episodes although I was glad to have read James Gleick‘s book, Chaos (years ago) before viewing the third episode, Prediction and I was a little puzzled by du Sautoy’s comment in the first episode, Numbers, that atoms are not divisible. As I recall, you create an atomic bomb when you split an atom but it may have been one of those comments that didn’t come out as intended or I misunderstood.

You can find out more about The Code DVDs at Athena Learning. The suggested retail cost is $39.99 US or $52.99 CAD (which seems a little steep for Canadian purchasers since the Canadian dollar is close to par these days and, I believe, has been for some time).

In sum, this is a very engaging look at numbers and mathematics.

More on memristors and a little bit on food packaging and nano

The folks at HP Labs have figured out a  way to control memristors and the information is being published in the July issue of Nature Nanotechnology (article will be behind a paywall). Memristors first came up in May this year when scientists at HP Labs confirmed that they existed. (Take a look at my June 19 posting and May 9 postings for more about memristors.) Briefly, a memristor retains information (memory of value) about current that passes through it. They’ve now created a memristor switch (50nm x 50nm) which the can be set to ‘1’ or ‘0’ or something in between. That’s right it can be used in a  binary (digital) fashion or an analogue fashion. One of the potential applications (noted in the earlier postings) is for saving energy and another is a computer that learns. There’s more info. here at HP Labs.

A friend told me about a report from Friends of the Earth called ‘Out of the Laboratory and Onto Our Plates’. It’s about nanotechnology being used in food packaging and agriculture. I find their approach a bit strident especially when taking into account their acronym, foe. Still, the report itself is well written, except for the strident bits, has a substantive set of references and can be downloaded from their website. There’s also a March 2008 article  in Scientific American here which discusses the report and includes some commentary from other interested parties to provide some journalistic balance.