Category Archives: forestry

Say goodbye to crunchy (ice crystal-laden) in ice cream thanks to cellulose nanocrystals (CNC)

The American Chemical Society (ACS) held its 2022 Spring Meeting from March 20 – 24, 2022 and it seems like a good excuse to feature ice cream.

Adding cellulose nanocrystals prevents the growth of small ice crystals (bottom left) into the large ones (top left) that can make ice cream (right) unpleasantly crunchy. Scale bar = 100 μm. Credit: Tao Wu

A March 20, 2022 news item on phys.org introduces an ice cream presentation given at the meeting on Monday, March 20, 2022,

Ice cream can be a culinary delight, except when it gets unpleasantly crunchy because ice crystals have grown in it. Today, scientists report that a form of cellulose obtained from plants can be added to the tasty treat to stop crystals cold—and the additive works better than currently used ice growth inhibitors in the face of temperature fluctuations. The findings could be extended to the preservation of other frozen foods and perhaps donated organs and tissues

A March 20, 2022 ACS press release, which originated the news item, provides more details about crunchy ice cream and how it might be avoided,

Freshly made ice cream contains tiny ice crystals. But during storage and transport, the ice melts and regrows. During this recrystallization process, smaller crystals melt, and the water diffuses to join larger ones, causing them to grow, says Tao Wu, Ph.D., the project’s principal investigator. If the ice crystals become bigger than 50 micrometers — or roughly the diameter of a hair — the dessert takes on a grainy, icy texture that reduces consumer appeal, Wu says. “Controlling the formation and growth of ice crystals is thus the key to obtaining high-quality frozen foods.”

One fix would be to copy nature’s solution: “Some fish, insects and plants can survive in sub-zero temperatures because they produce antifreeze proteins that fight the growth of ice crystals,” Wu says. But antifreeze proteins are costlier than gold and limited in supply, so they’re not practical to add to ice cream. Polysaccharides such as guar gum or locust bean gum are used instead. “But these stabilizers are not very effective,” Wu notes. “Their performance is influenced by many factors, including storage temperature and time, and the composition and concentration of other ingredients. This means they sometimes work in one product but not in another.” In addition, their mechanism of action is uncertain. Wu wanted to clarify how they work and develop better alternatives.

Although Wu didn’t use antifreeze proteins in the study, he drew inspiration from them. These proteins are amphiphilic, meaning they have a hydrophilic surface with an affinity for water, as well as a hydrophobic surface that repels water. Wu knew that nano-sized crystals of cellulose are also amphiphilic, so he figured it was worth checking if they could stop ice crystal growth in ice cream. These cellulose nanocrystals (CNCs) are extracted from the plant cell walls of agricultural and forestry byproducts, so they are inexpensive, abundant and renewable.

In a model ice cream — a 25% sucrose solution — the CNCs initially had no effect, says Min Li, a graduate student in Wu’s lab at the University of Tennessee. Though still small, ice crystals were the same size whether CNCs were present or not. But after the model ice cream was stored for a few hours, the researchers found that the CNCs completely shut down the growth of ice crystals, while the crystals continued to enlarge in the untreated model ice cream.

The team’s tests also revealed that the cellulose inhibits ice recrystallization through surface adsorption. CNCs, like antifreeze proteins, appear to stick to the surfaces of ice crystals, preventing them from drawing together and fusing. “This completely contradicted the existing belief that stabilizers inhibit ice recrystallization by increasing viscosity, which was thought to slow diffusion of water molecules,” adds Li, who will present the work at the meeting.

In their latest study, the scientists found that CNCs are more protective than current stabilizers when ice cream is exposed to fluctuating temperatures, such as when the treat is stored in the supermarket and then taken home. The team also discovered the additive can slow the melting of ice crystals, so it could be used to produce slow-melting ice cream. Other labs have shown the stabilizer is nontoxic at the levels needed in food, Wu notes, but the additive would require review by the U.S. Food and Drug Administration.

With further research, CNCs could be used to protect the quality of other foods — such as frozen dough and fish — or perhaps to preserve cells, tissues and organs in biomedicine, Wu says. “At present, a heart must be transplanted within a few hours after being removed from a donor,” he explains. “But this time limit could be eliminated if we could inhibit the growth of ice crystals when the heart is kept at low temperatures.”

Interesting to see that this research into ice cream crystals could lead to new techniques for organ transplants.

Massachusetts Institute of Technology (MIT) researchers achieve highest fraction of CNCs in a composite to date

Cellulose nanocrystals (CNCs), always of interest to me, are featured in research announced in a February 11, 2022 news item on Nanowerk,

The strongest part of a tree lies not in its trunk or its sprawling roots, but in the walls of its microscopic cells.

A single wood cell wall is constructed from fibers of cellulose — nature’s most abundant polymer, and the main structural component of all plants and algae. Within each fiber are reinforcing cellulose nanocrystals, or CNCs, which are chains of organic polymers arranged in nearly perfect crystal patterns. At the nanoscale, CNCs are stronger and stiffer than Kevlar. If the crystals could be worked into materials in significant fractions, CNCs could be a route to stronger, more sustainable, naturally derived plastics.

Now, an MIT team has engineered a composite made mostly from cellulose nanocrystals mixed with a bit of synthetic polymer. The organic crystals take up about 60 to 90 percent of the material — the highest fraction of CNCs achieved in a composite to date.

A February 10, 2022 MIT news release (also on EurekAlert), which originated the news item, delves further into the research (Note: A link has been removed),

The researchers found the cellulose-based composite is stronger and tougher than some types of bone, and harder than typical aluminum alloys. The material has a brick-and-mortar microstructure that resembles nacre, the hard inner shell lining of some molluscs.

The team hit on a recipe for the CNC-based composite that they could fabricate using both 3D printing and conventional casting. They printed and cast the composite into penny-sized pieces of film that they used to test the material’s strength and hardness. They also machined the composite into the shape of a tooth to show that the material might one day be used to make cellulose-based dental implants — and for that matter, any plastic products — that are stronger, tougher, and more sustainable.

“By creating composites with CNCs at high loading, we can give polymer-based materials mechanical properties they never had before,” says A. John Hart, professor of mechanical engineering. “If we can replace some petroleum-based plastic with naturally-derived cellulose, that’s arguably better for the planet as well.”

Hart and his team, including Abhinav Rao PhD ’18, Thibaut Divoux, and Crystal Owens SM ’17, have published their results today in the journal Cellulose.

Gel bonds

Each year, more than 10 billion tons of cellulose is synthesized from the bark, wood, or leaves of plants. Most of this cellulose is used to manufacture paper and textiles, while a portion of it is processed into powder for use in food thickeners and cosmetics.

In recent years, scientists have explored uses for cellulose nanocrystals, which can be extracted from cellulose fibers via acid hydrolysis. The exceptionally strong crystals could be used as natural reinforcements in polymer-based materials. But researchers have only been able to incorporate low fractions of CNCs, as the crystals have tended to clump and only weakly bond with polymer molecules.

Hart and his colleagues looked to develop a composite with a high fraction of CNCs, that they could shape into strong, durable forms. They started by mixing a solution of synthetic polymer with commercially available CNC powder. The team determined the ratio of CNC and polymer that would turn the solution into a gel, with a consistency that could either be fed through the nozzle of a 3-D printer or poured into a mold to be cast. They used an ultrasonic probe to break up any clumps of cellulose in the gel, making it more likely for the dispersed cellulose to form strong bonds with polymer molecules.

They fed some of the gel through a 3-D printer and poured the rest into a mold to be cast. They then let the printed samples dry. In the process, the material shrank, leaving behind a solid composite composed mainly of cellulose nanocrystals.

“We basically deconstructed wood, and reconstructed it,” Rao says. “We took the best components of wood, which is cellulose nanocrystals, and reconstructed them to achieve a new composite material.”

Tough cracks

Interestingly, when the team examined the composite’s structure under a microscope, they observed that grains of cellulose settled into a brick-and-mortar pattern, similar to the architecture of nacre. In nacre, this zig-zagging microstructure stops a crack from running straight through the material. The researchers found this to also be the case with their new cellulose composite.

They tested the material’s resistance to cracks, using tools to initiate first nano- and then micro-scale cracks. They found that, across multiple scales, the composite’s arrangement of cellulose grains prevented the cracks from splitting the material. This resistance to plastic deformation gives the composite a hardness and stiffness at the boundary between conventional plastics and metals.

Going forward, the team is looking for ways to minimize the shrinkage of gels as they dry. While shrinkage isn’t much of a problem when printing small objects, anything bigger could buckle or crack as the composite dries.

“If you could avoid shrinkage, you could keep scaling up, maybe to the meter scale,” Rao says. “Then, if we were to dream big, we could replace a significant fraction of plastics,with cellulose composites.”

This research was supported, in part, by the Proctor and Gamble Corporation, and by the National Defense Science and Engineering Graduate Fellowship.

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

Printable, castable, nanocrystalline cellulose-epoxy composites exhibiting hierarchical nacre-like toughening by Abhinav Rao, Thibaut Divoux, Crystal E. Owens & A. John Hart. Cellulose (2022) DOI: https://doi.org/10.1007/s10570-021-04384-7 Published: 10 February 2022

This paper is behind a paywall.

A graphene-inorganic-hybrid micro-supercapacitor made of fallen leaves

I wonder if this means the end to leaf blowers. That is almost certainly wishful thinking as the researchers don’t seem to be concerned with how the leaves are gathered.

The schematic illustration of the production of femtosecond laser-induced graphene. Courtesy of KAIST

A January 27, 2022 news item on Nanowerk announces the work (Note: A link has been removed),

A KAIST [Korea Advanced Institute of Science and Technology] research team has developed graphene-inorganic-hybrid micro-supercapacitors made of fallen leaves using femtosecond laser direct laser writing (Advanced Functional Materials, “Green Flexible Graphene-Inorganic-Hybrid Micro-Supercapacitors Made of Fallen Leaves Enabled by Ultrafast Laser Pulses”).

A January 27, 2022 KAIST press release (also on EurekAlert but published January 26, 2022), which originated the news item, delves further into the research,

The rapid development of wearable electronics requires breakthrough innovations in flexible energy storage devices in which micro-supercapacitors have drawn a great deal of interest due to their high power density, long lifetimes, and short charging times. Recently, there has been an enormous increase in waste batteries owing to the growing demand and the shortened replacement cycle in consumer electronics. The safety and environmental issues involved in the collection, recycling, and processing of such waste batteries are creating a number of challenges.

Forests cover about 30 percent of the Earth’s surface and produce a huge amount of fallen leaves. This naturally occurring biomass comes in large quantities and is completely biodegradable, which makes it an attractive sustainable resource. Nevertheless, if the fallen leaves are left neglected instead of being used efficiently, they can contribute to fire hazards, air pollution, and global warming.

To solve both problems at once, a research team led by Professor Young-Jin Kim from the Department of Mechanical Engineering and Dr. Hana Yoon from the Korea Institute of Energy Research developed a novel technology that can create 3D porous graphene microelectrodes with high electrical conductivity by irradiating femtosecond laser pulses on the leaves in ambient air. This one-step fabrication does not require any additional materials or pre-treatment. 

They showed that this technique could quickly and easily produce porous graphene electrodes at a low price, and demonstrated potential applications by fabricating graphene micro-supercapacitors to power an LED and an electronic watch. These results open up a new possibility for the mass production of flexible and green graphene-based electronic devices.

Professor Young-Jin Kim said, “Leaves create forest biomass that comes in unmanageable quantities, so using them for next-generation energy storage devices makes it possible for us to reuse waste resources, thereby establishing a virtuous cycle.” 

This research was published in Advanced Functional Materials last month and was sponsored by the Ministry of Agriculture Food and Rural Affairs, the Korea Forest Service, and the Korea Institute of Energy Research.

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

Green Flexible Graphene–Inorganic-Hybrid Micro-Supercapacitors Made of Fallen Leaves Enabled by Ultrafast Laser Pulses by Truong-Son Dinh Le, Yeong A. Lee, Han Ku Nam, Kyu Yeon Jang, Dongwook Yang, Byunggi Kim, Kanghoon Yim, Seung-Woo Kim, Hana Yoon, Young-Jin Kim. Advanced Functional Materials DOI: https://doi.org/10.1002/adfm.202107768 First published: 05 December 2021

This paper is behind a paywall.

TRIUMF (Canada’s national particle accelerator centre) welcomes Nigel Smith as its new Chief Executive Officer (CEO) on May 17, 2021and some Hollywood news

I have two bits of news as noted in the headline. There’s news about TRIUMF located on the University of British Columbia (UBC) endowment lands and news about Dr. Suzanne Simard (UBC Forestry) and her memoir, Finding the Mother Tree: Discovering the Wisdom of the Fores.

Nigel Smith and TRIUMF (Canada’s national particle accelerator centre)

As soon as I saw his first name, Nigel, I bet myself he’d be from the UK (more about that later in this posting). This is TRIUMF’s third CEO since I started science blogging in May 2008. When I first started it was called TRIUMF (Canada’s National Laboratory for Particle and Nuclear Physics) but these days it’s TRIUMF (Canada’s national particle accelerator centre).

As for the organization’s latest CEO, here’s more from a TRIUMF February 12, 2021 announcement page ( the text is identical to TRIUMF’s February 12, 2021 press release),

Dr. Nigel Smith, Executive Director of SNOLAB, has been selected to serve as the next Director of TRIUMF.  

Succeeding Dr. Jonathan Bagger, who departed TRIUMF in January 2021 to become CEO of the American Physical Society, Dr. Smith’s appointment comes as the result of a highly competitive, six-month international search. Dr. Smith will begin his 5-year term as TRIUMF Director on May 17, 2021. 

“I am truly honoured to have been selected as the next Director of TRIUMF”, said Dr. Smith. “I have long been engaged with TRIUMF’s vibrant community and have been really impressed with the excellence of its science, capabilities and people. TRIUMF plays a unique and vital role in Canada’s research ecosystem and I look forward to help continue the legacy of excellence upheld by Dr. Jonathan Bagger and the previous TRIUMF Directors”.  

Describing what interested him in the position, Smith spoke to the breadth and impact of TRIUMF’s diverse science programs, stating “TRIUMF has an amazing portfolio of research covering fundamental and applied science that also delivers tangible societal impact through its range of medical and commercialisation initiatives. I am extremely excited to have the opportunity to lead a laboratory with such a broad and world-leading science program.” 

“Nigel brings all the necessary skills and background to the role of Director,” said Dr. Digvir Jayas, Interim Director of TRIUMF, Chair of the TRIUMF Board of Management, and Vice-President, Research and International at the University of Manitoba. “As Executive Director of SNOLAB, Dr. Smith is both a renowned researcher and experienced laboratory leader who offers a tremendous track record of success spanning the local, national, and international spheres. The Board of Management is thrilled to bring Nigel’s expertise to TRIUMF so he may help guide the laboratory through many of the exciting developments on the horizon.  

Dr. Smith joins TRIUMF at an important period in the laboratory’s history, moving into the second year of our current Five-Year Plan (2020-2025) and preparing to usher in a new era of science and innovation that will include the completion of the Advance Rare Isotope Laboratory (ARIEL) and the Institute for Advanced Medical Isotopes (IAMI) [not to be confused with Amii {Alberta Machine Intelligence Institute}]. This new infrastructure, alongside TRIUMF’s existing facilities and world-class research programs, will solidify Canada’s position as a global leader in both fundamental and applied research. 

Dr. Smith expressed his optimism for TRIUMF, saying “I am delighted to have this opportunity, and it will be a pleasure to lead the laboratory through this next exciting phase of our growth and evolution.” 

Smith is leaving what is probably one of the more unusual laboratories, at a depth of 2km, SNOLAB is the deepest, cleanest laboratory in the world. (more information either at SNOLAB or its Wikipedia entry.)

Is Smith from the UK? Some clues

I found my subsequent clues on SNOLAB’s ‘bio’ page for Dr. Nigel Smith,

Nigel Smith joined SNOLAB as Director during July 2009. He currently holds a full Professorship at Laurentian University, adjunct Professor status at Queen’s University, and a visiting Professorial chair at Imperial College, London. He received his Bachelor of Science in physics from Leeds University in the U.K. in 1985 and his Ph. D. in astrophysics from Leeds in 1991. He has served as a lecturer at Leeds University, a research associate at Imperial College London, group leader (dark matter) and deputy division head at the STFC Rutherford Appleton Laboratory, before relocating to Canada to oversee the SNOLAB deep underground facility.

The answer would seem to be yes, Nigel James Telfer Smith is originally from the UK.

I don’t know if this is going to be a trend but this is the second ‘Nigel” to lead TRIUMF. (The Nigels are now tied with the Johns and the Alans. Of course, the letter ‘j’ seems the most popular with four names, John, John, Jack, and Jonathan.) Here’s a list of TRIUMF’s previous CEOs (from the TRIUMF Wikipedia entry),

Since its inception, TRIUMF has had eight directors [now nine] overseeing its operations.

The first Nigel (Lockyer) is described as an American in his Wikipedia entry. He was born in Scotland and raised in Canada. However, he has spent the majority of his adult life in the US, other than the five or six years at TRIUMF. So, previous Nigel also started life in the UK.

Good luck to the new Nigel.

UBC forestry professor, Suzanne Simard’s memoir going to the movies?

Given that Simard’s memoir, Finding the Mother Tree: Discovering the Wisdom of the Forest, was published last week on May 4, 2021, this is very heady news,. From a May 12, 2021 article by Cassandra Gill for the Daily Hive (Note: Links have been removed),

Jake Gyllenhaal is bringing the story of a UBC professor to the big screen.

The Oscar nominee’s production company, Nine Stories, is producing a film based on Suzanne Simard’s memoir, Finding the Mother Tree.

Amy Adams is set to play Simard, who is a forest ecology expert renowned for her research on plants and fungi.

Adams is also co-producing the film with Gyllenhaal through her own company, Bond Group Entertainment.

The BC native [Simard] developed an interest in trees and the outdoors through her close relationship with her grandfather, who was a horse logger.

Her 30 year career and early life is documented in the memoir, which was released last week on May 4 [2021]. Simard explores how trees have evolved, have memories, and are the foundation of our planet’s ecosystem — along with her own personal experiences with grief.

The scientists’ [sic] influence has had influence in popular culture, notably in James Cameron’s 2009 film Avatar. The giant willow-like “Tree of Souls” was specifically inspired by Simard’s work.

No mention of a script and no mention of financing, so, it could be a while before we see the movie on Netflix, Apple+, HBO, or maybe a movie house (if they’re open by then).

I think the script may prove to the more challenging aspect of this project. Here’s the description of Simard’s memoir (from the Finding the Mother Tree webpage on suzannesimard.com)

From the world’s leading forest ecologist who forever changed how people view trees and their connections to one another and to other living things in the forest–a moving, deeply personal journey of discovery.

About the Book

In her first book, Simard brings us into her world, the intimate world of the trees, in which she brilliantly illuminates the fascinating and vital truths – that trees are not simply the source of timber or pulp, but are a complex, interdependent circle of life; that forests are social, cooperative creatures connected through underground networks by which trees communicate their vitality and vulnerabilities with communal lives not that different from our own.

Simard writes – in inspiring, illuminating, and accessible ways – how trees, living side by side for hundreds of years, have evolved, how they perceive one another, learn and adapt their behaviors, recognize neighbors, and remember the past; how they have agency about the future; elicit warnings and mount defenses, compete and cooperate with one another with sophistication, characteristics ascribed to human intelligence, traits that are the essence of civil societies – and at the center of it all, the Mother Trees: the mysterious, powerful forces that connect and sustain the others that surround them.

How does Simard’s process of understanding trees and conceptualizing a ‘mother tree’ get put into a script for a movie that’s not a documentary or an animation?

Movies are moving pictures, yes? How do you introduce movement and action in a script heavily focused on trees, which operate on a timescale that’s vastly different.

It’s an interesting problem and I look forward to seeing how it’s resolved. I wish them good luck.

Sunlight makes transparent wood even lighter and stronger

Researchers at the University of Maryland (US) have found a way to make their wood transparent by using sunlight. From a February 2, 2021 news article by Bob Yirka on phys.org (Note: Links have been removed),

A team of researchers at the University of Maryland, has found a new way to make wood transparent. In their paper published in the journal Science Advances, the group describes their process and why they believe it is better than the old process.

The conventional method for making wood transparent involves using chemicals to remove the lignin—a process that takes a long time, produces a lot of liquid waste and results in weaker wood. In this new effort, the researchers have found a way to make wood transparent without having to remove the lignin.

The process involved changing the lignin rather than removing it. The researchers removed lignin molecules that are involved in producing wood color. First, they applied hydrogen peroxide to the wood surface and then exposed the treated wood to UV light (or natural sunlight). The wood was then soaked in ethanol to further clean it. Next, they filled in the pores with clear epoxy to make the wood smooth.

Caption: Solar-assisted large-scale fabrication of transparent wood. (A) Schematic showing the potential large-scale fabrication of transparent wood based on the rotary wood cutting method and the solar-assisted chemical brushing process. (B) The outdoor fabrication of lignin-modified wood with a length of 1 m [9 August 2019 (the summer months) at 13:00 p.m. (solar noon), the Global Solar UV Index (UVI): 7 to 8]. (C) Digital photo of a piece of large transparent wood (400 mm by 110 mm by 1 mm). (D) The energy consumption, chemical cost, and waste emission for the solar-assisted chemical brushing process and NaClO2 solution–based delignification process. (E) A radar plot showing a comparison of the fabrication process for transparent wood. Photo credit: Qinqin Xia, University of Maryland, College Park. [downloaded from https://advances.sciencemag.org/content/7/5/eabd7342]

Bob McDonald in a February 5, 2021 posting on his Canadian Broadcasting Corporation (CBC) Quirks & Quarks blog provides a more detailed description of the new ‘solar-based transparency process’,

Early attempts to make transparent wood involved removing the lignin, but this involved hazardous chemicals, high temperatures and a lot of time, making the product expensive and somewhat brittle. The new technique is so cheap and easy it could literally be done in a backyard.

Starting with planks of wood a metre long and one millimetre thick, the scientists simply brushed on a solution of hydrogen peroxide using an ordinary paint brush. When left in the sun, or under a UV lamp for an hour or so, the peroxide bleached out the brown chromophores but left the lignin intact, so the wood turned white.

Next, they infused the wood with a tough transparent epoxy designed for marine use, which filled in the spaces and pores in the wood and then hardened. This made the white wood transparent.

As window material, it would be much more resistant to accidental breakage. The clear wood is lighter than glass, with better insulating properties, which is important because windows are a major source of heat loss in buildings. It also might take less energy to manufacture clear wood because there are no high temperatures involved.

Many different types of wood, from balsa to oak, can be made transparent, and it doesn’t matter if it is cut along the grain or against it. If the transparent wood is made a little thicker, it would be strong enough to become part of the structure of a building, so there could be entire transparent wooden walls.

Adele Peters in her February 2, 2021 article for Fast Company describes the work in Maryland and includes some information about other innovative and possibly sustainable uses of wood (Note: Links have been removed),

It’s [transparent wood] just one of a number of ways scientists and engineers are rethinking how we can use this renewable resource in construction. Skyscrapers made entirely out of wood are gaining popularity in cities around the world. And scientists recently discovered a technique to grow wood in a lab, opening up the possibility of using wood without having to chop down a forest.

There were three previous posts here about this work at the University of Maryland,

University of Maryland looks into transparent wood May 11, 2016 posting

Transparent wood more efficient than glass in windows? Sept, 8, 2016 posting

Glass-like wood windows protect against UV rays and insulate heat October 21, 2020 posting

I have this posting, which is also from 2016 but features work in Sweden,

Transparent wood instead of glass for window panes? April 1, 2016 posting

Getting back to the latest work from the University of Maryland, here’s a link to and a citation for the paper,

Solar-assisted fabrication of large-scale, patternable transparent wood by Qinqin Xia, Chaoji Chen, Tian Li, Shuaiming He, Jinlong Gao, Xizheng Wang and Liangbing Hu. Science Advances Vol. 7, no. 5, eabd7342 DOI: 10.1126/sciadv.abd7342 Published: 27 Jan 2021

This paper is open access.

One last item, Liangbing Hu has founded a company InventWood for commercializing the work he and his colleagues have done at the University of Maryland.

Wood pulp and pomegranate peels as clothing

Lilly Smith’s Sept. 11, 2020 article for Fast Company profiles a new article of clothing from Volllebak (first mentioned here in a March 11, 2019 posting titled: It’s a very ‘carbony’ time: graphene jacket, graphene-skinned airplane, and schwarzite),

The Vollebak hoodie is made out of sustainably sourced eucalyptus and beech trees. The wood pulp from the trees is then turned into a fiber through a closed-loop production process (99% of the water and solvent used to turn pulp into fiber is recycled and reused). The fiber is then woven into the fabric you pull over your head.

The hoodie is a light green because it’s dyed with pomegranate peels, which typically are thrown out. The Vollebak team went with pomegranate as the natural dye for the hoodie for two reasons: It’s high in a biomolecule called tannin, which makes it easy to extract natural dye, and the fruit can withstand a range of climates (it loves heat but can tolerate temperatures as low as 10 degrees). Given that the material is “robust enough to survive our planet’s unpredictable future,” according to Vollebak cofounder Nick Tidball, it’s likely to remain a reliable part of the company’s supply chain even as global warming causes more extreme weather patterns.

… the hoodie won’t degrade from normal wear and tear—it needs fungus, bacteria, and heat in order to biodegrade (sweat doesn’t count). It will take about 8 weeks to decompose if buried in compost, and up to 12 if buried in the ground—the hotter the conditions, the faster it breaks down. “Every element is made from organic matter and left in its raw state,” says Steve Tidball, Vollebak’s other cofounder (and Nick’s twin brother). “There’s no ink or chemicals to leach into the soil. Just plants and pomegranate dye, which are organic matter. So when it disappears in 12 weeks, nothing is left behind.”

The article hosts a picture of the hoodie as does Vollebak website’s Product, Plant and Pomegranate Hoodie webpage,

Plant and Pomegranate Hoodie. Built from eucalyptus trees and dyed in a giant vat of fruit. The waiting list is now open.

5,000 years ago our ancestors made their clothes from nature, using grass, tree bark, animal skins and plants. We need to get back to the point where you could throw your clothes away in a forest and nature would take care of the rest. The Plant and Pomegranate Hoodie feels like a normal hoodie, looks like a normal hoodie, and lasts as long as a normal hoodie. The thing that makes it different is simply the way it starts and ends its life. All the materials we’ve used were grown in nature. Each hoodie is made from eucalyptus trees from sustainably managed forests before being submerged in a giant vat of pomegranate dye to give it its colour. As it’s made entirely from plants, the hoodie is fully biodegradable and compostable. When you decide your hoodie has reached the end of its life – whether that’s in 3 years’ time or 30 – you can put it out with the compost or bury it in your garden. Because the hoodie that starts its life in nature is designed to end up there too. Launching September 2020, the waiting list is now open.

Not much information, eh? I found the same dearth of detail the last time I looked for more technical information about a Vollebak product (their graphene jacket).

As for composting or burying the hoodies, how does that work? I live in an apartment building; I don’t think composting is allowed in my apartment and the building owners will likely get upset if I start digging holes in the front yard. There is a park nearby but it is city property and I’m pretty sure that digging into it to bury a hoodie will turn out to be illegal.

There is a recycling bin for organics but I don’t know if the businesses tasked with picking up the organic refuse and dealing with it will be familiar with biodegradable hoodies and I ‘m not sure hoodie disposal in the organics would be allowed by the city, which oversees the recycling programme.

These are not insurmountable problems but if people want to be mindful about their purchases and future disposal of said purchases, research may be needed.

Glass-like wood windows protect against UV rays and insulate heat

Engineers at the University of Maryland designed a transparent ceiling made of wood that highlights the natural woodgrain pattern. Credit: A. James Clark School of Engineering, University of Maryland [downloaded from https://phys.org/news/2020-08-glass-like-wood-insulates-tough-blocks.html]

An August 7, 2020 news item by Martha Hell on phys.org announces the latest research (links to previous posts about this research at the end of this post) on ‘transparent’ wood from the University of Maryland,

Need light but want privacy? A new type of wood that’s transparent, tough, and beautiful could be the solution. This nature-inspired building material allows light to come through (at about 80%) to fill the room but the material itself is naturally hazy (93%), preventing others from seeing inside.

An August 16, 2020 University of Maryland news release (also on EurekAlert) describes the work in more detail,

Engineers at the A. James Clark School of Engineering at the University of Maryland (UMD) demonstrate in a new study that windows made of transparent wood could provide more even and consistent natural lighting and better energy efficiency than glass

In a paper just published [July 31, 20202] in the peer-reviewed journal Advanced Energy Materials [this seems to be an incorrectly cited journal; I believe it should be Nature Communications as indicated in the phys.org news item], the team, headed by Liangbing Hu of UMD’s Department of Materials Science and Engineering and the Energy Research Center lay out research showing that their transparent wood provides better thermal insulation and lets in nearly as much light as glass, while eliminating glare and providing uniform and consistent indoor lighting. The findings advance earlier published work on their development of transparent wood.

The transparent wood lets through just a little bit less light than glass, but a lot less heat, said Tian Li, the lead author of the new study. “It is very transparent, but still allows for a little bit of privacy because it is not completely see-through. We also learned that the channels in the wood transmit light with wavelengths around the range of the wavelengths of visible light, but that it blocks the wavelengths that carry mostly heat,” said Li.

The team’s findings were derived, in part, from tests on tiny model house with a transparent wood panel in the ceiling that the team built. The tests showed that the light was more evenly distributed around a space with a transparent wood roof than a glass roof.

The channels in the wood direct visible light straight through the material, but the cell structure that still remains bounces the light around just a little bit, a property called haze. This means the light does not shine directly into your eyes, making it more comfortable to look at. The team photographed the transparent wood’s cell structure in the University of Maryland’s Advanced Imaging and Microscopy (AIM) Lab.

Transparent wood still has all the cell structures that comprised the original piece of wood. The wood is cut against the grain, so that the channels that drew water and nutrients up from the roots lie along the shortest dimension of the window. The new transparent wood uses theses natural channels in wood to guide the sunlight through the wood.

As the sun passes over a house with glass windows, the angle at which light shines through the glass changes as the sun moves. With windows or panels made of transparent wood instead of glass, as the sun moves across the sky, the channels in the wood direct the sunlight in the same way every time.

“This means your cat would not have to get up out of its nice patch of sunlight every few minutes and move over,” Li said. “The sunlight would stay in the same place. Also, the room would be more equally lighted at all times.”

Working with transparent wood is similar to working with natural wood, the researchers said. However, their transparent wood is waterproof due to its polymer component. It also is much less breakable than glass because the cell structure inside resists shattering.

The research team has recently patented their process for making transparent wood. The process starts with bleaching from the wood all of the lignin, which is a component in the wood that makes it both brown and strong. The wood is then soaked in epoxy, which adds strength back in and also makes the wood clearer. The team has used tiny squares of linden wood about 2 cm x 2 cm, but the wood can be any size, the researchers said.

Here’s a link to and a citation for the July 31, 2020 paper,

Scalable aesthetic transparent wood for energy efficient buildings by Ruiyu Mi, Chaoji Chen, Tobias Keplinger, Yong Pei, Shuaiming He, Dapeng Liu, Jianguo Li, Jiaqi Dai, Emily Hitz, Bao Yang, Ingo Burgert & Liangbing Hu. Nature Communications volume 11, Article number: 3836 (2020) DOI: https://doi.org/10.1038/s41467-020-17513-w Published 31 July 2020

This paper is open access.

There were two previous posts about this work at the University of Maryland,

University of Maryland looks into transparent wood May 11, 2016 posting

Transparent wood more efficient than glass in windows? Sept, 8, 2016 posting

I also have this posting, which is also from 2016 but features work in Sweden,

Transparent wood instead of glass for window panes? April 1, 2016 posting

I seem to have stumbled across a number of transparent wood stories in 2016. Hmm I think I need to spend more time searching previous titles for my postings so I didn’t end up with too many that sound similar.

CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 in the forest

It seems lignin is a bit of a problem. Its presence in a tree makes processing the wood into various products more difficult. (Of course, some people appreciate trees for other reasons both practical [carbon sequestration?] and/or aesthetic.)

In any event, scientists have been working on ways to reduce the amount of lignin in poplar trees since at least 2014 (see my April 7, 2014 posting titled ‘Good lignin, bad lignin: Florida researchers use plant waste to create lignin nanotubes while researchers in British Columbia develop trees with less lignin’; scroll down about 40% of the way for the ‘less lignin’ story).

(I don’t believe the 2014 research was accomplished with the CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 technique as it had only been developed in 2012.)

The latest in the quest to reduce the amount of lignin of poplar trees comes from a Belgian/US team, from an Oct. 6, 2020 news item on ScienceDaily,

Researchers led by prof. Wout Boerjan (VIB-UGent [Ghent University] Center for Plant Systems Biology) have discovered a way to stably finetune the amount of lignin in poplar by applying CRISPR/Cas9 technology. Lignin is one of the main structural substances in plants and it makes processing wood into, for example, paper difficult. This study is an important breakthrough in the development of wood resources for the production of paper with a lower carbon footprint, biofuels, and other bio-based materials. Their work, in collaboration with VIVES University College (Roeselare, Belgium) and University of Wisconsin (USA) appears in Nature Communications.

Picture Tailoring lignin and growth by creating CCR2 allelic variants (From left to right: wild type, CCR2(-/-), CCR2(-/*) line 206, CCR2(-/*) line 12) Courtesy: VIB (Flanders Institute of Biotechnology)

An Oct. 6, 2020 VIB (Vlaams Instituut voor Biotechnologie; Flanders Institute of Biotechnology) press release (also on EurekAlert), which originated the news item, explains the reason for this research and how CRISPR (clustered regularly interspaced short palindromic repeats) technology could help realize it,

Towards a bio-based economy

Today’s fossil-based economy results in a net increase of CO2 in the Earth’s atmosphere and is a major cause of global climate change. To counter this, a shift towards a circular and bio-based economy is essential. Woody biomass can play a crucial role in such a bio-based economy by serving as a renewable and carbon-neutral resource for the production of many chemicals. Unfortunately, the presence of lignin hinders the processing of wood into bio-based products.

Prof. Wout Boerjan (VIB-UGent): “A few years ago, we performed a field trial with poplars that were engineered to make wood containing less lignin. Most plants showed large improvements in processing efficiency for many possible applications. The downside, however, was that the reduction in lignin accomplished with the technology we used then – RNA interference – was unstable and the trees grew less tall.”

New tools

Undeterred, the researchers went looking for a solution. They employed the recent CRISPR/Cas9 technology in poplar to lower the lignin amount in a stable way, without causing a biomass yield penalty. In other words, the trees grew just as well and as tall as those without genetic changes.

Dr. Barbara De Meester (VIB-UGent): “Poplar is a diploid species, meaning every gene is present in two copies. Using CRISPR/Cas9, we introduced specific changes in both copies of a gene that is crucial for the biosynthesis of lignin. We inactivated one copy of the gene, and only partially inactivated the other. The resulting poplar line had a stable 10% reduction in lignin amount while it grew normally in the greenhouse. Wood from the engineered trees had an up to 41% increase in processing efficiency”.

Dr. Ruben Vanholme (VIB-UGent): “The mutations that we have introduced through CRISPR/Cas9 are similar to those that spontaneously arise in nature. The advantage of the CRISPR/Cas9 method is that the beneficial mutations can be directly introduced into the DNA of highly productive tree varieties in only a fraction of the time it would take by a classical breeding strategy.”

The applications of this method are not only restricted to lignin but might also be useful to engineer other traits in crops, providing a versatile new breeding tool to improve agricultural productivity.

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

Tailoring poplar lignin without yield penalty by combining a null and haploinsufficient CINNAMOYL-CoA REDUCTASE2 allele by Barbara De Meester, Barbara Madariaga Calderón, Lisanne de Vries, Jacob Pollier, Geert Goeminne, Jan Van Doorsselaere, Mingjie Chen, John Ralph, Ruben Vanholme & Wout Boerjan. Nature Communications volume 11, Article number: 5020 (2020) DOI: https://doi.org/10.1038/s41467-020-18822-w Published 06 October 2020

This paper is open access.

Improving batteries with cellulosic nanomaterials

This is a cellulose nanocrystal (CNC) story and in this story it’s derived from trees as opposed to banana skins or carrots or … A February 19, 2020 news item on Nanowerk announces CNC research from Northeastern University (Massachusetts, US),

Nature isn’t always generous with its secrets. That’s why some researchers look into unusual places for solutions to our toughest challenges, from powerful antibiotics hiding in the guts of tiny worms, to swift robots inspired by bats.

Now, Northeastern researchers have taken to the trees to look for ways to make new sustainable materials from abundant natural resources—specifically, within the chemical structure of microfibers that make up wood.

A team led by Hongli (Julie) Zhu, an assistant professor of mechanical and industrial engineering at Northeastern, is using unique nanomaterials derived from cellulose to improve the large and expensive kind of batteries needed to store renewable energy harnessed from sources such as sunlight and the wind.

A February 18, 2020 Northeastern University news release by Roberto Molar Candanosa, which originated the news item, provides more detail (Note: Links have been removed),

Cellulose, the most abundant natural polymer on Earth, is also the most important structural component of plants. It contains important molecular structures to improve batteries, reduce plastic pollution, and power the sort of electrical grids that could support entire communities with renewable energy, Zhu says.  

“We try to use polymers from wood, from bark, from seeds, from flowers, bacteria, green tea—from these kinds of plants to replace plastic,”  Zhu says.

One of the main challenges in storing energy from the sun, wind, and other types of renewables is that variation in factors such as the weather lead to inconsistent sources of power. 

That’s where batteries with large capacity come in. But storing the large amounts of energy that sunlight and the wind are able to provide requires a special kind of device.

The most advanced batteries to do that are called flow batteries, and are made with vanadium ions dissolved in acid in two separate tanks—one with a substance of negatively charged ions, and one with positive ones. The two solutions are continuously pumped from the tank into a cell, which functions like an engine for the battery. 

These substances are always separated by a special membrane that ensures that they exchange positive hydrogen ions without flowing into each other. That selective exchange of ions is the basis for the ability of the battery to charge and discharge energy. 

Flow batteries are ideal devices in which to store solar and wind energy because they can be tweaked to increase the amount of energy stored without compromising the amount of energy that can be generated. The bigger the tanks, the more energy the battery can store from non-polluting and practically inexhaustible resources.

But manufacturing them requires several moving pieces of hardware. As the membrane separating the two flowing substances decays, it can cause the vanadium ions from the solution to mix. That crossover reduces the stability of a battery, along with its capacity to store energy.

Zhu says the limited efficiency of that membrane, combined with  its high cost, are the main factors keeping flow batteries from being widely used in large-scale grids.

In a recent paper, Zhu reported that a new membrane made with cellulose nanocrystals demonstrates superior efficiency compared to other membranes used commonly in the market. The team tested different membranes made from cellulose nanocrystals to make flow batteries cheaper.

“The cost of our membrane per square meter is 147.68 US dollars, ” Zhu says, adding that her calculations do not include costs associated with marketing. “The price quote for the commercialized Nafion membrane is $1,321 per square meter.”

Their tests also showed that the membranes, made with support from the Rogers Corporation and its Innovation Center at Northeastern’s Kostas Research Institute, can offer substantially longer battery lifetimes than other membranes. 

Zhu’s naturally derived membrane is especially efficient because its cellular structure contains thousands of hydroxyl groups, which involve bonds of hydrogen and oxygen that make it easy for water to be transported in plants and trees. 

In flow batteries, that molecular makeup speeds the transport of protons as they flow through the membrane.

The membrane also consists of another polymer known as poly(vinylidene fluoride-hexafluoropropylene), which prevents the negatively and positively charged acids from mixing with each other. 

“For these materials, one of the challenges is that it is difficult to find a polymer that is proton conductive and that is also a material that is very stable in the flowing acid,” Zhu says. 

Because these materials are practically everywhere, membranes made with it can be easily put together at large scales needed for complex power grids. 

Unlike other expensive artificial materials that need to be concocted in a lab, cellulose can be extracted from natural sources including algae, solid waste, and bacteria. 

“A lot of material in nature is a composite, and if we disintegrate its components, we can use it to extract cellulose,” Zhu says. “Like waste from our yard, and a lot of solid waste that we don’t always know what to do with.” 

Here’s a link to and a citation for the paper mentioned in the news release,

Stable and Highly Ion-Selective Membrane Made from Cellulose Nanocrystals for Aqueous Redox Flow Batteries by Alolika Mukhopadhyay, Zheng Cheng, Avi Natan, Yi Ma, Yang Yang, Daxian Cao, Wei Wan, Hongli Zhu. Nano Lett. 2019, 19, 12, 8979-8989 DOI: https://doi.org/10.1021/acs.nanolett.9b03964Publication Date:November 8, 2019 Copyright © 2019 American Chemical Society

This paper is behind a paywall.