Category Archives: forestry

Nanocellulose sensors: 3D printed and biocompatible

I do like to keep up with nanocellulose doings, especially when there’s some Canadian involvement, and an October 8, 2019 news item on Nanowerk alerted me to a newish application for the product,

Physiological parameters in our blood can be determined without painful punctures. Empa researchers are currently working with a Canadian team to develop flexible, biocompatible nanocellulose sensors that can be attached to the skin. The 3D-printed analytic chips made of renewable raw materials will even be biodegradable in future.

The idea of measuring parameters that are relevant for our health via the skin has already taken hold in medical diagnostics. Diabetics, for example, can painlessly determine their blood sugar level with a sensor instead of having to prick their fingers.

An October 8, 2019 Empa (Swiss Federal Laboratories for Materials Science and Technology) press release, which originated the news item, provides more detail,

A transparent foil made of wood

Nanocellulose is an inexpensive, renewable raw material, which can be obtained in form of crystals and fibers, for example from wood. However, the original appearance of a tree no longer has anything to do with the gelatinous substance, which can consist of cellulose nanocrystals and cellulose nanofibers. Other sources of the material are bacteria, algae or residues from agricultural production. Thus, nanocellulose is not only relatively easy and sustainable to obtain. Its mechanical properties also make the “super pudding” an interesting product. For instance, new composite materials based on nanocellulose can be developed that could be used as surface coatings, transparent packaging films or even to produce everyday objects like beverage bottles.

Researchers at Empa’s Cellulose & Wood Materials lab and Woo Soo Kim from the Simon Fraser University [SFU] in Burnaby, Canada, are also focusing on another feature of nanocellulose: biocompatibility. Since the material is obtained from natural resources, it is particularly suitable for biomedical research.

With the aim of producing biocompatible sensors that can measure important metabolic values, the researchers used nanocellulose as an “ink” in 3D printing processes. To make the sensors electrically conductive, the ink was mixed with silver nanowires. The researchers determined the exact ratio of nanocellulose and silver threads so that a three-dimensional network could form.

Just like spaghetti – only a wee bit smaller

It turned out that cellulose nanofibers are better suited than cellulose nanocrystals to produce a cross-linked matrix with the tiny silver wires. “Cellulose nanofibers are flexible similar to cooked spaghetti, but with a diameter of only about 20 nanometers and a length of just a few micrometers,” explains Empa researcher Gilberto Siqueira.

The team finally succeeded in developing sensors that measure medically relevant metabolic parameters such as the concentration of calcium, potassium and ammonium ions. The electrochemical skin sensor sends its results wirelessly to a computer for further data processing. The tiny biochemistry lab on the skin is only half a millimeter thin.

While the tiny biochemistry lab on the skin – which is only half a millimeter thin – is capable of determining ion concentrations specifically and reliably, the researchers are already working on an updated version. “In the future, we want to replace the silver [nano] particles with another conductive material, for example on the basis of carbon compounds,” Siqueira explains. This would make the medical nanocellulose sensor not only biocompatible, but also completely biodegradable.

I like the images from Empa better than the ones from SFU,

Using a 3D printer, the nanocellulose “ink” is applied to a carrier plate. Silver particles provide the electrical conductivity of the material. Image: Empa
Empa researcher Gilberto Siqueira demonstrates the newly printed nanocellulose circuit. After a subsequent drying, the material can be further processed. Image: Empa

SFU produced a news release about this work back in February 2019. Again, I prefer what the Swiss have done because they’re explaining/communicating the science, as well as , communicating benefits. From a February 13, 2019 SFU news release (Note: Links have been removed),

Simon Fraser University and Swiss researchers are developing an eco-friendly, 3D printable solution for producing wireless Internet-of-Things (IoT) sensors that can be used and disposed of without contaminating the environment. Their research has been published as the cover story in the February issue of the journal Advanced Electronic Materials.

SFU professor Woo Soo Kim is leading the research team’s discovery, which uses a wood-derived cellulose material to replace the plastics and polymeric materials currently used in electronics.

Additionally, 3D printing can give flexibility to add or embed functions onto 3D shapes or textiles, creating greater functionality.

“Our eco-friendly, 3D-printed cellulose sensors can wirelessly transmit data during their life, and then can be disposed without concern of environmental contamination,” says Kim, a professor in the School of Mechatronic Systems Engineering. The SFU research is being carried out at PowerTech Labs in Surrey, which houses several state-of-the-art 3D printers used to advance the research.

“This development will help to advance green electronics. For example, the waste from printed circuit boards is a hazardous source of contamination to the environment. If we are able to change the plastics in PCB to cellulose composite materials, recycling of metal components on the board could be collected in a much easier way.”

Kim’s research program spans two international collaborative projects, including the latest focusing on the eco-friendly cellulose material-based chemical sensors with collaborators from the Swiss Federal Laboratories for Materials Science.

He is also collaborating with a team of South Korean researchers from the Daegu Gyeongbuk Institute of Science and Technology’s (DGIST)’s department of Robotics Engineering, and PROTEM Co Inc, a technology-based company, for the development of printable conductive ink materials.

In this second project, researchers have developed a new breakthrough in the embossing process technology, one that can freely imprint fine circuit patterns on flexible polymer substrate, a necessary component of electronic products.

Embossing technology is applied for the mass imprinting of precise patterns at a low unit cost. However, Kim says it can only imprint circuit patterns that are imprinted beforehand on the pattern stamp, and the entire, costly stamp must be changed to put in different patterns.

The team succeeded in developing a precise location control system that can imprint patterns directly resulting in a new process technology. The result will have widespread implications for use in semiconductor processes, wearable devices and the display industry.

This paper was made available online back in December 2018 and then published in print in February 2019. As to why there’d be such large gaps between the paper’s publication dates and the two institution’s news/press releases, it’s a mystery to me. In any event, here’s a link to and a citation for the paper,

3D Printed Disposable Wireless Ion Sensors with Biocompatible Cellulose Composites by Taeil Kim, Chao Bao, Michael Hausmann, Gilberto Siqueira, Tanja Zimmermann, Woo Soo Kim. Advanced Electronic Materials DOI: https://doi.org/10.1002/aelm.201970007 First published online December 19, 2018. First published in print: 08 February 2019 (Adv. Electron. Mater. 2/2109) Volume 5, Issue 2 February 2019 1970007

This paper is behind a paywall.

A fire-retardant coating made of renewable nanocellulose materials

Firefighters everywhere are likely to appreciate the efforts of researchers at Texas A&M University (US) to a develop a non-toxic fire retardant coating. From a February 12, 2019 news item on Nanowerk (Note: A link has been removed),

Texas A&M University researchers are developing a new kind of flame-retardant coating using renewable, nontoxic materials readily found in nature, which could provide even more effective fire protection for several widely used materials.

Dr. Jaime Grunlan, the Linda & Ralph Schmidt ’68 Professor in the J. Mike Walker ’66 Department of Mechanical Engineering at Texas A&M, led the recently published research that is featured on the cover of a recent issue of the journal Advanced Materials Interfaces (“Super Gas Barrier and Fire Resistance of Nanoplatelet/Nanofibril Multilayer Thin Films”).

Successful development and implementation of the coating could provide better fire protection to materials including upholstered furniture, textiles and insulation.

“These coatings offer the opportunity to reduce the flammability of the polyurethane foam used in a variety of furniture throughout most people’s homes,” Grunlan noted.

A February 8, 2019 Texas A&M University news release (also on EurekAlert) by Steve Kuhlmann, which originated the news item, describes the work being done in collaboration with a Swedish team in more detail,

The project is a result of an ongoing collaboration between Grunlan and a group of researchers at KTH Royal Institute of Technology in Stockholm, Sweden, led by Lars Wagberg. The group, which specializes in utilizing nanocellulose, provided Grunlan with the ingredients he needed to complement his water-based coating procedure.

In nature, both the cellulose – a component of wood and various sea creatures – and clay – a component in soil and rock formations – act as mechanical reinforcements for the structures in which they are found.

“The uniqueness in this current study lies in the use of two naturally occurring nanomaterials, clay nanoplatelets and cellulose nanofibrils,” Grunlan said. “To the best of our knowledge, these ingredients have never been used to make a heat shielding or flame-retardant coating as a multilayer thin film deposited from water.”

Among the benefits gained from using this method include the coating’s ability to create an excellent oxygen barrier to plastic films – commonly used for food packaging – and better fire protection at a lower cost than other, more toxic ingredients traditionally used flame-retardant treatments.

To test the coatings, Grunlan and his colleagues applied the flexible polyurethane foam – often used in furniture cushions – and exposed it to fire using a butane torch to determine the level of protection the compounds provided.

While uncoated polyurethane foam immediately melts when exposed to flame, the foam treated with the researchers’ coating prevented the fire from damaging any further than surface level, leaving the foam underneath undamaged.

“The nanobrick wall structure of the coating reduces the temperature experienced by the underlying foam, which delays combustion,” Grunlan said. “This coating also serves to promote insulating char formation and reduces the release of fumes that feed a fire.”

With the research completed, Grunlan said the next step for the overall flame-retardant project is to transition the methods into industry for implementation and further development. 

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

Super Gas Barrier and Fire Resistance of Nanoplatelet/Nanofibril Multilayer Thin Films by Shuang Qin, Maryam Ghanad Pour, Simone Lazar, Oruç Köklükaya, Joseph Gerringer, Yixuan Song, Lars Wågberg, Jaime C. Grunlan. Advanced Materials Interfaces Volume 6, Issue 2 January 23, 2019 1801424 DOI: https://doi.org/10.1002/admi.201801424 First published online: 16 November 2018

This paper is behind a paywall.

Nanocellulosic 3D-printed ears

It’s been a while since I’ve had a story abut cellulose nanocrystals (CNC) and this one comes from Switzerland’s Empa (Swiss Federal Laboratories for Materials Science and Technology) in a January 15, 2019 news item on Nanowerk (Note: A link has been removed),

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing (ACS Nano, “Dynamics of Cellulose Nanocrystal Alignment during 3D Printing”).

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains: “In viscous state cellulose nanocrystals can easily be shaped together with nother biopolymers into complex 3-dimensional structures using a 3D printer, such as the Bioplotter.”

Once cross-linked, the structures remain stable despite their soft mechanical properties. Hausmann is currently investigating the characteristics of the nanocellulose composite hydrogels in order to further optimize their stability as well as the printing process. The researcher already used X-ray analysis to determine how cellulose is distributed and organized within the printed structures.

At this point in time the printed ear is entirely and solely made of cellulose nanocrystals and a biopolymer. However, the objective is to incorporate both human cells and therapeutics into the base structure in order to produce biomedical implants.

Here’s one of the researchers (Michael Hausmann) showing off their ‘ear’,

A 3D-printed ear: Empa researcher Michael Hausmann uses nanocellulose as the basis for novel implants (Image: Empa)

Doesn’t look like much does, eh? It’s scaffolding or, you could say, a kind of skeleton and a January 15, 2019 Empa press release, which originated the news item, describes it and explains how it will house new cells,

A new project is currently underway, looking into how chondrocytes (cartilage cells) can be integrated into the scaffold to yield artificial cartilage tissue. As soon as the colonization of the hydrogel with cells is established, nanocellulose based composites in the shape of an ear could serve as an implant for children with an inherited auricular malformation as for instance, in microtia, where the external ears are only incompletely developed. A reconstruction of the auricle can esthetically and medically correct the malformation; otherwise the hearing ability can be severely impaired. In the further course of the project, cellulose nanocrystals containing hydrogels will also be used for the replacement of articular cartilage (e.g. knee) in cases of joint wear due to, for example, chronic arthritis.

Once the artificial tissue has been implanted in the body, the biodegradable polymer material is expected to degrade over time. The cellulose itself is not degradable in the body, but biocompatible. However, it is not only its biocompatibility that makes nanocellulose the perfect material for implant scaffolds. “It is also the mechanical performance of cellulose nanocrystals that make them such promising candidates because the tiny but highly stable fibers can extremely well reinforce the produced implant,” said Hausmann.

Moreover, nanocellulose allows the incorporation of various functions by chemical modifications into the viscous hydrogel. Thus, the structure, the mechanical properties and the interactions of the nanocellulose with its environment can be specifically tailored to the desired end product. “For instance, we can incorporate active substances that promote the growth of chondrocytes or that sooth joint inflammation into the hydrogel,” says the Empa researcher.

And last but not least, as raw material cellulose is the most abundant natural polymer on earth. Therefore, the use of cellulose nanocrystals not only benefits from the mere elegance of the novel process but also from the availability of the raw material.

The white nanocellulose ear lies glossy on the glass carrier. Just out of the Bioplotter, it is already robust and dimensionally stable. Hausmann can give the go-ahead for the next steps. 

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

Dynamics of Cellulose Nanocrystal Alignment during 3D Printing by Michael K. Hausmann, Patrick A. Rühs, Gilberto Siqueira, Jörg Läuger, Rafael Libanori, Tanja Zimmermann, and André R. Studart. ACS Nano, 2018, 12 (7), pp 6926–6937 DOI: 10.1021/acsnano.8b02366 Publication Date (Web): July 5, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Two new Canada Excellence Research Chairs (CERC) at the University of British Columbia (Canada) bring bioproducts and precision medicine skills

This is very fresh news. One of these chairs has not yet been listed (at the time of this writing) as a member of the institute that he will be leading. Here’s the big picture news from an
April 17, 2019 University of British Columbia (UBC) news release, Note: Links have been removed,

Two internationally recognized researchers join the University of British Columbia as Canada Excellence Research Chairs, bringing international talent in the fields of forest bioproducts and precision cancer drug design.

Orlando Rojas has accepted the Canada Excellence Research Chair in Forest Bioproducts, while Sriram Subramaniam will hold the Gobind Khorana Canada Excellence Research Chair in Precision Cancer Drug Design—named after late Nobel Prize-winning UBC biochemistry professor Har Gobind Khorana.

“We are delighted to welcome Dr. Rojas and Dr. Subramaniam to UBC,” said UBC President and Vice-Chancellor, Professor Santa J. Ono. “Thanks to the CERC program and the generous support of our partners, including VGH & UBC Hospital Foundation, we have an opportunity to continue to build on UBC’s reputation as a global leader in these vitally important research fields.”

The Canada Excellence Research Chairs (CERC) program was established by the federal government in 2008 to attract top research talent from abroad to Canada. UBC will receive up to $10 million over seven years to support each chair and their research teams. In addition, a philanthropic gift of $18 million made to VGH & UBC Hospital Foundation will support cancer drug design that will be carried out by Subramaniam in close partnership with UBC and the Vancouver Prostate Centre at VGH.

“VGH & UBC Hospital Foundation is honoured to announce an $18 million gift from Aqueduct Foundation on behalf of an anonymous donor that will increase capacity for discovering and testing new life-saving cancer treatments right here in B.C. This funding will specifically support the design of precise, targeted and cost-effective drugs for cancer in work led by Dr. Sriram Subramaniam in close partnership with UBC and the Vancouver Prostate Centre at VGH and other research centres,” says Barbara Grantham, president and CEO of VGH & UBC Hospital Foundation.

Bioproducts

The April 17, 2019 UBC news release, goes on to describe the two new chairs,

Breaking new ground in forest bioproducts

Orlando Rojas comes to UBC from Aalto University [Finland], where he directs with VTT, the Technical Research Centre of Finland, a scientific cluster to advance the Finnish materials bio-economy. A recipient of the Anselme Payen Award—one of the highest international recognitions in the area of cellulose and renewable materials—and an elected member of the American Chemical Society and the Finnish Academy of Science and Letters, Rojas is recognized as a worldwide leader in the area of nanocelluloses.

“I’m thrilled to join an already stellar team of researchers at UBC’s BioProducts Institute,” said Rojas. “My research is aimed at uncovering solutions that can be found in nature to fulfill our material needs by using sustainably, readily available bio-resources. I hope to break new grounds to create positive societal impacts and to better our quality of life.”

As the CERC in Forest Bioproducts, Rojas will establish a world-class research program in genomics, synthetic biology, materials science and engineering. Together with his team and by applying cutting-edge nano- and biotechnologies, he will discover new strategies to isolate and transform biomass components—non-fossil organic materials derived from plants (including wood)—as well as side-streams and residuals from forestry and agriculture, oils and biomolecules. The work will lead to the generation of new bio-based precursors and advanced materials critical to the future bioeconomy. Rojas will be the scientific director of the UBC BioProducts Institute, synergizing a distinguished group of professors and researchers across campus who will conduct multi- and cross-disciplinary research that will position UBC at the forefront in the area.

As climate change continues to be the greatest threat to our world, the need to transition toward a more sustainable bio-based circular economy is critical. Rojas’ research is vital in understanding the role of forest and other plant-based resources in facilitating the transition to renewable materials and bioproducts.

As I noted earlier, Rojas has yet to be added to the UBC BioProducts Institute roster but I did find a listing of his published papers on Google Scholar and noted a number of them are focused on nanocellulose with at least one study on cellulose nanocrystals (CNC),

  • Cellulose nanocrystals: chemistry, self-assembly, and applications [by] Y Habibi, LA Lucia, OJ Rojas Chemical reviews 110 (6), 3479-3500

The University of British Columbia was the site for much of the early work in Canada and internationally on cellulose nanocrystals. After the provincial government lost interest in supporting it, the researchers at FPInnovations (I think it was a university spin-off organization) moved their main headquarters (leaving a smaller group in British Columbia) to the province of Québec where they receive significant support . In turn, FPInnovations spun-off a company, CelluForce which produces CNC from forest products.This news about Roja’s appointment would seem to make for an interesting development in Canada’s nanocellulose story.

Precision medicine with cryo-electron microscopy

Now for the second CERC appointment, from the April 17, 2019 UBC news release,

Putting Canada at the forefront of precision medicine

Sriram Subramaniam is recognized as a global leader in the emerging field of cryo-electron microscopy, or cryo-EM, a technology that has sparked a revolution in imaging of protein complexes. Subramaniam and his team demonstrated that proteins and protein-bound drugs could be visualized at atomic resolution with cryo-EM, paving the way for this technology to be used in accelerating drug discovery.

Subramaniam comes to UBC’s faculty of medicine from the US National Cancer Institute (NCI) at the National Institutes of Health (NIH) where he led a research team that made seminal advances in molecular and cellular imaging using electron microscopy, including work on advancing vaccine design for viruses such as HIV. Subramaniam is also founding director of the National Cryo-EM Program at NCI, NIH.

As the Gobind Khorana Canada Excellence Research Chair in Precision Cancer Drug Design, Subramaniam will establish and direct a laboratory located at UBC, aimed at bringing about transformative discoveries in cancer, neuroscience and infectious disease. Subramaniam is appointed both in the department of urologic sciences and in biochemistry and molecular biology at UBC, and is linked to the precision cancer drug design program at the Vancouver Prostate Centre at VGH.

His research is supported by a philanthropic gift of $18 million made to VGH & UBC Hospital Foundation. He will work in close partnership with the Vancouver Prostate Centre at VGH.

“We would not be able to undertake this path aimed at leveraging advances in imaging technology to improve patient outcomes if it weren’t for the generous support of the donor, the Canadian government, and VGH & UBC Hospital Foundation,” said Subramaniam. “I am proud to be part of a team of outstanding researchers here in Vancouver, and working together to harness the true potential of cryo-EM to accelerate drug design. Our work has the potential to establish VGH, UBC and Canada at the forefront of the emerging era of precision medicine.”

I was not able to find much in the way of additional information about Subramaniam—other than this (from the High Resolution Electron Microscopy Lab Members webpage),

Sriram Subramaniam received his Ph.D. in Physical Chemistry from Stanford University and completed postdoctoral training in the Departments of Chemistry and Biology at M.I.T. [Massachusetts Institute of Technology] He is chief of the Biophysics Section in the Laboratory of Cell Biology at the Center for Cancer Research, National Cancer Institute. He holds a visiting faculty appointment at the Johns Hopkins University School of Medicine.

Welcome to both Orlando J. Rohas and Sriram Subramaniam!

Stronger than steel and spider silk: artificial, biodegradable, cellulose nanofibres

This is an artificial and biodegradable are two adjectives you don’t usually see united by the conjunction, and. However, it is worth noting that the artificial material is initially derived from a natural material, cellulose. Here’s more from a May 16, 2018 news item on ScienceDaily,

At DESY’s [Deutsches Elektronen-Synchrotron] X-ray light source PETRA III, a team led by Swedish researchers has produced the strongest bio-material that has ever been made. The artifical, but bio-degradable cellulose fibres are stronger than steel and even than dragline spider silk, which is usually considered the strongest bio-based material. The team headed by Daniel Söderberg from the KTH Royal Institute of Technology in Stockholm reports the work in the journal ACS Nano of the American Chemical Society.

A May 16, 2018 DESY press release (also on EurekAlert), which originated the news item, provides more detail,

The ultrastrong material is made of cellulose nanofibres (CNF), the essential building blocks of wood and other plant life. Using a novel production method, the researchers have successfully transferred the unique mechanical properties of these nanofibres to a macroscopic, lightweight material that could be used as an eco-friendly alternative for plastic in airplanes, cars, furniture and other products. “Our new material even has potential for biomedicine since cellulose is not rejected by your body”, explains Söderberg.

The scientists started with commercially available cellulose nanofibres that are just 2 to 5 nanometres in diameter and up to 700 nanometres long. A nanometre (nm) is a millionth of a millimetre. The nanofibres were suspended in water and fed into a small channel, just one millimetre wide and milled in steel. Through two pairs of perpendicular inflows additional deionized water and water with a low pH-value entered the channel from the sides, squeezing the stream of nanofibres together and accelerating it.

This process, called hydrodynamic focussing, helped to align the nanofibres in the right direction as well as their self-organisation into a well-packed macroscopic thread. No glue or any other component is needed, the nanofibres assemble into a tight thread held together by supramolecular forces between the nanofibres, for example electrostatic and Van der Waals forces.

With the bright X-rays from PETRA III the scientists could follow and optimise the process. “The X-rays allow us to analyse the detailed structure of the thread as it forms as well as the material structure and hierarchical order in the super strong fibres,” explains co-author Stephan Roth from DESY, head of the Micro- and Nanofocus X-ray Scattering Beamline P03 where the threads were spun. “We made threads up to 15 micrometres thick and several metres in length.”

Measurements showed a tensile stiffness of 86 gigapascals (GPa) for the material and a tensile strength of 1.57 GPa. “The bio-based nanocellulose fibres fabricated here are 8 times stiffer and have strengths higher than natural dragline spider silk fibres,” says Söderberg. “If you are looking for a bio-based material, there is nothing quite like it. And it is also stronger than steel and any other metal or alloy as well as glass fibres and most other synthetic materials.” The artificial cellulose fibres can be woven into a fabric to create materials for various applications. The researchers estimate that the production costs of the new material can compete with those of strong synthetic fabrics. “The new material can in principle be used to create bio-degradable components,” adds Roth.

The study describes a new method that mimics nature’s ability to accumulate cellulose nanofibres into almost perfect macroscale arrangements, like in wood. It opens the way for developing nanofibre material that can be used for larger structures while retaining the nanofibres’ tensile strength and ability to withstand mechanical load. “We can now transform the super performance from the nanoscale to the macroscale,” Söderberg underlines. “This discovery is made possible by understanding and controlling the key fundamental parameters essential for perfect nanostructuring, such as particle size, interactions, alignment, diffusion, network formation and assembly.” The process can also be used to control nanoscale assembly of carbon tubes and other nano-sized fibres.

(There are some terminology and spelling issues, which are described at the end of this post.)

Let’s get back to a material that rivals spider silk and steel for strength (for some reason that reminded me of an old carnival game where you’d test your strength by swinging a mallet down on a ‘teeter-totter-like’ board and sending a metal piece up a post to make a bell ring). From a May 16, 2018 DESY press release (also on EurekAlert), which originated the news item,

The ultrastrong material is made of cellulose nanofibres (CNF), the essential building blocks of wood and other plant life. Using a novel production method, the researchers have successfully transferred the unique mechanical properties of these nanofibres to a macroscopic, lightweight material that could be used as an eco-friendly alternative for plastic in airplanes, cars, furniture and other products. “Our new material even has potential for biomedicine since cellulose is not rejected by your body”, explains Söderberg.

The scientists started with commercially available cellulose nanofibres that are just 2 to 5 nanometres in diameter and up to 700 nanometres long. A nanometre (nm) is a millionth of a millimetre. The nanofibres were suspended in water and fed into a small channel, just one millimetre wide and milled in steel. Through two pairs of perpendicular inflows additional deionized water and water with a low pH-value entered the channel from the sides, squeezing the stream of nanofibres together and accelerating it.

This process, called hydrodynamic focussing, helped to align the nanofibres in the right direction as well as their self-organisation into a well-packed macroscopic thread. No glue or any other component is needed, the nanofibres assemble into a tight thread held together by supramolecular forces between the nanofibres, for example electrostatic and Van der Waals forces.

With the bright X-rays from PETRA III the scientists could follow and optimise the process. “The X-rays allow us to analyse the detailed structure of the thread as it forms as well as the material structure and hierarchical order in the super strong fibres,” explains co-author Stephan Roth from DESY, head of the Micro- and Nanofocus X-ray Scattering Beamline P03 where the threads were spun. “We made threads up to 15 micrometres thick and several metres in length.”

Measurements showed a tensile stiffness of 86 gigapascals (GPa) for the material and a tensile strength of 1.57 GPa. “The bio-based nanocellulose fibres fabricated here are 8 times stiffer and have strengths higher than natural dragline spider silk fibres,” says Söderberg. “If you are looking for a bio-based material, there is nothing quite like it. And it is also stronger than steel and any other metal or alloy as well as glass fibres and most other synthetic materials.” The artificial cellulose fibres can be woven into a fabric to create materials for various applications. The researchers estimate that the production costs of the new material can compete with those of strong synthetic fabrics. “The new material can in principle be used to create bio-degradable components,” adds Roth.

The study describes a new method that mimics nature’s ability to accumulate cellulose nanofibres into almost perfect macroscale arrangements, like in wood. It opens the way for developing nanofibre material that can be used for larger structures while retaining the nanofibres’ tensile strength and ability to withstand mechanical load. “We can now transform the super performance from the nanoscale to the macroscale,” Söderberg underlines. “This discovery is made possible by understanding and controlling the key fundamental parameters essential for perfect nanostructuring, such as particle size, interactions, alignment, diffusion, network formation and assembly.” The process can also be used to control nanoscale assembly of carbon tubes and other nano-sized fibres.

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

Multiscale Control of Nanocellulose Assembly: Transferring Remarkable Nanoscale Fibril Mechanics to Macroscale Fibers by Nitesh Mittal, Farhan Ansari, Krishne Gowda V, Christophe Brouzet, Pan Chen, Per Tomas Larsson, Stephan V. Roth, Fredrik Lundell, Lars Wågberg, Nicholas A. Kotov, and L. Daniel Söderberg. ACS Nano, Article ASAP DOI: 10.1021/acsnano.8b01084 Publication Date (Web): May 9, 2018

Copyright © 2018 American Chemical Society

This paper is open access and accompanied by this image illustrating the work,

Courtesy: American Chemical Society and the researchers [Note: The bottom two images of cellulose nanofibres, which are constittuents of an artificial cellulose fibre, appear to be from a scanning tunneling microsscope. Credit: Nitesh Mittal, KTH Stockholm

This news has excited interest at General Electric (GE) (its Wikipedia entry), which has highlighted the work in a May 25, 2018 posting (The 5 Coolest Things On Earth This Week) by Tomas Kellner on the GE Reports blog.

Terminology and spelling

I’ll start with spelling since that’s the easier of the two. In some parts of the world it’s spelled ‘fibres’ and in other parts of the world it’s spelled ‘fibers’. When I write the text in my post, it tends to reflect the spelling used in the news/press releases. In other words, I swing in whichever direction the wind is blowing.

For diehards only

As i understand the terminology situation, nanocellulose and cellulose nanomaterials are interchangeable generic terms. Further, cellulose nanofibres (CNF) seems to be another generic term and it encompasses both cellulose nanocrystals (CNC) and cellulose nanofibrils (CNF). Yes, there appear to be two CNFs. Making matters more interesting is the fact that cellulose nanocrystals were originally christened nanocrystalline cellulose (NCC). For anyone who follows the science and technology scene, it becomes obvious that competing terminologies are the order of the day. Eventually the dust settles and naming conventions are resolved. More or less.

Ordinarily I would reference the Nanocellulose Wikipedia entry in my attempts to clarify the issues but it seems that the writers for the entry have not caught up to the current naming convention for cellulose nanocrystals, still referring to the material as nanocrystalline cellulose. This means, I can’t trust the rest of the entry, which has only one CNF (cellulose nanofibres).

I have paid more attention to the NCC/CNC situation and am not as familiar with the CNF situation. Using, NCC/CNC as an example of a terminology issue, I believe it was first developed in Canada and it was Canadian researchers who were pushing their NCC terminology while the international community pushed back with CNC.

In the end, NCC became a brand name, which was trademarked by CelluForce, a Canadian company in the CNC market. From the CelluForce Products page on Cellulose Nanocrystals,

CNC are not all made equal. The CNC produced by CelluForce is called CelluForce NCCTM and has specific properties and are especially easy to disperse. CelluForce NCCTM is the base material that CelluForce uses in all its products. This base material can be modified and tailored to suit the specific needs in various applications.

These, days CNC is almost universally used but NCC (not as a trademark) is a term still employed on occasion (and, oddly, the researchers are not necessarily Canadian).

Should anyone have better information about terminology issues, please feel free to comment.

Cellulose aerogels for new wood-based composites

‘Frozen smoke’ or ‘solid smoke’ as it’s sometimes described, aerogel fascinates scientists.The latest on cellulose aerogels derived from wood is the focus for a February 14, 2018 Nanowerk Sportlight article by Michael Berger (Note: Links have been removed),

Aerogels, sometimes called frozen smoke, are nanoscale foams: solid materials whose sponge-like structure is riddled by pores as small as nanometers across. They can be made from different materials, for instance silicon.

Aerogels are among the lightest solid substances in the world yet flexible, extremely strong and water repellent, which makes them very interesting materials for engineers.

Cellulose aerogels, made from nanofibrils found in plants, have several unique features, one of which is super high oil absorption capacity that is several times higher than commercial sorbents available in the market.

“Encouraged from our previous work on transparent wood (“Transparent wood for functional and structural applications”; “Optically Transparent Wood from a Nanoporous Cellulosic Template: Combining Functional and Structural Performance”; “Nanostructured Wood Hybrids for Fire-Retardancy Prepared by Clay Impregnation into the Cell Wall”), we started to develop porous wood/epoxy biocomposite materials, which preserves the original hierarchical and porous structure of wood,” Qi Zhou, an associate professor in the Department of Chemistry at KTH Royal Institute of Technology, tells Nanowerk.

“Our strategy is different from traditional wood modification methods,” explains Zhou. “It involves two steps, a simple chemical treatment to remove the lignin (delignification) at first, then back infiltration of the wood cell wall with epoxy, leaving the lumen (a void space) open. In traditional wood polymer composites, both the cell wall and cell lumen are filled with polymer.”

The scientists don’t seem to have any particular applications in mind but they are hopeful that new materials will inspire new uses. Here’s a link to and a citation for Zhou’s latest paper,

Wood Nanotechnology for Strong, Mesoporous, and Hydrophobic Biocomposites for Selective Separation of Oil/Water Mixtures by Qiliang Fu, Farhan Ansari, Qi Zhou, and Lars A. Berglund. ACS Nano, Article ASAP DOI: 10.1021/acsnano.8b00005 Publication Date (Web): February 7, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Wood’s natural nanotechnology

“Wood’s natural nanotechnology: is an unusual term and it comes at the end of this February 7, 2018 University of Maryland (US) news release about a technique which will make wood stronger than titanium alloy,

Engineers at the University of Maryland in College Park have found a way to make wood more than ten times times stronger and tougher than before, creating a natural substance that is stronger than titanium alloy.

“This new way to treat wood makes it twelve times stronger than natural wood and ten times tougher,” said Liangbing Hu, the leader of the team that did the research, to be published on Thursday [February 7, 2018] in the journal Nature. “This could be a competitor to steel or even titanium alloys, it is so strong and durable. It’s also comparable to carbon fiber, but much less expensive.” Hu is an associate professor of materials science and engineering and a member of the Maryland Energy Innovation Institute.

“It is both strong and tough, which is a combination not usually found in nature,” said Teng Li, the co-leader of the team and the Samuel P. Langley associate professor of mechanical engineering at the University of Maryland. His team measured the dense wood’s mechanical properties.  “It is as strong as steel, but six times lighter. It takes 10 times more energy to fracture than natural wood. It can even be bent and molded at the beginning of the process.”

The team’s process begins by removing the wood’s lignin, the part of the wood that makes it both rigid and brown in color. Then it is compressed under mild heat, at about 150 F. This causes the cellulose fibers to become very tightly packed. Any defects like holes or knots are crushed together.  The treatment process was extended a little further with a coat of paint.

The scientists found that the wood’s fibers are pressed together so tightly that they can form strong hydrogen bonds, like a crowd of people who can’t budge – who are also holding hands. The compression makes the wood five times thinner than its original size.

The team also tested the material by shooting a bullet-like projectile at it. Unlike natural wood, which was blown straight through, the fully treated wood actually stopped the projectile partway through.

“Soft woods like pine or balsa, which grow fast and are more environmentally friendly, could replace slower-growing but denser woods like teak, in furniture or buildings,” Hu said.

“The paper provides a highly promising route to the design of light weight high performance structural materials, with tremendous potential for a broad range of applications where high strength, large toughness and superior ballistic resistance are desired, “ said Dr. Huajian Gao, a professor at Brown University, who was not involved in the study. “It is particularly exciting to note that the method is versatile for various species of wood and fairly easy to implement.”

“This kind of wood could be used in cars, airplanes, buildings – any application where steel is used,” Hu said.

“The two-step process reported in this paper achieves exceptionally high strength, much beyond what [is] reported in the literature,” said Dr. Zhigang Suo, a professor of mechanics and materials at Harvard University, also not involved with the study. “Given the abundance of wood, as well as other cellulose-rich plants, this paper inspires imagination.”

“The most outstanding observation, in my view, is the existence of a limiting concentration of lignin, the glue between wood cells, to maximize the mechanical performance of the densified wood. Too little or too much removal lower the strength compared to a maximum value achieved at intermediate or partial lignin removal. This reveals the subtle balance between hydrogen bonding and the adhesion imparted by such polyphenolic compound. Moreover, of outstanding interest, is the fact that that wood densification leads to both, increased strength and toughness, two properties that usually offset each other,” said Orlando J. Rojas, a professor at Aalto University in Finland.

Hu’s research has explored the capacities of wood’s natural nanotechnology [emphasis mine]. They previously made a range of emerging technologies out of nanocellulose related materials: (1) super clear paper for replacing plastic; (2) photonic paper for improving solar cell efficiency by 30%; (3) a battery and a supercapacitor out of wood; (4) a battery from a leaf; (5) transparent wood for energy efficient buildings; (6) solar water desalination for drinking and specifically filtering out toxic dyes. These wood-based emerging technologies are being commercialized through a UMD spinoff company, Inventwood LLC.

At a guess, “wood’s natural nanotechnology” refers to the properties of wood and other forms of cellulose at the nanoscale.

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

Processing bulk natural wood into a high-performance structural material by Jianwei Song, Chaoji Chen, Shuze Zhu, Mingwei Zhu, Jiaqi Dai, Upamanyu Ray, Yiju Li, Yudi Kuang, Yongfeng Li, Nelson Quispe, Yonggang Yao, Amy Gong, Ulrich H. Leiste, Hugh A. Bruck, J. Y. Zhu, Azhar Vellore, Heng Li, Marilyn L. Minus, Zheng Jia, Ashlie Martini, Teng Li, & Liangbing Hu. Nature volume 554, pages 224–228 (08 February 2018) doi:10.1038/nature25476 Published online: 07 February 2018

This paper is behind a paywall.

h/t Feb. 7, 2018 news item on Nanowerk and, finally, you can find out more about the wood-based emerging technologies being commcercialized by the University of Maryland here on the Inventwood website.

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.

Cellulosic nanomaterials in automobile parts and a CelluForce update

The race to find applications for cellulosic nanomaterials continues apace. The latest entrant is from Clemson University in South Carolina (US). From a July 27, 2016 news item on Nanowerk,

Trees that are removed during forest restoration projects could find their way into car bumpers and fenders as part of a study led by Srikanth Pilla of Clemson University.

Pilla is collaborating on the study with researchers from the USDA Forest Service’s Forest Products Laboratory in Madison, Wisconsin.

The Madison researchers are converting some of those trees into liquid suspensions of tiny rod-like structures with diameters 20,000 times smaller than the width of a human hair. Pilla is using these tiny structures, known as cellulosic nanomaterials, to develop new composite materials that could be shaped into automotive parts with improved strength.

The auto parts would also be biorenewable, which means they could go to a composting facility instead of a landfill when their time on the road is done. The research could help automakers meet automotive recycling regulations that have been adopted in Europe and could be on the way to the United States.

Pilla, an assistant professor in the Department of Automotive Engineering at Clemson University, wants to use the composite materials he is creating to make bumpers and fenders that will be less likely to distort or break on impact.

“They will absorb the energy and just stay intact,” he said. “You won’t have to replace them because there will be no damage at all. Parts made with current materials might resist one impact. These will resist three or four impacts.”

A July 27, 2016 Clemson University media release, which originated the news item, describes the project and the reason for the support provides an interesting view of the politics behind the science (Note: A link has been removed),

The U.S. Department of the Agriculture’s National Institute of Food and Agriculture is funding the $481,000 research project for five years. Pilla’s research will be based out of the Clemson University International Center for Automotive Research in Greenville, South Carolina.

Craig Clemons, a materials research engineer at the Forest Products Laboratory and co-principal investigator on the project, said that the Forest Service wants to find large-volume uses for cellulosic nanomaterials.

“We find appropriate outlets for all kinds of forest-derived materials,” he said. “In this case, it’s cellulosic nanomaterials. We’re trying to move up the value chain with the cellulosic nanomaterials, creating high-value products out of what could otherwise be low-value wood. We’ll be producing the cellulosic nanomaterials, which are the most fundamental structural elements that you can get out of wood and pulp fibers. We’ll also be lending our more than 25 years of experience in creating composites from plastics and wood-derived materials to the project.”

The research is environmentally friendly from start to finish.

The cellulosic nanomaterials could come from trees that are removed during forest restoration projects. Removing this material from the forests helps prevent large, catastrophic wildfires. Researchers will have no need to cut down healthy trees that could be used for other purposes, Pilla said.

Ted Wegner, assistant director at the Forest Products Laboratory, said, “The use of cellulosic nanomaterials will help meet the needs of people for sustainable, renewable and lightweight products while helping to improve the health and condition of America’s forests. The United States possesses abundant forest resources and the infrastructure to support a large cellulosic nanomaterials industry. Commercialization of cellulosic nanomaterials has the potential to create jobs, especially in rural America.”

One of the technical challenges Pilla and Clemons face in their work is combining the water-friendly cellulosic nanomaterials with the water-unfriendly polymers. They will need to show that the material can be mass produced because automakers need to make thousands of parts.

“We will use supercritical fluid as a plasticizer, allowing the nanoreinforcements to disperse through the polymer,” Pilla said. “We can help develop a conventional technique that will be scalable in the automotive sector.”

Robert Jones, executive vice president for academic affairs and provost at Clemson, congratulated Pilla on the research, which touches on Jones’ area of expertise.

Jones has a bachelor’s in forest management, a master’s in forestry from Clemson and a doctorate in forest ecology from the State University of New York College of Environmental Science and Forestry, Syracuse University.

“The research that Srikanth Pilla is doing with the USDA Forest Service is a creative way of using what might otherwise be a low-value wood product to strengthen automobile parts,” Jones said. “It’s even better that these parts are biorenewable. The research is good for the Earth in more ways than one.”

This research could grow in importance if the United States were to follow the European Union’s lead in setting requirements on how much of a vehicle must be recovered and recycled after it has seen its last mile on the road.

“In the U.S., such legislation is not yet here,” Pilla said. “But it could make its way here, too.”

Pilla is quickly establishing himself as a leading expert in making next-generation automotive parts. He won the 2016 Robert J. Hocken Outstanding Young Manufacturing Engineer Award from the nonprofit student and professional organization SME.

Pilla is nearing the end of the first year of a separate $5.81-million, five-year grant from the Department of Energy. As part of that research, Pilla and his team are developing ultra-lightweight doors expected to help automakers in their race to meet federal fuel economy standards.

Zoran Filipi, chair of Clemson’s automotive engineering, said that Pilla is playing a key role in making Clemson the premiere place for automotive research.

“Dr. Pilla is doing research that helps Clemson and the auto industry stay a step ahead,” Filipi said. “He is anticipating needs automakers will face in the future and seeking solutions that could be put into place very quickly. His research with the USDA Forest Service is another example of that.”

Congratulations also came from Anand Gramopadhye, dean of Clemson’s College of Engineering, Computing and Applied Sciences.

“Dr. Pilla’s work continues to have an impact on automotive engineering, especially in the area of manufacturing,” Gramopadhye said. “His innovations are positioning Clemson, the state, and the nation for strength into the future.”

This search for applications is a worldwide competition. Cellulose is one of the most abundant materials on earth and can be derived from carrots, bananas, pineapples, and more. It just so happens that much of the research in the northern hemisphere focuses on cellulose derived from trees in an attempt to prop up or reinvigorate the failing forest products industry.

In Canada we have three production facilities for cellulosic nanomaterials. There’s a plant in Alberta (I’ve never seen a name for it), CelluForce in Windsor, Québec, and Blue Goose Biorefineries in Saskatchewan. I believe Blue Goose derives their cellulosic from trees and other plant materials while the Alberta and CelluForce plants use trees only.

CelluForce Update

CelluForce represents a big investment by the Canadian federal government. The other companies and production facilities have received federal funds but my understanding is that CelluForce has enjoyed significantly more. As well, the company has had a stockpile of cellulose nanocrystals (CNC) that I first mentioned here in an Oct. 3, 2013 post (scroll down about 75% of the way). A June 8, 2016 CelluForce news release provides more information about CelluForce activities and its stockpile,

  •  In the first half of 2016, Cellulose nanocrystals (CNC) shipments to industrial partners have reached their highest level since company inception.
  • Recent application developments in the oil & gas, the electronics and plastics sectors are expected to lead to commercial sales towards year end.
  • New website to enhance understanding of CelluForce NCCTM core properties and scope of performance in industrial applications is launched.

Montreal, Québec – June 8th 2016 – CelluForce, a clean technology company, is seeing growing interest in its innovative green chemistry product called cellulose nanocrystals (CNC) and has recorded, over the first half of 2016, the largest CNC shipment volumes since the company’s inception.

“Over the past year, we have been actively developing several industry-specific applications featuring CelluForce NCCTM, a form of cellulose nanocrystals which is produced in our Windsor plant.   Three of these applications have now reached a high level of technical and commercial maturity and have been proven to provide cost benefits and sustained performance in the oil & gas, electronics and plastics segments,” said Sebastien Corbeil [emphasis mine], President and CEO of CelluForce. “Our product development teams are extremely pleased to see CelluForce NCCTM [nanocrystalline cellulose; this is a trade name for CNC] now being used in full scale trials for final customer acceptance tests”.

With the current shipment volumes forecast, the company expects to deplete its CelluForce NCCTM inventory by mid-2017 [emphasis mine]. The inventory depletion will pave the way for the company to start commercial production of CNC at its Windsor plant next year.

CelluForce has built a strong network of researchers with academic and industrial partners and continues to invest time and resources to develop, refine and expand applications for CNC in key priority industrial markets. Beyond oil & gas, electronics and plastics, some of these markets are adhesives, cement, paints and coatings, as well as personal and healthcare.

Furthermore, as it progressively prepares for commercial production, CelluForce has revamped its digital platform and presence, with the underlying objective of developing a better understanding of its product, applications and its innovative green technology capabilities.  Its new brand image is meant to convey the innovative, versatile and sustainable properties of CNC.

Nice to see that there is sufficient demand that the stockpile can be eliminated soon. In my last piece about CelluForce (a March 30, 2015 post), I noted an interim president, René Goguen. An April 27, 2015 CelluForce news release announced Sebastien Corbeil’s then new appointment as company president.

One final note, nanocrystalline cellulose (NCC) was the generic name coined by Canadian scientists for a specific cellulose nanomaterial. Over time, cellulose nanocrystals (CNC) became the preferred term for the generic material and CelluForce decided to trademark NCC (nanocrystalline cellulose) as their commercial brand name for cellulose nanocrystals.

University of Maryland looks into transparent wood

Is transparent wood becoming the material du jour? Following on the heels of my April 1, 2016 post about transparent wood and the KTH Royal Institute of Technology (Sweden), there’s a May 6, 2016 news item on ScienceDaily about the material and a team at the University of Maryland,

Researchers at the University of Maryland have made a block of linden wood transparent, which they say will be useful in fancy building materials and in light-based electronics systems.

Materials scientist Liangbing Hu and his team at the University of Maryland, College Park, have removed the molecule in wood, lignin, that makes it rigid and dark in color. They left behind the colorless cellulose cell structures, filled them with epoxy, and came up with a version of the wood that is mostly see-thru.

I wonder if this is the type of material that might be used in structures like the proposed Center of Nanoscience and Nanotechnology at Tel Aviv University building (my May 9, 2016 posting about a building design that features no doors or windows)?

Regardless, there’s more about this latest transparent wood in a May 5, 2016 Tufts University news release, which originated the news item,

Remember “xylem” and “phloem” from grade-school science class? These structures pass water and nutrients up and down the tree. Hu and his colleagues see these as vertically aligned channels in the wood, a naturally-grown structure that can be used to pass light along, after the wood has been treated.

The resulting three-inch block of wood had both high transparency—the quality of being see-thru—and high haze—the quality of scattering light. This would be useful, said Hu, in making devices comfortable to look at. It would also help solar cells trap light; light could easily enter through the transparent function, but the high haze would keep the light bouncing around near where it would be absorbed by the solar panel.

They compared how the materials performed and how light worked its way through the wood when they sliced it two ways: one with the grain of the wood, so that the channels passed through the longest dimension of the block. And they also tried slicing it against the grain, so that the channels passed through the shortest dimension of the block.

The short channel wood proved slightly stronger and a little less brittle. But though the natural component making the wood strong had been removed, the addition of the epoxy made the wood four to six times tougher than the untreated version.

Then they investigated how the different directions of the wood affected the way the light passed through it. When laid down on top of a grid, both kinds of wood showed the lines clearly. When lifted just a touch above the grid, the long-channel wood still showed the grid, just a little bit more blurry. But the short channel wood, when lifted those same few millimeters, made the grid completely invisible.

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

Highly Anisotropic, Highly Transparent Wood Composites by Mingwei Zhu, Jianwei Song, Tian Li, Amy Gong, Yanbin Wang, Jiaqi Dai, Yonggang Yao, Wei Luo, Doug Henderson, and Liangbing Hu. Advanced Materials DOI: 10.1002/adma.201600427 Article first published online: 4 MAY 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.