Tag Archives: Sweden

Spinning gold out of nanocellulose

If you’re hoping for a Rumpelstiltskin reference (there is more about the fairy tale at the end of this posting) and despite the press release’s headline, you won’t find it in this August 10, 2020 news item on Nanowerk,

When nanocellulose is combined with various types of metal nanoparticles, materials are formed with many new and exciting properties. They may be antibacterial, change colour under pressure, or convert light to heat.

“To put it simply, we make gold from nanocellulose”, says Daniel Aili, associate professor in the Division of Biophysics and Bioengineering at the Department of Physics, Chemistry and Biology at Linköping University.

The research group, led by Daniel Aili, has used a biosynthetic nanocellulose produced by bacteria and originally developed for wound care. The scientists have subsequently decorated the cellulose with metal nanoparticles, principally silver and gold. The particles, no larger than a few billionths of a metre, are first tailored to give them the properties desired, and then combined with the nanocellulose.

An August 10, 2020 Linköping University press release (also on EurekAlert), which originated the news item,expands on a few details about the work (sob … without mentioning Rumpelstiltskin),

“Nanocellulose consists of thin threads of cellulose, with a diameter approximately one thousandth of the diameter of a human hair. The threads act as a three-dimensional scaffold for the metal particles. When the particles attach themselves to the cellulose, a material that consists of a network of particles and cellulose forms”, Daniel Aili explains.

The researchers can determine with high precision how many particles will attach, and their identities. They can also mix particles of different metals and with different shapes – spherical, elliptical and triangular.

In the first part of a scientific article published in Advanced Functional Materials, the group describes the process and explains why it works as it does. The second part focusses on several areas of application.

One exciting phenomenon is the way in which the properties of the material change when pressure is applied. Optical phenomena arise when the particles approach each other and interact, and the material changes colour. As the pressure increases, the material eventually appears to be gold.

“We saw that the material changed colour when we picked it up in tweezers, and at first we couldn’t understand why”, says Daniel Aili.

The scientists have named the phenomenon “the mechanoplasmonic effect”, and it has turned out to be very useful. A closely related application is in sensors, since it is possible to read the sensor with the naked eye. An example: If a protein sticks to the material, it no longer changes colour when placed under pressure. If the protein is a marker for a particular disease, the failure to change colour can be used in diagnosis. If the material changes colour, the marker protein is not present.

Another interesting phenomenon is displayed by a variant of the material that absorbs light from a much broader spectrum visible light and generates heat. This property can be used for both energy-based applications and in medicine.

“Our method makes it possible to manufacture composites of nanocellulose and metal nanoparticles that are soft and biocompatible materials for optical, catalytic, electrical and biomedical applications. Since the material is self-assembling, we can produce complex materials with completely new well-defined properties,” Daniel Aili concludes.

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

Self‐Assembly of Mechanoplasmonic Bacterial Cellulose–Metal Nanoparticle Composites by Olof Eskilson, Stefan B. Lindström, Borja Sepulveda, Mohammad M. Shahjamali, Pau Güell‐Grau, Petter Sivlér, Mårten Skog, Christopher Aronsson, Emma M. Björk, Niklas Nyberg, Hazem Khalaf, Torbjörn Bengtsson, Jeemol James, Marica B. Ericson, Erik Martinsson, Robert Selegård, Daniel Aili. Advanced Functional Materials DOI: https://doi.org/10.1002/adfm.202004766 First published: 09 August 2020

This paper is open access.

As for Rumpelstiltskin, there’s this abut the story’s origins and its cross-cultural occurrence, from its Wikipedia entry,

“Rumpelstiltskin” (/ˌrʌmpəlˈstɪltskɪn/ RUMP-əl-STILT-skin[1]) is a fairy tale popularly associated with Germany (where it is known as Rumpelstilzchen). The tale was one collected by the Brothers Grimm in the 1812 edition of Children’s and Household Tales. According to researchers at Durham University and the NOVA University Lisbon, the story originated around 4,000 years ago.[2][3] However, many biases led some to take the results of this study with caution.[4]

The same story pattern appears in numerous other cultures: Tom Tit Tot in England (from English Fairy Tales, 1890, by Joseph Jacobs); The Lazy Beauty and her Aunts in Ireland (from The Fireside Stories of Ireland, 1870 by Patrick Kennedy); Whuppity Stoorie in Scotland (from Robert Chambers’s Popular Rhymes of Scotland, 1826); Gilitrutt in Iceland; جعيدان (Joaidane “He who talks too much”) in Arabic; Хламушка (Khlamushka “Junker”) in Russia; Rumplcimprcampr, Rampelník or Martin Zvonek in the Czech Republic; Martinko Klingáč in Slovakia; “Cvilidreta” in Croatia; Ruidoquedito (“Little noise”) in South America; Pancimanci in Hungary (from A Csodafurulya, 1955, by Emil Kolozsvári Grandpierre, based on the 19th century folktale collection by László Arany); Daiku to Oniroku (大工と鬼六 “A carpenter and the ogre”) in Japan and Myrmidon in France.

An earlier literary variant in French was penned by Mme. L’Héritier, titled Ricdin-Ricdon.[5] A version of it exists in the compilation Le Cabinet des Fées, Vol. XII. pp. 125-131.

The Cornish tale of Duffy and the Devil plays out an essentially similar plot featuring a “devil” named Terry-top.

All these tales are Aarne–Thompson type 500, “The Name of the Helper”.[6]

Should you be curious about the story as told by the Brothers Grimm, here’s the beginning to get you started (from the grimmstories.com Rumpelstiltskin webpage),

There was once a miller who was poor, but he had one beautiful daughter. It happened one day that he came to speak with the king, and, to give himself consequence, he told him that he had a daughter who could spin gold out of straw. The king said to the miller: “That is an art that pleases me well; if thy daughter is as clever as you say, bring her to my castle to-morrow, that I may put her to the proof.”

When the girl was brought to him, he led her into a room that was quite full of straw, and gave her a wheel and spindle, and said: “Now set to work, and if by the early morning thou hast not spun this straw to gold thou shalt die.” And he shut the door himself, and left her there alone. And so the poor miller’s daughter was left there sitting, and could not think what to do for her life: she had no notion how to set to work to spin gold from straw, and her distress grew so great that she began to weep. Then all at once the door opened, and in came a little man, who said: “Good evening, miller’s daughter; why are you crying?”

Enjoy! BTW, should you care to, you can find three other postings here tagged with ‘Rumpelstiltskin’. I think turning dross into gold is a popular theme in applied science.

Living with a mind-controlled prosthetic

This could be described as the second half of an October 10, 2014 post (Mind-controlled prostheses ready for real world activities). Five and a half years later, Sweden’s Chalmers University of Technology has announced mind-controlled prosthetics in daily use that feature the sense of touch. From an April 30, 2020 Chalmers University of Technology press release (also on EurekAlert but published April 29, 2020) by Johanna Wilde,

For the first time, people with arm amputations can experience sensations of touch in a mind-controlled arm prosthesis that they use in everyday life. A study in the New England Journal of Medicine reports on three Swedish patients who have lived, for several years, with this new technology – one of the world’s most integrated interfaces between human and machine.

See the film: “The most natural robotic prosthesis in the world” [Should you not have Swedish language skills, you can click on the subtitle option in the video’s settings field]

The advance is unique: the patients have used a mind-controlled prosthesis in their everyday life for up to seven years. For the last few years, they have also lived with a new function – sensations of touch in the prosthetic hand. This is a new concept for artificial limbs, which are called neuromusculoskeletal prostheses – as they are connected to the user’s nerves, muscles, and skeleton.

The research was led by Max Ortiz Catalan, Associate Professor at Chalmers University of Technology, in collaboration with Sahlgrenska University Hospital, University of Gothenburg, and Integrum AB, all in Gothenburg, Sweden. Researchers at Medical University of Vienna in Austria and the Massachusetts Institute of Technology in the USA were also involved.

“Our study shows that a prosthetic hand, attached to the bone and controlled by electrodes implanted in nerves and muscles, can operate much more precisely than conventional prosthetic hands. We further improved the use of the prosthesis by integrating tactile sensory feedback that the patients use to mediate how hard to grab or squeeze an object. Over time, the ability of the patients to discern smaller changes in the intensity of sensations has improved,” says Max Ortiz Catalan.

“The most important contribution of this study was to demonstrate that this new type of prosthesis is a clinically viable replacement for a lost arm. No matter how sophisticated a neural interface becomes, it can only deliver real benefit to patients if the connection between the patient and the prosthesis is safe and reliable in the long term. Our results are the product of many years of work, and now we can finally present the first bionic arm prosthesis that can be reliably controlled using implanted electrodes, while also conveying sensations to the user in everyday life”, continues Max Ortiz Catalan.

Since receiving their prostheses, the patients have used them daily in all their professional and personal activities.

The new concept of a neuromusculoskeletal prosthesis is unique in that it delivers several different features which have not been presented together in any other prosthetic technology in the world:

[1] It has a direct connection to a person’s nerves, muscles, and skeleton.

[2] It is mind-controlled and delivers sensations that are perceived by the user as arising from the missing hand.

[3] It is self-contained; all electronics needed are contained within the prosthesis, so patients do not need to carry additional equipment or batteries.

[4] It is safe and stable in the long term; the technology has been used without interruption by patients during their everyday activities, without supervision from the researchers, and it is not restricted to confined or controlled environments.

The newest part of the technology, the sensation of touch, is possible through stimulation of the nerves that used to be connected to the biological hand before the amputation. Force sensors located in the thumb of the prosthesis measure contact and pressure applied to an object while grasping. This information is transmitted to the patients’ nerves leading to their brains. Patients can thus feel when they are touching an object, its characteristics, and how hard they are pressing it, which is crucial for imitating a biological hand.

“Currently, the sensors are not the obstacle for restoring sensation,” says Max Ortiz Catalan. “The challenge is creating neural interfaces that can seamlessly transmit large amounts of artificially collected information to the nervous system, in a way that the user can experience sensations naturally and effortlessly.”
The implantation of this new technology took place at Sahlgrenska University Hospital, led by Professor Rickard Brånemark and Doctor Paolo Sassu. Over a million people worldwide suffer from limb loss, and the end goal for the research team, in collaboration with Integrum AB, is to develop a widely available product suitable for as many of these people as possible.

“Right now, patients in Sweden are participating in the clinical validation of this new prosthetic technology for arm amputation,” says Max Ortiz Catalan. “We expect this system to become available outside Sweden within a couple of years, and we are also making considerable progress with a similar technology for leg prostheses, which we plan to implant in a first patient later this year.”

More about: How the technology works:

The implant system for the arm prosthesis is called e-OPRA and is based on the OPRA implant system created by Integrum AB. The implant system anchors the prosthesis to the skeleton in the stump of the amputated limb, through a process called osseointegration (osseo = bone). Electrodes are implanted in muscles and nerves inside the amputation stump, and the e-OPRA system sends signals in both directions between the prosthesis and the brain, just like in a biological arm.

The prosthesis is mind-controlled, via the electrical muscle and nerve signals sent through the arm stump and captured by the electrodes. The signals are passed into the implant, which goes through the skin and connects to the prosthesis. The signals are then interpreted by an embedded control system developed by the researchers. The control system is small enough to fit inside the prosthesis and it processes the signals using sophisticated artificial intelligence algorithms, resulting in control signals for the prosthetic hand’s movements.

The touch sensations arise from force sensors in the prosthetic thumb. The signals from the sensors are converted by the control system in the prosthesis into electrical signals which are sent to stimulate a nerve in the arm stump. The nerve leads to the brain, which then perceives the pressure levels against the hand.

The neuromusculoskeletal implant can connect to any commercially available arm prosthesis, allowing them to operate more effectively.

More about: How the artificial sensation is experienced:

People who lose an arm or leg often experience phantom sensations, as if the missing body part remains although not physically present. When the force sensors in the prosthetic thumb react, the patients in the study feel that the sensation comes from their phantom hand. Precisely where on the phantom hand varies between patients, depending on which nerves in the stump receive the signals. The lowest level of pressure can be compared to touching the skin with the tip of a pencil. As the pressure increases, the feeling becomes stronger and increasingly ‘electric’.

I have read elsewhere that one of the most difficult aspects of dealing with a prosthetic is the loss of touch. This has to be exciting news for a lot of people. Here’s a link to and a citation for the paper,

Self-Contained Neuromusculoskeletal Arm Prostheses by Max Ortiz-Catalan, Enzo Mastinu, Paolo Sassu, Oskar Aszmann, and Rickard Brånemark. N Engl J Med 2020; 382:1732-1738 DOI: 10.1056/NEJMoa1917537 Published: April 30, 2020

This paper is behind a paywall.

Replacing human tissue with nanostructured rubber-like material?

The scientists started out with an idea for creating a bone-like material)and ended up with something completely different. A March 16, 2020 news item on ScienceDaily announces news about a new material that could be used to replace human tissue,

Researchers from Chalmers University of Technology, Sweden, have created a new, rubber-like material with a unique set of properties, which could act as a replacement for human tissue in medical procedures. The material has the potential to make a big difference to many people’s lives. The research was recently published in the highly regarded scientific journal ACS Nano.

In the development of medical technology products, there is a great demand for new naturalistic materials suitable for integration with the body. Introducing materials into the body comes with many risks, such as serious infections, among other things. Many of the substances used today, such as Botox, are very toxic. There is a need for new, more adaptable materials.

In the new study, the Chalmers researchers developed a material consisting solely of components that have already been shown to work well in the body.

A March 17, 2020 Chalmers University of Technology press release (also on EurekAlert but published on March 16, 2020), which originated the news item, describes the scientists’ surprising discovery and how they shifted their focus,

The foundation of the material is the same as plexiglass, a material which is common in medical technology applications. Through redesigning its makeup, and through a process called nanostructuring, they gave the newly patented material a unique combination of properties. The researchers’ initial intention was to produce a hard bone-like material, but they were met with surprising results.

“We were really surprised that the material turned to be very soft, flexible and extremely elastic. It would not work as a bone replacement material, we concluded. But the new and unexpected properties made our discovery just as exciting,” says Anand Kumar Rajasekharan, PhD in Materials Science and one of the researchers behind the study.

The results showed that the new rubber-like material may be appropriate for many applications which require an uncommon combination of properties – high elasticity, easy processability, and suitability for medical uses.

“The first application we are looking at now is urinary catheters. The material can be constructed in such a way that prevents bacteria from growing on the surface, meaning it is very well suited for medical uses,” says Martin Andersson, research leader for the study and Professor of Chemistry at Chalmers.

The structure of the new nano-rubber material allows its surface to be treated so that it becomes antibacterial, in a natural, non-toxic way. This is achieved by sticking antimicrobial peptides – small proteins which are part of our innate immune system – onto its surface. This can help reduce the need for antibiotics, an important contribution to the fight against growing antibiotic resistance.

Because the new material can be injected and inserted via keyhole surgery, it can also help reduce the need for drastic surgery and operations to rebuild parts of the body. The material can be injected via a standard cannula as a viscous fluid, so that it forms its own elastic structures within the body. Or, the material can also be 3D printed into specific structures as required.

“There are many diseases where the cartilage breaks down and friction results between bones, causing great pain for the affected person. This material could potentially act as a replacement in those cases,” Martin Andersson continues.

A further advantage of the material is that it contains three-dimensionally ordered nanopores. This means it can be loaded with medicine, for various therapeutic purposes such as improving healing and reducing inflammation. This allows for localised treatment, avoiding, for example, having to treat the entire body with drugs, something that could help reduce problems associated with side effects. Since it is non-toxic, it also works well as a filler – the researchers see plastic surgery therefore as another very interesting potential area of application for the new material.

“I am now working full time with our newly founded company, Amferia, to get the research out to industry. I have been pleased to see a lot of real interest in our material. It’s promising in terms of achieving our goal, which is to provide real societal benefit,” Anand concludes.

The path of the research to societal benefit and commercialisation, through start-up company Amferia and Chalmers Ventures

In order for the discovery of the new material to be useful and commercialised, the researchers patented their innovation before the study was published. The patent is owned by start-up company Amferia, which was founded by Martin Andersson and Anand Kumar Rajasekharan, two of the researchers behind the study, as well as researcher Saba Atefyekta who recently completed a PhD in Materials Science at Chalmers. Anand is now CEO of Amferia and will drive the application of the new material and development of the company.

Amferia has previously been noted for an antibacterial wound patch developed by the same team. Amferia now has the innovation of both the new nano-rubber and the antibacterial wound patch. The development of the company and the innovations’ path to making profit are now being carried out in collaboration with Chalmers Ventures, a subsidiary of Chalmers University of Technology.

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

Tough Ordered Mesoporous Elastomeric Biomaterials Formed at Ambient Conditions by Anand K. Rajasekharan, Christoffer Gyllensten, Edvin Blomstrand, Marianne Liebi, Martin Andersson. ACS Nano 2020, 14, 1, 241-254 DOI: https://doi.org/10.1021/acsnano.9b01924 Publication Date:December 17, 2019 Copyright © 2019 American Chemical Society

This paper is behind a paywall.

CARESSES your elders (robots for support)

Culturally sensitive robots for elder care! It’s about time. The European Union has funded the Culture Aware Robots and Environmental Sensor Systems for Elderly Support (CARESSES) project being coordinated in Italy. A December 13, 2018 news item on phys.org describes the project,

Researchers have developed revolutionary new robots that adapt to the culture and customs of the elderly people they assist.

Population ageing has implications for many sectors of society, one of which is the increased demand on a country’s health and social care resources. This burden could be greatly eased through advances in artificial intelligence. Robots have the potential to provide valuable assistance to caregivers in hospitals and care homes. They could also improve home care and help the elderly live more independently. But to do this, they will have to be able to respond to older people’s needs in a way that is more likely to be trusted and accepted.
The EU-funded project CARESSES has set out to build the first ever culturally competent robots to care for the elderly. The groundbreaking idea involved designing these robots to adapt their way of acting and speaking to match the culture and habits of the elderly person they’re assisting.

“The idea is that robots should be capable of adapting to human culture in a broad sense, defined by a person’s belonging to a particular ethnic group. At the same time, robots must be able to adapt to an individual’s personal preferences, so in that sense, it doesn’t matter if you’re Italian or Indian,” explained researcher Alessandro Saffiotti of project partner Örebro University, Sweden, …

A December 13, 2018 (?) CORDIS press release, which originated the news item, adds more detail about the robots and their anticipated relationship to their elderly patients,

Through its communication with an elderly person, the robot will fine-tune its knowledge by adapting it to that person’s cultural identity and individual characteristics. Using this knowledge, it will be able to remind the elderly person to take their prescribed medication, encourage them to eat healthily and be active, or help them stay in touch with family and friends. The robot will also be able to make suggestions about the appropriate clothing for specific occasions and remind people of upcoming religious and other celebrations. It doesn’t replace a care home worker. Nevertheless, it will play a vital role in helping to make elderly people’s lives less lonely and reducing the need to have a caregiver nearby at all times.

Scientists are testing the first CARESSES robots in care homes in the United Kingdom and Japan. They’re being used to assist elderly people from different cultural backgrounds. The aim is to see if people feel more comfortable with robots that interact with them in a culturally sensitive manner. They’re also examining whether such robots improve the elderly’s quality of life. “The testing of robots outside of the laboratory environment and in interaction with the elderly will without a doubt be the most interesting part of our project,” added Saffiotti.

The innovative CARESSES (Culture Aware Robots and Environmental Sensor Systems for Elderly Support) robots may pave the way to more culturally sensitive services beyond the sphere of elderly care, too. “It will add value to robots intended to interact with people. Which is not to say that today’s robots are completely culture-neutral. Instead, they unintentionally reflect the culture of the humans who build and program them.”

Having had a mother who recently died in a care facility, I can testify to the importance of cultural and religious sensitivity on the part of caregivers. As for this type of robot not replacing anyone, I take that with a grain of salt. They always say that and I expect it’s true in the initial stages but once the robots are well established and working well? Why not? After all, they’re cheaper in many, many ways and with the coming tsunami of elders in many countries around the world, it seems to me that displacement by robots is an inevitability.

Human lung enzyme can degrade graphene

Caption: A human lung enzyme can biodegrade graphene. Credit: Fotolia Courtesy: Graphene Flagship

The big European Commission research programme, Grahene Flagship, has announced some new work with widespread implications if graphene is to be used in biomedical implants. From a August 23, 2018 news item on ScienceDaily,

Myeloperoxidase — an enzyme naturally found in our lungs — can biodegrade pristine graphene, according to the latest discovery of Graphene Flagship partners in CNRS, University of Strasbourg (France), Karolinska Institute (Sweden) and University of Castilla-La Mancha (Spain). Among other projects, the Graphene Flagship designs based like flexible biomedical electronic devices that will interfaced with the human body. Such applications require graphene to be biodegradable, so our body can be expelled from the body.

An August 23, 2018 Grapehene Flagship press release (mildly edited version on EurekAlert), which originated the news item, provides more detail,

To test how graphene behaves within the body, researchers analysed how it was broken down with the addition of a common human enzyme – myeloperoxidase or MPO. If a foreign body or bacteria is detected, neutrophils surround it and secrete MPO, thereby destroying the threat. Previous work by Graphene Flagship partners found that MPO could successfully biodegrade graphene oxide.

However, the structure of non-functionalized graphene was thought to be more resistant to degradation. To test this, the team looked at the effects of MPO ex vivo on two graphene forms; single- and few-layer.

Alberto Bianco, researcher at Graphene Flagship Partner CNRS, explains: “We used two forms of graphene, single- and few-layer, prepared by two different methods in water. They were then taken and put in contact with myeloperoxidase in the presence of hydrogen peroxide. This peroxidase was able to degrade and oxidise them. This was really unexpected, because we thought that non-functionalized graphene was more resistant than graphene oxide.”

Rajendra Kurapati, first author on the study and researcher at Graphene Flagship Partner CNRS, remarks how “the results emphasize that highly dispersible graphene could be degraded in the body by the action of neutrophils. This would open the new avenue for developing graphene-based materials.”

With successful ex-vivo testing, in-vivo testing is the next stage. Bengt Fadeel, professor at Graphene Flagship Partner Karolinska Institute believes that “understanding whether graphene is biodegradable or not is important for biomedical and other applications of this material. The fact that cells of the immune system are capable of handling graphene is very promising.”

Prof. Maurizio Prato, the Graphene Flagship leader for its Health and Environment Work Package said that “the enzymatic degradation of graphene is a very important topic, because in principle, graphene dispersed in the atmosphere could produce some harm. Instead, if there are microorganisms able to degrade graphene and related materials, the persistence of these materials in our environment will be strongly decreased. These types of studies are needed.” “What is also needed is to investigate the nature of degradation products,” adds Prato. “Once graphene is digested by enzymes, it could produce harmful derivatives. We need to know the structure of these derivatives and study their impact on health and environment,” he concludes.

Prof. Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship, and chair of its management panel added: “The report of a successful avenue for graphene biodegradation is a very important step forward to ensure the safe use of this material in applications. The Graphene Flagship has put the investigation of the health and environment effects of graphene at the centre of its programme since the start. These results strengthen our innovation and technology roadmap.”

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

Degradation of Single‐Layer and Few‐Layer Graphene by Neutrophil Myeloperoxidase by Dr. Rajendra Kurapati, Dr. Sourav P. Mukherjee, Dr. Cristina Martín, Dr. George Bepete, Prof. Ester Vázquez, Dr. Alain Pénicaud, Prof. Dr. Bengt Fadeel, Dr. Alberto Bianco. Angewandte Chemie https://doi.org/10.1002/anie.201806906 First published: 13 July 2018

This paper is behind a paywall.

Preserving art canvases (think Van Gogh, Picasso, Vermeer, and others) with nanomaterials

It has to be disconcerting to realize that your precious paintings are deteriorating day by day.  In a June 22, 2017 posting titled ‘Art masterpieces are turning into soap‘,

This piece of research has made a winding trek through the online science world. First it was featured in an April 20, 2017 American Chemical Society news release on EurekAlert,

A good art dealer can really clean up in today’s market, but not when some weird chemistry wreaks havoc on masterpieces [emphasis mine]. Art conservators started to notice microscopic pockmarks forming on the surfaces of treasured oil paintings that cause the images to look hazy. It turns out the marks are eruptions of paint caused, weirdly, by soap that forms via chemical reactions. Since you have no time to watch paint dry, we explain how paintings from Rembrandts to O’Keefes are threatened by their own compositions — and we don’t mean the imagery.

Here’s the video,


Now, for the latest: canavases are deteriorating too. A May 23, 2018 news item on Nanowerk announces the latest research on the ‘canvas issue’ (Note: A link has been removed),

Paintings by Vincent van Gogh, Pablo Picasso and Johannes Vermeer have been delighting art lovers for years. But it turns out that these works of art might be their own worst enemy — the canvases they were painted on can deteriorate over time.

In an effort to combat this aging process, one group is reporting in ACS Applied Nano Materials (“Combined Nanocellulose/Nanosilica Approach for Multiscale Consolidation of Painting Canvases”) that nanomaterials can provide multiple layers of reinforcement.

A May 23, 2018 American Chemical Society (ACS) news release (also on EurekAlert), which originated the news item,  expands on the theme,

One of the most important parts of a painting is the canvas, which is usually made from cellulose-based fibers. Over time, the canvas ages, resulting in discoloration, wrinkles, tears and moisture retention, all greatly affecting the artwork. To combat aging, painting conservators currently place a layer of adhesive and a lining on the back of a painting, but this treatment is invasive and difficult to reverse. In previous work, Romain Bordes and colleagues from Chalmers University of Technology, Sweden, investigated nanocellulose as a new way to strengthen painting canvases on their surfaces. In addition, together with Krzysztof Kolman, they showed that silica nanoparticles can strengthen individual paper and cotton fibers. So, they next wanted to combine these two methods to see if they could further strengthen aging canvas.

The team combined polyelectrolyte-treated silica nanoparticles (SNP) with cellulose nanofibrils (CNF) for a one-step treatment. The researchers first treated canvases with acid and oxidizing conditions to simulate aging. When they applied the SNP-CNF treatment, the SNP penetrated and strengthened the individual fibers of the canvas, making it stiffer compared to untreated materials. The CNF strengthened the surface of the canvas and increased the canvas’s flexibility. The team notes that this treatment could be a good alternative to conventional methods.

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

Combined Nanocellulose/Nanosilica Approach for Multiscale Consolidation of Painting Canvases by Krzysztof Kolman, Oleksandr Nechyporchuk, Michael Persson, Krister Holmberg, and Romain Bordes. ACS Appl. Nano Mater., Article ASAP DOI: 10.1021/acsanm.8b00262 Publication Date (Web): April 26, 2018

Copyright © 2018 American Chemical Society

This image illustrating the researchers’ solution accompanies the article,

Courtesy: ACS

The European Union’s NanoRestART project was mentioned here before they’d put together this introductory video, which provides a good overview of the research,

For more details about the problems with contemporary and modern art, there’s my April 4, 2016 posting when the NanoRestART project was first mentioned here and there’s my Jan. 10, 2017 posting which details research into 3D-printed art and some of the questions raised by the use of 3D printing and other emerging technologies in the field of contemporary art.

Killer graphene spikes to kill bacteria on medical implants

Implants of all kinds (hip replacements, knee replacements, etc.) seem to be on the rise and along with that an increasing number of infections. A Swedish research team announces a technology that could make implants safer in an April 16, 2018 news item on Nanowerk,

A tiny layer of graphene flakes becomes a deadly weapon and kills bacteria, stopping infections during procedures such as implant surgery. This is the findings of new research from Chalmers University of Technology, Sweden, recently published in the scientific journal Advanced Materials Interfaces (“Vertically Aligned Graphene Coating is Bactericidal and Prevents the Formation of Bacterial Biofilms”).

An April 16, 2018 Chalmers University of Technology press release (also on EurekAlert), which originated the news item, provides more detail about the scope of the problem and the proposed solution (Note: A link has been removed),

Operations for surgical implants, such as hip and knee replacements or dental implants, have increased in recent years. However, in such procedures, there is always a risk of bacterial infection. In the worst case scenario, this can cause the implant to not attach to the skeleton, meaning it must be removed.

Bacteria travel around in fluids, such as blood, looking for a surface to cling on to. Once in place, they start to grow and propagate, forming a protective layer, known as a biofilm.

A research team at Chalmers has now shown that a layer of vertical graphene flakes forms a protective surface that makes it impossible for bacteria to attach. Instead, bacteria are sliced apart by the sharp graphene flakes and killed. Coating implants with a layer of graphene flakes can therefore help protect the patient against infection, eliminate the need for antibiotic treatment, and reduce the risk of implant rejection. The osseointegration – the process by which the bone structure grow to attach the implant – is not disturbed. In fact, the graphene has been shown to benefit the bone cells.

Chalmers University is a leader in the area of graphene research, but the biological applications did not begin to materialise until a few years ago. The researchers saw conflicting results in earlier studies. Some showed that graphene damaged the bacteria, others that they were not affected.

“We discovered that the key parameter is to orient the graphene vertically. If it is horizontal, the bacteria are not harmed” says Ivan Mijakovic, Professor at the Department of Biology and Biological Engineering.

The sharp flakes do not damage human cells. The reason is simple: one bacterium is one micrometer – one thousandth of a millimeter – in diameter, while a human cell is 25 micrometers. So, what constitutes a deadly knife attack for a bacterium, is therefore only a tiny scratch for a human cell.

“Graphene has high potential for health applications. But more research is needed before we can claim it is entirely safe. Among other things, we know that graphene does not degrade easily” says Jie Sun, Associate Professor at the Department of Micro Technology and Nanoscience.

Good bacteria are also killed by the graphene. But that’s not a problem, as the effect is localised and the balance of microflora in the body remains undisturbed.

“We want to prevent bacteria from creating an infection. Otherwise, you may need antibiotics, which could disrupt the balance of normal bacteria and also enhance the risk of antimicrobial resistance by pathogens” says Santosh Pandit, postdoc at Biology and Biological Engineering.

Vertical flakes of graphene are not a new invention, having existed for a few years. But the Chalmers research teams are the first to use the vertical graphene in this way. The next step for the research team will be to test the graphene flakes further, by coating implant surfaces and studying the effect on animal cells.

Chalmers cooperated with Wellspect Healthcare, a company which makes catheters and other medical instruments, in this research. They will now continue with a second study.

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

Vertically Aligned Graphene Coating is Bactericidal and Prevents the Formation of Bacterial Biofilms by Santosh Pandit, Zhejian Cao, Venkata R. S. S. Mokkapati, Emanuele Celauro, Avgust Yurgens, Martin Lovmar, Fredrik Westerlund, Jie Sun, Ivan Mijakovic. Advanced Materials Interfaces Volume5, Issue7 April 9, 2018 Pages 1701331 [sic] https://doi.org/10.1002/admi.201701331 First published [online]: 2 February 2018

This paper is behind a paywall.

Finally, here’s a ‘killer spikes’ video made available by Chalmers University of Technology,

Equality doesn’t necessarily lead to greater women’s STEM (science, technology, engineering, and mathematics) participation?

It seems counter-intuitive but societies where women have achieved greater equality see less participation by women in STEM (science, technology, engineering and mathematics) than countries where women are treated differently. This rather stunning research was released on February 14, 2018 (yes, Valentine’s Day).

Women, equality, STEM

Both universities involved in this research have made news/press releases available. First, there’s the February 14, 2018 Leeds Beckett University (UK) press release,

Countries with greater gender equality see a smaller proportion of women taking degrees in science, technology, engineering and mathematics (STEM), a new study by Leeds Beckett has found.

Dubbed the ‘gender equality paradox’, the research found that countries such as Albania and Algeria have a greater percentage of women amongst their STEM graduates than countries lauded for their high levels of gender equality, such as Finland, Norway or Sweden.

The researchers, from Leeds Beckett’s School of Social Sciences and the University of Missouri, believe this might be because countries with less gender equality often have little welfare support, making the choice of a relatively highly-paid STEM career more attractive.

The study, published in Psychological Science, also looked at what might motivate girls and boys to choose to study STEM subjects, including overall ability, interest or enjoyment in the subject and whether science subjects were a personal academic strength.

Using data on 475,000 adolescents across 67 countries or regions, the researchers found that while boys’ and girls’ achievement in STEM subjects was broadly similar, science was more likely to be boys’ best subject.

Girls, even when their ability in science equalled or excelled that of boys, were often likely to be better overall in reading comprehension, which relates to higher ability in non-STEM subjects.

Girls also tended to register a lower interest in science subjects. These differences were near-universal across all the countries and regions studied.

This could explain some of the gender disparity in STEM participation, according to Leeds Beckett Professor in Psychology Gijsbert Stoet.

“The further you get in secondary and then higher education, the more subjects you need to drop until you end with just one.

“We are inclined to choose what we are best at and also enjoy. This makes sense and matches common school advice.

“So, even though girls can match boys in terms of how well they do at science and mathematics in school, if those aren’t their best subjects and they are less interested in them, then they’re likely to choose to study something else.”

The researchers also looked at how many girls might be expected to choose further study in STEM based on these criteria.

They took the number of girls in each country who had the necessary ability in STEM and for whom it was also their best subject and compared this to the number of women graduating in STEM.

They found there was a disparity in all countries, but with the gap once again larger in more gender equal countries.

In the UK, 29 per cent of STEM graduates are female, whereas 48 per cent of UK girls might be expected to take those subjects based on science ability alone. This drops to 39 per cent when both science ability and interest in the subject are taken into account.

Countries with higher gender equality tend also to be welfare states, providing a high level of social security for their citizens.

Professor Stoet said: “STEM careers are generally secure and well-paid but the risks of not following such a path can vary.

“In more affluent countries where any choice of career feels relatively safe, women may feel able to make choices based on non-economic factors.

“Conversely, in countries with fewer economic opportunities, or where employment might be precarious, a well-paid and relatively secure STEM career can be more attractive to women.”

Despite extensive efforts to increase participation of women in STEM, levels have remained broadly stable for decades, but these findings could help target interventions to make them more effective, say the researchers.

“It’s important to take into account that girls are choosing not to study STEM for what they feel are valid reasons, so campaigns that target all girls may be a waste of energy and resources,” said Professor Stoet.

“If governments want to increase women’s participation in STEM, a more effective strategy might be to target the girls who are clearly being ‘lost’ from the STEM pathway: those for whom science and maths are their best subjects and who enjoy it but still don’t choose it.

“If we can understand their motivations, then interventions can be designed to help them change their minds.”

Then, there’s the February 14, 2018 University of Missouri news release, some of which will be repetitive,

The underrepresentation of girls and women in science, technology, engineering and mathematics (STEM) fields occurs globally. Although women currently are well represented in life sciences, they continue to be underrepresented in inorganic sciences, such as computer science and physics. Now, researchers from the University of Missouri and Leeds Beckett University in the United Kingdom have found that as societies become wealthier and more gender equal, women are less likely to obtain degrees in STEM. The researchers call this a “gender-equality paradox.” Researchers also discovered a near-universal sex difference in academic strengths and weaknesses that contributes to the STEM gap. Findings from the study could help refine education efforts and policies geared toward encouraging girls and women with strengths in science or math to participate in STEM fields.

The researchers found that, throughout the world, boys’ academic strengths tend to be in science or mathematics, while girls’ strengths are in reading. Students who have personal strengths in science or math are more likely to enter STEM fields, whereas students with reading as a personal strength are more likely to enter non-STEM fields, according to David Geary, Curators Professor of Psychological Sciences in the MU College of Arts and Science. These sex differences in academic strengths, as well as interest in science, may explain why the sex differences in STEM fields has been stable for decades, and why current approaches to address them have failed.

“We analyzed data on 475,000 adolescents across 67 countries or regions and found that while boys’ and girls’ achievements in STEM subjects were broadly similar in all countries, science was more likely to be boys’ best subject,” Geary said. “Girls, even when their abilities in science equaled or excelled that of boys, often were likely to be better overall in reading comprehension, which relates to higher ability in non-STEM subjects. As a result, these girls tended to seek out other professions unrelated to STEM fields.”

Surprisingly, this trend was larger for girls and women living in countries with greater gender equality. The authors call this a “gender-equality paradox,” because countries lauded for their high levels of gender equality, such as Finland, Norway or Sweden, have relatively few women among their STEM graduates. In contrast, more socially conservative countries such as Turkey or Algeria have a much larger percentage of women among their STEM graduates.

“In countries with greater gender equality, women are actively encouraged to participate in STEM; yet, they lose more girls because of personal academic strengths,” Geary said. “In more liberal and wealthy countries, personal preferences are more strongly expressed. One consequence is that sex differences in academic strengths and interests become larger and have a stronger influence college and career choices than in more conservative and less wealthy countries, creating the gender-equality paradox.”

The combination of personal academic strengths in reading, lower interest in science, and broader financial security explains why so few women choose a STEM career in highly developed nations.

“STEM careers are generally secure and well-paid but the risks of not following such a path can vary,” said Gijsbert Stoet, Professor in Psychology at Leeds Beckett University. “In more affluent countries where any choice of career feels relatively safe, women may feel able to make choices based on non-economic factors. Conversely, in countries with fewer economic opportunities, or where employment might be precarious, a well-paid and relatively secure STEM career can be more attractive to women.”

Findings from this study could help target interventions to make them more effective, say the researchers. Policymakers should reconsider failing national policies focusing on decreasing the gender imbalance in STEM, the researchers add.

The University of Missouri also produced a brief video featuring Professor David Geary discussing the work,

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

The Gender-Equality Paradox in Science, Technology, Engineering, and Mathematics Education by Gijsbert Stoet, David C. Geary. Psychological Studies https://doi.org/10.1177/0956797617741719 First Published February 14, 2018 Research Article

This paper is behind a paywall.

Gender equality and STEM: a deeper dive

Olga Khazan in a February 18, 2018 article for The Atlantic provides additional insight (Note: Links have been removed),

Though their numbers are growing, only 27 percent of all students taking the AP Computer Science exam in the United States are female. The gender gap only grows worse from there: Just 18 percent of American computer-science college degrees go to women. This is in the United States, where many college men proudly describe themselves as “male feminists” and girls are taught they can be anything they want to be.

Meanwhile, in Algeria, 41 percent of college graduates in the fields of science, technology, engineering, and math—or “STEM,” as its known—are female. There, employment discrimination against women is rife and women are often pressured to make amends with their abusive husbands.

According to a report I covered a few years ago, Jordan, Qatar, and the United Arab Emirates were the only three countries in which boys are significantly less likely to feel comfortable working on math problems than girls are. In all of the other nations surveyed, girls were more likely to say they feel “helpless while performing a math problem.”

… this line of research, if it’s replicated, might hold useful takeaways for people who do want to see more Western women entering STEM fields. In this study, the percentage of girls who did excel in science or math was still larger than the number of women who were graduating with STEM degrees. That means there’s something in even the most liberal societies that’s nudging women away from math and science, even when those are their best subjects. The women-in-STEM advocates could, for starters, focus their efforts on those would-be STEM stars.

Final thoughts

This work upends notions (mine anyway) about equality and STEM with regard to women’s participation in countries usually described as ‘developed’ as opposed to ‘developing’. I am thankful to have my ideas shaken up and being forced to review my assumptions about STEM participation and equality of opportunity.

John Timmer in a February 19, 2018 posting on the Ars Technica blog offers a critique of the research and its conclusions,

… The countries where the science-degree gender gap is smaller tend to be less socially secure. The researchers suggest that the economic security provided by fields like engineering may have a stronger draw in these countries, pulling more women into the field.

They attempt to use a statistical pathway analysis to see if the data is consistent with this being the case, but the results are inconclusive. It may be right, but there would be at least one other strong factor that they have not identified involved.

Timmer’s piece is well worth reading.

For some reason the discussion about a lack of social safety nets and precarious conditions leading women to greater STEM participation reminds me of a truism about the arts. Constraints can force you into greater creativity. Although balance is necessary as you don’t want to destroy what you’re trying to encourage. In this case, it seems that comfortable lifestyles can lead women to pursue that which comes more easily whereas women trying to make a better life in difficult circumstance will pursue a more challenging path.

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.