Tag Archives: wood pulp

Wood pulp and pomegranate peels as clothing

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

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

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

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

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

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

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

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

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

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

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

Wooden supercapacitors: a cellulose nanofibril story

A May 24, 2018 news item on Nanowerk announces a technique for making sustainable electrodes (Note: A link has been removed),

Carbon aerogels are ultralight, conductive materials, which are extensively investigated for applications in supercapacitor electrodes in electrical cars and cell phones. Chinese scientists have now found a way to make these electrodes sustainably. The aerogels can be obtained directly from cellulose nanofibrils, the abundant cell-wall material in wood, finds the study reported in the journal Angewandte Chemie (“Wood-Derived Ultrathin Carbon Nanofiber Aerogels”).

A May 24, 2018 Wiley Publications press release, which originated the news item, explains further,

Supercapacitors are capacitors that can take up and release a very large amount of energy in a very short time. Key requirements for supercapacitor electrodes are a large surface area and conductivity, combined with a simple production method. Another growing issue in supercapacitor production–mainly for smartphone and electric car technologies–is sustainability. However, sustainable and economical production of carbon aerogels as supercapacitor electrode materials is possible, propose Shu-Hong Yu and colleagues from the University of Science and Technology of China, Hefei, China.

Carbon aerogels are ultralight conductive materials with a very large surface area. They can be prepared by two production routes: the first and cheapest starts from mostly phenolic components and produces aerogels with improvable conductivity, while the second route is based on graphene- and carbon-nanotube precursors. The latter method delivers high-performance aerogels but is expensive and non-environmentally friendly. In their search for different precursors, Yu and colleagues have found an abundant, far less expensive, and sustainable source: wood pulp.

Well, not really wood pulp, but its major ingredient, nanocellulose. Plant cell walls are stabilized by fibrous nanocellulose, and this extractable material has very recently stimulated substantial research and technological development. It forms a highly porous, but very stable transparent network, and, with the help of a recent technique–oxidation with a radical scavenger called TEMPO–it forms a microporous hydrogel of highly oriented cellulose nanofibrils with a uniform width and length. As organic aerogels are produced from hydrogels by drying and pyrolysis, the authors attempted pyrolysis of supercritically or freeze-dried nanofibrillated cellulose hydrogel.

As it turns out, the method was not as straightforward as expected because ice crystal formation and insufficient dehydration hampered carbonization, according to the authors. Here, a trick helped. The scientists pyrolyzed the dried gel in the presence of the organic acid catalyst para-toluenesulfonic acid. The catalyst lowered the decomposition temperature and yielded a “mechanically stable and porous three-dimensional nanofibrous network” featuring a “large specific surface area and high electrical conductivity,” the authors reported.

The authors also demonstrated that their wood-derived carbon aerogel worked well as a binder-free electrode for supercapacitor applications. The material displayed electrochemical properties comparable to commercial electrodes. The method is an interesting and innovative way in which to fabricate sustainable materials suitable for use in high-performance electronic devices.

This is the first time I’ve seen work on wood-based nanocellulose from China. Cellulose according to its Wikipedia entry is: ” … the most abundant organic polymer on Earth.” For example, there’s more cellulose in cotton than there is wood. So, I find it interesting that in a country not known for its forests, nanocellulose (in this project anyway) is being derived from wood.

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

Wood‐Derived Ultrathin Carbon Nanofiber Aerogels by Si‐Cheng Li, Bi‐Cheng Hu, Dr. Yan‐Wei Ding, Prof. Hai‐Wei Liang, Chao Li, Dr. Zi‐You Yu, Dr. Zhen‐Yu Wu, Prof. Wen‐Shuai Chen, Prof. Shu‐Hong Yu. Angewandt Chemie First published: 23 April 2018 DOI: https://doi.org/10.1002/anie.201802753

This paper is behind a paywall.