Transparent wood can store and release heat

Wood may seem more at home in log cabins than modern architecture, but a specially treated type of timber could be tomorrow’s trendy building material. Today, scientists report a new kind of transparent wood that not only transmits light, but also absorbs and releases heat, potentially saving on energy costs. The material can bear heavy loads and is biodegradable, opening the door for its eventual use in eco-friendly homes and other buildings.

“Back in 2016, we showed that transparent wood has excellent thermal-insulating properties compared with glass, combined with high optical transmittance,” says Céline Montanari, a Ph.D. student who is presenting the research at the meeting. “In this work, we tried to reduce the building energy consumption even more by incorporating a material that can absorb, store and release heat.”

As economic development progresses worldwide, energy consumption has soared. Much of this energy is used to light, heat and cool homes, offices and other buildings. Glass windows can transmit light, helping to brighten and heat homes, but they don’t store energy for use when the sun goes down.

Three years ago, lead investigator Lars Berglund, Ph.D., and colleagues at KTH Royal Institute of Technology in Stockholm, Sweden, reported an optically transparent wood in the ACS journal Biomacromolecules. The researchers made the material by removing a light-absorbing component called lignin from the cell walls of balsa wood. To reduce light scattering, they incorporated acrylic into the porous wood scaffold. The team could see through the material, yet it was hazy enough to provide privacy if used as a major building material. The transparent wood also had favorable mechanical properties, enabling it to bear heavy loads.

Building on this work, Montanari and Berglund added a polymer called polyethylene glycol (PEG) to the de-lignified wood. “We chose PEG because of its ability to store heat, but also because of its high affinity for wood,” Montanari says. “In Stockholm, there’s a really old ship called Vasa, and the scientists used PEG to stabilize the wood. So we knew that PEG can go really deep into the wood cells.”

Known as a “phase-change material,” PEG is a solid that melts at a temperature of 80 F, storing energy in the process. The melting temperature can be adjusted by using different types of PEGs. “During a sunny day, the material will absorb heat before it reaches the indoor space, and the indoors will be cooler than outside,” Montanari explains. “And at night, the reverse occurs — the PEG becomes solid and releases heat indoors so that you can maintain a constant temperature in the house.”

Source: Transparent wood can store and release heat – ScienceDaily, 2019-04-03

Wood-based technology creates electricity from heat

A University of Maryland-led team of researchers has created a heat-to-electricity device that runs on ions and which could someday harness the body’s heat to provide energy.

A University of Maryland-led team of researchers has created a heat-to-electricity device that runs on ions and which could someday harness the body’s heat to provide energy.

Source: Wood-based technology creates electricity from heat – Phys.org, 2019-03-25

Inventors of bullet-proof wood create fire-proof wood

By Ian Randall
A fire-retardant structural material can be made by chemically softening and compressing wood to remove the spaces between cell walls. When burnt, the resulting material forms a protective char layer on its outside which helps preserve its internal strength.

The use of wood in structural applications is limited by both its inherent flammability and susceptibility to rapid collapse on burning. Wood can be made more fire-proof by chemical treatments – such as through injections of halogenated flame retardants, or coatings of inorganic nanoparticles – but these approaches are typically either prohibitively expensive, fail environmental and health standards, or result in insufficient structural strength.

Liangbing Hu and colleagues of the University of Maryland in the US show that their process to create bullet-proof wood through densification also confers fire-resistant properties without recourse to potentially toxic or environmentally-unfriendly materials.

The densified material – which Hu dubs ‘super wood’ – is created by first chemically treating timber with sodium hydroxide and sodium sulfite to partially remove its lignin, the organic polymer which makes cell walls rigid. Subsequent hot pressing creates a dense, laminated material free of lumina – the tiny channels that create a porous structure, supplying oxygen and increasing flammability.

Source: Inventors of bullet-proof wood create fire-proof wood – Chemistry World, 2019-03-06

A downtown parking lot is being repaved with nanomaterials. Here’s why.

By Andrew Moore
The tiny rod-like structures have been shown to improve the strength and durability of concrete structures and reduce the carbon footprint of manufacturing cement.

If you were to walk through downtown Greenville, you would likely notice several landmarks, including the Liberty Bridge and the old county courthouse.

While these iconic structures are unique in their own right, they share one commonality: They’re made of concrete. The coarse, gray material is the very foundation of modern infrastructure. It’s been used in the construction of everything from buildings and bridges to roads and sidewalks.

But despite all its benefits of strength and durability, there’s a major downside to using concrete.

The production of cement, which when mixed with water forms the binding agent in concrete, accounts for 5 to 10 percent of all human-caused carbon dioxide emissions, according to the International Energy Agency. These emissions have been on the rise since the industrial revolution and remain the leading cause of global warming.

Over the past decade, though, researchers from across the country have been working together to create a cleaner version of the versatile building material. And now they plan to test the capabilities of their environmentally friendly alternative in Greenville.

The U.S. Endowment for Forestry and Communities, a Greenville-based environmental nonprofit, has partnered with the U.S. Forest Service, Oregon State University, and Purdue University to study a concrete mixture infused with cellulosic nanomaterials.

Cellulosic nanomaterials are produced by breaking down wood to its smallest, strongest components through mechanical and chemical processes similar to making paper. These tiny rodlike structures have diameters 20,000 times smaller than the width of a human hair and can be seen only using an electron microscope, yet they are as strong as steel with only one-fifth the weight.

“Researchers are testing these cellulosic nanomaterials in a wide range of applications from substrate for computer chips, they don’t warp under heat like plastics do, to car and airplane bodies, lighter and stronger than steel,” said Dr. Alan Rudie, a chemist with the U.S. Forest Service’s Forest Products Laboratory in Wisconsin, in a news release. “Our team expects that concrete will be among the first commercial applications.”

Source: A downtown parking lot is being repaved with nanomaterials. Here’s why. – Greenville Journal, 2018-12-05

Bioplastics sourced from wood

The shift from fossil-based industries to a bioeconomy is creating a growing demand for biobased chemicals, materials and fuels as sustainable and renewable alternatives. One possible source is fructose from wood for use in the production of bioplastics.

Lignocellulosic biomass is typically nonedible plant material, including dedicated crops of wood and grass, as well as waste material from agroforestry. It is also the single most abundant renewable resource on earth and available all year round. Furthermore, lignocellulosic biomass does not need valuable space in fields as it has no agricultural or nutritional use. It’s noteworthy, that wood can be harvested sustainably from certified forests. In the Nordic countries, more forest is grown than gets harvested each year.

Compared to other lignocellulosic feedstocks like straw, wood-based feedstocks for biorefinery have the greatest potential to replace fossil derived compounds in the chemical industry. Establishing competitive value chains based on lignocellulosic feedstock will not only secure an abundant alternative industrial feedstock but also strengthen the competitive position of biobased chemicals and materials compared to their fossil-based counterparts.

The EU-funded Horizon 2020 ReTAPP project investigated the production of fructose sugar using lignocellulosic biomass from hardwood and softwood feedstocks. “Researchers employed enzyme solutions to replace food/starch-based-fructose with wood derived fructose and prepared the entire value chain for launching the product onto the market,” says project coordinator Matti Heikkilä.

Source: Bioplastics sourced from wood – CORDIS, European Commission, 2018-09-24

Oregon seeks to become U.S. mass timber hub

By George Plaven
Timm Locke relishes a chance to drive around Portland and showcase the latest commercial buildings made with mass timber, a construction material that uses wood beams and panels instead of concrete and steel.

First stop: Albina Yard, a four-story office building that opened in 2016 featuring cross-laminated timber panels from D.R. Johnson, a lumber company south of Roseburg.

Every piece of cross-laminated timber — or CLT for short — is prefabricated, designed for a specific part of the building, said Locke, director of forest products at the Oregon Forest Resources Institute. That means buildings go up faster, with fewer workers.

Wood is also environmentally superior to steel and concrete, Locke said, because it sequesters carbon and takes less energy to produce.

“There are so many benefits, it doesn’t matter which one you choose to start with,” Locke said.

First developed in Europe, mass timber is now catching on in the U.S., and Oregon is working to position itself as the industry hub, kick-starting rural economies that have traditionally relied on forest products. On Aug. 1, Oregon became the first state to approve language in its building codes allowing for wood-framed buildings up to 18 stories tall.

Source: Oregon seeks to become U.S. mass timber hub – Blue Mountain Eagle, 2018-09-18

This startup wants your next T-shirt to be made from wood

BY ADELE PETERS
Spinnova has found a way to spin any cellulose–wood, potato peels, even old T-shirts–into new, strong fiber.

In a new pilot factory in Jyväskylä, Finland–a city surrounded by forests and known in part for its lumber and paper industries–a startup will soon begin to turn wood pulp into something new: a type of fabric that could eventually compete with cotton.

Making wood into fabric isn’t new, but older wood-based fabrics like rayon use harsh chemicals that can pollute water and poison workers. The new fabric, made by a startup called Spinnova, uses a mechanical process instead of chemicals; the only byproduct is evaporated water, which is reused in production. Unlike cotton, which uses massive amounts of water in areas often prone to droughts, it needs little water, no pesticides, and no farmland.

The new process uses FSC-certified wood pulp that’s ground into a gel-like material called microfibrillated cellulose, which is made of tiny fibers. The material flows through the startup’s patented machinery to create a network of fibers that are spun and dried into a fluffy, firm wool that can be knit or woven into fabric and then made into clothing, shoes, or other textiles.

Source: This startup wants your next T-shirt to be made from wood – Fast Company, 2018-08-01

Fireproof Wood Poised to Save Houses, the Earth

By Emily Pollock
M-Fire’s fire-inhibiting wood looks increasingly important in an industry turning back to wood buildings.

The phrase “wood buildings” conjures up images of flammable, unsafe architecture, but M-Fire Suppression Inc. is looking to change that picture. And it wants its fire-resistant wood to be the new face of ecologically friendly building.

One of the most common tests of a material’s fire resistance is a spread test, where inspectors measure how long it takes fire to spread across the material as compared to control materials. Class A is the most fire-resistant class, and M-Fire is currently the only company making Class A fire-protected cross-laminated timber. To do that, the company infuses wood with surfactants that allow fire inhibitors to migrate into the pockets of oxygen in the wood. The result is a product much eco-friendlier than most traditional fire inhibition. M-Fire is currently the only Class A fire inhibitor with UL Greenguard Gold certification, which means that it’s safe around children and schools.

“We don’t even like the name fire retardant near our brand. We’re a fire inhibitor,” said Steve Conboy, the company’s chairman and general manager. “What happens is, we inhibit fire because we break the chemical reaction in the fire.” The inhibitor breaks the chain of free radicals (H+, OH- and O-) released during combustion, giving the fire nothing to feed on.

The fire protection results in what Conboy calls “defended carbon”: carbon that is stored in the wood and will never be released into the atmosphere. A carbon-absorbing building material gives M-Fire’s wood a distinct advantage over carbon-producing alternatives like structural steel.

Source: Fireproof Wood Poised to Save Houses, the Earth – engineering.com, 2018-07-03

Termite gut holds a secret to breaking down plant biomass

In the Microbial Sciences Building at the University of Wisconsin-Madison, the incredibly efficient eating habits of a fungus-cultivating termite are surprising even to those well acquainted with the insect’s natural gift for turning wood to dust.

According to a study published today (April 17, 2017) in the journal Proceedings of the National Academy of Sciences, when poplar wood undergoes a short, 3.5-hour transit through the gut of the termite, the emerging feces is almost devoid of lignin, the hard and abundant polymer that gives plant cells walls their sturdiness. As lignin is notorious for being difficult to degrade, and remains a costly obstacle for wood processing industries such as biofuels and paper, the termite is the keeper of a highly sought after secret: a natural system for fully breaking down biomass.

“The speed and efficiency with which the termite is breaking down the lignin polymer is totally unexpected,” says John Ralph, a UW-Madison professor of biochemistry, researcher at the Great Lakes Bioenergy Research Center (GLBRC) and lignin expert. “The tantalizing implication is that this gut system holds keys to breaking down lignin using processes that are completely unknown.”

Source: Termite gut holds a secret to breaking down plant biomass – EurekAlert! Science News, 2017-04-17