Senator Urges Collaboration in Nanocellulose Research

Nanocellulose was in the spotlight last week during a Senate Energy and Natural Resources Committee hearing. U.S. Senator Angus King (I-Maine) highlighted work done at the University of Maine to support the forest economy and biobased industries, and emphasized the need for research and development institutions across the country to work together in support of American manufacturing and other home-grown industries.

    Collaborative research and development is encouraged to put these tiny wood fibers to big use.

Collaborative research and development is encouraged to put these tiny wood fibers to big use.

“One of the most important areas [of research] is nanocellulose technology. We have a goldmine of fiber in Maine, which historically has been used to make paper, [but] the paper industry has been brutally hammered in the last five or six years,” said Senator King. “We need a George Washington Carver of fiber – I remember from the sixth grade that George Washington Carver was the scientist who figured out a hundred ways to use peanuts. We need that kind of research [on uses of forest fiber].”

The Forest Products Laboratory (FPL) and the University of Maine have partnered on nanocellulose research for several years. In 2013, a nanocellulose pilot plant was constructed at the University of Maine through a joint venture with the U.S. Forest Service. The plant has the capacity to produce one ton of cellulose nanofibrils per day.

The University of Maine is part of a consortium of universities and non-profits led by FPL who work together to improve methods of isolating nanomaterials, characterize and develop standards for various grades of nanocellulose, and support emerging markets for products made from wood-derived renewable nanomaterials.

Nanocellulose Facility Under Study in Yreka, California

The following is a news release from the Klamath National Forest:

Scientists are working with local government officials and timber processors on a project that could help turn small-diameter trees into high-tech products. The key ingredient is microscopic particles of cellulose, called “nanocellulose.”  Scientists have found that nanocellulose materials have unique properties and may be useful in a variety of applications.

Nanocellulose is part of the emerging field of nanotechnology. Nanocellulose materials are strong, lightweight, colorless, and biodegradable. Possible uses may include lightweight armor, ballistic glass, car body panels, computer cases, food storage, and flexible electronics. Other products, such as concrete and structural panels, can be strengthened with the addition of nanocellulose.

Scientists and engineers are designing a larger version of the Forest Products Lab's nanocellulose facility, seen here,  that could one day be built in Yreka, California.

Scientists and engineers are designing a larger version of the Forest Products Lab’s nanocellulose facility, seen here, that could one day be built in Yreka, California.

The Yreka Cellulose Nanomaterials Project began in 2014, when the Siskiyou County Board of Supervisors met with Forest Service officials. From that meeting came a proposal to evaluate the possible construction of a commercial-scale cellulose nanomaterials production facility in Yreka, California. Yreka was identified as a promising location due to the plentiful supply of wood and the support from local government.

On March 29 local officials received an update on the project from Dr. Alan Rudie, a chemist with the USDA Forest Products Laboratory in Madison, Wisconsin.

Dr. Rudie explained two different focuses of their research. One part of their work is to help develop commercial uses for cellulose nanomaterials. To that end, they have built a pilot facility at the Forest Products Lab in Madison, Wisconsin. The pre-prototype facility produces both cellulose nano-crystals and cellulose nano-fibrils, and shares or sells them at cost to industry and research partners. The Forest Products Company mill in Yreka has supplied wood to the nanocellulose facility in Madison.

The other focus is on preliminary designs for a cellulose nanomaterial production facility in Yreka. Industry and university cooperators are studying six different methods of isolating cellulose nanomaterial. Dr. Rudie and his partners expect that in 2016 they will identify one or two designs to further explore. Actually building a facility would require a more detailed design and an industry investor.

Dan Blessing, Natural Resources Officer for the Klamath National Forest, is the local Forest Service contact for the Yreka Cellulose Nanomaterials Project. Dan emphasizes how operation of such a facility would benefit natural resource management on the Klamath National Forest.

“To help restore fire-resilient ecosystems here on the Klamath National Forest, we need to reduce forest fuels. We have a market for mid-sized trees when we do thinning or fire salvage. But much of the fuels on the Forest are smaller-diameter trees,” said Blessing. “Removing the smaller diameter trees is expensive and there are limited local facilities that have much use for them. Finding a market for cellulose nanomaterials and encouraging construction of a local facility to produce the materials will create a demand for the smaller diameter trees that will reduce the costs of local fuel reduction, benefiting our public forest and providing local jobs.”

Blessing emphasized that the project is still in the early stages. “While the commercial properties of cellulose nanomaterials are promising, much work remains. We’re hoping at least one industry partner will find the materials valuable enough to warrant construction of a larger facility. By having preliminary design of such a facility complete, maybe we can encourage a partner to build it here in Yreka.”

Also presenting at the March meeting was Michael Goergen, Vice President for Innovation with the U.S. Endowment for Forestry & Communities. One of their projects is the “Public-Private Partnership for Nanotechnology,” referred to as P3Nano. They see promise in the use of wood-based nanomaterial for a wide-range of commercial products, and are assisting with the Yreka project.

Register Now! Free Cellulose Nanomaterials Webinar

The Forest Products Society is offering a free webinar titled “Overview of Cellulose Nanomaterials and Nanocomposites” on Tuesday, October 6, 2015, at 1:30 p.m. EDT. Forest Products Laboratory (FPL) Research Materials Engineer Ronald Sabo will be presenting.

Ronald Sabo (left) will present the nano webinar. Here he explains a composites research project to USDA Under Secretary Robert Bonnie.

The one-hour webinar will provide an introduction to and overview of cellulose nanomaterials and nanocomposites. Production methods and properties of cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) will be described, and cellulose nanocomposites, their properties, and applications will be discussed. The enormous potential of these materials, as well as some of the associated challenges, will also be addressed in this webinar, which will provide a good foundation for anyone looking to begin research in this area or to incorporate these materials into products.

Sabo works in the Engineered Composites Sciences group at FPL. His research interests include cellulose nanomaterials and nanocomposites, “green” polymers and composites, and recycling and remediation of forest-based resources. He has authored over 50 publications, including peer-reviewed journal articles, book chapters and conference proceedings. Sabo obtained a bachelor’s degree in Chemical Engineering and Mathematics from Vanderbilt University and a Ph.D. in Chemical Engineering from the University of Florida.

Register now for this free webinar and begin to explore the many possibilities of nanocellulose!

Nanocellulose Used in Medical Devices

 

Transmission electron microscopy image of freeze-dried CNCs that were redispersed in deionized water and stained with aqueous uranyl acetate.

Transmission electron microscopy image of freeze-dried CNCs that were redispersed in
deionized water and stained with aqueous uranyl acetate.

The Journal of Applied Polymer Science features groundbreaking work from FPL Materials Research Engineer Robert Moon and others. “Enhanced thermal stability of biomedical thermoplastic polyurethane with the addition of cellulose nanocrystals” by Jen-Chieh Liu, Darren J. Martin, Robert J. Moon, and Jeffrey P. Youngblood takes us to the world of nanocellulose in medical devices.

Thermoplastic polyurethanes (TPUs) are used in manufacturing biomedical devices, such as vascular grafts or ventricular assistance devices, where mechanical performance and biocompatibility and nontoxicity are crucial. However, to increase the range of biomedical device applications and improve end use performance, improved thermal stability during fabrication and the ability to controllably manipulate strength and toughness without loss of biocompatibility is required. And because these devices are to be used in the human body, they must be nontoxic. Cellulose nanocrystals (CNCs) are cellulose-based nanoparticles produced from wood or plant fibers. As candidates for nano-reinforcement materials for TPUs, CNCs work well because they have high mechanical properties, good thermal properties, and low toxicity.

In many cases, TPU fabrication (such as extrusion and injection molding) to make products involves high temperatures and long manufacturing time because of blending and homogenization. These factors degrade polymer chains and decrease mechanical properties. If nano-reinforced TPUs can achieve a higher decomposition temperature, they could be processed under a wider range of operation temperatures and manufacturing times without loss of mechanical properties.

This research showed that higher solid loadings of CNCs in a commercial TPU commonly used in biomedical applications resulted in a higher onset degradation temperature of the nanocomposite, providing a wider processing temperature for manufacturing products to be used in biomedical devices without loss of mechanical properties.

FPL cooperated with Purdue University; University of Queensland, Brisbane, Australia; and Georgia Institute of Technology, Atlanta, Georgia, on this project.

 

Natural Nanocrystals Shown to Strengthen Concrete

The following is a Purdue University news release:

Cellulose nanocrystals derived from industrial byproducts have been shown to increase the strength of concrete, representing a potential renewable additive to improve the ubiquitous construction material.

This transmission electron microscope image shows cellulose nanocrystals, tiny structures derived from renewable sources that might be used to create a new class of biomaterials with many potential applications. The structures have been shown to increase the strength of concrete. (Purdue Life Sciences Microscopy Center)

This transmission electron microscope image shows cellulose nanocrystals, which have been shown to increase the strength of concrete. (Purdue Life Sciences Microscopy Center)

The cellulose nanocrystals (CNCs) could be refined from byproducts generated in the paper, bioenergy, agriculture and pulp industries. They are extracted from structures called cellulose microfibrils, which help to give plants and trees their high strength, lightweight and resilience. Now, researchers at Purdue University have demonstrated that the cellulose nanocrystals can increase the tensile strength of concrete by 30 percent.

“This is an abundant, renewable material that can be harvested from low-quality cellulose feedstocks already being produced in various industrial processes,” said Pablo Zavattieri, an associate professor in the Lyles School of Civil Engineering.

The cellulose nanocrystals might be used to create a new class of biomaterials with wide-ranging applications, such as strengthening construction materials and automotive components.

Research findings were published in February in the journal Cement and Concrete Composites. The work was conducted by Jason Weiss, Purdue’s Jack and Kay Hockema Professor of Civil Engineering and director of the Pankow Materials Laboratory; Robert J. Moon, a researcher from the U.S. Forest Service’s Forest Products Laboratory; Jeffrey Youngblood, an associate professor of materials engineering; doctoral student Yizheng Cao; and Zavattieri.

One factor limiting the strength and durability of today’s concrete is that not all of the cement particles are hydrated after being mixed, leaving pores and defects that hamper strength and durability.

“So, in essence, we are not using 100 percent of the cement,” Zavattieri said.

However, the researchers have discovered that the cellulose nanocrystals increase the hydration of the concrete mixture, allowing more of it to cure and potentially altering the structure of concrete and strengthening it.  As a result, less concrete needs to be used.

The cellulose nanocrystals are about 3 to 20 nanometers wide by 50-500 nanometers long – or about 1/1,000th the width of a grain of sand – making them too small to study with light microscopes and difficult to measure with laboratory instruments. They come from a variety of biological sources, primarily trees and plants.

The concrete was studied using several analytical and imaging techniques. Because chemical reactions in concrete hardening are exothermic, some of the tests measured the amount of heat released, indicating an increase in hydration of the concrete. The researchers also hypothesized the precise location of the nanocrystals in the cement matrix and learned how they interact with cement particles in both fresh and hardened concrete. The nanocrystals were shown to form little inlets for water to better penetrate the concrete.

The research dovetails with the goals of P3Nano, a public-private partnership supporting development and use of wood-based nanomaterial for a wide-range of commercial products.

“The idea is to support and help Purdue further advance the CNC-Cement technology for full-scale field trials and the potential for commercialization,” Zavattieri said.

This research was funded by the National Science Foundation.

Writer: Emil Venere, 765-494-4709, venere@purdue.edu