To understand what nanocellulose is and what it could be, all you have to do is look at the world around you.
That tree outside your window? The plants in your garden? The seaweed on the beach? The lettuce in your salad? That’s where it comes from.
In the very fiber of every plant and tree is a building block like no other, with the potential to be the next material that changes the world. Think about the introduction of nylon, polyester or plastic. But this foundational material — nanocellulose — is natural, biodegradable, abundant and renewable.
When it comes to possibility, you have to think big. Really, really big. Not necessarily or exclusively in terms of size — nanocellulose’s name gives away that it starts small — but of scope.
To narrow it down, start with your basic needs: water, food, shelter. How could nanocellulose factor in? Filters made with nanocellulose could remove contaminants to provide clean, safe drinking water. Packaging made with nanocellulose offers properties that can keep food fresher longer. Materials made with nanocellulose could form the structure of your home and at least some part of nearly everything in it.
Sound far-fetched? It’s not — and it’s happening in Maine. All of the possible applications listed above are areas that University of Maine researchers are exploring today, and those represent only a fraction of the nanocellulose research that UMaine is conducting in Orono and fueling around the world through the manufacture and distribution of nanocellulose.
Colleen Walker, director of UMaine’s Process Development Center and a pilot plant that can churn out 2 tons of nanocellulose per day, is the ultimate advocate for the material itself and for Maine’s capacity to lead the societal transformation she knows it can bring.
“The opportunity is huge,” says Walker. “This is a great material with great potential. If you just look at the number of publications and innovations globally that make use of nanocellulose — Japan built a car from it — you get a sense of what could be possible. And Maine can lead that because we have the raw materials in our forests, the processing infrastructure both here at the university and in current and former mill facilities throughout the state, people who understand how to make it and how we could use it, and the entrepreneurial spirit to make it happen.
“That’s why I refer to Maine as ‘Nanocellulose Valley,’ because we have all the ingredients to make this state a hub of nanocellulose innovation. It’s already happening, but we need more venture capital and we just have to keep pushing it forward.”
Pushing it forward is what Walker and others at UMaine, plus partners in Maine and beyond, are working on every day. For the PDC director, it is almost an obsession.
“I don’t want Maine to miss the boat,” says Walker. “If we don’t invest in this, it will all be coming from somewhere else, and that would be a shame, because this could be the next chapter in Maine’s forest products history. There’s no place better suited to drive the changes that nanocellulose will bring.”
To understand why, you have to go back to the early days of nanocellulose research at UMaine, and consider how longtime leadership in forestry and pulp and paper processing paved the way for the material of tomorrow.
Less than two decades ago, some of the first nanocellulose produced at UMaine was made using a high-pressure benchtop homogenizer. If the word “homogenizer” makes you think of milk, you’d be on the right track. The equipment, not unlike a dairy homogenizer used to mechanically break down the fat molecules in milk, was then the standard for refining cellulose fibers, the kind used to make paper, to nanoscale.
“It was a nightmare,” remembers professor of forest operations, bioproducts and bioenergy Doug Gardner, who has been involved with UMaine’s nanocellulose research program since it started around 2006. “It kept clogging. A homogenizer is used to process milk or paint, and putting solid material in there was a mess.”
At around the same time, UMaine’s industrial-scale pulp and paper research facility, the Process Development Center, was beginning to produce nanocellulose for paper industry clients through repeated, energy-intensive mechanical refinement cycles that took days.
“We’d use our pilot refiner, and we would just sit there and run it over and over and over and over again for days, refine it down through brute force,” says Mike Bilodeau, who served as PDC director from 2003–18 and now provides consulting services to industry clients as principal of Papyrus Consulting Group.
From those humble beginnings not even 20 years ago, UMaine’s nanocellulose research program is today one of the most advanced in the world and the university holds 87 patents on 12 technologies related to nanocellulose production and applications. Today, nanocellulose’s potential as a renewable, biodegradable, high-performance material is widely recognized as almost limitless.
UMaine’s Forest Bioproducts Research Institute (FBRI), which evolved from the National Science Foundation-funded Forest Bioproducts Research Initiative, is dedicated to helping realize that potential. The institute works to advance all manner of renewable materials derived from wood, and UMaine’s leadership in nanocellulose is a point of particular pride for FBRI director Hemant Pendse.
“We recognized very early on the promise of forest bioproducts, and built FBRI as a commitment to fostering R&D and encouraging commercialization,” says Pendse. “UMaine’s leadership in cellulose nanomaterials clearly shows the enduring impact of that commitment and reflects the deep dedication of an interdisciplinary group of researchers and scientists, including many students. Our expertise has expanded to include non-woody plant fibers as starting materials, and where we initially used nanocellulose primarily as an additive for product enhancement, we’re now reaching into the development of novel nanocellulose composites.”
In the early aughts, research into highly refined cellulose was just beginning to take off in the United States, roughly three decades after researchers at what was then the ITT Rayonier Eastern Research Division Lab in Whippany, New Jersey experimented in the late 1970s with running pulp slurry through a milk homogenizer and created what is regarded to be the first nanocellulose.
UMaine’s entry into the nascent field coincided with the establishment of FBRI in 2007, but the university’s long history of pulp and paper research and industrial collaboration provided a foundation that would help UMaine distinguish itself — first through process innovations, and then through the creation of an unrivaled production and distribution network that is driving nanocellulose research and development across the globe.
PDC has collaborated closely with the industry for decades. The facility was established to support the needs of the pulp and paper industry, and is funded almost exclusively through contract work. Uniquely positioned at the intersection of research and real-world needs, the center has developed a reputation for innovation and problem-solving, leading to discoveries that have become standard practice.
For example, UMaine researchers helped develop nonelemental chlorine bleaching, a process that significantly reduced dioxin generation and discharges. The process became the industry standard. Together with industrial collaborators, the center developed new processes for nonsulfur and oxygen delignification, optimized use of recycled materials, designed equipment and process changes to reduce emissions, and developed and implemented significant strategies for reducing water, raw material, and energy consumption.
These developments benefited Maine’s numerous paper companies through economic and environmental improvements while also advancing basic scientific understanding. When nanocellulose entered the picture, it was no surprise that pulp and paper companies turned to UMaine.
“We had requests from longtime clients to make this type of material because it wasn’t available commercially,” says Bilodeau, who, as PDC director, led UMaine into large-scale nanocellulose production. “They wanted to evaluate it and keep track of when and how it could be deployed in their products, or how they could use it to make new products.”
The problem was producing it at scale relevant to industrial paper producers, and the homogenizer method was not going to cut it.
“A homogenizer can make a little bit of high-quality stuff, but it’s very expensive,” says Bilodeau. “There was already research published (about nanocellulose) and we started to get clients coming to us asking about making a cheaper version, a coarser version, a less expensive version to put in commodity papers.”
In some ways, nanocellulose research at UMaine evolved along parallel tracks. As the Forest Bioproducts Research Institute was taking shape, UMaine researchers were exploring the properties and potential applications of nanocellulose with small quantities of the high-quality substance they could produce using a homogenizer or purchase from other research institutions. At the same time, PDC’s industrial pulp and paper partners, inspired by research discoveries involving nanocellulose, were clamoring for access to the material to use in their own experiments.
Responding to the needs of their industrial clients, Bilodeau and his PDC team also began making highly refined cellulose, jury-rigging a process involving the center’s existing refining equipment used to prepare stock for making paper.
“A client would say ‘We’re going to do a study and we’re going to use nanocellulose, and could you make some for us?’” Bilodeau remembers. “And then we’d spend days making the stuff. It was extremely energy intensive and slow, and eventually the staff started saying ‘Let’s see if we can’t do it faster, because I don’t want to stay all night making this.’”
Once again, PDC’s long-term industrial relationships were key.
“It wasn’t just paper companies we had as clients, we also had equipment manufacturers, including companies who made refining and stock prep equipment,” says Bilodeau. “And so we worked with them and came up with ways of making it better and better and more efficient, and finally we ended up with a process that we thought was significantly better than what was available, and so we patented the process of making cellulose nanofibrils at a much lower energy consumption.”
A major patent for the high-efficiency production of nanocellulose was filed in 2014 and granted three years later. By that time, UMaine nanocellulose research and development was humming along at a rapid clip, thanks in large part to PDC’s ability to produce the substance in large quantities and make it available to UMaine researchers interested in exploring its uses and properties.
“It wasn’t like we invented the material or we invented its use,” says Bilodeau. “Our claim to fame is really that we could make a lot of it — cheap.”
While pulp and paper expertise, infrastructure and industrial connections gave UMaine a leg up in early nanocellulose research, the university’s ascendance since has been the result of deliberate decision-making and calculated investment. A critical partnership with the U.S. Forest Products Laboratory (FPL) funded construction of UMaine’s nanocellulose pilot plant through a joint venture agreement with the USDA Forest Service in 2012.
UMaine’s facility, opened in April 2013, was constructed in parallel with the FPL’s Nanocellulose Pilot Plant in Madison, Wisconsin, which opened about eight months earlier. The U.S. Forest Products Lab also sited research scientist Jinwu Wang at UMaine as part of the ongoing research collaboration. Jinwu contributes to cellulose nanocomposite research and participates in graduate student education.
UMaine was a key member of a research consortium led by FPL and including six other universities — Georgia Institute of Technology, North Carolina State University, Oregon State University, Pennsylvania State University, Purdue University and University of Tennessee — all working to develop scalable methods to convert wood components into novel, high-performance nanomaterials. Members of the consortium were central to a lobbying effort to inform federal granting agencies of the opportunity to use nanocellulose in a wide range of commercial products, differentiating it from the National Nanotechnology Initiative that was focused on highly specialized applications for different types of nanoscale matter.
“At the time, the National Nanotechnology Institute was getting a lot of funding for nanotechnology, but they were working on very small-scale, high-tech technology that wasn’t easily commercialized,” says Bilodeau. “We were trying to make a pitch for a nanomaterial that was biobased, that we could make up in ton quantities, and that you could actually commercialize really quickly.”
Tom Vilsack, when he first served as secretary of agriculture under President Barack Obama, was central to securing funding for the expansion of nanocellulose research in the United States. Recognizing an opportunity to support rural communities, Vilsack made support for broader nanocellulose R&D a USDA priority. As a result, UMaine’s nanocellulose pilot plant was established not only as a distribution point for product made at UMaine, but also for cellulose nanocrystals produced by the FPL.
“It’s difficult for companies to do business with the federal government,” says Bilodeau. “There’s a lot of paperwork and a high cost involved. The Forest Products Lab decided to send the material to UMaine to distribute and that was great, because then everybody came to us.
“At first, we thought we might sell about $50,000 worth of samples. We ended up selling several hundred thousand dollars worth,” Bilodeau says. “Then, we started selling truckloads of the stuff because those are the volumes that are required to be able to do the type of prototyping at scale in the paper industry to decide whether it was worth it.”
Scaling up in-house production and becoming a distributor for research and demonstration material jump-started not only UMaine’s nanocellulose research capacity, but also put the university squarely into the business of nanocellulose. With its in-house pulp and paper expertise and the addition of this new material, PDC could not only push the material out into the world, but also show companies how to use it.
“When UMaine started making and distributing cellulose nanomaterials, it caused a massive shift,” says Sean Ireland, who was deeply involved in efforts to ramp up U.S. nanocellulose R&D and is now vice president of business development at FiberLean Technologies, the leading global producer of microfibrillated cellulose.
“Up to that point, if any researcher wanted to work with nanocellulose, it usually took a couple of Ph.D.s a week or more to make a few grams. So that meant you had to really plan your project and you couldn’t take any risks. Instead of pushing the boundaries of R&D and really understanding the basic principles of what you were developing, you had to go after what you needed, and only that. Then, all of a sudden, you could get a 55-gallon drum.
“When this material became available in large quantities, there was an explosion of publications and patents because people were finally able to really start doing development and unlocking the secrets of cellulosic nanomaterials. It probably changed globally the amount of work being done on nanocellulose, but there’s no question that it accelerated the United States,” Ireland says.
Initially, pulp and paper industry companies were PDC’s primary nanocellulose customers — both to buy material and use the pilot facility for contract work that often led to new research discoveries and patents. At the same time, UMaine researchers now had ready access to the material and began exploring applications, some far from the realm of pulp and paper.
“Now the researchers at UMaine were able to apply for federal grant money to research applications,” says Bilodeau. “Biomedical applications, building products, paper products, a whole bunch of different areas that expanded the use of the material.”
UMaine Nanocellulose Sample Distribution
- 50 countries
- Over 600 organizations
- 305 companies
- 276 universities
- 49 government and other entities
Blue indicates countries where PDC has shipped samples. UMaine has shipped almost 4 tons of 1 pound samples of CNF worldwide.
Created with mapchart.net ©
The volume picked up so quickly and the possibilities being discovered — both at UMaine and elsewhere — were so numerous, that Bilodeau, in cooperation with colleagues at FPL, National Institute of Standards and Technology (NIST) and the Technical Association of the Pulp and Paper Industry (TAPPI), put together a book on the topic.
Production and Applications of Cellulose Nanomaterials was published in 2013. Its foreword promises “short research summaries, targeted for a level where they can be understood by non-specialists in the research fields, and with a lot of figures and pictures to help convey the science.” It covered applications, including coating, films, medical, composites, liquid gels and aereogels, and even incorporated cellulose nanocrystals into the overcoat varnish of a vibrant pink, purple and yellow cover that showed a magnified image of cellulose nanofibrils.
For a technical volume, it was a hit.
“All we did was take a look at all the research that was being done and compile it into one book,” says Bilodeau. “It was marketing — we did it as another way to make it known that there were materials available and to show all the different applications. It was published through TAPPI and at the time, it was the most popular technical publication they had done. They actually had a second printing. ”
Bilodeau was seeing that interest firsthand through the nanocellulose-
related contract work coming through PDC.
“If we were working with a client that was utilizing cellulose nanofiber and something commercially interesting came out of the research, they would generally want to file a patent,” Bilodeau says. “Sometimes, we’d get funding to do work ourselves and file patents on those discoveries, and a lot of that was in order to generate more revenue and more traffic through PDC.
“We’d use the patent as a calling card, and it differentiated us from other contract labs because we had something that clients wanted us to demonstrate for them. It kept our books full.”
Established in 2013, the Laboratory of Renewable Nanomaterials led by associate professor of renewable nanomaterials Mehdi Tajvidi is devoted exclusively to applications of cellulose nanomaterials with a special focus on large-volume production and end uses. Tajvidi’s position was created as part of the formation of FBRI and in parallel to UMaine’s increasing profile in nanocellulose production and research.
Tajvidi’s research takes advantage of the tendency that nanofibrils, particularly the type that UMaine produces, have to agglomerate together.
“They bond to each other and bond to things with similar chemical interactions,” says Tajvidi. “That gave us the idea some years ago. What if nanocellulose could actually be used as a binder to replace all these formaldehyde-based binders and other synthetic binders or adhesives? That’s basically my core research, and there are a lot of other things around this, especially dewatering, but these binder properties are present in almost everything that we look at and we use them as an enabling platform to make a lot of different things.”
Among those things are particleboards, fiberboards and laminates of paper (UMaine holds patents for several of these applications) that could be used in everything from construction to interior automotive components to a variety of household items. The lab also is working on a variety of foam products, everything from nanocellulose-wood fiber composites formed in a microwave to a substance that pairs nanocellulose with mushroom-based organic materials. The resulting materials have some intriguing properties, showing strength, water resistance and the ability to withstand extreme temperatures. Assistant research professor Islam Hafez is leading a project that employs a nanocellulose-based foam purification system to remove arsenic from water.
Tajvidi’s lab often collaborates with professor of chemical and biomedical engineering Doug Bousfield, whose research includes exploring the barrier properties that nanocellulose can bring to packaging applications.
“One property that we found, almost 10 years ago, is that a layer of this cellulose nanofiber is a very good oxygen barrier that, under the right conditions, does better than most plastics,” says Bousfield. “And that leads to something more recently that it’s also a good grease and oil barrier.”
Bousfield points to the increasingly controversial use of a group of manufactured chemicals, per- and polyfluoroalkyl substances (PFAS), that have long been widely used for the grease-resistant properties. According to the U.S. Environmental Protection Agency, PFAS can accumulate in the environment and the human body over time, and there is evidence that exposure to the chemicals can lead to adverse human health effects.
“One kind of easy, low-hanging fruit would be to coat cellulose nanofibers onto paper to create that grease barrier so you avoid using those chemicals,” says Bousfield. “That’s one area that I’m really trying to push along and it’s
very simple. Another of my big projects was trying to replace the potato chip bag. A lot of those bags have a metal layer in them, and that’s to get the oxygen barrier that plastics can’t get. We’d like to go to a fully cellulose-based package for chips or granola or all those dry goods that are in plastic, especially metalized plastic, which you can’t recycle if you wanted to.”
Bousfield also is exploring combining nanocellulose with calcium carbonate (a chemical compound found in limestone and other rocks) to create a biodegradable material with properties similar to plastic that could be used to make single-use items such as drink lids and disposable cutlery.
“When you combine cellulose nanofibers with calcium carbonate or some other low-cost pigment and dry it, you get a plastic-like object that, if I handed it to you, you couldn’t tell was made from cellulose,” says Bousfield. “And at the end of use, if you wanted to recycle it, it could go right into a paper recycling system. If someone litters it onto the side of the road, it’s going to break down. If someone throws it in the ocean, it will quickly break down into calcium carbonate and cellulose, which are harmless materials.”
Bousfield is quick to acknowledge technical challenges associated with the applications he’s pursuing, and there are still regulatory questions related to the use of nanocellulose in applications related to food, but says the capability is there, particularly for the grease and oxygen barrier applications.
“The pilot plant can do this already — add a layer at the wet end of the paper machine or through various coating methods,” says Bousfield. “The challenge with coffee cup lids and utensils is getting the right size and shape when you dry them, but I think these problems can be overcome with resources and time to figure it out.”
Doug Gardner is part of a team collaborating with Oak Ridge National Laboratory to launch the first large-scale biobased additive manufacturing program in the U.S. The $20 million initiative involves scores of researchers at UMaine and Oak Ridge, all working to develop next-generation recyclable material systems. Gardner’s background is in surface chemistry, adhesion and wood-based composite materials. Since the earliest days of nanocellulose research at UMaine, he has been concerned with the problem of drying nanocellulose.
“One of the first things I worked on with some of my grad students back in 2006–07 was a literature review around applications of nanocellulose,” says Gardner. “One of the things that kept coming up was that when you make nanocellulose, it’s in water, and if you’re going to use it in situations where you don’t want water, you’ve got to get rid of the water. But when you do that, you lose the nanoscale aspects of the material and it’s a real problem.”
With the help of then-graduate student Yucheng Peng, they landed on spray drying as a fairly successful method and hold a patent on that process. Gardner has more recently pursued ultrasonic spray drying and electrospraying technology, though still confronts the challenge of maintaining the nanoscale properties in drying.
An interest in 3D printing developed separately from nanocellulose, and around 2015, long before UMaine was home to the world’s largest 3D printer, Gardner started thinking about how to replace thermoplastic feedstocks.
“I saw that one pound of thermoplastic filament was selling for $50 or $60, and you could buy those polymers for $1 to $1.50 a pound,” remembers Gardner. “I thought, ‘Well, what if you could make composites?’ That’s what got me into the area — thinking we could put wood and we could put cellulose into these things and make a better filament than just pure plastic.”
For Gardner, the promise of such wood-plastic composites is thrilling.
“Putting a very small amount of this material — 1%, 5% — into a plastic polymer. If you do it right, you can increase the properties by 40, 50, 100%, depending on what the problem is,” says Gardner. “At the millimeter- or micron-length scale, you might get small bumps, a 5 or 10% increase.
“When you get to the nanoscale and you get things
well done, all of a sudden the increases in material properties are just beyond what you think they might be, all because of the nanoscale interactions with plastic.”
Will Gramlich, associate professor of chemistry, oversees a lab that gets to the heart of this type of interaction, and many others.
“We essentially do chemistry to the nanocellulose to try and change its behavior,” says Gramlich. “So, you have your foundational, renewably sourced biobased material, and then we do chemistry to make it have different properties, serve different functions, where they aim to improve it so that it can have different types of applications.”
As such, Gramlich’s team collaborates with many of the others on campus who work with nanocellulose, from huge initiatives such as the Oak Ridge collaboration at the Advanced Structures and Composites Center to individual researchers exploring narrower questions. The lab’s primary focus is on sustainable materials, including hydrogels, derived from nanocellulose.
“One of the unique things about the chemistry that we do in my lab is that we try to do everything in water,” says Gramlich. “My group is focused on sustainable materials. Nanocellulose is sustainable, it has a lot of potential applications, but it also has a lot of challenges. By doing some of the challenging chemistry to the surface of the material, we can help characterize it, answer some of those fundamental questions and challenges, and potentially make something that’s commercially relevant.”
While Gramlich’s lab uses water as a solvent, one of the questions they’re trying to help answer is how to make it easier to remove the water from nanocellulose and to make nanocellulose compatible in applications where it might need to repel water, something it’s not naturally inclined to do.
“For chemists, the fact that it’s in water can be challenging, for applications, that’s challenging, and removing water can be challenging, mostly from a cost standpoint,” says Gramlich. “It’s not compatible for some of the things you want to use it for, and some of the stuff that we do is trying to improve that compatibility — putting it into a plastic, for example.”
The hydrogels that Gramlich’s lab works with have potential for use in biomedical applications, yet another area where nanocellulose shows great promise and one in which UMaine researchers are making new discoveries. Not only is nanocellulose biocompatible — not harmful to living tissue — it also shows intriguing biostatic properties.
Caitlin Howell, assistant professor of biomedical engineering, is deeply interested in these biostatic aspects, whereby nanocellulose doesn’t kill microbes, but also doesn’t let them grow.
“There were all these anecdotes about how you can leave a bucket of this stuff in the pilot plant and it won’t grow anything,” says Howell. “And I thought, ‘No way. This is water and food in a place that’s warm. That’s the recipe for growing stuff. Microbes love that. There’s no way that this doesn’t grow anything.’”
Howell, working with a group of undergraduate students through the FBRI Research Experiences for Undergraduates (REU) program, set out to test this.
“Test after test after test after test proved it,” says Howell. “It actually does not grow anything. This should not be possible. So, one of the research focuses in my group is to figure out what exactly is happening. Why does this material not grow stuff, and how can we make use of that property?
“That biostatic property, for medical applications, could be really big and really important to solving one of the major crises that is bearing down on us right now, antibiotic resistance. The more we can develop technologies that can help mitigate this without making it worse, and at the same time still be using a natural renewable material, would be a huge win.”
David Neivandt, professor of chemical and biomedical engineering, in close collaboration with recently graduated Ph.D. student Nicklaus Carter, has been studying the use of nanocellulose to make nerve conduits — tube-like structures that can be implanted over a peripheral nerve injury site to facilitate natural recovery. Through funding associated with this work, Carter designed and built a clean room at UMaine’s Technology Research Center in Old Town to process nanocellulose under controlled conditions that would make it suitable for use in a medical setting.
“To our knowledge, there isn’t currently a supplier of medical grade cellulose nanofiber,” says Neivandt. “What we set out to create with the clean room was a manner of processing that was entirely reproducible, trackable and consistent.”
This topic also is relevant to the work that professor of biomedical engineering Michael Mason is doing with nanocellulose. Mason’s lab has developed and is in the process of commercializing a nanocellulose composite material for use in orthopedics that promotes the growth of strong natural bone while safely dissolving over time, eliminating the need for metal devices that can be expensive, dense, stiff, prone to infection, and often require costly follow-up surgeries for removal.
Importance of national, international research patnerships
Collaboration with industry has always been a central part of the Process Development Center’s mission and operations, and as the University of Maine has forged ahead with nanocellulose R&D, these relationships are as important as ever. From an exclusive licensing agreement with pulp and paper technologies supplier Valmet that has seen UMaine cellulose nanomaterial production technology installed in commercial facilities around the world to an expansive and groundbreaking multimillion-dollar research collaboration with Oak Ridge National Laboratory, to ongoing research explorations with Sappi, one of the world’s largest manufacturers of paper products and itself a nanocellulose innovator, UMaine is working closely with a range of partners that are all seeking to advance commercialization.
“Our work with UMaine is a productive collaboration that centers around advancing cellulose materials, including nanomaterials, into new markets. We’re doing work in a lot of the same areas. When you’re looking at new engineered materials and you’re trying to get traction in the market, often you might be replacing an incumbent material. And sometimes you’re trying to create a whole new market, which is even more difficult. So, if you’re asking someone who used to use plastic to change to a cellulose material, it takes a lot of work to show them why they should, and UMaine is doing that work. R&D at UMaine is helping to advance the market and advance the industry because the more people are talking about and learning about all the things that cellulose can do, the more comfortable our eventual new customers will be that this material can work. That is really, really valuable.”
Beth Cormier, vice president research, development and sustainability, Sappi North America
“I rely on the University of Maine for having a North American pilot plant where I can bring customers to do out-of-the-box R&D on refining and processing fiber. Valmet has invested significantly in the facilities at the Process Development Center because they provide us the flexibility to work with our customers. At UMaine, we can test new concepts and experiment with different approaches in ways that we can’t anywhere else, and we can do it economically. UMaine’s facilities were built and have been developed specifically for research and application, and the people at UMaine are very open and supportive of our customers and our work. If a customer has a crazy idea they want to try, I know that the team at UMaine will do their best to accomplish it.”
David Cowles, global market development manager, nanotechnologies, Valmet
“The core of our work with Oak Ridge National Laboratory is how to take these cellulose materials — including, but not exclusively nanocellulose — and utilize them within large-area additive manufacturing to create new markets for value-added products from wood. We already know that nanocellulose can be incorporated into the plastic feedstock for printed material to improve its strength. We’re trying to get to a similar performance enhancement, but using less energy intensive and more scalable methods. Our goal is to overcome some of the major roadblocks around affordability and processability of nanocellulose and use it to improve the performance of some of these bio-derived materials. It’s a huge project that is run through the Advanced Structures and Composites Center, but spans across the university. There are probably more than 50 UMaine researchers involved — not to mention graduate students, undergraduates and post-docs — and equal participation at Oak Ridge.”
Susan MacKay, senior R&D program manager, University of Maine Advanced Structures and Composites Center
This patented technology developed at UMaine is a cost-effective, customizable, resorbable, porous platform biomaterial with the potential to help optimize the healing process for patients. It could be used as a synthetic bone, surgical bone scaffold or bone grafting implement, designed for dissolution and gradual replacement with native bone cells.
And the medical applications for nanocellulose don’t stop with humans. Deborah Bouchard, director of the Aquaculture Research Institute, is studying the use of nanocellulose as a component in injectable fish vaccines. Bouchard and a team of aquaculture and engineering experts, including Mason, are investigating how nanocellulose performs as a vaccine adjuvant, a substance that helps boost an immune response and/or a vaccine depot that keeps the antigen of the vaccine in place, and also helps stimulate the intended immune response.
Typically, adjuvants are water- and oil-based and those currently used in fish vaccines are expensive to produce and also can cause some undesirable side effects, including lower growth rates and adhesions and pigmentation around the injection site. These side effects can be particularly problematic in farmed fish production systems.
“Disease is the number one impediment for all aquaculture and vaccines are just as important for controlling disease in fish as they are in humans,” says Bouchard.
“The adhesions and the discoloration can degrade fillet quality, but the growth penalty really adds to costs because it adds to the time spent raising and feeding the fish. Vaccines made with nanocellulose would be cheaper to produce, and if we could eliminate those side effects, it would make operations more efficient and increase production capabilities.”
Bouchard and her team are experimenting with different types of nanocellulose and, so far, it shows promise not only as a reliable adjuvant substance that can help keep the vaccine antigen in place, but also appears not to cause negative side effects. The potential nanocellulose has shown for aquatic animal vaccines has Bouchard mulling a variety of other prospective uses, including as a binder for feed, another area she and her team have begun investigating.
All the newest research initiatives at UMaine and beyond make Colleen Walker smile. Knowingly.
This, she confirms, is what Nanocellulose Valley is all about.
Walker is confident that nanocellulose from UMaine could be the catalyst for discoveries and products that will soon impact lives around the globe.
“In 2019, we had a booth at the TAPPI Nano conference in Japan,” says Walker. “It was nonstop. Everybody came to the booth — all these researchers, companies, everyone knew who the University of Maine was and what we were doing.
“I came back from that trip thinking ‘The world knows who we are,’” she says.
The trick, though, is translating that international research reputation into commercialization in the United States, but Walker has a vision for that, too.
“I would love to see an existing paper mill in Maine build a nanocellulose fiber plant,” says Walker. “If you’re making pulp and paper already, this technology is very easy to use. You add a little slip stream to your existing production and you can use just a little bit of nanocellulose to offset fiber and add strength to your paper.
“They do this a lot in Brazil, and they’re using UMaine’s technology licensed through Valmet. And then, as a joint venture, you could build up around the mill a little innovation park filled with satellite businesses who would get the material directly from the plant and use it for whatever they’re producing.”
Walker is particularly bullish on Maine not just because UMaine’s research expertise could support the development of these innovation businesses, but because the physical mill infrastructure and skilled workforce needed for large-scale nanocellulose production is already in place.
“You have people here who have worked on paper machines, people who know how to handle and process fiber,” says Walker. “All of that is transferable. Even if it’s going into new applications, they know this material, they know fiber. There’s all this knowledge that sits here in the state, and nobody else has that.”
Beyond the job skills, Walker sees something else in Maine — a mindset.
“Papermaking is in people’s souls here,” says Walker. “I came from Georgia, which is another really heavy-duty paper producer, but they treat trees like a crop. Here, it’s a respected resource. People want to take advantage of the resource, but with respect.
“Everything goes back to that respect for the forest, which is just part of the culture.”
The future of food?
You already consume cellulose. In fact, there’s a good chance that you should be eating more of it.
Cellulose is merely fiber — complex carbohydrates that your body can’t entirely digest — and most Americans don’t get enough fiber. Occurring naturally in all plants (e.g. any vegetable you eat), cellulose also is a common food and pharmaceutical additive, offering benefits as an anti-caking agent, emulsifier and texturizer, among other uses. It’s found in everything from Parmesan cheese to pills, and its many applications are sanctioned by the U.S. Food and Drug Administration. Cellulose is on the FDA’s list of substances that are “generally recognized as safe” (often abbreviated as GRAS), a distinction that means the regulator recognizes no hazards related to its use under certain circumstances.
But what about nanocellulose? Researchers have found that it shares many of the same useful properties as cellulose when it comes to food additives, and many of the packaging and other applications being explored could bring nanocellulose materials into direct contact with food and other consumable substances.
While nanocellulose is just cellulose reduced to the nanoscale, U.S. regulators have not yet formalized rules on its safety for food and other applications. Successful commercialization for this range of uses will depend on demonstrating the safety of cellulose nanomaterials, paving the way for the substance to achieve GRAS status, like cellulose.
It’s an issue that Jo Anne Shatkin, president of Boston-based research and consulting firm Vireo Advisors, focuses on daily. Shatkin is an environmental health scientist with expertise in nanoscale technologies, and her firm counsels clients on market and regulatory requirements for new technologies with the goal of advancing a safer and more sustainable economy.
For more than a decade, Vireo has been working on an environmental health and safety road map for cellulose nanomaterials and has assessed different forms of the material in nearly 60 different scenarios to date, studying everything from material handling and inhalation to food safety. While not yet complete, a wide-ranging and collaborative food safety study offers promising initial results.
Researchers working with both public and private funding have completed both animal and cell-based studies using different cellulose nanomaterials, including UMaine CNF. Their results suggest that both cellulose nanocrystals and cellulose nanofibers behave similarly to conventional cellulose and raise no safety concerns, supporting evidence for use in food.
Backed by this research, Vireo is preparing to seek GRAS designation for cellulose nanomaterials and is exploring the pathway for regulatory authorization in non-U.S. markets.
“We still have a couple of endpoints that are outstanding, a bit more work to do for specific applications, but I feel quite confident that we have demonstrated the safety of cellulose nanomaterials,” Shatkin told the audience at UMaine’s Cellulose Nanomaterials Forum in August 2021. “We have the data, now we need the regulatory authorities to agree with us and to put that in writing.”