Cellulose is the most abundant material on Earth. If you take a very close look, perhaps with a magnifying glass, at some kinds of paper – for example, tissue or newsprint – you will be able to see tiny hair-like filaments. Those are pulp fibers made from cellulose. As we all learned in school, paper comes from wood, and wood is made up of tiny fibers made of cellulose that are glued together with other compounds called lignin and hemicellulose. Wood (and other cellulose-rich plants such as cotton) can be shredded into the tiny bits that contain long chains of cellulose polymers – repeating, end-to-end chains of sugar molecules that plants and trees make during the process of photosynthesis.
Clearly, because it is natural and does indeed grow on trees, cellulose is extremely abundant, renewable, and inexpensive. Plant/wood fiber have been added to cementitious materials for centuries for greater strength and durability in finished structures. Indeed, due to its many desirable features, natural cellulose fiber is still a popular and ubiquitous ingredient in the current manufacture of concrete. The advantages of natural cellulose as an additive in concrete include the ability to hold water to keep the cement hydrated during curing; uniform distribution when added to other substances; improvement in both tension resistance and compression resistance, which leads to crack resistance in the finished product; greater temperature resistance; and increased durability. However, adding whole wood or plant fibers has some disadvantages too: the alkaline cement tends to eat away the fiber surface, leading to some loss in strength over time.
The Debut of Nanocellulose
After millennia of adding plant fibers to concrete, a new and very exciting development in the history of cellulose has occurred in just the past 50 years. Cellulose fibers can be further and dramatically reduced in size to their smallest building block, nanocellulose. In its crystallized form, this substance appears as tiny rods that are about 50-300 nanometers (nm) in length and 5-20 nm wide.
“Dr. Plaza has stood out as a committed, engaged, and brilliant scientist working to make the world more sustainable by showing how wood can reduce our dependence on greenhouse gas intensive materials like concrete, steel, and plastic. I have been particularly impressed with her scientific output, her leadership, and her commitment to a better future,” stated Zwick in Plaza’s nomination letter.
The Forest Products Laboratory (FPL), in cooperation with Mississippi State University (MSU), has developed a strong graduate education and research program over the past several years that has attracted outstanding scholars from South America. Many have completed graduate degrees and are now providing leadership in academic, research and industry programs, both here in the United States and abroad.
“I’m very proud of the strong partnership between FPL and MSU,” said Rubin Shmulsky, professor and head of the Department of Sustainable Bioproducts at Mississippi State University. “It’s humbling for me to be a part of this team’s efforts to attract and train the next generation of diverse professionals and leaders in support of sustainable forest products research and development.”
Two Brazilian scientists are excellent examples of how effective this relationship is.
Research Scientist Hongmei Gu has recently been named as the winner of the L.J. Markwardt Award for 2022.
At the awards luncheon on June 15 of this year’s 75th Annual Forest Products Society International Conference, Hongmei received a beautiful plaque and an award check for $1,000.
“This is a total surprise to me!” said Hongmei in her acceptance speech. “I didn’t even know about the award until I heard I’d gotten it. I really, really appreciate this.”
The L.J. Markwardt Wood Engineering Award is intended to encourage research and promote knowledge of wood in the engineering field as a means of enhancing the efficient use of wood. This Award was established in 1969 by L.J. Markwardt, a Charter member of the Forest Products Society, who was for many years an Assistant Director at the USDA Forest Products Laboratory in Madison, Wisconsin, in charge of Wood Engineering Research.