Wood and Cellulose: Natural Nanomaterials

In our past few posts, we have primarily looked at naturally-occuring nanomaterial sources, such as a crab's claw and silk. Today, for a change, we present to you a potential source of nanomaterials that can easily be found in one's backyard - wood pulp. Before looking into the actual properties and benefits of the nanocellulose, we need to understand the physical properties of cellulose itself.

Cellulose, pictured to the right, with chemical formula (C6H10O5)n, is one of the main components of cell walls in plants. Its primary use in the industry is the manufacturing of paper; the cellulose obtained for this process can be extracted from wood pulp. Cellulose is a polar molecule, as evidenced from its various OH groups, which contribute a dipole movement. It has a high melting point of 773 K, which is a result of its IMF's. Cellulose also is a highly viscous fluid as a result; this poses a problem for manufacturers, as pulp flow is highly difficult. Despite its polarity, cellulose is insoluble in water, meaning that it does not dissociate at all.

Nanocellulose, on the other hand, has physical properties antithetic to those of cellulose. The wood pulp is taken, and gently beaten to reduce to cellulose to thin fibers. The cellulose then takes on a needle like crystalline structure, pictured to the left. The nanocellulose has its most impressive properties once it dries. It has eight times the tensile strength of steel, and is almost as stiff as Kelvar. The US Forest Service, which opened the first nanocellulose lab in the United States at Madison, WI, reports that nanocellulose can sell for just a few dollars per kilo. This has extreme economic implications; if nanocellulose is stronger and cheaper than steel, it could one day replace steel in the industry.

For more information about nanocellulose, check out the embed video right below this post. A few posts later, we will be publishing an interview we had with Fiorenzo Omenetto, Guggenheim Fellow, who worked with silk and its applications as a potential nanomaterial. Stay tuned for more posts.