The University of Maine PDC nanoplatform

In a state where pulp and paper mills are struggling to survive, innovations at the University of Maine Process Development Center offer economically stimulating and environmentally sustaining products from small, but significant, plant sources: one found in trees and plants and another in corn. Michael Bilodeau, PDC Director, cites two ongoing projects as currently being at the forefront of the center's work: nanocellulose products, and agricultural mulch film.

Nanocellulose

At the PDC, the mechanical strength imparted to trees and plants by nanocellulose fibrils is being incorporated into building products from sheetrock to fiberboard to foam insulation.

At the Cellulose Nanocrystal Pilot Plant/Forest Products Lab in Madison, Wisconsin, nanocellulose crystals are used to make products that require transparency and/or a gel-like consistency. The Maine and Wisconsin centers cooperate in an effort to advocate and promote the engineering of products using bio-based materials.

Because trees and plants produce about a trillion tons of cellulose per year, it is naturally an inherently sustainable resource. The substance is also found in all wood and plants in any condition, providing "a great way to get rid of diseased and low-grade wood", according to Bilodeau.

For the past twelve years, the PDC has been working to develop a scalable, economic process to produce cellulose nanofibrils. Since 2011, the PDC has entered into a joint venture with the USDA to develop market demand for cellulose nanomaterials made from insect-damaged and dead wood.

Hydrogel

Cellulose nanomaterials, when mixed with water, form a hydrogel, even at very low concentrations. The cellulose nanofibrils (CNF) produced at the PDC form a gel at a ratio of 3% nanocellulose to 97% water. CNFs are often selected for products that require higher strength but don't require transparency.

Various drying techniques determine the density of the end product. Freeze-drying produces a light and fluffy (like freeze-dried food, or Styrofoam) consistency. Air-drying produces a product as dense as plastic.

Fiberboard

The UMaine School of Forest Resources, in conjunction with the Process Development Center, has received funding to develop a fiberboard manufacturing process that uses cellulose nanofibrils instead of formaldehyde-containing binders. The fiberboard product can be used for exterior and interior building materials, such as sheetrock, plywood, and laminate cores.

The Process Development Center will provide samples of cellulose nanomaterials, at cost, to anyone requesting such a sample. So far, it's provided samples to nearly 200 companies, in 37 countries.

CNCs

In Madison, cellulose nanocrystals are being used for products that require a gel-like consistency, and/or transparency. These include nutritional uses (food-thickeners, meat emulsifiers); medical uses (carriers for drugs in the body; wound dressings); and cosmetics (moisturizers, for example).

Because the CNCs don't add calories to food, they're useful in diet foods. And because they're hypoallergenic, they provide less risk of adverse reactions to medical and cosmetic products that contain them. The gel is also used in a thin layer to protect printed images. The FPL sends samples of its CNC hydrogel to the PDC, which in turn distributes samples to interested parties.

Agricultural Mulch Film

Holdout is a patented nontoxic, biodegradable oil- and grease-resistant coating additive made with zein, a corn protein. It replaces paper and packaging coatings that contain synthetic compounds, and was co-developed by Tony Jabar, an entrepreneurial chemist and owner of Cerealus in Waterville,Maine, and scientists at the PDC.

Jabar's Maine-based company, Cerealus LLC, is a client of the PDC. Together, they have developed Agricultural Mulch Film, an eco-friendly crop cover coated with zein and other biodegradable materials, that can effectively duplicate the functions of the black plastic commonly used to suppress weeds, regulate moisture, and increase temperature.

Replacing the traditional plastic with Ag Mulch enables farmers to till it into the soil rather than having to remove it. Additionally, if the plastic has any pesticide residue, it must be disposed of as hazardous waste when removed. Prototypes are being developed in the UMaine greenhouses for field testing, and product will be "going into the ground" in the spring of 2016. Growers using Ag Mulch hope for an improved yield on top of the ecological advantages.

Cerealus and the PDC will be involved in the technical aspects of Ag Mulch, but the search is underway for manufacturers. Some paper mills are being considered as possible production plants. Federal funding is available. The film will be manufactured for use in residential gardens, and both small farms and large farms. Currently, at least three companies are reported to be interested in production.