College of Forestry - Oregon State University

Features
Mixing It Up: The Might of the Matrix
Tiny crystals confer astounding strength
Dwarfs in mythology were often considered
to have magical powers, and so it
seems with the tiny particles known as
nanoparticles. Named from the Greek
word for dwarf, these particles are beyond
small, on the scale of a billionth of a meter. (Imagine
splitting the width of a human hair into 100,000 pieces to
get some idea of their size.) Mixed in a matrix of another
material, however, they confer great strength and other
desirable properties.
“Naturally renewable materials have a legitimate
role in nanotechnology,” says John Simonsen, materials
scientist, Associate Professor of Wood Science and
Engineering, and “card-carrying member” of the Oregon
Nanoscience and Microtechnologies Institute. “Cellulose
nanocrystals in particular are truly remarkable—they’re
stronger than steel and stiffer than aluminum; they’re
organic, biodegradable, biocompatible, and nontoxic.
Furthermore, the chemistry of cellulose is well known,
and we can do lots of chemistry on cellulose fibers that is
straightforward, easy, and relatively ‘green’. ”
Simonsen is interested in nanocrystals as part of a
whole biorefinery concept—taking biological materials,
such as trees, agricultural waste, and straw; putting them
into a factory; separating the biomass into its various
components; doing some chemical engineering; and getting
dozens to hundreds of products. “It’s
just like taking a barrel of crude oil and
refining it into jet fuel, gasoline, and
heating and motor oil,” explains
Simonsen. “If we can do
that, cellulose
nanocrystals
should be cost-effective
and useful for many applications.”
In line with the biorefinery
idea, he has been collaborating
with Jeff Morrell (University
Distinguished Professor, WSE)
and Hong Liu (Assistant Professor,
Biological & Ecological
Engineering) on renewable energy
recovery using microbial
fuel cells that would directly
convert organic matter from
waste biomass to electricity.
Simonsen also has been exploring
the properties afforded
to materials by inclusion of cellulose
nanocrystals in diverse
other applications. In one project,
he used cellulose nanocrystals
to create films that bar
toxic agents but allow moisture
to pass through a fabric. Such
a film could be applied to protective
clothing in industrial
uses. He also has been investigating
the use of cellulose
nanocrystals in hemodialysis
tubing for use in a home dialysis
unit being developed in the
OSU Department of Chemical Engineering. “Such a unit
would make dialysis much more efficient, and patients
could use it overnight at home instead of spending hours
every week at a dialysis center,” says Simonsen. “It would
be easier on the body, cut drug use, and greatly improve
the quality of life for these patients.”
Not leaving behind his long-standing interests in
wood preservation and the properties of wood-polymer
composites, Simonsen has been collaborating with Morrell
and Lech Muszyński, Assistant Professor of Wood
Science and Engineering, to determine the properties of
wood-plastic composites and the mechanisms and effects
of biological degradation.
“When I came here 16 years ago, what I wanted to
do was something useful. I’m still working on it!” says
Simonsen. It sounds like he’s on the right track.
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