June 22, 2005 ‹ In some of the
first research to probe how buckyballs will interact
with natural ecosystems, Rice University¹s
Center for Biological and Environmental Nanotechnology
finds that the molecules spontaneously clump together
upon contact with water, forming nanoparticles
that are both soluble and toxic to bacteria.
The research challenges conventional wisdom: since
buckyballs are notoriously insoluble by themselves,
most scientists had assumed they would remain insoluble
in nature. The findings also raise questions about
how the buckyball aggregates dubbed nano-C60 will
interact with other particles and living things
in natural ecosystems.
The findings appear in the June 1 issue of the
journal Environmental Science & Technology.
³The fact that nano-C60 dissolves in water
raises questions about water as a vector for the
movement of these types of materials,² said
Vicki Colvin, CBEN director, professor of chemistry
and a co-author on the study.
Buckyballs are soccer ball-shaped molecules of
60 carbon atoms that were discovered at Rice in
1985. While a few companies are already using trace
amounts of buckyballs in products, large-scale
production of buckyballs is still a year or two
away. Ultimately, companies hope to use buckyballs
in everything from pharmaceuticals to sporting
The research team was led by Georgia Tech environmental
engineer Joseph Hughes and included almost a dozen
Rice collaborators. They found that nano-C60 readily
dissolves in water. The clumps, which measured
between 25 and 500 nanometers in diameter, were
also found to persist for up to 15 weeks in freshwater.
The researchers also exposed nano-C60 to two common
types of soil bacteria.
They found the particles inhibited both the growth
and respiration of the bacteria at very low concentrations ‹ as
little as 0.5 parts per million.
³The antibacterial properties of the C60 aggregates
also raise some interesting questions,² said
Colvin. ³We think it may be possible to harness
those properties for good applications, but we
also advocate continued research on the potentially
negative effects that these materials could have
on the health of natural ecosystems.²
Hughes, the study¹s lead author, said scientists
don¹t yet know enough to accurately predict
what impact buckyballs will have on the environment
or in living systems, but he said the findings
do illustrate the shortcomings of federal guidelines
for the handling and disposal of buckyballs, which
are subject to the same regulations as bulk carbon
³Not all carbon is the same,² said Hughes. ³Graphite
and diamonds are both bulk carbon, for example,
but current standards call for handling them in
completely different ways. Our results suggest
buckyballs also should be handled differently.²
Other Rice collaborators include CBEN Executive
Director Kevin Ausman; Jane Tao, assistant professor
of biochemistry and cell biology; Wenhua Guo, research
scientist; Lawrence Alemany, senior research scientist;
and graduate students J.D. Fortner, D. Y. Lyon,
C.M. Sayes, A.M. Boyd, J.C.
Falkner and E.M. Hotze.
University is consistently ranked one of America¹s best teaching and research universities.
It is distinguished by its: size‹2,850 undergraduates
and 1,950 graduate students; selectivity‹10
applicants for each place in the freshman class;
resources‹an undergraduate student-to-faculty
ratio of 6-to-1, and the fifth largest endowment
per student among American universities; residential
college system, which builds communities that are
both close-knit and diverse; and collaborative
culture, which crosses disciplines, integrates
teaching and research, and intermingles undergraduate
and graduate work. Rice¹s wooded campus is
located in the nation¹s fourth largest city
and on America¹s South Coast.