From the Special Topic of
According to our Special Topics analysis of mesoporous
materials research over the past decade, the work of
Professor Osamu Terasaki ranks at #6 by total cites, by
number of papers, and by cites/paper, with 64 papers cited
a total of 2,910 times to date. Three of his papers also
appear on the list of the 20 most-cited papers in this
Topic over the past decade.
Science IndicatorsSM from
Reuters, Professor Terasaki's citation record includes
170 papers, mainly found in the fields of Chemistry and
Materials Science, cited a total of 6,314 times between
January 1, 1998 and June 30, 2008.
Professor Terasaki is the Head of Structural Chemistry, in the
Department of Physical, Inorganic & Structural Chemistry at the
University of Stockholm in Sweden a position he has held since 2003.
In the interview below,
ScienceWatch.com correspondent Gary Taubes talks with
Professor Terasaki about his highly cited work.
How did your research on mesoporous
I was in the physics department at Tohoku University in Japan, in the late
1990s, studying microporous crystals called zeolites. I came across a paper
from Shinji Inagaki on the mesoporous material FSM-16 and I thought it was
something I should study—especially its crystal symmetry and growth
procedure. I contacted Inagaki, and together we worked on and published a
paper in the journal Microporous and Mesoporous Materials
suggesting that the "folded sheet mechanism" he had discussed in his
original paper had to be modified. We’ve continued to collaborate
Your most-cited article discusses nanoporous
arrays (Joo SH, et al., "Ordered nanoporous arrays of carbon
supporting high dispersions of platinum nanoparticles,"
Nature 412: 169-72, 12 July 2001). What’s the
connection there with mesoporous materials?
We were interested in arrayed nanostructured materials within crystals.
"Mesoporous" means the material has pores 20 to 100 angstroms in diameter.
These materials are crystals, which mean the pores are imbedded in
amorphous silica and are arranged periodically. Then we can study entirely
new materials, like nano-network materials, synthesized in the pores of the
When you published the paper on nanoporous
materials in Nature, were you aware of how significant it
"These materials can be used or can
be useful for drug delivery and biomedical
Well, it is embarrassing that I wasn’t aware of the importance of
carbon, which is what we were using in that paper. Ryong Ryoo is a very
clever guy and he knows about the actual requirements in the real world. He
was the one who developed nano-casted carbon, synthesized composite with Pt
nano-particles and thought this paper was important. So, no, I never
suspected this paper would be so highly cited.
On the other hand, our 1999 JACS paper with Inagaki (Inagaki S,
et al., "Novel mesoporous materials with a uniform distribution of
organic groups and inorganic oxide in their frameworks," JACS 121:
9611-4, 1999), that one I thought from the very first would get a lot of
attention. This was unfortunately rejected by Nature but
was accepted by JACS within a month. I cannot understand why after
our paper appeared in JACS, Nature published a paper on
the same topic.
Why do you think they rejected yours?
They said it was too specialized; that Nature is a general
interest journal and this was paper was of narrow interest. It seems from
their latter publication that they changed their mind.
Why did you choose Nature to begin
Because it is a general interest journal. If we were successful with
Nature we’d attract many more readers, and, to be honest,
that’s quite helpful in receiving a research grant. We published one
paper in Nature—Sakamoto Y, et al., "Direct imaging
of the pores and cages of three-dimensional mesoporous materials,"
Nature 408(6811): 449-53, 23 November 2000—followed by a few
more Nature papers. These helped me a lot in raising research
What do you consider the most challenging aspects
of research on mesoporous and nanoporous materials?
Personally, I am not good at making these materials. I worked with a Ph.D.
student in Yokohama University named Shunai Che who can do this, and she is
now a Cheung Kong Professor in Shanghai and one of my most important
material suppliers. Ryong, Inagaki, and Dong Yuan Zhao can also make the
novel materials, and my group extends the method to solve/characterize the
structures of new crystals and then we publish together.
Even for the chemists, it’s not easy to create highly crystalline
materials. These materials inevitably contain various kinds of defects.
They’re also electron-beam sensitive, which means they are easily
damaged during the electron microscope observation. If you use X-ray
diffraction you can only detect a few reflections, so it's impossible to
obtain enough information for structural solution from the X-ray powder
diffraction. We can do it with our method, and, as far as I know,
we’re the only ones to ever solve three-dimensional mesoporous
How does your method work?
I think it’s deceptively simple. We take high-resolution electron
microscope images, and from these images we obtain Fourier
diffractograms—like electron diffraction patterns, but these also
contain the phase information of structure factors. This phase information
is essential to solving the structure—that’s our advantage.
Once we’re able to get the phase information, then we can obtain
unique structural solutions. This is the method we described in the 2000
How rapidly has the state of knowledge in your
field evolved since your 1999 paper with Inagaki?
I think we built a lot of the conceptual framework when I was in Japan,
before 2003. After that, we’ve received interesting new materials, so
we’ve been extending the method further to new materials. Recently
Miyasaka and I developed quite a big step; however, this was rejected by
Nature. We’ll submit it to another high-ranking journal.
What was the new step?
"...as far as I know, we’re
the only ones to ever solve three-dimensional
In our previous method described in Nature in 2000, we solve the
structure with the help of gas adsorption data, therefore we can solve only
after the surfactant is removed. Now we have proposed a way to solve the
structure and to provide pore volume and surface area with the surfactant
intact. That means we can solve it in its synthesized state. As prepared,
these crystals contain a lot of surfactant, and when you want to use these
mesoporous materials—for drug delivery, for example—then an
existence of the surfactant is important. It can stabilize/protect a drug
or peptide in these materials. It can contribute to slow delivery of the
drug, so you want the structure with the surfactant, ideally.
I hate to ask this question, but why did
Nature reject it?
Again, they said this was too specialized for them.
Where do you see your research going in the next
I have to retire in one and a half years and I hope to contribute a little
to society before I do. These materials can be used or can be useful for
drug delivery and biomedical applications. In the one and a half years I
have left until retirement, I want to be able to show the potential of
these materials for those kinds of purposes—that they can really be
useful for society. One and a half years can be a short time or a long
time—it’s all in your perspective. Since I only moved here five
and a half years ago, I hope I will be able to do this and make it truly
Why did you leave Japan for Stockholm and do it so
late in your career?
I worked as an academic staff in the same place, Department of Physics,
Tohoku University for more than 36 years. A big change in the Japanese
university system had started, and I thought this would be the last chance
for me to restart. During my career, I spent time at Cambridge for one and
a half years, and also 15 years ago I was a guest professor at Lund
University in Sweden. Cambridge is extremely active in science; however,
from my perspective, Sweden was the most attractive country. I wanted to
start from the beginning with young scientists, and Sweden was ideal. So
when this position was announced, I applied for it and I am happy to say
that I got it.
Which of your professional achievements brings you
the most satisfaction?
I think this Nature paper with Sakamoto. This is unique. As I told
you, all mesoporous crystal structures that have ever been solved were
solved by us. The method itself is very simple. Everything is described in
this Nature paper, and I hope many scientists will use the method
on a daily basis. So the development of this methodology to solve structure
of mesoporous crystals is the most satisfying.
Professor Osamu Terasaki
Department of Physical, Inorganic & Structural Chemistry
University of Stockholm
Keywords: mesoporous materials, nanoporous arrays, carbon,
pores, cages, imaging, three-dimensional mesoporous structures,
highly crystalline materials, high-resolution electron microscopy,