department+of+chemistry
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Ten Breakthroughs of the Year 2011 by Science
Porous Zeolite Crytals
Science, an internationally renowned scientific journal based in the US, has recently released a special issue of “Breakthrough of the Year, 2011,” dated December 23, 2011. In the issue, the journal introduces ten most important research breakthroughs made this year, and Professor Ryong Ryoo, Department of Chemistry at KAIST, was one of the scientists behind such notable advancements in 2011. Professor Ryoo has been highly regarded internationally for his research on the development of synthetic version of zeolites, a family of porous minerals that is widely used for products such as laundry detergents, cat litters, etc. Below is the article from Science, stating the zeolite research:
For Science’s “Breakthrough of the Year, 2011”, please go to:
http://www.sciencemag.org/site/special/btoy2011/
[Excerpt from the December 23, 2011 Issue of Science]
Industrial Molecules, Tailor-Made
If you ever doubt that chemistry is still a creative endeavor, just look at zeolites. This family of porous minerals was first discovered in 1756. They"re formed from different arrangements of aluminum, silicon, and oxygen atoms that crystallize into holey structures pocked with a perfect arrangement of pores. Over the past 250 years, 40 natural zeolites have been discovered, and chemists have chipped in roughly 150 more synthetic versions.
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Porous zeolite crystals are widely used as filters and catalysts. This year, researchers found new ways to tailor the size of their pores and create thinner, cheaper membranes.
CREDIT: K. VAROON ET AL., SCIENCE334, 6052 (7 OCTOBER 2001)
This abundance isn"t just for show. Three million tons of zeolites are produced every year for use in laundry detergents, cat litter, and many other products. But zeolites really strut their stuff in two uses: as catalysts and molecular sieves. Oil refineries use zeolite catalysts to break down long hydrocarbon chains in oil into the shorter, volatile hydrocarbons in gasoline. And the minerals" small, regularly arranged pores make them ideal filters for purifying everything from the air on spaceships to the contaminated water around the nuclear reactors destroyed earlier this year in Fukushima, Japan.
Zeolites have their limitations, though. Their pores are almost universally tiny, making it tough to use them as catalysts for large molecules. And they"re difficult to form into ultrathin membranes, which researchers would like to do to enable cheaper separations. But progress by numerous teams on zeolite synthesis this year gave this “mature” area of chemistry new life.
Researchers in South Korea crafted a family of zeolites in which the usual network of small pores is surrounded by walls holed with larger voids. That combination of large and small pores should lead to catalysts for numerous large organic molecules.
Labs in Spain and China produced related large- and small-pore zeolites by using a combination of inorganic and organic materials to guide the structures as they formed.
Meanwhile, researchers in France and Germany discovered that, by carefully controlling growth conditions, they could form a large-pore zeolite without the need for the expensive organic compounds typically used to guide their architecture as they grow. The advance opens the way for cheaper catalysts. In yet another lab, researchers in Minnesota came up with a new route for making ultrathin zeolite membranes, which are likely to be useful as a wide variety of chemically selective filters.
This surge of molecular wizardry provides a vivid reminder that the creativity of chemists keeps their field ever young.
Related References and Web Sites
2011.12.23 View 11408 -
Scientists develop highly efficient industrial catalyst
http://english.yonhapnews.co.kr/business/2011/07/14/48/0501000000AEN20110714009600320F.HTML
SEOUL, July 15 (Yonhap) -- South Korean scientists said Friday that they have developed a highly efficient nanoporous industrial catalyst that can have a considerable impact on chemical and oil-refining sectors.
The team of scientists led by Ryoo Ryong, a chemistry professor at the Korea Advanced Institute of Science and Technology (KAIST), said the solid zeolite compound developed in the laboratory has a reaction speed five to 10 times faster than that of conventional materials.
Zeolite, which is made from silica and aluminium, is frequently used as an absorbent, water purifier and in nuclear reprocessing, although it is mainly employed in the chemical industry.
The annual size of the zeolite market is estimated at US$2.5 billion with output using the material topping $30 billion. At present, 41 percent of all catalysts used in the chemical sector are nano-scale zeolite materials.
The KAIST team said that because the new zeolite is made up of different sized pores, the material can be used as a catalyst when existing materials are unable to act as a changing agent.
"Existing zeolites only have pores under 1 nanometer in diameter, but the new material has holes that range from 1 nanometer to 3.5 nanometers, which are all arranged in a regular honeycomb arrangement," Ryoo said. A nanometer is one-billionth of a meter.
He said the ability to have both micro- and meso-sized pores is key to the faster reaction speed that is an integral part of raising efficiency. The South Korean researchers used a so-called surfactant process to make the different sizes of pores.
The development is a breakthrough because researchers and companies such as Exxon Mobil Corp. have been trying to build zeolite with different sizes of pores for the past two decades without making serious headway. There are more than 200 different types of zeolites in the world.
Ryoo, who received funding from the government, has requested intellectual property rights for the discovery, which has been published in the latest issue of Science magazine. He also developed another zeolite in the past that can transform methanol to gasoline up to 10 times more efficiently than existing catalysts.
Exxon Mobil has expressed interest in the two zeolites made by Ryoo"s team. Undisclosed South Korean petrochemical companies have also made inquiries that may lead to commercial development in the future.
"There are some technical issues to resolve, mainly related with mass production and stability," the scientist said.
He said full-fledge production will be determined by how much companies are willing to spend on research to speed up development that can bring down overall production costs.
The KAIST team said it took two years to make the new zeolite, which can be custom made to meet specific needs.
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2011.07.15 View 11361 -
Biomimetic Carbon Nanotube Fiber Synthesis Technology Developed
The byssus of the mussel allows it to live in harsh conditions where it is constantly battered by crashing waves by allowing the mussel to latch onto the seaside rocks. This particular characteristic of the mussel is due to the unique structure and high adhesiveness of the mussel’s byssus.
KAIST’s Professor Hong Soon Hyung (Department of Material Science and Engineering) and Professor Lee Hae Shin (Department of Chemistry) and the late Professor Park Tae Kwan (Department of Bio Engineering) were able to reproduce the mussel’s byssus using carbon nanotubes.
The carbon nanotube, since its discovery in 1991, was regarded as the next generation material due to its electrical, thermal, and mechanical properties. However due to its short length of several nanometers, its industrial use was limited.
The KAIST research team referred to the structure of the byssus of the mussel to solve this problem.
The byssus is composed of collagen fibers and Mefp-1 protein which are in a cross-linking structure. The Mefp-1 protein has catecholamine that allows it to bind strongly with the collagen fiber.
In the artificial structure, the carbon nanotube took on the role of the collagen fibers and the macromolecular adhesive took on the role of the catecholamine. The result was a fiber that was ultra-light and ultra-strong.
The results of the experiment were published in the Advanced Materials magazine and is patent registered both domestically and internationally.
2011.06.20 View 11817
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Artificial Spore Production Technology Developed
The core technology needed in the development of ‘biosensors’ so crucial in diagnosing illnesses or pathogens was developed by Korean research team.
KAIST’s Professor Choi In Seung of the department of Chemistry developed the technology that allows for the production of Artificial Spore by selectively coating a live cell.
In the field of engineering the problem in developing the next generation bio sensor, the cell based sensor, was that it was difficult to keep a cell alive without division for a long time. Once a cell is taken out of the body, it will either divide or die easily.
Professor Choi’s research team mimicked the spore, which has the capability to survive harsh conditions without division, and chemically coated a live cell and artificially created a cell similar to that of a spore.
The physical and biological stabilities of the cell increased by coating an artificial shell over the yeast cell. The shell is composed with a protein similar to that of the protein that gives mussels its stickiness. In addition by controlling the thickness of the shell, the division rate of the yeast can be controlled.
Professor Choi commented that this technology will serve as the basis for the single cell based biosensor.
The research was conducted together with Professor Lee Hae Shin of KAIST department of Chemistry and Professor Jeong Taek Dong of Seoul National University’s department of Chemistry and was published as the cover paper of ‘Journal of the American Chemical Society’.
2011.04.01 View 11902
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Nanowire crystal transformation method was newly developed by a KAIST research team.
Figure 1
Schematic illustration of NW crystal transformation process. FeSi is converted to Fe3Si by high-temperature thermal annealing in diluted O2 condition and subsequent wet etching by 5% HF.
Figure 2
Low-resolution TEM images of FeSi; Fe3Si@SiO2 core—shell; Fe3Si NW after shell-etching; and Scale bars are 20 nm
Professor Bongsoo Kim of the Department of Chemistry, KAIST, and his research team succeeded to fabricate Heusler alloy Fe3Si nanowires by a diffusion-driven crystal structure transformation method from paramagnetic FeSi nanowires. This methodology is also applied to Co2Si nanowires in order to obtain metal-rich nanowires (Co) as another evidence of the structural transformation process. The newly developed nanowire crystal transformation method, Professor Kim said, would be valuable as a general method to fabricate metal-rich silicide nanowires that are otherwise difficult to synthesize.
Metal silicide nanowires are potentially useful in a wide array of fields including nao-optics, information technology, biosensors, and medicine. Chemical synthesis of these nanowires, however, is challenging due to the complex phase behavior of silicides.
The metal silicide nanowires are grown on a silicon substrate covered with a thin layer of silicon oxide via a simple chemical vapor deposition (CVD) process using single or multiple source precursors. Alternatively, the nanowires can be grown on the thin silicon oxide film via a chemical vapor transport (CVT) process using solid metal silicide precursors.
The CVT-based method has been highly effective for the syntheses of metal silicide NWs, but changing the composition of metal silicide NWs in a wider range, especially achieving a composition of a metal to silicon, has been quite difficult.
Thus, developing efficient and reliable synthetic methods to adjust flexibly the elemental compositions in metal silicide NWs can be valuable for the fabrication of practical spintronic and neonelectronic devices.
Professor Kim expliained, “The key concept underlying this work is metal-enrichment of metal silicide NWs by thermal diffusion. This conversion method could prove highly valuable, since novel metal-rich silicide NWs that are difficult to synthesize but possess interesting physical properties can be fabricated from other metal silicide NWs.”
The research result was published in Nanao Letters, a leading peer-reviewed journal, and posted online in early August 2010.
2010.08.25 View 10424 -
New Text Book on Chemistry Published by KAIST Professor and Student
A chemistry textbook written in English and Korean will aid Korean students to learn General Chemistry in a global academic setting.
Korean students majoring in chemistry and looking for an opportunity to study abroad will have a new, handy textbook that presents them with a practical introduction to an English speaking lecture on general chemistry.
Aiming for advanced Korean high school and college/university students, the inter-language textbook is written by two incumbent professors teaching chemistry at a university in Korea and the US. The book will help Korean students prepare for a classroom where various topics of general chemistry are presented and discussed in English. Clear, collated sections of English and Korean text provide the student with sufficient explanation of the rudimentary topics and concepts.
Composed of 15 chapters on the core subjects of General Chemistry, i.e., Stoichiometry and Chemical Reactions, Thermochemistry, Atomic Structure, and Bonding, the textbook includes essential English vocabulary and usage sections for each chapter; it also contains a pre-reading study guide on the subject that prepares the student for listening to a lecture. This section includes view-graph type slides, audio files, and follow-up questions the student can use to prepare for an English-speaking course. The various accompanying audio files are prepared to expose the student to English scientific dialogue and serve as examples for instruction at Korean secondary and tertiary schools.
The book was coauthored by Korean and American scientists: A father and son, who have taught chemistry at an American and Korean university, wrote the book. Professor Melvyn R. Churchill at the State University of New York at Buffalo and Professor David G. Churchill at KAIST prepared all of the technical English text which was adapted from General Chemistry course lecture notes; the text was further shaped by original perspectives arising from many student interactions and questions.
This English text was translated into Korean by Professor Kwanhee Lee from the Department of Life and Food Science at Handong Global University, who coauthored a previous preparatory book for Korean students in a different subject. He also supplied an important introductory section which serves as a general guide to the classroom student. Kibong Kim, a doctoral student in the Department of Chemistry at KAIST, helped in preparing the book as well.
“This has been definitely a collaborative undertaking with an international academic crew and it underscores that the Korean internationalization in science is mainstream. Professors and a Korean student created a new book for Korean consumption and benefit,” Professor David G. Churchill says.
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Bibliography: “How to Prepare for General Chemistry Taught in English” by David George Churchill, Melvyn Rowen Churchill, Kwanhee Lee & Kibong Kim, Darakwon Publishing, Paju, Republic of Korea, 2010, 400 pp, ISBN 978-89-5995-730-9 (1 Audio CD included)
2010.04.02 View 13513
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Prof. Ryoo's Team Discovers Breakthrough Method to Create New Zeolite
A group of scientists led by Prof. Ryong Ryoo of the Department of Chemistry, KAIST, has found a method to direct the growth of zeolite, a crystalline substance that is frequently used as catalyst in the chemical and petrochemical industries, the university authorities said on Thursday (Sept. 10).
Ryoo"s research team successfully created ultrathin nano-sheets, only two nano-meters thick, that are efficiently used as long-life catalysts for hydrocarbon cracking and other petrochemical applications. The breakthrough finding, which is credited with taking acidic zeolite catalysts to the limit in terms of thickness, was published in the latest edition of the peer-review journal, "Nature."
A team from the Polytechnic Univeristy of Valencia, Spain, also contributed to the research.
Zeolites are already widely used in the petrochemical industry, but making the catalysts very thin means that reactant molecules can easily diffuse into the zeolite structure and product molecules can get out quickly. This improves the efficiency of the catalyst and reduces unwanted side reactions that can produce polymeric hydrocarbon "coke" that clogs the zeolite pores and eventually kills the catalytic activity, Prof. Yoo said.
To make the thin sheets, Ryoo and his team used a surfactant as a template to direct the growth of the zeolite structure. The surfactant molecule has a polar "head" group - with two quaternary ammonium groups around which the aluminosilicate zeolite crystal grows - and a long hydrocarbon "tail," which prevents the sheets from aggregating together into larger, three dimensional crystals. When the surfactant is removed, these flakes pile up randomly with gaps in between which further aids diffusion to the catalyst sites.
"Zeolite could be used as a catalyst to convert heavy oil into gasoline. Our new zeolite could provide even more possibilities, such as being used as catalysts for transforming methanol into gasline," Ryoo said.
Prof. Ryoo, a Distinguished Professor of KAIST, has won a variety of academic awards, which included the Top Scientist Award given by the Korean government in 2005 and the 2001 KOSEF Science and Technology Award for his work on the synthesis and crystal structure of mezzoporous silica.
Ryoo obtained his bachelor"s degree from Seoul National University in 1977, master"s from KAIST in 1979, and doctorate from Stanford University in 1985.
In 2006, Ryoo and his research team announced the discovery of a form of zeolite that can catalyze petrochemical reactions much more effectively than previous zeolites. Because of the potential of this to streamline the gasoline refining process, it was greeted as a "magical substance" by the South Korean press.
2009.09.11 View 11801 -
Prof. Song Develops Nano-Structure to Enhance Power of Rechargeable Lithium-ion Battery
A team of scientists led by Prof. Hyun-Joon Song of the Department of Chemistry, KAIST, developed a nano-structure that could increase the power of rechargeable lithium-ion batteries, university sources said on Monday (Feb. 16).
The research team found that a nano-structured material using copper oxide (CuO) could produce lithium-ion batteries with some 50 percent more capacity than conventional products. The study was published in the online edition of peer-review journal Advanced Materials.
In rechargeable lithium-ion batteries, lithium ions move between the battery"s anode and cathode. The high-energy density of the batteries led to their common use in consumer electronics products, expecially portable devices. Their demand in automotive and aerospace applications is growing, and nano-structured, or nano-enabled batteries are emerging as the new generation of lithium-ion batteries for their edge in recharging time, capacity and battery life.
Graphite has been a popular material for cathodes in lithium-ion batteries. However, graphite cathodes are also blamed for lost capacity due to their consumption of lithium ions, which are linked to shorter battery life.
As such, scientists have been looking for materials that could replace graphite in cathodes, and silicon and metal oxide have been studied as possible alternatives.
2009.02.17 View 11272
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KAIST Professor Exposes Structural Dynamics of Protein in Solution
-- Dr. Hyot-Cherl Ihee"s 3-Year Research Is Valuable in Pharmaceutical Application
Prof. Hyot-Cherl Ihee and his team at the Department of Chemistry, KAIST, has successfully unveiled the structural dynamics of protein in solution as a result of more than three years" research work.
Nature Methods, a sister publication of the authoritative science magazine Nature, published the treatise, titled "Tracking the structural dynamics of proteins in solution using time-resolved wide-angle X-ray scattering" in its Sept. 22 online edition. The research paper will be carried in the magazine"s printed version in its October edition, according to Dr. Lee who is its correspondence author.
In May 2005, Prof. Ihee successfully photographed the structural dynamics of protein in solid state and his findings were published in the Proceedings of National Academy of Science of the United States. As protein normally exists in human body in solution, not in solid state, he directed his research to developing the technology to capture protein"s dynamics in resolved state.
In July that year, Prof. Ihee succeeded in measuring the structural changes of simple organic molecules in real time. He further developed the technology to uncover the structural dynamics of hemoglobin, myoglobin and cytochrome C.
Prof. Ihee"s research, helped with the Education-Science-Technology Ministry"s Creative Research Promotion Fund, can be applied to new pharmaceutical development projects as well as nanotechnology development, according to KAIST officials.
Prof. Ihee who earned his doctorate at California Institute of Technology in 1994 began teaching at KAIST in 2003. He won the Young Scientist Award given by the Korean government in 2006.
2008.09.22 View 12618 -
Professor Jie-Oh Lee of the Department of Chemistry of KAIST
Professor Jie-Oh Lee of the Department of Chemistry of KAIST was selected as the "KAIST Man of the Year."
Lee was cited for his successful identifying of the three-dimensional structure of protein that causes sepsis. His research is expected to contribute greatly to the development of medicines for immune system treatment.
The prize was given by KAIST President Suh Nam Pyo at the New Year"s ceremony on Jan. 2, 2008 at the KAIST auditorium.
Professor Lee published a series of research papers in Science, one of the world"s most prestigious scientific journals. Most recently, Lee was awarded the "Scientist of the Year" prize by the Korean Science Reporters Association.
2008.01.02 View 13457 -
Professor Jie-Oh Lee awarded 'Scientist of the Year'
Professor Jie-Oh Lee of the Department of Chemistry was awarded the ‘Scientist of the Year’ prize for identifying the three-dimensional structure of protein that causes sepsis, and it was announced by the Korean Science Reporters Association (KOSRA) on November 26th.“Humans have about 30,000 different kinds of proteins, and they all have different structures, just like our faces,” said Professor Lee. “It is extremely helpful to know the three-dimensional shape of proteins when you are trying to understand what their functions in an organism are and trying to develop medicine for them.”
When looking for the three-dimensional structure, protein must first be crystallized and radiated with x-ray, so that reflected x-ray can be interpreted. The three-dimensional structure of sepsis immunity proteins TLR1-TLR2 and TLR4-MD2 could not be found until now because they would not even crystallize.
“I began to doubt if it was even possible to crystallize them because we went through so many failures,” reflected Professor Lee.
In August of last year, after about three years of research, the team finally came up with a new idea. The team decided to ‘stick’ the sepsis immunity protein to protein that easily crystallizes. If the combined structure of sepsis immunity protein and the known protein could be identified, the structure of sepsis immunity protein would be a combined structure subtracted by the known structure.
The three-dimensional structure was obtained with x-ray radiation from combined protein crystal. The combined protein was derived from an insect cell with altered DNA.
“This method seems very simple but no one ever tried it or no one ever succeeded in it,” said Professor Lee.
The result was a horseshoe shaped protein structure. The research team also expects the new protein-combining technology to contribute to the development of a new immune system treatment medicine.
The prize-awarding ceremony was held on November 26th in an event hosted by the Korean Hospital Association.
Also, Professor Ryong Ryoo of the Department of Chemistry was selected as the National Scientist last month.By KAIST Herald on November, 2007
2007.12.21 View 13071 -
Professor Churchill listed on international biographical dictionary
Professor Churchill listed on international biographical dictionary
Professor David G. Churchill (Department of Chemistry) is listed in Who’s Who in the World in its edition for 2007, international biographical dictionary published by Marquis Who’s Who.
Professor Churchill majored in Organometallic Chemistry and Chemistry of Complex at Colombia University in U.S. and began lectures at KAIST Chemistry department in July 2004.
Professor Churchill has presented 56 papers as member of the American Chemical Society and the Korea Chemical Society and is recognized for his excellent research performances. Recently, he is studying on a method to sense and counteract various toxic nervous substances by bonding them with metals.
2006.11.08 View 16151