Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Scientists at Tokyo Tech have developed a new self-assembled nanostructure that can survive very hot or saline environments

Fig. 1 The team used linear and cyclic block copolymers to create flower-shaped micelles. The cyclic-based micelles withstood considerably higher temperatures and salinity levels, and could have numerous applications in industry and green chemistry.
Fig. 1 The team used linear and cyclic block copolymers to create flower-shaped micelles. The cyclic-based micelles withstood considerably higher temperatures and salinity levels, and could have numerous applications in industry and green chemistry.

Abstract:
Nanostructures that assemble themselves from polymer molecules could prove to be useful tools in chemistry and industry. However, it is difficult to develop structurally robust self-assembling materials because they are often adversely affected by their surroundings.

Scientists at Tokyo Tech have developed a new self-assembled nanostructure that can survive very hot or saline environments

Tokyo, Japan | Posted on May 27th, 2013

Many natural organisms have evolved to protect themselves in hostile environments. For example, types of archaea - single-cell microorganisms living in hot springs - have cyclic molecules in their cell membranes that form shields to preserve the cell under extreme heat.

Inspired by nature's use of cyclic structures, Takuya Yamamoto and co-workers at the Department of Organic and Polymeric Materials, Tokyo Institute of Technology, have dramatically enhanced both the thermal and salt stability of self-assembling polymeric structures, simply by changing the shape of the founding polymers from linear to cyclic.

The team designed new block copolymers - structures comprising several polymers connected by covalent bonding - which self-assembled into shapes called micelles (Fig.1). Micelles have a hydrophilic (water-attracting) outer membrane, and a hydrophobic (water-repelling) core.

"We designed a cyclic amphiphilic block copolymer by mimicking fat molecules in the cell membrane of archaea," explains Yamamoto. "Both linear and cyclic copolymers were then used to create identical self-assembling flower-shaped micelles." The team discovered that although the chemical composition, concentration and dimensions of micelles built from the two differently shaped block copolymers remained the same, the cyclic-based micelles were able to withstand higher temperatures.

"The micelle from cyclic block copolymers withstood temperatures up to 40°C higher than the linear-based micelles," explains Yamamoto. The researchers found that the tail ends of the linear copolymers were more likely to break loose from the flower-shaped structure during heating, allowing for bridging between micelles to occur. This meant that the micelles join together in an agglomerate blob at a relatively low temperature. The micelles created by the cyclical copolymers, on the other hand, had no ‘loose ends' to form bridges, meaning the structures remained stable up to far higher temperatures.

The same structural differences allow for a greater tolerance of salt concentrations in the cyclic-based micelles. The loose tails in linear-based micelles allowed rapid dehydration to occur in highly saline environments, whereas the closed cyclic structures are structurally stronger, making them more resilient to salt.

"The combination of higher salting-out concentrations and thermal resistance means these micelles have numerous potential applications," explains Yamamoto. "Possibilities include drug delivery systems, where heating is not possible and salt provides an alternative method for controlling how a micelle responds in order to release a drug." The team also hope that their micelles could provide the basis for many new materials in the field of green chemistry, because their structural robustness is based purely on their shape rather than on complex chemical reactions.

Reference:

1 S. Honda et al. Topology-directed control on thermal stability: micelles formed from linear and cyclized amphiphilic block copolymers. JACS Communications, published online July 2010.

2 S. Honda et al. Tuneable enhancement of the salt and thermal stability of polymeric micelles by cyclized amphiphiles. Nature Communications 4, Mar 2013.

####

About Tokyo Institute of Technology, Center for Public Information
As one of Japan’s top universities, Tokyo Institute of Technology seeks to contribute to civilization, peace and prosperity in the world, and aims at developing global human capabilities par excellence through pioneering research and education in science and technology, including industrial and social management. To achieve this mission, we have an eye on educating highly moral students to acquire not only scientific expertise but also expertise in the liberal arts, and a balanced knowledge of the social sciences and humanities, all while researching deeply from basics to practice with academic mastery. Through these activities, we wish to contribute to global sustainability of the natural world and the support of human life.

For more information, please click here

Contacts:
Miwako Kato and Yukiko Tokida, Center for Public Information

Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan

Tel: +81-3-5734-2975, Fax: +81-3-5734-3661

Copyright © Tokyo Institute of Technology, Center for Public Information

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Nano-supercapacitors for electric cars July 25th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Chemistry

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Fundamental Chemistry Findings Could Help Extend Moore’s Law: A Berkeley Lab-Intel collaboration outlines the chemistry of photoresist, enabling smaller features for future generations of microprocessors July 15th, 2014

Researchers discover boron 'buckyball' July 14th, 2014

Highlights for 2014 national meeting of world’s largest scientific society July 8th, 2014

Self Assembly

Berkeley Lab researchers create nanoparticle thin films that self-assemble in 1 minute June 9th, 2014

Design of self-assembling protein nanomachines starts to click: A nanocage builds itself from engineered components June 5th, 2014

Molecular self-assembly scales up from nanometers to millimeters June 5th, 2014

Nano world: Where towers construct themselves: How physicists get control on the self-assembly process June 2nd, 2014

Discoveries

New imaging agent provides better picture of the gut July 25th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Announcements

Nano-supercapacitors for electric cars July 25th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Industrial

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Compact Vibration Harvester Power Supply with Highest Efficiency Opens Door to “Fix-and-Forget” Sensor Nodes July 23rd, 2014

Non-Enzyme Sensor Detects Lead, Hydrogen Peroxide July 10th, 2014

New Method Introduced for Synthesis of Hydroxyapatite Nanoparticles July 5th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE