Featured Research

from universities, journals, and other organizations

Reversible Process For Forming Supramolecular Polymers Could Be The Basis Of Fibers, Molecular Transport Mechanisms

Date:
March 23, 1999
Source:
Virginia Tech
Summary:
Virginia Tech chemistry graduate student Nori Yamaguchi and professor Harry W. Gibson are using the basic, familiar tool of hydrogen bonding to allow self-assembly to create large aggregate structures for the creation of fibers or for transport of target molecules.

Virginia Tech chemistry graduate student Nori Yamaguchi and professor Harry W. Gibson are using the basic, familiar tool of hydrogen bonding to allow self-assembly to create large aggregate structures for the creation of fibers or for transport of target molecules. In presentations at the 217th American Chemical Society national meeting in Anaheim March 21-26, the chemists will describe how, using the same components -- crown ethers as hosts and secondary ammonium ions as guests, they have created two different, novel, and reversible structures based on hydrogen-bonding.

Related Articles


In one process, a linear supramolecular pseudorotaxane polymer is formed that can be drawn into fibers. The structure is the threading of one molecular component through another to form a linear aggregate that can be undone at the molecular level, using heat or pH.

Yamaguchi and Gibson were the first to demonstrate the linear array. The work was first published in Angewandte Chemie just this year. (Angew. Chem. Int. Ed. 1999, 38, No. 1/2: "Formation of Supramolecular Polymers from Homoditopic Molecules Containing Secondary Ammonium Ions and Crown Ether Moieties," by Yamaguchi and Gibson.)

The second arrangement of the same components resulted in dendritic pseudorotaxanes. Benzyl ether dendrons (wedge shaped molecules) with crown ether hosts at the "focal point" assemble in layers on a three-armed ammonium salt to form a macromolecular aggregate.

The huge supramolecule takes three days to form. Again the process was first described in Angewandte Chemie. (Angew. Chem. Int. Ed. 1998, 37, No. 23: "Dendritic Pseudorotaxanes," by Yamaguchi, Lesley M. Hamilton, and Gibson.) The result is "kind of a glob," says Gibson. Within the glob are pockets of a specific size that can be used to trap target molecules, which can then be transported and released by reversing the construction of the dendrimer. Gibson explains that the structures are sensitive to pH and synthesis can be reversed by exposure to base.


Story Source:

The above story is based on materials provided by Virginia Tech. Note: Materials may be edited for content and length.


Cite This Page:

Virginia Tech. "Reversible Process For Forming Supramolecular Polymers Could Be The Basis Of Fibers, Molecular Transport Mechanisms." ScienceDaily. ScienceDaily, 23 March 1999. <www.sciencedaily.com/releases/1999/03/990323045900.htm>.
Virginia Tech. (1999, March 23). Reversible Process For Forming Supramolecular Polymers Could Be The Basis Of Fibers, Molecular Transport Mechanisms. ScienceDaily. Retrieved January 30, 2015 from www.sciencedaily.com/releases/1999/03/990323045900.htm
Virginia Tech. "Reversible Process For Forming Supramolecular Polymers Could Be The Basis Of Fibers, Molecular Transport Mechanisms." ScienceDaily. www.sciencedaily.com/releases/1999/03/990323045900.htm (accessed January 30, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, January 30, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nanoscale Sensor Could Help Wine Producers and Clinical Scientists

Nanoscale Sensor Could Help Wine Producers and Clinical Scientists

Reuters - Innovations Video Online (Jan. 30, 2015) — A nanosensor that mimics the oral effects and sensations of drinking wine has been developed by Danish and Portuguese researchers. Jim Drury saw it in operation. Video provided by Reuters
Powered by NewsLook.com
Tesla 'Insane Mode' Gives Unsuspecting Passengers the Ride of Their Life

Tesla 'Insane Mode' Gives Unsuspecting Passengers the Ride of Their Life

RightThisMinute (Jan. 29, 2015) — If your car has an "Insane Mode" then you know it&apos;s fast. Well, these unsuspecting passengers were in for one insane ride when they hit the button. Tesla cars are awesome. Video provided by RightThisMinute
Powered by NewsLook.com
Now Bill Gates Is 'Concerned' About Artificial Intelligence

Now Bill Gates Is 'Concerned' About Artificial Intelligence

Newsy (Jan. 29, 2015) — Bill Gates joins the list of tech moguls scared of super-intelligent machines. He says more people should be concerned, but why? Video provided by Newsy
Powered by NewsLook.com
Senate Passes Bill for Keystone XL Pipeline

Senate Passes Bill for Keystone XL Pipeline

AP (Jan. 29, 2015) — The Republican-controlled Senate has passed a bipartisan bill approving construction of the Keystone XL oil pipeline. (Jan. 29) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins