Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Relaxation dynamics of 2D nanoparticle systems

Abstract:
Soft matters maintain their structures via weak interactions, such as Van der Waals, capillary, hydrogen bonds etc. The entropy plays a key role in the ordering of this kind of materials. They behave as a solid until a sufficiently large stress is applied, and then behave as a viscoelastic liquid. Due to the unique structures and rheological properties, soft matter such as concentrated suspensions, emulsions, pastes and gels often exhibit unusual slow relaxation and aging effect. Studying the relaxation dynamics may gain more insight into the microstructure of the material and may also shed light on the understanding of the physical origin of glass transition.

Relaxation dynamics of 2D nanoparticle systems

PR China | Posted on October 24th, 2011

Nanoparticle can be trapped at the air-water interface. The formed layer is a typical 2D soft matter, which plays essential role in foams, emulsification and pharmacy. However, owing to the low dimension and absence of theory, the study of 2D relaxation is quite a challenge. By using the Langmuir troughs technique and oscillating bubbles or drops methods, a deformation can be exerted on the layer rapidly. The relaxation then can be studied by monitoring the time viaration of the surface pressure. However, these techniques can not obtain the anisotropy of the layers and hence are limited.

Dr. ZANG Duyang et al from the Key Laboratory of Space Applied Physics and Chemistry of Ministry of Education, School of Science, Northwestern Polytechnical University, has developed a novel approach in which two orthogonal Wilhelmy plates have been utilized to measure the surface pressure in the two directions. By comparing the relaxation dynamics under static and oscillation state, the relaxation mechanisms have been elucidated.

Unlike the surfactant of low molecular weight, the adsorption of nanoparticles at the interfaces is irreversible. This leads to the different Π-Γ isotherms. With the increase of surface density, as well as the textual change, the surface pressure present remarkable anisotropic effect. The anisotropy suggests that the layer is under non-equilibrium state. The relaxation towards equilibrium occurs by means of particle rearrangement. When the layer is kept static, the particle rearrangement is driven by the inner stress stored in the layer. Thus, the relaxation is slow. While under barrier oscillation, additional driving force is exerted by the barriers. Consequently, the relaxation is accelerated significantly.

This work is supported by the Northwestern Polytechnical University Foundation for Fundamental Research (NPU-FFR-JC20100242).

See the article: Zang D Y, Zhang Y J. Surface pressure anisotropy and complex relaxation of silica nanoparticle monolayer at the air-water interface. Sci China Phys Mech Astro, 2011, 41(9)

####

For more information, please click here

Contacts:
ZANG Duyang

0086-298-843-1618

Copyright © Science in China Press

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

New Biological Nano-Fertilizers Presented in Iran as Appropriate Replacements for Chemical Fertilizers April 18th, 2015

Iranian Foodstuff, Agricultural Industries Welcome Nanotechnology Packaging Bags April 18th, 2015

Nanocomposites Play Effective Role in Production of Smart Fibers April 18th, 2015

Dais Analytic Corporation Appoints Eliza Wang to Board of Directors: Company's Newest Director Brings Expertise in Commercial and Legal Matters Both in the United States and China; Joins on the Heels of Successful Business Development Trade Mission to China April 18th, 2015

Chemistry

Protein Building Blocks for Nanosystems: Scientists develop method for producing bio-based materials with new properties April 17th, 2015

Major advance in artificial photosynthesis poses win/win for the environment: Berkeley Lab researchers perform solar-powered green chemistry with captured CO2 April 16th, 2015

How can you see an atom? (video) April 10th, 2015

Carnegie Mellon chemists create tiny gold nanoparticles that reflect nature's patterns April 9th, 2015

Physics

Light in a spin: Researchers demonstrate angular accelerating light April 15th, 2015

Quantum physics -- hot and cold at the same time: Measurements at the Vienna University of Technology show that a cloud of quantum particles can have several temperatures at once; the experiment provides new insight into the behavior of large quantum systems April 9th, 2015

Discoveries

Iranian Foodstuff, Agricultural Industries Welcome Nanotechnology Packaging Bags April 18th, 2015

Nanocomposites Play Effective Role in Production of Smart Fibers April 18th, 2015

Protein Building Blocks for Nanosystems: Scientists develop method for producing bio-based materials with new properties April 17th, 2015

Lanthanide-Organic Framework Nanothermometers Prepared by Spray-Drying April 16th, 2015

Announcements

New Biological Nano-Fertilizers Presented in Iran as Appropriate Replacements for Chemical Fertilizers April 18th, 2015

Iranian Foodstuff, Agricultural Industries Welcome Nanotechnology Packaging Bags April 18th, 2015

Nanocomposites Play Effective Role in Production of Smart Fibers April 18th, 2015

Dais Analytic Corporation Appoints Eliza Wang to Board of Directors: Company's Newest Director Brings Expertise in Commercial and Legal Matters Both in the United States and China; Joins on the Heels of Successful Business Development Trade Mission to China April 18th, 2015

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 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE