Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanoscale study gives new insight into heat transfer in biological systems

21.10.2005


One of the first things we learn in chemistry class is that solids conduct heat better than liquids. But a new study suggests that in nanoscale materials, this is not necessarily the case.



Using computer simulations, researchers at Rensselaer Polytechnic Institute have found that heat may actually move better across interfaces between liquids than it does between solids. The findings, which were published online Oct. 11 in the journal Nano Letters, provide insights that could prove useful in fields ranging from computer chip manufacturing to cancer treatment.

Conduction is the movement of heat from a warmer substance to a cooler substance, as when a spoon heats up after sitting in a cup of hot soup. "Liquids generally have low thermal conductivity when compared to solids," says Pawel Keblinski, associate professor of materials science and engineering at Rensselaer and coauthor of the paper. "For example, diamond is one of the best conductors around, with a conductivity of about 5,000 times that of water." Metals also tend to be good conductors, which is why the same spoon would normally feel cold to the touch -- it conducts heat away from the hand.


But this conventional wisdom refers only to "bulk" thermal conductivity, which occurs at the macroscale. In nanoscale materials, the conductivity across interfaces plays a major role. "Conductivity at the interface of two materials is controlled by the nature of the interaction between molecules," says Shekhar Garde, associate professor of chemical and biological engineering at Rensselaer and also coauthor of the paper. "Even if the two substances are good conductors, the nature of the interface could affect heat transfer between them."

Garde and Keblinski performed molecular simulations of a variety of interfaces and found that thermal conductivity between liquid interfaces turns out to be surprisingly high.

The findings could have immediate practical application for cancer therapy, according to Keblinski. "Scientists are developing cancer treatments based on nanoparticles that attach to specific tissues, which are then heated to kill the cancerous cells," he says. "It is vital to understand how heat flows in these systems, because too much heat applied in the wrong spot can kill healthy cells."

Garde’s and Keblinski’s research also could be important to the electronics industry, because of the growing interest in nanocomposite materials for computer chips, which generate a great deal of heat. Chip designers are increasingly combining solid surfaces with softer organic materials, and understanding heat flow will be a key aspect of continuing to shrink the dimensions of chip components, the researchers say.

The findings also provide more fundamental insights that are extremely important for understanding any system with nanoscale features, which tend to have huge numbers of interfaces, according to the researchers.

Biological systems are a key example. The surfaces of proteins, DNA, and other biomolecules interact with water to form the very basis of life. In water-based solutions, proteins instinctively fold into unique three-dimensional structures, which do much of the work in the body. Misfolded proteins also are implicated in diseases such as Alzheimer’s and Parkinson’s, and the ability of proteins to function depends on how much they can vibrate in their folded state.

The next step, according to Keblinski and Garde, is to focus on studying heat transfer between proteins and water, which will give them a better understanding of how water governs protein dynamics.

Jason Gorss | EurekAlert!
Further information:
http://www.rpi.edu

More articles from Life Sciences:

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

nachricht Pollen taxi for bacteria
18.07.2018 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>