Corporate Banner
Satellite Banner
Stem Cells, Cellular Therapy & Biobanking
Scientific Community
Become a Member | Sign in
Home>News>This Article

Physicists Crack Science of Ice Formation

Published: Thursday, February 28, 2013
Last Updated: Thursday, February 28, 2013
Bookmark and Share
Salt - and just about anything else that dissolves in water, which is called a solute - lowers water's melting point, which is why it's useful for de-icing roads.

And the higher the solute concentration, the slower ice forms. That's why solutes, or "cryoprotectants," are added to proteins, cells, tissues and even dead bodies to slow down ice formation during cryopreservation.

Intrigued by this rather poorly understood process, Cornell physicists have discovered that, for a variety of common cryoprotectants, the time for ice to form has a simple exponential variation with concentration. It's the first molecular-level understanding of exactly how solutes slow down ice formation, and it has implications in fields ranging from climate physics to cryopreservation and artificial insemination.

Matthew Warkentin, a physics postdoctoral associate, together with professors of physics Robert Thorne and James Sethna, published these findings online in Physical Review Letters in January.

Ice forms in supercooled pure water in about 1 microsecond (one-millionth of one second). That time gets multiplied by 10 for every incremental increase in solute concentration. In a 50 percent glycerol-water solution, for example, ice formation can take almost a minute.

The simple exponential behavior suggested that there might be a correspondingly simple explanation, Warkentin said.

In order for ice to form, a small cluster of about 50 water molecules must form a crystalline "nucleus"; a smaller cluster will tend to shrink and disappear, but larger clusters will keep growing as long as liquid water is available. The researchers postulated that the solute molecules "get in the way" of water molecules trying to form a nucleus.

By calculating the probability of finding a nucleus-size volume free of the solute molecules that were preventing nucleation, they derived the exponential dependence on solute concentration and were able to quantitatively replicate data for eight different solutes, ranging from salt to sugar to alcohol. The resulting simple theory used statistical mechanics to extend classical nucleation theory.

In looking at the implications of the work for climate change, for example, Thorne said that modern climate models must take into account a measure of the Earth's reflectiveness, which is influenced by cloud cover. This in turn requires understanding of when and why cloud particles crystallize or remain liquid.

Furthermore, cryopreservation is widely used in medicine and biotechnology, where ice formation can be lethal to cells and tissues. Fertility clinics routinely freeze sperm, eggs and fertilized embryos, and nearly all domestic cattle and swine are propagated using cryopreserved semen, Thorne said.

Aside from its simplicity, an exciting feature of the new theory is that it is generalizable to other liquids and to any system undergoing nucleation, the researchers added.

The work was supported by the National Science Foundation and the National Institutes of Health.

Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,800+ scientific posters on ePosters
  • More than 4,000+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Turn out the Light: 'Switch' Determines Cancer Cell Fate
Like picking a career or a movie, cells have to make decisions – and cancer results from cells making wrong decisions.
Friday, May 03, 2013
DNA Editor Named Runner-up Breakthrough of 2012
A discovery that allows life scientists to precisely edit genomes for everything from crop and livestock improvement to human gene and cell therapy was named runner-up for Science magazine's 2012 Breakthrough of the Year.
Wednesday, February 27, 2013
Puppy Born from Frozen Embryo Fetches Good News
Breakthrough shows hope for endangered canids.
Tuesday, February 05, 2013
Some Stem Cells Can Trigger Tumors
When in contact with even trace amounts of cancer cells, stem cells can create a microenvironment suitable for more tumors to grow.
Wednesday, June 06, 2012
Scientific News
Fat Cells Originating from Bone Marrow Found in Humans
Cells could contribute to diabetes, heart disease.
Ancient Viral Molecules Essential for Human Development
Genetic material from ancient viral infections is critical to human development, according to researchers at the Stanford University School of Medicine.
CRI Identifies Emergency Blood-formation Response
Researchers report that when tissue damage occurs, an emergency blood-formation system activates.
New Way to Force Stem Cells to Become Bone Cells
Potential therapies based on this discovery could help people heal bone injuries or set hardware, such as replacement knees and hips.
Dead Bacteria to Kill Colorectal Cancer
Scientists from Nanyang Technological University (NTU Singapore) have successfully used dead bacteria to kill colorectal cancer cells.
Promise of Newborn Stem Cells to Revolutionize Clinical Practice
In this article Shweta Sharma, PhD, discusses the potential of an Umbilical Cord Blood bank as an untapped source of samples for research and clinical trials.
The Life Story of Stem Cells
A model analyses the development of stem cell numbers in the human body.
Novel Stem Cell Line Avoids Risk of Introducing Transplanted Tumors
Progenitor cells might eventually be used to repair or rebuild damaged or destroyed organs.
Advancing Genome Editing of Blood Stem Cells
Genome editing techniques for blood stem cells just got better, thanks to a team of researchers at USC and Sangamo BioSciences.
Molecule Proves Key to Brain Repair After Stroke
Scientists found that a molecule known as growth and differentiation factor 10 (GDF10) plays a key role in repair mechanisms following stroke.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,800+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,000+ scientific videos