New theory changes old view of bubbles

WEST LAFAYETTE, Ind., Aug. 21 (UPI) -- U.S. scientists have discovered what they say is a fundamental flaw in the conventional view of how liquids form bubbles that grow and turn into vapors.

The findings by Purdue University chemical engineers led by Associate Professor David Corti cast doubt on some aspects of a long-standing theory that attempts to describe the underlying molecular mechanism behind a phenomenon called "homogeneous nucleation."

In the conventional view, a liquid boiling and turning into a vapor takes place in a systematic process known as "nucleation and growth." The liquid first forms tiny "nuclei," or microscopic bubbles, that grow as they pick up particles. Such a conventional view is described by "classical nucleation theory," which was proposed in the 1920s.

"Our findings indicate this is not what's going on," Corti said. "The bubble grows via a mechanism very different from classical nucleation theory."

The findings by Corti and chemical engineering doctoral student Mark Uline are detailed online in the journal Physical Review Letters.