October 17, 2011 13:00
Physics made solidify liquid with an electric field.
Under the influence of sufficiently high electric fields drop certain liquids can solidify. Under the conditions of temperature and pressure, the liquid state of matter begin to form solid crystals.
Such a transformation, called electrocrystallization demonstrated scientists from Georgia Institute of Technology. The experiment succeeded to a strong electric field to cause a phase transition without changing the thermodynamic parameters.
The new study is based on the work of Geoffrey Taylor, who in 1964 described the transformation of spherical droplets of water in the needle during the passage of an electric field.
A new study by U.S. researchers did not use the water, and 10-nanometer droplets formamide. This fluid is made up of small molecules with a dipole moment is twice higher than that of water molecules.
Under the influence of the field less than 0.5 V / nm spherical drops of formamide lengthened slightly, but when the field strength was increased to a value close to 0.5 V / nm, drops began to gather in the long spindle with up to 12 times greater than the cross section . When the field strength was increased to 1.5 V / nm, thin "needle" was a transitional stage of solidification to the freezing of diffusive motion, and then turned into a crystal. After switching off the field formamide went further in a liquid state and has a spherical shape.
A new experiment, along with an understanding of the causes of the behavior of matter, can help in the development of new control technologies, a variety of materials, such as high precision drug delivery nanokapsulyatsii, printing of nanostructures, aerosol spray, printing, etc.