TY - JOUR
T1 - Demixing in simple fluids induced by electric field gradients
AU - Tsori, Yoav
AU - Tournilhac, François
AU - Leibler, Ludwik
N1 - Funding Information:
Acknowledgements We thank D. Andelman and P. G. de Gennes for discussions and suggestions, and R. Bonnecaze and A.-V. Ruzette for comments on the manuscript. We gratefully acknowledge support from ATOFINA.
Funding Information:
Acknowledgements We thank K. Kohn and K. Hagdorn for samples, and the DFG and the BMBF for financial support. M. F. thanks T. Elsässer for continuous support.
PY - 2004/7/29
Y1 - 2004/7/29
N2 - Phase separation in liquid mixtures is mainly controlled by temperature and pressure, but can also be influenced by gravitational, magnetic or electric fields. However, the weak coupling between such fields and concentration fluctuations limits this effect to extreme conditions. For example, mixing induced by uniform electric fields is detectable only at temperatures that are within a few hundredths of degree or less of the phase transition temperature of the system being studied. Here we predict and demonstrate that electric fields can control the phase separation behaviour of mixtures of simple liquids under more practical conditions, provided that the fields are non-uniform. By applying a voltage of 100 V across unevenly spaced electrodes about 50 μm apart, we can reversibly induce the demixing of paraffin and silicone oil at 1 K above the phase transition temperature of the mixture; when the field gradients are turned off, the mixture becomes homogeneous again. This direct control over phase separation behaviour depends on field intensity, with the electrode geometry determining the length-scale of the effect. We expect that this phenomenon will find a number of nanotechnological applications, particularly as it benefits from field gradients near small conducting objects.
AB - Phase separation in liquid mixtures is mainly controlled by temperature and pressure, but can also be influenced by gravitational, magnetic or electric fields. However, the weak coupling between such fields and concentration fluctuations limits this effect to extreme conditions. For example, mixing induced by uniform electric fields is detectable only at temperatures that are within a few hundredths of degree or less of the phase transition temperature of the system being studied. Here we predict and demonstrate that electric fields can control the phase separation behaviour of mixtures of simple liquids under more practical conditions, provided that the fields are non-uniform. By applying a voltage of 100 V across unevenly spaced electrodes about 50 μm apart, we can reversibly induce the demixing of paraffin and silicone oil at 1 K above the phase transition temperature of the mixture; when the field gradients are turned off, the mixture becomes homogeneous again. This direct control over phase separation behaviour depends on field intensity, with the electrode geometry determining the length-scale of the effect. We expect that this phenomenon will find a number of nanotechnological applications, particularly as it benefits from field gradients near small conducting objects.
UR - http://www.scopus.com/inward/record.url?scp=3242877689&partnerID=8YFLogxK
U2 - 10.1038/nature02758
DO - 10.1038/nature02758
M3 - Article
AN - SCOPUS:3242877689
SN - 0028-0836
VL - 430
SP - 544
EP - 547
JO - Nature
JF - Nature
IS - 6999
ER -