TY - JOUR
T1 - Manipulation of colloids by a nonequilibrium depletion force in a temperature gradient
AU - Jiang, Hong Ren
AU - Wada, Hirofumi
AU - Yoshinaga, Natsuhiko
AU - Sano, Masaki
PY - 2009/5/18
Y1 - 2009/5/18
N2 - The nonequilibrium distribution of colloids in a polymer solution under a temperature gradient is studied experimentally. A slight increase of local temperature by a focused laser drives the colloids towards the hot region, resulting in the trapping of the colloids irrespective of their own thermophoretic properties. An amplification of the trapped colloid density with the polymer concentration is measured, and is quantitatively explained by hydrodynamic theory. The origin of the attraction is a migration of colloids driven by a nonuniform polymer distribution sustained by the polymer's thermophoresis. These results show how to control the thermophoretic properties of colloids.
AB - The nonequilibrium distribution of colloids in a polymer solution under a temperature gradient is studied experimentally. A slight increase of local temperature by a focused laser drives the colloids towards the hot region, resulting in the trapping of the colloids irrespective of their own thermophoretic properties. An amplification of the trapped colloid density with the polymer concentration is measured, and is quantitatively explained by hydrodynamic theory. The origin of the attraction is a migration of colloids driven by a nonuniform polymer distribution sustained by the polymer's thermophoresis. These results show how to control the thermophoretic properties of colloids.
UR - http://www.scopus.com/inward/record.url?scp=66049083036&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=66049083036&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.102.208301
DO - 10.1103/PhysRevLett.102.208301
M3 - Article
AN - SCOPUS:66049083036
VL - 102
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 20
M1 - 208301
ER -