TY  - JOUR
AU  - Singh Negi, A.
AU  - Sengupta, K.
AU  - Sood, A. K.
TI  - Frequency-Dependent Shape Changes of Colloidal Clusters under Transverse Electric Field
JO  - Langmuir
VL  - 21
SN  - 0743-7463
CY  - Washington, DC
PB  - ACS Publ.
M1  - PreJuSER-48459
SP  - 11623
PY  - 2005
N1  - Record converted from VDB: 12.11.2012
AB  - We have studied clustering of colloidal particles under the influence of an ac electric field as a function of frequency. The field was applied in a direction perpendicular to the confining walls. Two regimes are observed, a low frequency regime where the clusters are isotropic with a local triangular order, as reported earlier in the literature, and a new high-frequency regime where the clusters are highly elongated (anisotropic) with no local order. The crossover from one regime to the other occurs at a critical frequency, f(c). The threshold field for the cluster formation, E(th), increases with frequency in both the regimes. An increase in the particle size leads to a reduction in both E(th) and f(c). We present evidence to show that the elongated structures seen at high frequency are related to the field inhomogeneities at imperfections on the conducting surface. We also propose a possible mechanism based on hydrodynamic flow considerations to explain the formation of these clusters.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:16316092
UR  - <Go to ISI:>//WOS:000233730200016
DO  - DOI:10.1021/la051258b
UR  - https://juser.fz-juelich.de/record/48459
ER  -