Pair Interaction between Two Colloidal Particles under DC Electric Field

2012 ◽  
pp. 201-228
Keyword(s):  
Electric Field ◽  
Colloidal Particles ◽  
Pair Interaction ◽  
Dc Electric Field

Activity waves and freestanding vortices in populations of subcritical Quincke rollers

2021 ◽  
Vol 118 (40) ◽  
pp. e2104724118
Author(s):  
Zeng Tao Liu ◽  
Yan Shi ◽  
Yongfeng Zhao ◽  
Hugues Chaté ◽  
Xia-qing Shi ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Electric Field ◽  
Colloidal Particles ◽  
Threshold Field ◽  
Active Matter ◽  
Active Particles ◽  
Fast Activity ◽  
Excitable Systems ◽  
Dc Electric Field ◽  
The Many

Virtually all of the many active matter systems studied so far are made of units (biofilaments, cells, colloidal particles, robots, animals, etc.) that move even when they are alone or isolated. Their collective properties continue to fascinate, and we now understand better how they are unique to the bulk transduction of energy into work. Here we demonstrate that systems in which isolated but potentially active particles do not move can exhibit specific and remarkable collective properties. Combining experiments, theory, and numerical simulations, we show that such subcritical active matter can be realized with Quincke rollers, that is, dielectric colloidal particles immersed in a conducting fluid subjected to a vertical DC electric field. Working below the threshold field value marking the onset of motion for a single colloid, we find fast activity waves, reminiscent of excitable systems, and stable, arbitrarily large self-standing vortices made of thousands of particles moving at the same speed. Our theoretical model accounts for these phenomena and shows how they can arise in the absence of confining boundaries and individual chirality. We argue that our findings imply that a faithful description of the collective properties of Quincke rollers need to consider the fluid surrounding particles.

scholarly journals Small-Angle Neutron Scattering Study of Transformer Oil-Based Ferrofluids

2020 ◽  
Vol 65 (8) ◽  
pp. 729
Author(s):  
M. Karpets ◽  
M. Rajnak ◽  
O. Ivankov ◽  
K. Paulovicova ◽  
M. Timko ◽  
...  
Keyword(s):  
Electric Field ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Colloidal Particles ◽  
Transformer Oil ◽  
Particle Assembly ◽  
Nanoparticle Aggregates ◽  
Dc Electric Field ◽  
Neutron Scattering Study

It is known that ferrofluids typically respond to magnetic fields and can be manipulated by such external fields. The particle assembly in magnetic nanofluids can be induced even by a direct current (dc) electric field. An experimental study of magnetic colloidal particles and their changes induced by an external electric field in a ferrofluid based on 2 transformer oils with different concentrations of nanoparticles is presented. By small-angle neutron scattering (SANS), we show the influence of the electric field intensity and the concentration on magnetic nanoparticle aggregates.

Nonlinear photoacoustic effect of semiconductors in dc electric field

1990 ◽  
Vol 68 (8) ◽  
pp. 3865-3871 ◽  
Author(s):  
Jian‐chun Cheng ◽  
Shu‐yi Zhang ◽  
Yue‐sheng Lu
Keyword(s):  
Electric Field ◽  
Photoacoustic Effect ◽  
Dc Electric Field
Sign in / Sign up

Export Citation Format

Share Document