Inhalt des Dokuments
Project Area B - Soft Matter: Collective dynamics and hydrodynamic interactions in complex fluids.
We study the complex
collective dynamics of interacting entities such as colloidal
spheres and rods or molecular machines (e.g., proteins) in a liquid
environment.
Due to the size of the dispersed objects ranging
from nano- to micrometers, any
inertial effects (both in the
liquid and of the suspended objects) are negligible.
Although a
liquid in the regime of small Reynolds numbers only allows for simple
laminar flow, interacting objects suspended in it may exhibit
complex motional
patterns that we aim to investigate in this
project area.
To keep the suspended objects out of equilibrium,
they constantly have to be under
the influence of external or
internal driving forces to counteract the strong dissipation
in
the viscous environment. One advantage of colloidal systems for the
following
projects is that they can easily be manipulated by
external magnetic, electric, or light
fields including optical
tweezers, or by shear forces. In contrast, molecular machines
constantly consume chemical energy and hence operate naturally out
of equilibrium.
Light and chemicals are used here to regulate
their performance.
The suspended entities are coupled to each
other by direct interactions, e.g., screened
Coulombic,
dipolar, and steric forces, or by indirect interactions mediated by
the liquid
solvent or capillary forces at water-air interfaces.
One prominent example is the hydro-
dynamic interaction due to
the flow fields created by the motion of the particles. This
interaction introduces a nonlinear long-range coupling into the
equations of motion that
is able to create oscillatory and even
transient chaotic motional patterns.
The projects of area B
are as follows:
- B1: Structure
formation of ferrofluids driven by oscillating magnetic fields. [1]
- B2: Collective dynamics in colloidal model
systems. [2]
- B3: Shear-induced
instabilities and structure formation in colloidal nano-rods. [3]
- B4: Active microfluidics based on
self-propelling molecular machines. [4]
n_and_research/funding_period_i_102009_032014/project_a
reas/b_soft_matter/project_b1/parameter/minhilfe/
n_and_research/funding_period_i_102009_032014/project_a
reas/b_soft_matter/project_b2/parameter/minhilfe/
n_and_research/funding_period_i_102009_032014/project_a
reas/b_soft_matter/project_b3/parameter/minhilfe/
n_and_research/funding_period_i_102009_032014/project_a
reas/b_soft_matter/project_b4/parameter/minhilfe/