| dc.description.abstract | The electric double layer (EDL) is a very important aspect in surface science. Small
objects on the surface around which the EDL has formed can change the composition
of the EDL. This change can be used to detect small objects. We have prepared a
setup in which we can use this technique to visualise a nanosping, which then can be
used to determine the mobility of a particle. The setup consisted of a potentiodynamic
optical contrast microscope and conductive sampleslides. The samples we created
are PEG linkers adhered to an ITO surface, to act as the nanosprings, with gold
nanoparticles on top.
To give advice on specific parameters to use in the experiments, we created a simulation
in python. In the simulation, a nanoparticle is subject to spring, drag and
electric forces as well as Brownian motion. In the electric field, some influences of
the electric double layer were introduced in the form of the so-called Debye Hückel
approximation.
Upon analysing the simulation data my advise on carrying out the experiment as
described in part I is to use a timestep between dt = 105 and dt = 103 s. For the
simulation, my advice would be to use Nt = 105. For optimal results, the length
nanospring should around 25 nm, with an applied potential of around 0.07 V. | |
