Colloidal Dynamics and Interactions at Interfaces
The properties of solvent suspended synthetic and biological nanoscopic particles are markedly different in the ultimate vicinity of an interface as compared to their behaviour in bulk. These alterations are caused by static and hydrodynamic interactions between particles and the interface and lead eventually to interface induced variations of macroscopic material properties like, rheology or phase behaviour. Besides their scientific interest, these effects are important in many technological, biological and bio-medical processes spanning form drying kinetics of coatings over the approach of a virus or a drug carrier to a cell wall to the motion of proteins in membranes.
Using interface sensitive scattering techniques, we are investigating the underlying mechanisms on the nanometre scale.
Employing total internal reflection microscopy (TIRM) we can determine the interaction energy profiles between colloidal particles and flat wall with an unprecedented force resolution in the femto-Newton range.
Evanescent dynamic light scattering enables studying the Brownian particle dynamics within a range from an interface, where it is slowed down due to hydrodynamic interaction with the interface. We are investigating the variation of this effect with particle concentration, particle interaction and particle morphology. Current research is concerned with the dynamics of protein coated particles in the vicinity of supported lipid bilayers, as a first step towards a model system for proteins close to cell membranes.
- Colloidal interactions
- Brownian dynamics
- Scattering techniques
Prof. Dr. Peter R. Lang
Building 04.6 / Room 77
On the effect of morphology and particle-wall interaction on colloidal near-wall dynamics, J. A. Rivera-Morán et al., Soft Matter 17,10301 (2021). DOI: 10.1039/d1sm01191j
Near-wall dynamics of concentrated hard-sphere suspensions: comparison of evanescent wave DLS experiments, virial approximation and simulations,
Y. Liu et al., Soft Matter 11, 7316 (2015). DOI: 10.1039/c5sm01624j
Translational and Rotational Near-Wall Diffusion of Spherical Colloids Studied by Evanescent Wave Scattering,
M. Lisicki, et al., Soft Matter 10, 4312 (2014). DOI: 10.1039/c4sm00148f
Rotational near wall dynamics studied by evanescent wave dynamic light scattering,
S. Rogers et al., Phys. Rev. Lett. 109, 098305 (2012). DOI: 10.1103/PhysRevLett.109.098305.
Flow Dichroism as a Reliable Method to Measure the Hydrodynamic Aspect Ratio of Gold Nanoparticles,
N. K. Reddy et al., ACSNano 5, 4935 (2011). DOI: 10.1021/nn201033x