Suppported by the  FORSKER21  Researcher Project Large-scale Interdisciplinary Researcher Project Sustainable Stable Ground (Bærekraftig Grunn) we study how quick clay, found everywhere in Norway, can be stabilzed. In collaboration with PIs from several departments we study the struncture and elemental composition of these systems at atomistic to mesoscopic scales.

We use light-scattering techniques such as Diffusing Wave Spectroscopy (DWS), Dynamic Light Scattering (DLS) and optical tweezers (OT) to study the viscoselastic properties of many self-assembling systems as function of time and tepmerature. For example,  we investigated the temperature-reversible formation of DNA hydrogels, shake gels and the viscoelastic changes of aqueous solutions of triblock-copolymers as they undergo microphase separation.

We have establish resin based 3D-printing to build custom-made macroscopic flow cells to study two-phase flow in posous media. In particular,  we are establishing Particle Image Velocimetry (PIV) and other image-analysis techniques to test a recently established, thermodynamic-based description of two-phase flow, put forward by Alex Hansen.

Typical non-specific interactions between colloids are hard sphere,  van der Waals, Coulomb or depletion forces to name the most common ones. These give rise to specific phase behaviours.  By coating colloid surfaces with short, complementary DNA-strands we can suppress these forces and replace them by well-defined, highly specific interaction. Such programmable colloids can be used to design completely new materials with interesting porous structures. Recently we showed that they also can be developed as new, inexpensive diagnostic tool to detect whole-gemone DNA of bacteria.

We develop and utilize a variety of image analysis techniques to analyse microscopy and video images. Amongst those are: Cord Length Analysis, allowing us to obtain the size-distribution of pores and colloidal gel-networks; structure-factor analysis of confocal images;  Differential Dynamic Analysis (DDM) to compute the diffusivity of colloids from videos.

Recently we started using fluctuating Lattice-Bolzmann calculations to study the accumulation of colloids at a water-air interface, caused by capillary-driven flows. But we also utilize Multiple Particle Collision dynamics  (MPC) to study flow induced by thermophoresis. Many of our simulation studies are in collaboration with Ignacio Pagonabarraga, Daan Frenkel and others.