Anisotropic colloidal particles will be used to explore effects of directional interactions and nematic order-disorder transitions in colloidal gels formed under different conditions (volume fraction, attraction strength) exposed to external and internal stimuli. The former will include shear and flow (steady and oscillatory) in bulk and under confinement. The latter will include micromanipulation via the addition of inclusions (solid granular particles or gas bubbles) vibrated via externally imposed ultrasound waves (with CNRS and TUD). Different anisotropic particles (rod-like silica particles and soft SU8 polymer, clay particles) will be used. Different regimes in the phase diagram will be mapped including dilute fractal type gels, concentrated phase separating systems and attractive (nematic) glasses. Combined rheometry and confocal microscopy, DDM / light scattering, will be used to study the link between microstructure and mechanical properties. Computer simulations will be performed with UU (de Graaf). Experimental protocols will be implemented on industrial personal care products with UNIL (Poulos) and drilling fluid SLB (Clarke) and under high pressures (up to 1000 bar) with home-made DLS/DWS.
Industrial secondment: The DC will be at SUNL (12M/M22-M33), SLB (3M/M16-M18), and at UNIL (3M/M19-M21) working on industrial slurries for energy applications (SUNL), drilling muds (SLB) and food products (UNIL).
Academic secondments: TUD (0.5M/M15): Utilize ultrasonic induced bubble oscillations to tune local structure of rod gels; CNRS (0.5M/M14): Study effects of ultrasonic vibrations in rod-gels;
