Characterising colloidal silica particle interactions using atomic force microscopy

In this talk I will be investigating the forces observed between silica colloids using atomic force microscopy. This is done by using a quantitative analysis of force curves generated from interacting a silica tip with a borosilica surface. From the curves it is observed that as the ionic strength increases the repulsive forces and screening length in turn decrease, eventually yielding to the attractive van der Waals forces between the two surfaces at high ionic strengths. This transitional region between the repulsive and attractive forces at contact is characterised using the atomic force microscope and discussed in a rheological context.