A direct method of studying colloid interactions and adsorption at solid/liquid interfaces

A new cell for direct in situ observations of colloid particle adsorption w as developed. The controlled convective transport conditions were created b y exploiting the slot impinging jet (SIJ) principle. Numerical solutions of the governing Navier-Stokes equation showed that the how pattern in the ce ll can be approximated by the plane-parallel stagnation flow with the perpe ndicular velocity component independent of the lateral distance X. Thus, th e solid/liquid interface at distances close to the symmetry plane was found uniformly accessible for particle transport. This flow field was used to d erive the mass transport equation which was then numerically solved to obta in the initial flux (adsorption rate) for various transport conditions. The se theoretical predictions were verified experimentally using monodisperse polystyrene latex particles. A good agreement between predicted and measure d initial flux was found for a broad range of Reynolds number and ionic str ength of the particle suspension. This confirmed that the SIJ cell can be u sed as a useful tool of studying colloid and bioparticle interactions and a dsorption under well-defined transport conditions.