Kinetics of spreading wetting of blood over porous substrates

Blood rheology and spreading of blood over porous substrates in the case of complete and partial wetting are reviewed. It is shown that the blood is well described by a model of non-Newtonian shear thinning power law liquid. In the case of complete wetting a theory is developed, which predicts a universal behaviour of radius of blood droplet, contact angle and wetted spot on time. The predicted theoretical behaviour is a good agreement with experimental observation. In the case of particle wetting the experimental data show also a universal behaviour in the case of sufficiently big pore sizes but a new phenomenon was found in the case then red blood cells are bigger than the pore sizes: they accumulate on the membrane surface, which allow serration of plasma and red blood cells without damaging red blood cells.