Dynamics of transportation of glucose and urea water solutions through a porous polyethyleneterephthalate membrane studied by optical interference

The paper reports an interferometric method for characterisation of the dynamics of transportation of glucose and urea water solutions through a porous polyethyleneterephthalate membrane. The method is based on measurements of the changes in the light refraction indices of solutions partitioned by the membrane, using a Jamina interferometer. Synthetic membranes have been used among others in haemodialysis. In this process selective transportation of substances through a membrane permits elimination of toxic substances form the patient's blood employing the phenomena of osmosis, filtration, ultrafiltration and diffusion. The process efficiency depends on the parameters of the membrane pores (diameter, channel length, number of channels per diffusion active area). The process of haemodialysis can be optimised by changing the parameters influencing its course, whose effect is determined by measurements of diffusion rate of substances of the known molar weight, molecule size and permeability (glucose, urea) in laboratory conditions. In this paper, assuming the porous model of the membrane structure, the permeability P and mean number of pores m per a unit of the diffusion active area have been determined in order to establish the parameters at which the course of haemodialysis will be the most effective.