COTRANSPORT OF WATER AND LOW-MOLECULAR ELECTROLYTES IN MODERATELY HYDROPHOBIC POLYMERS

The theory of co-transport of water and electrolytes in moderately hyd rophobic polymers is developed in terms of the chemical-potential grad ient. The proposed model takes into account a heavy dependence of the water solubility on the water activity and salt concentration in polym er and a limited electrolyte solubility in a hydrophobic matrix. An ap proach to measuring thermodynamic diffusion coefficients in polymers d iffering in water absorbing capacity is devised. Successful measuremen t of the diffusion coefficients of KCl and NaCl in hydrophobic poly (h ydroxybutyrate) testifies to the suitability of the conductance-measur ing method for studying multi-component transport of low-molecular spe cies in polymers. Experiments intended to support the proposed theoret ical model are carried out.