Temperature effect on transport parameters and structure of regenerated cellulose membranes

The effect of annealing temperature (25 °C < T < 97 °C) on transport and structural parameters for two different regenerated cellulose membranes (dense and nanoporous) is studied. Results show different temperature dependence for water permeability and NaCl diffusion coefficient depending on the membrane structure, with an increase from 25 °C to 60 °C and a more significant reduction between 70°°C and 97 °C for the dense sample, but practically constant for the nanoporous. These results seem to be directly related to the membrane's elastic behaviour according to the temperature effect on degree of swelling. Moreover, diffusional permeability-concentration curves also allow the determination of other membrane parameters (fixed charge concentration and partition coefficient) which are independent of temperature.