New express dynamic technique for liquid permeation measurements in a wide range of trans-membrane pressures

In this work a new dynamic pressure decay (DPD) self-calibration technique was proposed for the express determination of liquid flux through flat-sheet membranes and films in a wide pressure range. The main principle is based on precise registration of elastic deformations of tested liquid as a function of pressure. When the volume of the pressurized liquid above the membrane keeps constant the developed method enables measuring of liquid permeability. By using this technique, the ethanol and propanol permeability coefficients were determined by DPD technique for dense PTMSP membranes (2 cm of diameter and 30 μm of thickness) in the pressure range of 30–150 bar. These results are in good agreement with traditional dead-end cell measurements. The reversible character of membrane compaction is of great importance. In addition, possible collapsing of porous support of commercial membranes currently available on the market could significantly limit the range of operated pressures in DPD technique.