In-situ measurement of oxygen concentration under high pressure and the application to oxygen permeation through polymer films

摘要: Up until now, gas permeation through polymers under high pressure has not been able to be measured continuously. The combination of a special cell and commercially available fluorescence-based oxygen measurement system allows in-situ monitoring polymer sample in an aqueous environment. principle the sensor is based on dynamic fluorescence quenching decay time. It was observed that time increases non-linearly with applied pressure, hence, displayed concentration corrected. This deviation between real depends only but also absolute water. To obtain calibration curve, tests were performed range 1 2000 bars initial concentrations 40 280 μmol/l. polynomial curve fourth order, describing raw data coefficient determination R(2) > 0.99. effective polymeric samples can calculated this function. A hysteresis test undertaken no found. No temperature dependence signal 20 °C 30 °C. study presents for first showing rates polyethylene film at 23 °C.