title: A systematic approach for the accurate and rapid measurement of water vapor transmission through ultra-high barrier films.
abstract: Flexible organic electronic devices are often protected from degradation by encapsulation in multilayered films with very high barrier properties against moisture and oxygen. However, metrology must be improved to detect such low quantities of permeants. We therefore developed a modified ultra-low permeation measurement device based on a constant-flow carrier-gas system to measure both the transient and stationary water vapor permeation through high-performance barrier films. The accumulation of permeated water vapor before its transport to the detector allows the measurement of very low water vapor transmission rates (WVTRs) down to 2 × 10-5g m-2d-1. The measurement cells are stored in a temperature-controlled chamber, allowing WVTR measurements within the temperature range 23-80 °C. Differences in relative humidity can be controlled within the range 15%-90%. The WVTR values determined using the novel measurement device agree with those measured using a commercially available carrier-gas device from MOCON®. Depending on the structure and quality of the barrier film, it may take a long time for the WVTR to reach a steady-state value. However, by using a combination of the time-dependent measurement and the finite element method, we were able to estimate the steady-state WVTR accurately with significantly shorter measurement times.
authors.affiliation: Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser St. 35, Freising 85354, Germany.
authors.forename: Sandra
authors.identifier: 0000000187705641
authors.initials: S
authors.lastname: Kiese
authors.affiliation: Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser St. 35, Freising 85354, Germany.
authors.forename: Esra
authors.identifier: 0000000159061615
authors.initials: E
authors.lastname: Kücükpinar
authors.affiliation: Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser St. 35, Freising 85354, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Reinelt
authors.affiliation: Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser St. 35, Freising 85354, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Miesbauer
authors.affiliation: Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser St. 35, Freising 85354, Germany.
authors.forename: Johann
authors.initials: J
authors.lastname: Ewender
authors.affiliation: Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser St. 35, Freising 85354, Germany.
authors.forename: Horst-Christian
authors.identifier: 0000000168028569
authors.initials: HC
authors.lastname: Langowski