Reliable, fast and accurate WVTR measurement technology. Dr. Jörg Koch SEMPA SYSTEMS GmbH

Transcription

1 Reliable, fast and accurate WVTR measurement technology Dr. Jörg Koch SEMPA SYSTEMS GmbH

2 INTRODUCTION Starting point Food industry Pharmaceutical industry Anorganic solar cells Organic solar cells Vacuum isolation panel Organic LED Water transmission rate WVTR g[h 2 O] m -2 d ,1 0,01 1E-3 1E-4 1E-5 1E

3 METHODS Coulometric State of the art WVTR technologies Ca-Test Isostatic setup P 2 O 5 Sensor Signal caused by electro-chemical reaction of water Preparation of thin Ca-coating Signal caused by change of transparency resulting from reaction of Ca + 2H 2 O Ca(OH) 2 + H 2 Others Tritium: (Radioactive!) GC: (Accumulation!) Pressure: (Accumulation!) 3

4 BASICS General setup for permeation measurements Feed gas chamber Barrier sample H 2 O H 2 O H 2 O H 2 O Permeate chamber Sensor What the sensor really measures? H 2 O

5 SORPTION Sample Mirror Stainless steel Adsorption of moisture H 2 O! Moisture molecules are adsorbing at the sample, the mirror and the chamber surfaces Moisture sensors only measure the permeated moisture remaining in the gas phase Concentration of the moisture in gas phase represents the WVTR only in the steady state!

6 SENSITIVIY Sensitivity of a WVTR measurement N 2 + H 2 O Sensor sensitivity Adsorption / desorption of moisture H 2 O N 2 Sealing of the test cell

7 HiBarSens N 2 + H 2 O Realization Sensor Adsorption/ Desorption Tunable LASER Measurement under steady state condition H 2 O N 2 Sealing Active Seal

8 VERSATILITY Measurement Modes Different measurement modes have been developed to enable low detection limits

9 MODES Derive WVTR correctly!! Dynamic Combination Diffusive ϕ 10-5 gm -2 d gm -2 d gm -2 d -1 All modes in steady state -> get WVTR correctly!!

10 DYNAMIC Steady-state conditions Dynamic Mode n sorption@sample n sorption@cell V purge; n in n n permeatio n n out n = amount of substance (moisture) n sorption p p n = n 0 = n perm = 0 n desorption out = 0 n adsorption = 0 Calculation of WVTR V Purge M WVTR = R T A H O Sample 2 p ϕ 1 ϕ

11 DIFFUSION Diffusive Mode

12 DIFFUSION Diffusion controlled WVTR measurement A capillary A sample Fick s law Detector x ϕ WVTR sample A = J H O) sample c J = D x x ( 2 capillary A capillary Constant water vapor partial pressure (concentration) = isocapnic condition High level of water vapor concentration Level of water vapor concentration can be tuned by the length and diameter of capillary ϕ A WVTR = D x A capillary sample D H2O Diffusion coefficient of water vapor = 2.60E-05 m 2 /s

13 COMB. Combination mode C H2O (Gas phase) ch O V dt = m 2 H 2O m A t g = WVTR 2 m d time

14 RESULTS Typical Measurement

15 OUTLINE Measurement Time Reduction Preconditioning Elevated Temperature Outlook next steps Summary

16 INNOVATION Measurement Time scale Sample conditioning Measurement Steady state

17 PreConCell HiBarSens PreConCell Establishes required moisture gradient Increases throughput and system utilization, reduces measurement time Features Accurate temperature regulation (20 90 C) Accurate humidity regulation in wet chamber (50 95 % r.h.) Low moisture concentration (0 % r.h.) in dry chamber PreConCell (cross-section)

18 PreConCell Results Time reduction >10 times

19 PreConCell - Fast Fast Measurement Preconditioned Sample 10-5 in 72h

20 HiBarSens 2.0 HT High Temperature Measurements Required for OPV Tremendous effect on measurement time Requirements: Precise thermal management up to 90 C Perfect insulation of Laser

21 HT in Action normalized water vapor transmission rate WVTR n / % Arrhenius behavior :14 02:24 24:00 240:00 time t / hh: mm Sample Honeywell, P8000TR, 198 µm HT Measurements - Results Break Thru Measurement 85 C 75 C 65 C 50 C 38 C 22 C time to 90% of steady state / h temperature ϑ / C t 90 Time

22 HT in Action ln(wvtr) Faster results with HT Arrhenius-plot 50 C (7, ) 38 C (2, ; 65 days) E-3 3.2E-3 3.4E-3 3.6E-3 1/T [1/K] 20 C (~2, ) Ultra barrier sample (10-6 g m -2 d -1 ) (R2R processed, 90 % r.h.

23 INNOVATION Next Steps

24 INNOVATION Use of He for quick check Especially for monitoring a production process fast feedback loops are mandatory He as a premeate may serve as alternative Currently tests are underway to integrate He functionality

25 INNOVATION Integration of O 2 Some applications require to measure the oxygen barrier properties HiBarSens may offer the unique possibility to integrate both measurements in one system

26 SUMMARY HiBarSens 2.0 Fast Summary >10x with PreConCell ~300x with HT Reliable Optimized setup Accurate Measuring under steady state

27 THANK YOU Acknowledgement Johannes Grübler Kurt Pietsch Harald Beese Wulf Grählert 27