Bifunctional Acoustooptical Cell of the Sensor Type for Studying Gas Chemosorption by Polymer Films

摘要

Potentialities of the bifunctional cell of the sensor type,in which acoustoelectric (based on surface-acoustic waves) and optical (in the visible spectral region) measurements of ammonia chemosorption by thin films of a PDMS-based functional polymer may be simultaneously performed,have been demonstrated.It has been found that the gas diffusion coefficient associated with chemosorption and calculated from optical measurements (2.65 x 10~(-11) cm~2/s) differs from that obtained from acoustoelectric studies (4.16 x 10~(-12) cm~2/s).The diffusion coefficient determined from the acoustoelectric data presumably characterizes the propagation of structural relaxation of polymer chains from chemosorption sites into the polymer bulk.