Monitoring Thin Film Properties with Surface Acoustic Wave Devices: Diffusion, Surface Area and Pore Size Distribution.

摘要

The ability of surface acoustic wave (SAW) devices to monitor adsorption of N2 onto the surfaces of porous films and diffusion of species into polymer films has been demonstrated. Calculations based on the N2 adsorption isotherms illustrate how sol-gel solution chemistry can be used to tailor the surface area and pore size distribution of thin films. BET surface areas from unity to over 30 cm sup 2 /cm sup 2 of film have been obtained with median pore diameters from less than 0.4 nm to greater than 6 nm. SAW frequency transients occurring during the diffusion of small molecular species into polymer films have been used to obtain diffusion coefficients from 10/sup /minus/9/ to 10/sup /minus/15/ cm sup 2 /sec. 26 refs., 5 figs. (ERA citation 14:022601)