Microscale Mass Diffusion Sensing of Polymer Solutions Using Soret Forced Rayleigh Scattering

In the casting process of highly functional films, the control of complex micro and nano structures inside the polymer films is one of the most critical factors. The control requires the cross diffusion coefficients in multicomponent solutions because it has a direct influence on the formation of fine structures inside polymer films during the casting process [1]. However, most studies on diffusion in polymer solutions concentrate on measuring diffusion coefficients in binary solutions and only a few measurement techniques of the cross diffusion coefficient can be found. We have developed a measurement technique for the mutual diffusion coefficient in binary solutions, namely Soret forced Rayleigh scattering method [2–4]. In the present paper, we have applied Soret forced Rayleigh scattering method to measure the binary mass diffusion coefficient for the clarification of the cross diffusion phenomena in multicomponent diffusion.