Complex investigations of the critical n.amylic alcohol.nitromethane Mixture with acousto· optic methods

Acoustic properties of tho critical n-amylic alcohol-nitro methane mixture
have been analysed in the ultra- and hypersonic range for two concentrations
and at two temperatures. On the basis of obtained values of propagation velocities
and acoustic wave absorption coefficients, fundamental physical, chemical
and acoustic parameters have been determined, as well as the ratio of the total
intensity of the central component to two MANDEJ.SZTAM-BRfLLOUIN components
for individual concentrations of the investigated mixturc.
Expcrimental results of iuvestigations of absorption coefficients in a wide
range of acoustic wave frequencies have been compared to the theories of FIXhfAN
and CZABAN. Also average life-times of concentration fluctuations in the n-amylio
alcohol-nitromcthane mixture have been estimated with the application of
experimental results. This was done not only in tbe direct nearness of the
tempcrature of component separation, but at temperatures distant from it also~
according to the method given by M. J. SZACRPARONOW and P . K. CHAB1BUŁ
l.A,lEF.
The method of determining the mean correlation radius of concentration
fluctuations and the mean radius of intermolecular interactions on the basis
of the intensity of dispersed light in terms of the angle is described and measuremel1t
results of these quantities in the invcstigated mixture in the direct
nearness of the critical point are given.
The kinetics of concentration fluctuations in the n-amylic alcohol-nitromethane
mixture are analysed. 'Vith the application of the achieved mean
concentration relaxation time, t'a, correlation radius of concentration fluctuations,
~, and the diffusion cocfficient, D, the average length of concentration waves~
A/H in the mixture under investigation has been determined.