Small angle neutron scatteirng study on the salt-induced phase separation of 1-propanol aqueous solution

摘要

Small angle neutron scattering (SANS) measurements have been carried out over a wide range of Q from 0.003 to 7 A~ on the 1-propanol-water solution with KCI and that without KCl in relation to the salt-induced reentrant phase-separation phenomena. The Q dependence of the SANS intensity for both solutions is characterized by the same fractal structure with the fractal dimension d~ of 1.9. Tne only difference between the two solutions is the value of con-elation length A In the solution ~~hout KC1 the value of ~ is rather small, ranging from 7.4 to 6.2 A depending on temperature.while in the solution with KCl it becomes very large. from 48 to 355 A or more depending on temperature. and diverees toward the phase-separation emperatures in a similar way for both the nee-phase regions. No significant differences have heen found on the growing structure of fluctuation in the upper lower one-phase regions.