title: Tricritical phenomena in quasi-ternary mixtures of water + n-decane + n-undecane + tert-butanol.
abstract: Coexistence curves for the quasi-ternary system of water + n-decane + n-undecane + tert-butanol have been determined by measurements of the refractive index in three coexisting liquid phases. The binary mixtures of n-decane + n-undecane constructed the quasi-pure components in which the mass fraction beta of n-decane controls the approach to the tricritical point. The coexistence curves can be fitted to Scott's extended theory and can be extrapolated to a tricritical point at (44.1 +/- 0.3) degrees C and beta = 0.77 +/- 0.02 corresponding to an average n-alkane-carbon number of 10.19 +/- 0.02. The nonclassical critical amplitude ratio has been confirmed to be 4-5% smaller than the classical value, which is consistent with Fisher's prediction.
authors.affiliation: Department of Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Xiang
authors.forename: Xueqin
authors.initials: X
authors.lastname: An
authors.forename: Nong
authors.initials: N
authors.lastname: Wang
authors.forename: Weiguo
authors.initials: W
authors.lastname: Shen