Critical behaviour of binary mixture of {xC6H5CN+(1−x)CH3(CH2)7CH3}: Measurements of coexistence curves, light scattering, and heat capacity

Critical behavior of binary mixture of {x C6H5CN + (1 −x) CH3(CH2)12CH3}: Measurements of coexistence curves, turbidity, and heat capacity

“…slightly dependence on the temperature range. However, in the region sufficiently close to the critical temperature, they are consistent with that of the theoretical prediction 0.326 and the experimental results for other binary solutions we reported previously [15][16][17][18][19]. In order to obtain more accurate critical amplitude B, we fitted the experimental data within temperature range t < 0.003 to equation (1) with b being fixed at the theoretical value 0.326.…”

“…The values of b sig eff were obtained from the numerical derivative of the singular term, which are in good agreement with those calculated by equation (15) in the temperature range close to the critical point, but significantly departure from them as the temperature is far away from the critical point. It is consistent with that the contribution of the regular term is remarkable as the temperature is far away from the critical point.…”

“…The detailed description of the apparatus and the principle of the measurement could be found in a previous article [15]. The special sample cell used for the measurement of isobaric heat capacity per unit volume takes advantage of avoiding the presence of the vapor phase over the liquid sample, which made the vapor phase correction neglected [20].…”

“…In principle, the values of u; c 0:5 t =K; B0, and a can be obtained by fitting the experimental data to equations (15) to (17), however, the strong coupling among the parameters makes the fit quite difficult. Since the value of u is of the order of unity for simple fluid systems, we set u at the values between 0.05 and 3 with an increment of 0.05 separately, and with each of the setting values we fitted the experimental values of Dx to equation (15) with c 0:5 t =K; B0, and a as adjustable parameters.…”

“…Much effort has been devoted to such phenomena in simple binary fluid mixtures, polymer solutions, aqueous electrolyte solutions and some other complex fluid systems [10][11][12][13][14][15].…”