Application of Flory's Statistical Theory for the Estimation of Internal Pressure of the Liquid Mixtures

Abstract

Flory's Statistical Theory has been employed for the evaluation of internal pressure of liquid mixtures at varying conditions. The method used for the evaluation does not use any empirical relation, unlike the approaches of previous workers. The computed values have been compared against the values obtained from thermodynamic relation taken as an experimental method. To the best of our knowledge, the present approach has not been employed previously by any worker. The excellent agreements between the computed and experimental values prove the applicability of this approach for the evaluation of internal pressure in liquid mixtures.

Speeds of Sound, Densities, Isobaric Thermal Expansion, Compressibilities, and Internal Pressures of Heptan-1-ol, Octan-1-ol, Nonan-1-ol, and Decan-1-ol at Temperatures from (293 to 318) K and Pressures up to 100 MPa

“…where (∂p/∂T) V is the thermal pressure coefficient. Equation 4 can be rewritten in the following form: Thus, two definitions of the internal pressure can be found in the literature: one as given by eq 4 [31][32][33][34][35][36][37][38][39][40][41][42][43] or multiplied by -1. [44][45][46][47][48] The total pressure of the system consists of two parts.…”

Estimation of Thermodynamic Properties of Binary Liquid Mixtures on the Basis of Statistical Mechanical Theories

“…Ultrasonic velocity is also calculated for pure components using Flory theory. Theoretically obtained values on the basis of a refined version of Flory theory developed by Pandey et al Pandey & Sanguri, 2001;Pandey & Sanguri, 2002;Pandey & Sanguri, 2003;Dey & Pandey et al, 2006), are compared with the experimental findings. It is clear from Table 2, that in general there is a good agreement between theoretical and experimental values of ultrasonic velocity of pure components.…”

“…The relevant equations are summarized here. The details of these equations are given in earlier papers Pandey & Sanguri, 2001;Pandey & Sanguri et al, 2002;Pandey & Sanguri et al, 2003;Dey & Pandey, 2006et al, 2006.…”

“…It would be interesting to mention some liquid state models e.g. Flory's statistical theory (FST) (Flory et al, 1964;Flory, 1965;Abe & Flory, 1965;Dewan et al, 1971;Pandey & Alec David, 1981;Pandey & Sanguri, 2001;Pandey & Sanguri et al, 2002;Pandey & Sanguri et al, 2003;Dey & Pandey et al, 2006), Hard sphere equation of state (HSE) (Percus & Yevick, 1958;Lebowitz et al, 1965;Thiele, 1963;Lebowitz & Frisch et al, 1961;Carnahan & Starling, 1969;Frisch, 1964;Hoover & Ree, 1964) and Hole theory (HT) (Pandey & Sanguri et al, 2010;Pandey & Sanguri et al, 2007;Sanguri et al, 2008), that were utilized to deduce ultrasonic velocity and other thermodynamic properties of liquids and liquid mixtures (binary and higher orders). A comparative study of the applicability of various liquid state theories employed for the estimation of thermodynamic and other related properties has, so far, not been done.…”

Comments on ‘Prediction of internal pressure of binary liquid mixtures using Flory's statistical theory’

“…Thus, observed discrepancies between the experimental [Eqns (7)-(9)] and empirically calculated [Eqns (2) and (3)] values of α p and κ T (Tables 1 to 3) also clearly invalidate the claim of Pandey et al 42 to determine α p and κ T from Eqns (2) and (3) and hence, computation of π int cannot be considered reliable. Additionally, Pandey and co-workers [43][44][45][46] continue to use these unreliable and unacceptable values of α p and κ T derived from empirical relations (2) and (3) to further calculate several thermodynamic, acoustic and physical properties, which is not appropriate and will mislead readers less experienced in thermodynamics of liquid mixtures. Now coming to point (ii), the selection of mixtures in the paper under consideration 1 on which to apply the Flory statistical theory, it is well known that the Flory statistical theory 2,3 as been developed and applied mostly to mixtures involving non-polar components where specific interactions are non-existent.…”