Herbert Charles Klotz

Equation-of-State mixing rules for multicomponent mixtures: the problem of invariance

Mathias P.M., Klotz H.C. and Prausnitz J.M., 1991. Equation-of-state mixing rules for multicomponent mixtures: the problem of invariance. Fluid Phase Equilibria, 67: 31-44. Several researchers have recently extended the usual quadratic mixing rules in equations of state by using higher-order polynomials in component mole fraction. Most of these higher-order polynomials exhibit a serious deficiency for multicomponent systems since they are not invariant when a component is divided into two or more identical subcomponents. In this paper we investigate the source of this deficiency and propose a formulation to overcome it. While our analysis here is illustrated with the Peng-Robinson equation of state, it is applicable to other equations of state and to excess-Gibbs-energy models for calculating activity coefficients.

Molecular modeling in engineering design and materials development

Due to the recent developments in computer hardware, theoretical methods and software, molecular modeling is emerging as a practical tool for the chemical industry. What has been accomplished, and how can molecular modeling provide significant value to industry in the future? We study these questions by grouping the applications of molecular modeling into engineering design and materials development (the legacy of engineering correlations and estimation method; property prediction by classical simulation; heat of formation prediction by quantum mechanics; gas storage by adsorption; gas separation by adsorption; materials design for xerographic applications; polyurethane catalysis; corrosion in ammonia reactors; molecular fluorination).

An equation of state for polymer/polymer systems

Abstract Polymer blends offer an extremely promising method to produce polymer materials with commercially desirable properties. In this work, we assess the capability of equations of state to describe and predict the properties of polymer mixtures, particularly those that have specific interactions. A promising approach is a lattice model that uses a site-site quasichemical theory to describe nonrandomness.