New Methodology to Study the Dispersive Component of the Surface Energy and Acid–Base Properties of Silica Particles by Inverse Gas Chromatography at Infinite Dilution

Abstract

A new methodology was proposed to determine the dispersive component of the surface energy ${\gamma}_s^d$ of a solid taking into account the effect of the temperature on the surface area of n-alkanes, methylene group (${a}_{- CH2-}$) and polar molecules, thus defeating the method used by Dorris–Gray Schultz et al. We determined the correct ${\gamma}_s^d$ of the surface energy, the specific free energy, enthalpy and entropy of adsorption of polar molecules as well as the acid base constants of silica particles with an excellent accuracy. We confirmed the dependence of the dispersive component of the surface energy on the variations of the surface areas of organic molecules used in IGC technique at infinite dilution. The specific properties of interactions of silica particles were determined. The new proposed model took into account this thermal effect. Obtained results proved that the other used IGC methods gave inaccurate values of the specific parameters of silica surface, except for the vapor pressure method that led to excellent results of the specific free energy, enthalpy and entropy of adsorption, and the acid–base constants of the silica particles.

Surface Thermal Behavior and RT CO Gas Sensing Application of an Oligoacenaphthylene with p-Hydroxyphenylacetic Acid Composite

“…Knowing Δ H a sp and the normalized donor DN′ and acceptor AN′ numbers of electrons of the various probes, − one obtained the acid K A and base K D constants of the solid surfaces from eq . − …”

“…The effect of OAN on the surface energy of p -HPA has been evaluated. The dispersive surface free energy component is the most important physical parameter. − The London dispersive surface free energy component γ s d ( T ) as a function of temperature has been assessed by using nine different models all based on the Fowkes relation. Two models, the Dorris–Gray relation and Hamieh–Dorris–Gray model and six models, the Kiselev, cylindrical, geometric, spherical, van der Waals and Redlich–Kwong–Hamieh models have been applied using six molecular methods for determining the surface areas of organic molecules .…”

Surface thermodynamic properties by reverse phase chromatography and visual traits using computer vision techniques on Amberlite XAD‐7 acrylic‐ester‐resin

“…Where is a thermodynamic parameter relative to the organic solvents and and are constants relative to the probes. The physicochemical variable can be one of the following parameters: vapor pressure , 15 boiling point BP , 14 deformation polarizability , 16 standard enthalpy of vaporization , 18 enthalpy of vaporization depending on the temperature, 12 topological index , 17 standard enthalpy of formation of organic solvents 12 …”

“…Hamieh's works 12,13,20–22 demonstrated that the surface area of organic molecules varies as a function of the temperature and showed an important dependence of the surface area of methylene group a –CH2– versus the temperature. Recently, in a recent paper, Hamieh 12 gave an expression of (in Å 2 with T in K ): …”

“…The dispersive surface free energy component is most important physical parameter 6–10 The London dispersive surface free energy component has been assessed by using Dorris‐Gray relation, 11 Hamieh‐Dorris‐Gray model 12 and the six other models based on the values of the surface areas of organic molecules such as Kiselev, cylindrical, geometric, spherical, van der Waals, Redlich–Kwong and Hamieh models 13 . The Gibbs specific component of surface free energy was determined by using 14 IGC methods and models such as the molecular models, the boiling point BP , 14 the vapor pressure , 15 the deformation polarizability , 16 the topological index , 17 the standard enthalpy of vaporization , 18 the enthalpy of vaporization as a function of the temperature , 12 the standard enthalpy of formation 12 methods. Similarly, the Guttmann Lewis acid–base parameters were estimated using the above stated methods.…”