scholarly journals Semi-empirical linear correlation between surface tension and thermodynamics properties of liquids and vapours

2021 ◽  
Vol 545 ◽  
pp. 111145
Author(s):  
Diego Elustondo
Keyword(s):  
Surface Tension ◽  
Linear Correlation ◽  
Thermodynamics Properties ◽  
Semi Empirical

Modelling of Surface Properties of Selected Silicate System

2011 ◽  
Vol 291-294 ◽  
pp. 444-448
Author(s):  
Jana Dobrovská ◽  
Rostislav Dudek ◽  
Silvie Vitásková ◽  
František Kavička
Keyword(s):  
Surface Tension ◽  
Surface Properties ◽  
Sessile Drop ◽  
Theoretical Modelling ◽  
Compact Set ◽  
Data Modelling ◽  
Silicate System ◽  
Heterogeneous Processes ◽  
Semi Empirical ◽  
Data Surface

Presented paper deals with investigation of selected ternary oxidic system with high content of silicates from the viewpoint of surface properties. Research was focused not only on experimental investigation, but mostly on theoretical modelling of surface tension. This approach was chosen due to absence of compact set of information from the area of heterogeneous processes at high temperatures. It is moreover very often difficult to access appropriate data. Surface propertieswere investigated by sessile drop method. Afterwards calculation was made with use of selected semi-empirical models and obtained outputs were confronted with experimentally obtained data. Modelling comprised also temperature dependence of surface tension and influence of SiO2 on its values.

Interpreting of XPS C1s Binding Energies in Silicon Containing Polymers and Nanoparticles

2006 ◽  
Vol 518 ◽  
pp. 375-380
Author(s):  
E.A. Hoffmann ◽  
Lj. Korugić-Karasz
Keyword(s):  
Linear Correlation ◽  
Binding Energies ◽  
Am1 Method ◽  
Atomic Charges ◽  
Xps Spectra ◽  
Silicon Compounds ◽  
Current Contribution ◽  
Partial Atomic Charges ◽  
Semi Empirical ◽  
Similar Equation

A method for predicting XPS C1s binding energies in polymers has been developed previously [1]. The calculation uses partial atomic charges determined quantum chemically (by the semi-empirical AM1 Method), which are found to provide a linear correlation with the binding energies corrected by the so-called Madelung intramolecular potential. We used this method successfully for interpreting XPS spectra of partially degraded fluoropolymers [2]. In the current contribution we investigate the possibility of developing a similar equation to describe siliconcontaining polymers that are medically and technologically important, and also some nanoparticles based on organo-silicon compounds.

scholarly journals Oxidative carbonylation of dipropargylarylamines

2016 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
S.A. Vizer ◽  
K.B. Yerzhanov ◽  
Z.N. Manchuk ◽  
A.G. Wieser
Keyword(s):  
Catalytic System ◽  
Oxidative Carbonylation ◽  
Thermodynamics Properties ◽  
Consecutive Reactions ◽  
Semi Empirical

<p>The catalytic oxidative methoxycarbonylation reaction of N,N-dipropargylarylamines has been investigated. PdCl<sub>2</sub>-CuCl<sub>2</sub> has been studied as a catalytic system. Consecutive reactions of substitutive and additive methoxycarbonylation have been going in this process, which has been complicated by dimerisation, polymerization and cyclization processes. Apparently the results of process are determined by stability of intermediate reactionary complexes with participation of catalytic system PdCl<sub>2</sub>-CuCl<sub>2</sub>. The structures of synthesized cyclic amino triesters are established by analysis of experimental spectra NMR <sup>1</sup>H and <sup>13</sup>C, comparison with calculated spectra of possible hypothetic structures and estimation of thermodynamics properties by Joback fragmentation and MOPAC Semi-empirical PM3 methods.</p>

scholarly journals Development of a Semi-Empirical Model for Droplet Size Determination of a Three-Channel Spray Nozzle for Pellet Coating Based on the Optical Method Concept

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 86
Author(s):  
Sara Vidovič ◽  
Alan Bizjak ◽  
Anže Sitar ◽  
Matej Horvat ◽  
Biljana Janković ◽  
...  
Keyword(s):  
Surface Tension ◽  
Droplet Size ◽  
Process Parameters ◽  
Flow Rate ◽  
Empirical Model ◽  
Optical Method ◽  
Spray Nozzle ◽  
Production Scale ◽  
Dispersion Properties ◽  
Semi Empirical

The purpose of this study was to investigate the droplet size obtained with a three-channel spray nozzle typically used in fluid bed devices and to construct a semi-empirical model for prediction of droplet size. With the aid of a custom-made optical method concept, the impact of the type of polymer and solvents used through dispersion properties (viscosity, density, and surface tension), dispersion flow rate, atomization pressure, and microclimate pressure on droplet size was investigated. A semi-empirical model with adequate predictability for calculating the average droplet size (R2 = 0.90, Q2 = 0.73) and its distribution (R2 = 0.84, Q2 = 0.61) was constructed by employing dimensional analysis and design of experiments. Newtonian and non-Newtonian dispersion and process parameters on laboratory and on production scale were included, thereby enabling constant droplet size irrespective of the scale. Based on the model results, it would be possible to scale-up the atomization process (e.g., coating process) from laboratory to production scale in a systematic fashion, regardless of the type of solvent or polymer used. For the system investigated, this can be performed by understanding the dispersion properties, such as viscosity, density, and surface tension, as well as the following process parameters: dispersion flow rate, atomization, and microclimate pressure.

Pair correlation function in a fluid with density inhomogeneities: parametrization for hard spheres near a hard wall

1985 ◽  
Vol 400 (1818) ◽  
pp. 163-174 ◽  
Keyword(s):  
Surface Tension ◽  
Correlation Function ◽  
Pair Correlation Function ◽  
Hard Spheres ◽  
Pair Correlation ◽  
Hard Wall ◽  
Sum Rule ◽  
Density Inhomogeneities ◽  
Semi Empirical ◽  
Good Agreement

The pair correlation function, g( z 1 , z 2 , r 12 ), of a system of hard spheres near a hard wall is approximated by a simple function that interpolates in a reasonable manner between the Percus shielding approximation for the case when the line of centres of the spheres is normal to the surface of the wall and the bulk pair correlation function, with a semi-empirical modification, for the case when the spheres are equidistant from the wall. This modification is chosen so that the surface tension, calculated from the pair correlation function, is given correctly. The resulting pair correlation function is in good agreement with computer simulations and satisfies a sum rule for the slope of the density profile fairly well.

scholarly journals Predicting Viscosity and Surface Tension at High Temperature of Porcelain Stoneware Bodies: A Methodological Approach

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2475 ◽  
Author(s):  
Sonia Conte ◽  
Chiara Zanelli ◽  
Matteo Ardit ◽  
Giuseppe Cruciani ◽  
Michele Dondi
Keyword(s):  
Surface Tension ◽  
High Temperature ◽  
Chemical Composition ◽  
Physical Properties ◽  
Viscous Flow ◽  
Methodological Approach ◽  
Theoretical Background ◽  
Whole Body ◽  
Diffraction Patterns ◽  
Semi Empirical

The shear viscosity and the glass-vapor surface tension at high temperature are crucial to understand the viscous flow sintering kinetics of porcelain stoneware. Moreover, the pyroplastic deformation depends on the viscosity of the whole body, which is made up of a suspension of crystals dispersed in the melt. The existing fundamental theoretical background, along with semi-empirical constitutive laws for viscous flow sintering and glass densification, can be exploited through different approaches to estimate the physical properties at high temperatures starting from amount and chemical composition of the melt. In this work, a comprehensive attempt to predict the properties of the liquid phase is proposed by means of a detailed overview of existing models for viscosity and surface tension of glasses and melts at high temperature. The chemical composition of the vitreous phase and its physical properties at high temperature are estimated through an experimental approach based on the qualitative and quantitative chemical and phase analyses (by Rietveld refinement of X-ray powder diffraction patterns) of different porcelain-like materials. Repercussions on the firing behavior of ceramic bodies, are discussed. Comparative examples are provided for porcelain stoneware tiles, vitreous china and porcelain bodies, disclosing differences in composition and properties but a common sintering mechanism.

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