Effect Of Thermodynamic Factors Research Articles

Effect of Thermodynamic Factors on Colloid Stability

Colloid is more and more widely used in daily life. No matter medical application, or food additive in the food industry, or electrolyte in the lead battery, all are deeply connected with it. Among them, the stability of colloid is an important direction for people to explore. According to DLVO theory, the stability of colloid is determined by the height of energy barrier. In this paper, the effect of temperature on colloid aggregation or sedimentation will be discussed by calculating and observing the settling process of colloid. This paper will also put forward the optimum temperature position to keep the highest energy barrier height and the way to estimate the value of energy barrier by reaction, which gives new possibilities for controlling colloid stability.

Physicochemical study of the sustainable preparation of nano-Fe2O3 from ferrous sulfate with coke

A route to produce nano-Fe2O3 by reduction of ferrous sulfate with coke to was proposed to improve the utilization of waste residues from TiO2 production. The effects of thermodynamic factors on the reaction were analyzed via Factsage 6.0 software, which showed that SO2 and O2 atmospheres have a significant inhibition effect on the decomposition of ferrous sulfate. Then, the optimal reaction condition (heating at 600 °C for 40 min with ferrous sulfate to coke ratio of 4:8) was obtained by single-factor and orthogonal experiments. Under the optimal reaction condition, the average desulfurization rate was found to reach 99.92%. Moreover, scanning electron microscopy images showed that the products were nanopowders with a porous structure and particle sizes between 40 and 70 nm. Finally, the non-isothermal decomposition kinetic parameters and mechanism of the reaction were determined. Two reaction stages, which were named “random nucleation and then growth” and “symmetric cylindrical diffusion (3D),” were determined. Using the Coats–Redfern, Flynn–Wall Ozawa (FWO), and Kissinger–Akahira–Sunose (KAS) methods, the apparent activation energy and pre-factor of the first reaction stage were determined to be 291.10 kJ mol−1 and 1.41 × 1016 s−1, while those of the second reaction stage were determined to be 285.94 kJ mol−1 and 3.27 × 1014 s−1. The most probable mechanism functions of the two stages were also determined. This process can make use of ferrous sulfate not only highly valuable, but also to improve the recycling of sulfur and iron resources after the production of white titanium.

Correlation between physical bonding and mechanical properties of wood–plastic composites: part 2: effect of thermodynamic factors on interfacial bonding at wood–polymer interface

The main objective of this study was to find out if there is any significant correlation between physical properties and interfacial bonding of interphases in wood–plastic composites. To this end, high-density polyethylene (HDPE), mixture of 3% maleic anhydride grafted polyethylene (MAPE) and HDPE (coded as MHDPE) and polylactic acid (PLA) were separately interacted with veneers to identify factors underlying interfaces. Plastics were first melted at 180 °C and dispensed on wood surfaces so that the contact angle (CA) could be directly measured. Wood sanding moderately decreased the CAs of plastics in order of PLA, MHDPE, and HDPE. The treatment of veneers with MAPE comprehensively improved wetting, as the CA of HDPE was significantly reduced on the wood surface after the treatment. Thereafter, the interfacial shear strengths (IFSS) of the wood–polymer interface were determined using the automated bonding evaluation system. PLA had the highest IFSS both for unsanded and sanded veneers. Comparing both parts of this research finally revealed that applying sanding or/and MAPE treatments resulted in lower surface free energy and higher IFSS at the wood–polymer interface. However, our observations support the idea that, at higher temperatures, wetting of composites is mainly influenced by polymer properties rather than interfacial tension at the wood–polymer interface.

Effect of thermodynamic factors on the effective dipole moments of molecules

Effect of thermodynamic factors on the effective dipole moments of molecules

Effect of thermodynamic factors on the effective dipole moment of molecules

Effect of thermodynamic factors on the effective dipole moment of molecules

Effect of thermodynamic factors on the effective dipole moment of molecules

Effect of thermodynamic factors on the effective dipole moment of molecules

Mechanism of thermal decomposition of salts of carboxylic acids

1. The thermal decomposition of Ca, Ba, Li, Rb, Ag, and Cu acetates at 473–873°K was analyzed thermodynamically. In all cases apart from Ag and Cu acetates, and regardless of the nature of the acid radical, the decomposition of the salt to the anhydride and the metal oxide was thermodynamically forbidden. The results of the calculations are confirmed by experimental data. 2. The characteristics of the topochemical decomposition of Ca, Ba, Cd, Mg, and Zn acetates were examined: they were the lack of an induction period, the fact thatn in Erofeev's equationα=1−e−kτn is close to unity, the planar form of the reaction nucleus, and the fact that the reaction proceeds in the kinetic region. The decomposition proceeds by the growth of initial centers present in the substance and the activation energy determined experimentally is the activation energy of the growth of the reaction nuclei. 3. In the case of the decomposition of Li, Na, K, and Rb acetates, which occurs in the melt, an interpretation is given for the effect of the nature of the metal on the activation energy and pre-exponent. The effect of thermodynamic factors on the course of the change in activation energy is discussed.