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Interaction Mechanisms Between Biochar and Herbicides
Published in Kassio Ferreira Mendes, Interactions of Biochar and Herbicides in the Environment, 2022
Rodrigo Nogueira de Sousa, Matheus Bortolanza Soares, Felipe Hipólito dos Santos, Camille Nunes Leite, Kassio Ferreira Mendes
The possibility of interaction of electronic clouds of nonpolar and polar molecules with each other characterizes the famous intermolecular forces of van der Waals: dipole–dipole, induced dipole–dipole, and dispersion forces. In the dipole–dipole force, two polar molecules interact through the opposite charges of their resulting dipoles. In induced dipole–dipole force, the resulting dipole of a polar molecule induces a polarization in a nearby nonpolar molecule, forming an induced dipole. Scattering forces (or London forces) are interactions between nonpolar molecules that arise from the fluctuation in the distribution of electrons in atoms created from temporary induced dipoles (instant dipole), which arise from momentary spatial arrangements.
Introduction
Published in Armen S. Casparian, Gergely Sirokman, Ann O. Omollo, Rapid Review of Chemistry for the Life Sciences and Engineering, 2021
Armen S. Casparian, Gergely Sirokman, Ann O. Omollo
The subject of chemical bonding centers around the concept of the transfer or the sharing of electrons between atoms. Further, the sharing may be equal or unequal. The first type, i.e., transfer of electrons, is referred to as ionic bonding and is very common among salts (metal atoms bonding with nonmetal atoms), while the second type, i.e., sharing of electrons, is referred to as covalent bonding (and frequently occurs between two nonmetal atoms). If the sharing is purely equal, it is further referred to as nonpolar covalent bonding, while if the sharing is unequal, the bonding is referred to as polar covalent. In a nonpolar covalent bonded molecule, the molecule is essentially electrically neutral. In a polar covalent bonded molecule, one part or end of the molecule has a partial positive charge while the other end or part (where the electrons spend more time) has a partial negative charge. The degree to which a molecule is polar-covalent is determined by its dipole moment (or charge separation measured in units of debyes) and by its polarizability (a kind of shape or distortion factor). The type of bonding helps determine its physical and chemical properties, which in turn helps to determine its suitability in applications. For example, a long-chain hydrocarbon like octane present in gasoline is a nonpolar covalent molecule. Water, on the other hand, is a polar covalent molecule. A well-known principle of solubility in chemistry is “Like dissolves like.” Thus, we can assume that octane will NOT dissolve in water, which is actually the case.
Common Sense Emergency Response
Published in Robert A. Burke, Common Sense Emergency Response, 2020
Ethanol is miscible with water and if spilled in a water source would be difficult to clean up. Polarity is one of the major differences between ethanol and gasoline and diesel fuel. Several physical characteristics of flammable liquids are important in terms of the combustion of those liquids. These include flashpoint, ignition temperature, flammable range, vapor density, and heat output. Flashpoint, boiling point, and ignition temperature of flammable liquids are affected by polarity. Compounds that are polar have a tendency to have higher boiling points and flashpoints then nonpolar compounds with similar molecular weights. Within the parameters of combustion, several things need to be in place for combustion to occur. First and most importantly, a flammable liquid must be at or above its flashpoint temperature.
Machine learning models for occurrence form prediction of heavy metals in tailings
Published in International Journal of Mining, Reclamation and Environment, 2023
Jiashuai Zheng, Mengting Wu, Zaher Mundher Yaseen, Chongchong Qi
Overall, the average importance value of EC was 0.442, placing it as the most important factor influencing the percentages of the seven occurrence forms. The significant influence of EC occurs due to this parameter’s ability to affect solubility by influencing the strength of intermolecular forces between the solute and solvent molecules. Polar solvents typically have a higher propensity to dissolve polar solutes, whereas non-polar solvents tend to dissolve non-polar solutes. The solubility generally increases with the polarity and electronegativity of the solvent species [51,52]. Following EC, the atomic number, atomic mass, and sum of the total concentrations also ranked highly with average feature importance scores of 0.211, 0.142, and 0.091, respectively. Ho and Egashira et al. [53] also found a significant effect of total concentration on the occurrence form, and the similar conclusions was reached by Guan et al [54]. Unlike the other fractions, the most important feature of F5 was not EC but instead the sum of the BCR concentration, which has a feature importance value of 0.332; this was followed by the total element concentration and EC, which had values of 0.267 and 0.237, respectively.
Experimental investigation of elastomer compatibility and engine performance of biodiesel derived from deodorizer distillate
Published in Biofuels, 2023
Kamalesh A. Sorate, Purnanand V. Bhale
The swelling in B100 of Viton and neoprene was greater than that of other elastomers, i.e. CR and PVC. This is because these highly polar elastomers were dissolved to a greater extent by the highly polar ester components of VODD biodiesel (B100). The positive ends of the molecules in a polar solvent are constantly drawn to the opposing ends of the molecules in the solute, creating an intermolecular force known as the dipole–dipole interacting force. Compared to diesel, biodiesel shows a higher dipole–dipole interaction. This is because biodiesel is composed of higher polar esters than diesel [45]. Biodiesel contains palmitate, stearate, oleate, and linoleate. Elastomer surfaces immersed in biodiesel may have lost volume due to these varied components [46]. Swelling depends upon the crosslink density. Crosslinking is a chemical bond formed between chains of atoms in a polymer or other complex molecules. An elastomer crosslinked above the gel point would not dissolve in its solvent but would instead imbibe it and swell [43].
Mechanism underlying initiation of migration of film-like residual oil
Published in Journal of Dispersion Science and Technology, 2022
Xu Han, Lihui Wang, Huifen Xia, Peihui Han, Ruibo Cao, Lili Liu
The OCA-20 contact angle tester was used to measure the contact angles of different interfacial tension ternary composite systems and the core, as shown in Figure 11. As the surfactant concentration increases, the interfacial tension gradually decreases, and the contact angle between the ternary composite system and the core gradually decreases. The interaction between material interfaces can be divided into dispersion, dipole interactions, induced dipole interactions, and hydrogen bonding. There is dispersion between polar molecules, although strong hydrogen bonds may also exist. In contrast, there is only dispersion between nonpolar molecules. Therefore, according to the “similar structure and mutual dissolution” principle, all substances with similar molecular structures easily dissolve each other; this rule is called the principle of similar dissolution.[38–40] Because the polarity of the molecules is similar, solubility is important. Therefore, the similar principle of compatibility can be understood as follows: polar molecules are soluble in polar solvents, and nonpolar molecules are soluble in nonpolar solvents. Thus, a higher surfactant concentration corresponds to a higher solution. The stronger the property, the stronger the affinity between the core and a large proportion of the polar components that contribute to the solid surface energy, the smaller the contact angle, and the larger the work of adhesion.